Sharad Pawar Dental College and Hospital - Datta Meghe ...

Sharad Pawar Dental College and Hospital,

Sawangi (Meghe), Wardha

Department of prosthodontics, Crown and Bridge

“Evaluation of the effect of functional contouring of the palatal

vault of maxillary complete denture on clarity of speech sounds in

edentulous patients.”

An In-Vivo Study

By

Dr. Surekha Godbole Dubey

Research Supervisor

Dr. Ashok J. Pakhan

Professor and Dean

Department of Prosthodontics, Crown and Bridge



2017

Introduction

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Declaration by the Candidate

I hereby declare that the thesis entitled “Evaluation of the effect of functional

contouring of the palatal vault of maxillary complete denture on clarity of

speech sounds in edentulous patients.”- An In-Vivo Study is a bonafide and a

genuine research work carried out by me, under the guidance of Dr. Ashok J.

Pakhan, Professor and Dean, Department Of Prosthodontics, Crown and

Bridge, S.P.D.C.

I hereby solemnly affirm that the contents of this thesis have not been

submitted earlier in candidature for any degree elsewhere. The university is

permitted to have legal rights for subsequent uses.

Date:

Place: Sawangi (Meghe), Wardha

Dr. Surekha Godbole Dubey

Ph.D. Scholar

Department Of Prosthodontics, Crown and

Bridge.



Introduction

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Sharad Pawar Dental College and Hospital, Sawangi (Meghe), Wardha

Datta Meghe Institute of Medical Sciences (Deemed University)

Certificate

This is to certify that the work embodied in this thesis for the degree of

Doctor of Philosophy (Prosthodontics, crown and bridge) of Datta Meghe

Institute of Medical Sciences (Deemed University), Nagpur, entitled

“Evaluation of the effect of functional contouring of the palatal vault of

maxillary complete denture on clarity of speech sounds in edentulous

patients.” An In-Vivo Study, was undertaken by Dr. Surekha Godbole Dubey

and was carried out in the Department of Prosthodontics, Sharad Pawar Dental

College, Sawangi (Meghe), Wardha, under my guidance and direct supervision

to my satisfaction.

This thesis fulfills the basic ordinance governing the submission of

thesis laid down by Datta Meghe Institute of Medical Sciences University,

Nagpur.

Date:

Place: Sawangi (Meghe), Wardha.

Dr. Ashok J Pakhan

Ph.D. Supervisor

Professor and Dean

Department of Prosthodontics.




Introduction

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Sharad Pawar Dental College and Hospital, Sawangi (Meghe), Wardha

Datta Meghe Institute of Medical Sciences Deemed University

Certificate

This is to certify that the work “Evaluation of the effect of functional


speech sounds in edentulous patients.” An In-Vivo Study for the degree of


Institute of Medical Sciences (Deemed University), Nagpur 2013-2016 is

undertaken by Dr. Surekha Godbole Dubey, Professor and Head, Department

of Prosthodontics, crown and bridge, Sharad Pawar Dental College and

Hospital, Sawangi (Meghe), Wardha.

I have great pleasure in forwarding this thesis to Datta Meghe Institute

of Medical Sciences (Deemed University), Nagpur.

Date:

Place: Sawangi (Meghe), Wardha.

Dr. Ashok J Pakhan

Dean



Introduction

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Sawangi (Meghe), Wardh

Datta Meghe Institute of Medical Sciences (DU), Nagpur.

This is to certify that the work “Evaluation of the effect of functional


speech sounds in edentulous patients.” An In-Vivo Study for the degree of


Institute of Medical Sciences (Deemed University), Nagpur 2013-2016 is

undertaken by Dr. Surekha Godbole Dubey, Professor and Head, Department

of Prosthodontics, crown and bridge, Sharad Pawar Dental College and

Hospital, Sawangi (Meghe), Wardha.

I have great pleasure in forwarding this thesis to Datta Meghe Institute

of Medical Sciences (Deemed University), Nagpur.

Date :

Place :

Dr Sunita Shrivastava

Dean Academics

Sharad Pawar Dental College

Sawangi (M)

Introduction

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All creatures great and small, even the tiny amoeba are connected in an

endless ebb and flow of messages. The process that makes this connection possible is

the process of communication. Communication is the essence of life. The act of

communication is a process, not an entity. In its simplest form it consists of the

transfer of a message (M) from a sender (S) to a receiver (R) However, the fastest

mode of communication for human being is through speech. In this mode of

communication, there is a speaker and one or more listeners. To produce speech the

participation of various systems is required. Speaking is a complex and highly

coordinated process involving many systems of the human body. Any problem in the

structure and function or the coordination between the systems may lead to

impairment in speech.1

“Say now shiboleth; and he said siboleth, for he could not frame to

pronounce it right……….”- Judges xii;6

According to the Bible, failure to pronounce this single word correctly not

only cost the Ephraimite who mispronounced it his life, but forty and two thousand of

his fellow tribes’ men were slain in the ensuring battle with the Giledites. It is likely

that the consequence of a single oral inaccuracy is unparalleled in history, but this

classic report is indicative of the significant role speech has played in shaping man’s

destiny.2

As speech is the basic fundamental means of communication become the

cornerstone for the establishment and organization of society. In the highly complex

international society of today with the sophisticated systems for transmitting the

voice, the spoken word becomes increasingly important in establishing and

maintaining a niche in the social structure. Today man is judged not only by what he

says, but equally by the way he says it. Proper speech is a reflection of education,

careless speech is an imputation of slovenliness and faulty speech is a handicap

directly proportionate to the speech incapability.

The dental profession, as the guardian of oral health is engaged to a great

extent in altering structures within the oral cavity to alleviate the ravages of disease

and developmental abnormalities. A major portion of speech articulation takes place

Introduction

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within the oral cavity and any alteration of structures therein will adversely affect

speech proportionate to the location and magnitude of the alteration.2

Phonetics was studied as early as 2500 years ago in ancient India, with

Panini’s account of the place and manner of articulation of consonants in his 5th

century BC treatise on Sanskrit. The major Indian alphabets today order their

consonants according to Panini's classification.

The ability to produce, manipulate and articulate with sounds is called speech.

Speech is such an accepted part of man’s makeup that we seldom pause to consider

that this is a learned function.

Phonetics is the science of sounds used in speech. It is derived from the Greek

word ‘phone’ meaning ‘sound/voice’ and is branch of linguistics that comprises the

study of the sounds of human speech. It is concerned with the physical properties of

speech sounds (phonemes) and the processes of their physiological production,

auditory reception and neurophysiological perception.3

Thus, speech consists of a discrete series of sounds that corresponds to the

letters and words of a written language. Producing and recognizing the sounds of a

language is a highly complex motor and perceptual skill that involve considerable

mental processing. The development of vocal sounds into a meaningful speech was

one of the major accomplishments that has enabled man to reach the pinnacle of the

animal kingdom. Thus, speech is essential to human life but is often taken for

granted.2

The production of various speech sounds is done by the articulatory system,

which consists of several structures of the oral cavity – tongue, lips, teeth, hard palate

and soft palate8. Any alteration or loss of these structures therein will adversely affect

speech sounds produced. This is especially true in case of an edentulous patient who

has lost the teeth and adjacent structures resulting in poor quality of speech sounds,

which the clinician should take note of during fabrication of complete denture.

Though complete dentures are less than perfect replacements for the natural teeth,

they have proven to be effective for countless individuals and are comfortable to

wear, if a person has reasonable expectations and recognizes that there will be an

adaptation phase.

Introduction

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A successful denture is one in which the three cardinal factors of mechanics ,

esthetics and phonetics are so completely and perfectly harmonized that the patient

not only chews his food but also experiences satisfaction from the contribution of his

denture to the facial expression and speech. Problems in speech is a very common ,

unpleasant and embarrassing experience faced by the patient using new complete

dentures, despite all the efforts made by the dentist in clinical and laboratory

procedures of denture fabrication. Ability to speak clearly while adapting to new

dentures, significantly reinstates the patient’s confidence, a factor that is usually given

secondary importance by the general dental practitioner.4

Of the above mentioned three major factors, considerable progress has been

made in improving the first two factors, mechanics and esthetics but phonetics has not

been given its due attention. This can be reasoned by the fact that most patients get

used to the dentures over a period of time and improve their speech. 4

A scientific approach to the phonetic factor in denture construction often

places the burden on the tongue to adapt, so as to compensate speech changes. If

dentures are to contribute effectively to the functions of speech dentist should utilize

the studies in speech science field to implement their clinical knowledge of the

phonetic factor in denture construction.3

A missing bicuspid will permit a lateral emission, which is intolerable to the

precise speaker or singer. A missing anterior tooth will permit an anterior emission

which impairs speaking until an accommodating articulation pattern is learned. Gross

removal of gingival tissue denies the tongue its usual soft tissue contact and leaves

potential escape of the air stream between the interspaces of the exposed root portions

of the teeth. Mechanical movement of the tooth or teeth in the maxillary arch, as well

as the expansion or constriction of the arch, will increase or decrease the area for

speech articulation. Therefore, it behooves the dental practitioner to be familiar with

speech articulations, particularly those which take place within the oral cavity, in

order to prognosticate the effect of intraoral remedial procedure on speech. Speech

rehabilitation following dental treatment is an obligation of the profession, and failure

to include phonetics in the dental curriculum is not coincident with the high standards

established by dental educators to provide maximum health service.

The poorly contoured replacement for a single tooth can cause speech

impediment, and larger prosthetic restorations fabricated without regard for speech

Introduction

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articulation will impair speech until an accommodating articulation pattern is learned.

A very high percentage of the English speaking sound are produced by contact of the

tongue with some portion of the palate and teeth. Since these contact areas are

replaced or covered by the complete denture, speech rehabilitation for the edentulous

patient becomes the onerous task of the Prosthodontist. Failure to contour the palate to

accommodate normal tongue contact usually results in poor speech for a period of

several days or several weeks, depending upon the aptitude of the patient and the

discrepancy in palatal contour. This inarticulate period, generally accepted as getting

used to dentures, could be markedly reduced or completely eliminated if proper

attention were given to palatal contour at the time of the waxed trial denture try-in.

Faulty speech is never desirable, even for short periods of time. It is unpleasant for the

listener, embarrassing to the patient, and adds to the burden of adaptation to dentures.

The fact that most denture patients recover from improper articulation after a post-

insertion practice period does not justify neglect of this phase in complete denture

construction nor minimize the Prosthodontist’s responsibility for speech rehabilitation

following delivery of dentures. Contour of palate for proper tongue contact is not

difficult, time consuming, or expensive; however it does require some knowledge of

the fundamentals of phonetics and a precise knowledge of the normal tongue contact

areas for speech articulation. 2

The complete denture may modify speech due to the following reasons –

• Changes in surface will affect resonance and articulation.

• Thickness of the denture in the palatal area reduces the tongue space, again

affecting the resonance and articulation.

• It will also affect the sensory feedback mechanism.

• Emotional behavior of the patients.

Thus, though initial experiences in speech disturbance are transient, the

treatment objective should be to make the dentures conform to the individual patient’s

existing neuromuscular pattern. The dentist should therefore recognize the role of

prosthetic treatment on speech activity4

Speech has been used in the prosthodontic practice to achieve proper anterior

tooth positioning, vertical dimension and in general to simplify the designing of

dentures. Allen (1958)6, Pound E.(1951)

7, Silvermann M.M.(1953)

8, H. Tanaka

Introduction

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(1973)9, B. Goyal and P. Greenstein (1982)

10 have done pioneering work through

several studies on phonetics in relation to complete denture, in an attempt to

improvise the clarity and intelligibility speech of the edentulous patients who are

acclimatizing to new dentures. However, there have been very few studies in the

literature that use sound spectrographic analysis in combination with individual

perceptions to analyze changes that use of dentures would produce. Hence, the

following study is conducted to assess the changes in the speech sound production in

edentulous patients after rehabilitation with complete dentures after functionally

contouring the palatal vault of the maxillary complete denture.

Complete maxillary and mandibular dentures are required to serve the three

basic functions in the oral cavity: mastication, esthetics and speech. Because

mastication and esthetics assume higher priority from the patient’s point of view and

during the edentulous period speech is not impaired to the same extent as esthetics

and mastication, these two categories have been given more consideration than the

function of speech when dentures have been made. Another factor that reduces the

incentive to improve speech is that most patients learn to speak fairly well once the

tongue “gets used to” and “adapts to” the presence of dentures in the oral cavity. Thus

maxillary complete denture continue to be made with arbitrarily contoured polished

palatal surfaces and depend on the adaptability of the patient to provide “normal

speech” which might takes a few weeks to a few months. So this study was designed

to contour the palatal vault of the maxillary complete denture according to the

individual tongue-to-palate contact and incorporation of newly developed contour in

the same denture10

.Therefore the objective of the present investigation is to develop a

procedure in denture construction which would enable the patient to speak clearly at

the time of insertion of denture thus reducing the getting used period.

Research Question

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Research Gap Analysis

The speech is the basic fundamental means of communication. The production

of various speech sounds is done by the articulatory system, which consists of several

structures of the oral cavity- tongue, lips, teeth, hard palate and soft palate. Any

alteration or loss of these structures will adversely affect speech sound produced. This

is especially true in case of edentulous patients who lost the teeth and adjacent

structures resulting in poor quality of speech sounds. Complete dentures are proven to

effective for countless individuals as substitute for replacement of natural teeth. A

successful complete denture is one in which three cardinal factors of mechanics,

esthetics and phonetics are so completely and perfectly harmonized that the patient

should be able to perform not only mastication but also experiences satisfaction from

contribution of his denture to facial expression and speech.

Considerable progress has been made in improving the first two factors,

mechanics and esthetics but phonetics has not given its due attention, this can be

reasoned by the fact that most patients get used to the dentures over a period of time

and improve their speech. A very high percentage of sounds are produced by contact

of tongue with different areas of palate and teeth, since these contacts are replaced by

complete denture and failure to contour the palatal morphology results in poor speech.

So this study was designed to contour the palatal vault of the maxillary complete

denture according to the individual's tongue- to-palate contact and incorporation of

newly developed contour for that particular denture, therefore the purpose of the

present investigation was to develop a procedure in denture construction which would

enable the patient to speak clearly at the time of denture insertion and there on. Faulty

speech is never desirable even for the short periods of time. It is unpleasant for the

listener, embarrassing to the patient and adds to the burden of adaptation to the

dentures. The fact that most denture patients recover from improper articulation after

a post insertion practice period does not justify neglect of this phase in complete

denture construction nor minimize the prosthodontist's responsibility for speech

rehabilitation following delivery of dentures. This gap of 8 to 10 days adaptation

period after denture delivery or insertion needs to be minimized. This study is an

attempt to overcome this vital issue in prosthetic dentistry.

Research Question

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• Various experiments done in past to contour the palate with different materials

like waxes, hydrocolloids, auto polymerizing resin ,rubber base materials, relining

materials which has their own drawbacks.

• So this study was designed to functionally contour the palatal vault of maxillary

complete denture according to the individual’s tongue-to-palate contact by

application of visible light cure resin material which can be molded by tongue

pressure. Results in the improvement in quality of speech

Research Question

Does the functional contouring of palatal vault using visible light cure resin in

maxillary complete denture of edentulous patient improves the quality of speech

sounds?

Generated Hypothesis

Functional contouring of palatal vault using visible light cure acrylic resin in

the maxillary complete denture may improve the quality of speech in edentulous

patients.

Null hypothesis

• There is no improvement in the quality of speech after functional contouring of

palatal vault using visible light cure resin in maxillary denture of edentulous

patients.

Aim and Objectives

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AIM:-

To evaluate and compare the quality of speech sounds in edentulous patients

before and after functional contouring of palatal vault using visible light cure resin in

Maxillary complete denture.

OBJECTIVES: -

• To evaluate the quality of speech sounds in edentulous subjects wearing

conventional complete dentures without modification of palatal vault using

spectrograph.-(G1)

• To evaluate the quality of speech sounds in edentulous subjects wearing

functionally contoured palatal vault of maxillary complete dentures by visible

light cure acrylic resin using spectrograph .(G2)

• To compare the changes in the quality of speech sounds produced by dentures

made for both the groups –( G1 and G2)

• To establish the association between quality of speech improvement and

functional contouring of palate.

Mechanism of Speech

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The sound of the voice is unique. It is sufficiently universal to be understood

by millions of people throughout the world who speak the same language, and at the

same time it is sufficiently particular to identify the individual. It is so simple that the

child learns it as speech, and so complicated that a room full of electronic equipment

manipulated by experts cannot simulate it. The cacophony of modern environment

should make it easy to recall that any vibrating body will produce sound and that the

prerequisites for sound are a source of energy and a vibrator. The sound of energy for

the voice is air in the lungs which breathing automatically maintain sufficient quantity

to accomplish the vital exchange of impure gases of metabolism. Lung capacity

varies with the physiology of the individual but with training can be increased to

accommodate the most vicious physical exercise or to permit the opera singer to attain

and sustain a high note on the musical scale.2

Speech, language and communication

Human communication has several modalities, such as speaking, reading,

writing, use of gestures, signing. However, we talk, we listen, and we “think” using

language and speech.

Humans communicate with others about the present, as do other living

creatures but the complexity of language usage and intellectual capacity allows

communication attention to matters of the past and future as well. Human

communication is not bound by time. It is not limited to “here and now”.

Communication is the process of exchanging and / or sharing information – thoughts,

ideas and opinions via the use of language. Language as defined by Lahey, suggest it

to be “a code whereby ideas about the world are represented through a conventional

system of arbitrary signals for communication.”

Communication is a two way process which involves receiving information and

sending information. In verbal communication we receive the message by ear or by

listening and we send the message by speaking i.e., by mouth or orally. During non-

verbal communication receiving the message is mainly based on the visual sense. Here

information by writing the message, through gestures, signs and signing system.

Speech may be called as the communication through vocal and oral symbols.

According to Van Riper, “speech is an audible manifestation of language”. Speech is

very rapid, complex activity and requires very finely tuned muscle movements.

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According to Simon (1957) speech can be viewed as learned behavior, social

phenomenon, novel responses, and oral gestures and as means of establishing

interpersonal relation, maintaining emotional homeostasis and manipulating human

behavior.1

Mechanism of speech production

Now imagine the phone rings, you pick it up and say “Hello”. To say this there

is a complex chain of events between the thought and the spoken message. While

saying “hello” you see a whole series of nerves, muscles and body organs. We will try

to understand the processes by which air in the lungs is transformed into the

meaningful sequence of sounds i.e. speech. Speech is a highly coordinated fine motor

act. It involves a high integration and co-ordination between various structures. The

structures involved in speech production are the organs and structures that are a part

of the systems in the human body that participate in the speech production. These

structures include:

FIG 1

• Structures in the respiratory system: lungs, trachea, bronchi, the rib cage,

diaphragms and other muscles of respiration.

• Structures in the phonatory system: larynx, the vocal folds in the larynx and the

muscles of the larynx.

• Structures in the articulatory system: Lips, tongue, teeth, jaw, teeth, and palate.

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• Structures in the resonatory system: Oral cavity (mouth), nasal cavity (nose)

and pharyngeal cavities (throat).

• Structures in the nervous system which acts as controlling or regulating

centers during speech:

Air is drawn into the lungs during inspiration. It is placed under a modest

amount of pressure during expiratory phases. During the phase of expiration

appropriate adjustments into the internal larynx will vibrate the vocal folds and

produce phonation. The tongue, jaw and lip movements change the shape and length

of vocal tract, which will produce various speech sounds (vowels and consonants).

Various resonators add more effects in the speech production. Each system

contributes to the production of speech. The primary role of systems and structures is

not to produce speech but to sustain life. Speech is the secondary function and

therefore speech production is called as an overlaid function.

The Respiratory Mechanism

FIG 2

The first requisite of speaking is a supply of pressurized air. Respiration

provides a power source for speaking. The respiratory tract begins at the mouth and a

nose opening terminates deep within the lungs. One part of the respiratory tract is

upper respiratory tract, which is formed by nasal cavity, oral cavity, pharynx, and

larynx. The other lower part is composed of the trachea, two bronchi, and the lungs.

The lower respiratory tract functions exclusively for respiration for speech production

(elevation of ribs).

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The lungs are housed in the bony rib cage, which formed by 12 pairs of ribs.

The first pair of ribs is joined directly to the sternum by cartilage and it is immovable.

The second to seventh pairs of ribs are attached in thoracic vertebrae by synovial

stern-costal joints with the sternum and are therefore mobile. The eighth to tenth pairs

are inter-costal joints to costal cartilage above and is called as “false ribs”. The last

two pairs are called as “floating ribs” because they are indirectly attached to the

sternum. All the ribs are joined to each other by muscles which are called as

intercostal muscles.

The lungs are composed of elastic, non-muscular tissue surrounding the

alveoli or air. They are supplied profusely with blood vessels. The lungs are capable

of expansion and contraction only by intervention of the respiratory movements

activated by the muscles of respiration. It enters the lungs through the passage of

nose, pharynx, larynx, trachea and bronchi. The trachea is made up of about 16-20

rings which are made up of cartilage. There is bifurcation of last cartilage into 2

bronchi. Bronchi are divide into bronchioles. These bronchioles open into alveoli.

Larynx and Bronchial Tree

FIG 3

The actual gaseous exchange between the blood and oxygen rich air takes

place in the lungs. The oxygen is absorbed from the air by blood circulating through

capillaries of air-sacs. While at the same time carbon dioxide passes from the blood

into the air sacs to be exhaled during exhalation. There is dome shaped muscle the

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diaphragms, which lies on each side below the lungs. It separated the thoracic cavity

and abdominal cavity.

There are various muscles, which take part in the act of breathing. They

include two types:

FIG 4

Chief muscles: External and internal intercostal muscles and diaphragm. The

diaphragm is always actively involved in the act of inspiration. When on

inspiration it contracts, its fiber shorten and straighten and cause the domes to

descend. It thereby flattens and comes forward. This increases the length and

capacity of the thoracic cavity, pushes the abdomen and allow air to rush into the

lungs.

Accessory muscles: External oblique, Rectus abdominus and latissims-dorsi.

Respiration is a coordinated muscular act in which the volume of the cavity of

the thorax is alternately increased and decreased in the perpetual rhythmic movements

of inspiration and expiration. During quiet breathing the following activities take

place. Air is inhaled by active muscular contraction that causes the thorax to enlarge

volume. Because of the contour and oblique orientation of the ribs, elevation is not

only upward but outward; thoracic volume increases. This increase also results from

lowering of the diaphragm muscles. While speaking inhalation phase is shorter than

exhalation.

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Quiet breathing is usually under subconscious reflex control, predominantly

driven by elastic forces and the level of CO2.Quiet breathing requires little physical

energy, as it is relaxing. The average quiet respiration airflow is about 500 ml, 12-18

times per minute. The ratio of inhalation and exhalation is equal. Quiet respiration

primarily involves nasal breathing, respiration provides the power source for the act

of speaking. We speak during expiration. During the act of speaking there is quick

inhalation and prolonged exhalation.

Phonatory Mechanism

After the air has been inhaled during inspiration the larynx acts on the exhaled

air stream to create voice. This act is called as “phonation”. Voice is produced by the

vibration of the two vocal folds (also called vocal cords) in the larynx.

The larynx lies in the anterior midline of the neck extending from the root of

the tongue to the trachea. It is at level of the third to sixth cervical vertebrae. It forms

a continuous tube with the laryngeal portion of the pharynx above. It consists of a

skeletal framework of various cartilages bound together by ligaments and membranes

and activated by the intrinsic laryngeal muscles. It is about 44mm in males and 36mm

in females. Until puberty the male larynx grows rapidly and become larger than that

of females.

Structure of Larynx

FIG 5

• Structure of larynx: The larynx is made up of skeletal framework cartilages. These

cartilages are connected by joints, ligaments, and membranes and are moved by a

number of muscles. This cavity of the larynx is lined by mucous membrane.

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The skeleton of larynx is made up of 9 cartilage, 3 paired and 3 unpaired .The

unpaired cartilages are thyroid cartilage, cricoid cartilage and epiglottis.

• Thyroid cartilage: This is the largest cartilage of the larynx. It is shaped like a

shield and can be thought as shielding the structures inside. The most anterior

angle of this cartilage is commonly referred to as the Adam’s apple, which can be

seen on the neck in some men. Thyroid cartilage is composed of two plates of

cartilage, joined at midline to form an angle. Posteriorly thyroid cartilage has two

horns or cornea. The superior horn connects hyoid bone and the inferior connects

the cricoid cartilage. The vocal folds extend from the interior thyroid angle to the

arytenoids across the laryngeal cavity.

• Cricoid cartilage: It’s a ring shaped cartilage, narrow in front and broad behind.

It is attached to the thyroid cartilage on its upper end and to the first tracheal ring.

• Epiglottis: It is a leaf shaped larger cartilage. It is not considered important for

phonation. It is attached to the posterior cricoid elevation and the root of tongue. It

funnels the food to the esophagus and away from the laryngeal inlet.

The paired cartilages are arytenoids cartilages, corniculate cartilages and

cuneiform cartilages. The corniculates are small coned shaped cartilages that form

the apex of the arytenoids. The cuneiform cartilages are small rod shaped

cartilages found within the ary-epiglottic-fold, a fold of tissue and muscle

coursing from the arytenoids to the epiglottis.

• Arytenoids cartilages: These two cartilages each positioned on either side of the

midline on the supra-posterior surface of the cricoid cartilage. They are roughly

pyramidal in shape. The most anterior angle of the base of the arytenoids is called

vocal process. On this the vocal folds are attached. The body of vocal folds are

made of thyroartenoid muscle. There are various muscles attached to these

cartilages. Some, muscles are extrinsic muscles, which alter the position of the

larynx. Other muscles are called intrinsic muscles, which help in phonation.

The vocal folds are two muscle bands that serve to open and close the trachea

by vibrating to and fro. When the vocal folds are open, free flow of air from the

trachea to the oral and nasal cavities is possible. The opening between the two vocal

folds is called the glottis. During the normal breathing, the vocal folds are separated

from each other (glottis is open), allowing air to flow easily. When the vocal folds

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vibrate to and fro, the air stream coming from the lungs is released into the cavities

above the larynx in small air puffs. This results in the production of a complex sound

called the laryngeal tone. (Phonation) The laryngeal muscles play an important part in

opening and closing the glottis. The glottis can be completely open when the vocal

folds are away from each other and it can be completely closed when the vocal folds

are tightly closed against each other. The laryngeal muscles can also close the glottis

only lightly so that the vocal folds can be parted by air pressure from the lungs,

causing rhythmic opening and closing of the glottis for phonation. During phonation,

the vocal folds follow a rhythmic cycle:

• Vocal folds come together.

• Air pressure below the glottis is increased.

• Due to the pressure the vocal folds open up.

• Emission of puff of air.

• Vocal folds close again due to the decrease in air pressure and constant muscle

tension.

When the vocal folds close, air pressure below the glottis again increase and

the pattern is repeated. The resulting periodic puffs of breath give the sound of voice.

The frequency at which the vocal folds vibrate (number of vibrations per

second) determines the fundamental frequency of the voice. The fundamental

frequency of the voice depends on an interaction between the height of the larynx in

the neck and the length, thickness and tension of the vocal folds. The vocal folds of

males vibrate at a lower frequency while that of females vibrate at a higher

fundamental frequency, the frequency of vibration is highest in the children. The

fundamental frequency of vibration decides the individual’s vocal pitch. When the

increase in air pressure below the glottis is considerable, the vocal folds are forced

farther apart during the close - open - close cycle. The pitch and loudness of the voice

can be voluntarily changes by an individual to some extent.

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Articulatory Mechanism

FIG 6

After phonation, that is the production of voice, the next action is to create

specific speech sounds needed to speak. This is done by the articulatory system.

The production of various speech sounds such as consonants and vowels is

done by the articulatory system. The structures in the oral cavity which are

responsible for articulation of the phonemes are called the articulators. These included

the tongue, lips, teeth, lower jaw (mandible), the hard palate and soft palate (velum).

The articulators can be classified into two types:

• Active articulators are the organs in the oral cavity which take an active part in

articulation. These include the parts which move to change the shape of the vocal

tract. Active articulators in the vocal tract are lips, tongue, mandible and soft

palate.

• Passive articulators are the organs in the oral cavity which do not move but take

part in articulation by providing a surface for contact by the active articulators.

The alveolar ridge (gums just behind the upper front teeth), hard palate and teeth

are passive articulators.

Role of various articulators:

• Tongue: The tongue is a highly mobile muscular organ arising from the floor of

the mouth. It occupies most of the space in the oral cavity. Muscles within the

tongue enable it to change its shape easily. Other muscles coming from various

sites allow important movements such as tongue elevation or upward movement,

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protrusion or outward movement, retraction or backward movement and

lateralization or side to side movement. The tongue can be divided into its tip,

middle portion and back. The tongue can narrow and point as it does for the sound

l as in letter, or it can present a broad front surface as it does in the production of

the sound sh as in shirt. The back of the tongue can be elevated independently of

the front portion as in the production of the sound k as in kite. The vowels and

diphthongs of our speech are produced primarily by the movement of the tongue.

The tongue is the most important structure for articulate speech. In some children

there may be tongue tie, the tongue tip may not be free and hence may cause

difficulty in raising the tongue. This will cause the child to have difficulty in

producing sounds which require tongue elevations, such as l, t and r.

• Lips: The lips are made up mainly of facial muscles which make it possible for

them to spread, round, come together or pucker. They are most visible structures

of the mouth and are also used in various facial expressions. The lips can close to

stop the air stream as in the production of sounds such as p in parrot, b in bag and

m in mummy. The lower lip can touch the upper front teeth for production of

sounds such as f in father and v in van. Rounding the lips and changing the degree

of lip opening contributes to the production of vowel sounds such as u in pull and

o in four. If there is structural defect such as cleft lip it may cause speech problem.

• Teeth: The teeth that are most important for production of speech sounds are the

four front teeth in each jaw lower and upper. They are used in the production of

speech sounds are such an f in father, v in van, s in six and z in zebra. If teeth are

mal-aligned they will affect the speech.

• Alveolar ridge: This is the gum ridge just behind the upper front teeth. This is an

important point of contact for sounds such as t in ten, d in dog, n in nose, l in

letter, s in six and z in zebra.

• Mandible: The lower jaw or the mandible helps in opening or closing of the

mouth (oral cavity). It also changes the size and shape of the oral cavity required

for different vowels. Mandibular movements are also important in maintaining

optimal vocal resonance.

• Palate: This is the structure separating the oral and the nasal cavities. It extends

from the alveolar ridge to the back of the mouth. The part of the palate just behind

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the alveolar ridge is bony and hard. This is called hard palate. The part toward the

back of the oral cavity is soft, muscular and mobile. This is known as the soft

palate or the velum. His hard palate helps to direct the air stream towards the front

of the mouth during consonants articulation. It also contributes to vowel

resonance. It provides various points of contact by the tongue for articulation of

different speech sounds. The soft palate is a mobile structure and can be raised or

lowered. When elevated, it is in contact with the wall of the throat (posterior

pharyngeal cavities to the nasal cavity. When it is not elevated, air can flow from

the oral and pharyngeal cavities to the nasal cavities. This is required in the

production of nasal sounds like m in mat and n in nose. The velum also serves as a

point of contact for the back of the tongue during production of sounds such as k

in kite and g in go. Any structural defect such as cleft palate will have its effect on

speech.

Resonatory Mechanism

The physical (acoustic) changes made in the original vocal tone are called as

resonance phenomenon. The excitation of the air in the spaces above the larynx, in the

pharynx and oral cavity is created by the laryngeal tone. The sound waves created by

vibrations in the larynx travel up through the other structures of the airway, primarily

the hypopharynx, the oropharynx, oral cavity, nasopharynx and nasal cavity.

The place where the velum meets pharynx is the beginning of nasopharynx,

which leads to the nasal cavity. The site is known as the “velopharyngeal port”. When

the velum hangs down during breathing, it connects nasal cavity with oral cavity. This

nasal-oral coupling is required for nasal resonance for nasal consonants m, n. When

the velum is lifted by the muscular action the velopharyngeal port is closed. This

closed position is required for the oral resonance of all vowels and consonants except

nasal sounds. Failure to move the velum rapidly enough, when required can result in

excessively nasal utterance which is called “hypernasality”. Sometimes the

nasopharynx, the pharynx above the velar closure site may become blocked with the

swollen tissues (perhaps because of the allergies and colds) that will block the passage

of the sound waves and airflow through the nasal cavities. Excessive tonsil and

adenoid tissue in nasopharynx and nasal cavities will sometimes create enough

obstruction to give the voice a denasal vocal quality.

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Nervous System (Regulatory System)

FIG 7

The role of nervous system is to control the ongoing speech activity. The

ability to communicate effectively is primarily related to the complex nervous system.

This system permits and facilitates communication between a person and his

environment, other creatures and people. It is our brain that allows us to understand

and use the complex structure language. It is the ultimate mediator of most of our

voluntary behavior as well as immediate environment. The system investigates and

transmits neural impulses that stimulate our muscle to contract. At the same time

muscle contraction and movements about the joints initiate neural impulses, and they

turn travel back to the coordinating centers of the brain to “tell it” what is happening

and if things are happening as planned.

The nervous system is divided into a central nervous system and peripheral

nervous system. The central nervous system consists of the brain and spinal cord. The

brain consists of cerebral hemispheres which have different lobes such as frontal lobe,

temporal lobe, parietal lobe, occipital lobe, cerebellum and brainstem. The brain stem

finally leads to the spinal cord. The peripheral nervous system is divide into voluntary

part (cranial nerves and spinal nerves) and involuntary part (autonomous nervous

system).

There are specialized centers in the brain respectively for the various speech

and language functions. The functions of these centers are discussed below:

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• The Broca’s Area: It is located on frontal lobe of the left hemisphere. The

Broca’s area is responsible for motor speech. This area is responsible for

originating, planning and carrying out the transmission of messages. Damage to

the area leads to a problem in production of speech and comprehension of spoken

language may also affected but to a lesser degree.

• The Wernike’s Area: Wernike’s area is located in the temporal lobe of the left

hemisphere in most of the individuals. This area is responsible for comprehension

(understanding).

• Cerebellum: The role of cerebellum is coordination of movements required for

production of speech.

• Cranial nerves: The command centers in the cerebral hemispheres relay orders to

the specific muscle groups of speech production and receive information from the

sense organ of hearing through the peripheral nervous system. This is done

through the cranial nerves. There are 12 pairs of cranial nerves. They emerge from

the base of the brain and are named primarily according to the function they serve.

For the control of speech mechanism the fifth (trigeminal), seventh (facial), ninth

(glossopharyngeal), tenth (vagus) and twelfth (hypoglossal) nerves play important

roles. The eighth cranial nerve is the auditory nerve, which is responsible for

hearing and balance.

Parameters of Speech

Speech is produced by a complex interaction between the processes of

respiration, phonation, articulation and resonation. Speech has a number of

parameters that are considered to be a result of various processes involved in the

production of speech. The main parameters of speech are voice, articulation, fluency

and prosody.

Voice: Voice is the sound (tone) generated by the vocal folds in the larynx (voice

box). It is the result of the processes respiration, phonation and resonance. The

various parameters of the vibration of the vocal folds determine the parameters of

voice. Different aspects of the respiratory and resonatory processes also affect the

parameters of voice. Voice can be described in terms of its pitch – which depends

on the fundamental frequency of vibration of the vocal folds, loudness-which

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depends on the amplitude of the vibration of the vocal folds and quality – which

depends mainly on the resonatory effects. Very often, the parameters of speech

discussed above are referred to in a different way that categorizes them into the

segmental, non-segmental and the supra- segmental aspects of speech. In that

view voice may be considered as non-segmental feature.

Ling (1976) provides an extensive discussion about these aspects for the purpose

of teaching of speech to the hearing impaired. According to Ling, non-segmental

features of speech are:

Pitch and its control

Loudness and its control

Duration and its control

Quality.

• Articulation: the process of sound production is called articulation. It consists of

a series of finely coordinated overlapping movements to the articulators, placing

varying degrees of obstruction to the outgoing air stream and simultaneously

modifying the size, shape and coupling of the resonating cavities. Correct

articulation of speech sounds require accuracy in the placement of articulators,

timing, direction of movement, strength of movement, speed of movement and the

coordination of all events. Speech sounds are classified mainly as vowels and

consonants. Consonants are further classified depending on the place of

articulation, manner of articulation and presence of voicing during articulation.

• Fluency: Fluency is the smoothness with which sounds, syllables, words and

phrases are joined together during speaking. Speech that flows uninterrupted, at an

optimal rate and easily without unusual hesitations, pauses or breaks is considered

as fluent. In other words, appropriate and timely sequencing of these units of

speech is necessary to maintain the fluency of speech. Fluent speech , then , is that

which is :

Relatively effortless

Relatively free of abnormal pauses or discontinuities

Moves forward quite rhythmically and easily

Spoken at an optimal rate, which is neither too fast nor too slow.

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• Rhythm or prosody or supra segmental: prosodic features of speech are those,

which give speech its melody and rhythm. Speech rhythm carries meaning aids

under-standing, conveys emotional state and expresses esthetic qualities. Rhythm

features are produced by changes in voice and articulation, and usually by a

combination of the two.

Features such as intonation, emphasis, phrasing and rate of speech contributes to

the prosody of speech. Because prosodic features such as stress, intonation and

emphasis are often spread over more than a single consonants or vowels, they are

often referred to as the “suprasegemental” aspects of speech.

Rhythm features that are relevant to speech include:

• Emphasis: Increased stress to a word in a phrase. Emphasis is produced primarily

by an increase in intensity and duration of syllables within the stressed word. An

accompanying change in frequency also occurs. The stress on a word or a syllable

will give more meaning.

• Intonation: Change in pitch from syllable to syllable, rather than from word to

word. Important linguistic information can be conveyed through intonation

without using additional words. There are different intonation patterns we use to

convey meaning. For example, while asking a question we use a rising intonation,

while for statement we use falling intonation.

• Phrasing: Organization of words into groups related to units of meaning. It has

two components- the words linked in speech and the pauses between phrases.

Pause help the speaker to inhale air, to mark grammatical boundaries and to

provide time for planning of new material while speaking. If there are no pauses

then speech will be difficult to follow. Also if the pauses then speech will be

difficult to follow. Also if pauses are given at inappropriate places then it will

change the meaning. For example “go slow work in progress”. In this sentence if

the pause is taken before the word slow then meaning of sentence will be “go,

slow work in progress”. And if we take a pause after the word slow then the

sentence will become “go slow, work in progress”.

• Rate: Number of syllables uttered in per unit of time. Individuals vary in the rate

at which they talk. Rate is usually measured as the number of words per minute or

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the number of syllables per second. Most adults read only from 160 to 180 words

per minute. In connected conversational speech, we average 5 to 5.5 syllables per

second or about 270 words per minute. If the speech is very fast it will be difficult

to flow. If it is too slow then it will be too boring to listen.

Speech Intelligibility

Intelligibility refers to the degree to which a message can be understood. It is

the clarity with which an average listener can understand one’s utterances. In other

words, it is that aspect of oral speech language output that allows a listener to

understand what a speaker is saying. We therefore describe a person’s speech in terms

of its intelligibility. For example, when we understand everything that Mr. X say that

“Mr. X’s speech intelligibility is good”.

Intelligibility of speech depends on various factors such as:

• Appropriate use of the speech parameters discussed above,

• Listener’s ability to predict parts of the message,

• Location of pauses,

• Speed with which the utterances are produced, and

• Grammatical complexity of the sentences.

Functions of Speech

Speech is one of the fastest and most efficient mode of communication. It is

most fundamental to human beings. Speech can serve a number of functions. Some of

these are:

• Gaining attention: The most primary function of speech can be that of helping an

individual in gaining attention of another person. In a crowded place calling out

someone’s name or using some predetermined words to signal someone rather

than whistling are examples of this.

• Exchange of information: Individuals can give and get information about a lot of

things by speaking. As it is very commonly seen, information spreads very fast

by” word of mouth”. Exchange of information can occur not only between two

individuals, but also between members of two groups, two cities, two countries

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and two generations. Important about legacies, traditions, religious rituals, etc. is

passed from one generation to another through speech.

• Sharing of emotions: Speech is an important medium through which an

individual expresses his or her emotions and feelings. It helps individuals to elate

better with each other, build interpersonal relations with each other and promote

intimacy. Speech also serves as a medium for ventilating one’s pent –up emotions.

• Speech as a controlling medium: Through speech an individual can influence

and control the behavior of another individual. Speech can be used for intents such

as requesting, asking, reprimanding, convincing, warning and many more, which

help in changing, monitoring or effectively for gaining cooperation of other

persons in a cooperative Endeavour. It is through speech that great leaders could

gate the respect and cooperation of their countrymen.

• Speech reflects individuality: Every individual has his ways to communicate. An

individual can express his or her individuality by speaking his or her mind or by

expressing his or her opinion in his own style. It is through speech that an

individual can achieve his or her identity and entity. Actors and other public

figures are often remembered by their unique styles of speaking.

• Speech as recreation: Through silent movies, mime acts and other forms of non-

speech entertainment are available, they are not as popular. Some of the best

forms of recreation and entertainment use speech as the medium. Theatre, cinema,

drama, mimicry and singing all make use of the oral mode of communication. The

functions of speech thus can be summarized as follows:

• To gain attention

• To give information

• To get information.

• To bind one generation to another.

• To express emotions.

• To promote intimacy.

• To influence other’s behavior.

• To facilitate cooperative activities

• To express individuality

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Characteristics of Normal Speech

For the speech to be effective and contribute to appropriate social interactions,

it must have certain characteristics. We will now discuss these:

• Purposiveness: For speech to be effective, it should be purposeful. It should serve

the purpose with which the speech was initiated to begin with. If speech is meant

to seek information about something, it should do so. If it intends to express an

emotion, it should do so correctly. Speech that does not serve its purpose is not

effective.

• Communicativeness: Speech should be purposive and should carry a sense of

personal contact and rapport with the listeners. Communicativeness is possible

only when there is a full realization of the meaning s that are being conveyed.

Also, for speech to be communicative, it should be direct and logical.

• Agreeable voice quality: To be most effective as an instrument of

communication, the speaker’s voice should be of good quality. It should not be

breathy, harsh, shrill, excessively nasal or unpleasant. It should be age and gender-

appropriate, of optimum pitch and adequately loud.

• Flexibility: Flexibility of speech refers to flexibility if features such as pitch,

loudness, rate, quality and stress, without flexibility, speech will become

monotonous and boring. Flexibility refers to variations that a speaker creates

while speaking. This can be achieved by varying the quality of speech i.e., varying

the length of the sentences, varying the rate of speech and varying the number and

length of pauses.

• Adequate projection: Projection refers to speech and voice that is sufficiently

strong. Good projection arises from a good voice mechanism, proper use of the

voice mechanism, interest, enthusiasm and animation on the part of the speaker.

Failure to open the mouth adequately, failure to provide adequate breath stream

and indistinctly articulation lead to inadequate projection.

• Adequate articulation: Distinctness of speech requires flexibility and agility of

speech organs. For correct and adequate articulation, the sounds in the language

should be formed at the right place of articulation and in correct manner of

articulation.

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• Correct pronunciation: The pronunciation of a good speaker should be

acceptable by the listeners. This is especially relevant to the variations in the

pronunciation of a particular word in different dialects and religion.

• Ease of bearing: The posture and the body language of the speaker convey a lot

about the speaker. Awkwardness, stiffness and an immovable and inflexible

posture may not convey ease and comfort on the part of the speaker. An erect

posture, but not an arrogant or rigidly tense one, may be more effective.

• Absence of excessive fear and timidity: A wholesome attitude towards speaking,

one that is free of fear, anxiety and timidity will definitely be more effective to the

listener. If the speaker reflects these feelings, it may give an expression that the

speaker is not well versed with the topic of discussion.

• Semantic/linguistic soundness: A good and effective speaker is one who makes

good and apt choice of the right words in the right context. A powerful vocabulary

with good knowledge of linguistic rules contributes immensely to effective

speech.

Speech as an Overlaid Function

Overlaid means secondary function. The overlaid function has a great

importance along with the primary function. It is often paradox that our body does not

have any special organ for speech production. All the systems, which are involved in

speech production, have many biological functions on which our body is entirely

dependent on for survival. Without speech an individual can live but without lungs he

cannot survive. As far as speech is concerned it is secondary function of each organ,

which is directly or indirectly helpful for production of speech. However, it has been

found that the various organs of our body, which have other primary functions, like

eating, chewing, respiration (breathing) etc., help in production of speech. Thus speech

is an imposed function on them and it is therefore said to be overlaid. According to

Negus (1923). Speech is overlaid upon non-vegetative functions”. Thus speech

production is a secondary process for various organs whose main function is to perform

various primary biological functions to keep the human being alive. The respiratory,

phonatory, resonatory and articulatory systems along with nervous coordination

combine to form a whole body functional unit during the production of speech.

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All the above structures and the muscles involved in speech production are

used for other bodily activities that are important for sustaining life. Breathing which

provides the airstream for speaking is very necessary for life. The lungs transfer

oxygen to the blood and then to the muscles and remove impurities. The larynx or the

voice box has the basic function of preventing the foreign objects and food from

entering the lungs. The vocal folds also help to cough up anything, such as food and

phlegm, which the lungs reject. The larynx also help in fixation of the chest cavity

during activities such as pushing, pulling, lifting heavy objects and childbirth. The

structures in the articulators are basically used for chewing and swallowing which are

also functions necessary for life. The tongue directs food to the back of the cavity, the

lips help in keeping the food from escaping out of the mouth, the teeth cut, grind and

chew the food, the palate provides a hard upper surface for swallowing and the velum

or soft palate keeps food from entering the nasal cavity. The resonating structures are

the cavities through which necessary food or air passes. But these same organs are

also used to produce very delicately and very accurately modulated chains of sound

through which we communicate. Because the speech process utilizes the same

structures that are used in important biological (bodily) functions, speech is called an

overlaid function. This means that speech is a secondary function of the organs which

basically works towards sustaining life.1

COMPONENTS OF SPEECH

Kantner and West divided speech into 5 components:-

Respiration, phonation, resonations, articulations and neurologic integrations,

Chierici and Lawson added audition, or the ability to hear sounds, to this list. The

successful performance of these functions is necessary for the production of

acceptable speech.

• RESPIRATION:-

During respiration, inhalations and expirations are approx., equal in duration

and the airflow and regular and repetitive. During speech, however, the inhalation

phase is shortened and the exhalation phase in prolonged and not repetitive. In

normal discourse, the volume and pressure of the expelled air is comparable to the

vegetative breathing. Upward movement of the diaphragm with contraction of the

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costal cartilage and contiguous musculature creates an intrapulmonary pressure which

is greater than atmospheric pressure, the permitting air to be expelled from the lungs.

Prolongation of exhalation is achieved by the valve mechanism along the laryngeal,

pharyngeal, oral and nasal components of the respiratory tract these valves impede the

expired air and help to create speech signals. Subglottic pressure is maintained by the

balanced elasticity between the inspiratory intercostal musculature and the expiratory

abdominal musculature. If the vital capacity of lungs is compromised, as in

emphysema, speech will be perceived as “breathy”. The poor projections of the voice,

in such cases are due to the reduced volume and pressure of the expired air.

• PHONATION:-

The larynx provided the first level of constrictions for controlling the

respiration air stream. The primary function of vocal cords is to protect the lungs and

the lower respiratory tract from inhalation of particulate matter. This mechanism

requires a simple, forceful approximation of the vocal folds. Speech, conversely,

requires a multitude of positions, varying tensions and vibratory cycles, and an

intricate co-ordination of the vocal folds with other structures. If the vocal folds are

partially or completely adducted or closed, they impede the expired air. With the

proper degree of tension and sufficient sub-glottal pressure, the vocal cords may set in

vibration and thus impart phonation to air stream. Whereas phonation is essential for

certain speech sounds, other speech signals do not require phonation, hence, the vocal

folds are abducted or open. The tension and position of vocal folds will, in part,

determine the pitch of the phonated sound. In the production of low pitched sounds,

the vocal folds are relatively thick and flaccid. In high-pitched sounds, the margins of

the approximated folds are thin and tense.

• RESONATION:-

The sounds produced at the level of vocal folds, is not the final acoustic signal

with is perceived as speech. This sound is augmented and modified by the chambers

and structures above the level of glottis. The pharynx, the oral cavity and the nasal

cavity act as resonating chambers and the structures above the level of glottis. The

pharynx being a muscular tube, services as an excellent resonating chamber. This

tube is formed by 3 closely associated muscles namely: - inferior, middle and superior

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constrictor. These muscles are unique in that they share common insertions, the

medial pharyngeal raphe, but have a different anterior origin. Also, it appears that

each muscle constrictor, as well as portions of each muscle can contact selectively.

The dimensional changes imparted by this muscular action influence the resonant

characteristics of the pulsating air stream as it emerges from the larynx. The

velopharngeal mechanism proportions the sound and / or air stream between the oral

and nasal cavities and influences voice quality (or the basic sound) that is perceived

by the listener. If velopharangeal closure is compromised, or if the structural integrity

or relative size of the oral, pharyngeal or nasal cavities has been altered, voice quality

can be compromised.

• ARTICULATION:-

Amplified, resonated sound is formulated into meaningful speech by the

articulators, namely, the lips, tongue, cheek, teeth and palate, by changing the relative

spatial relationship of these structures. The tongue is considered to be the single most

important articulator of speech because of its ability to affect rapid changes in

movement and shape. The tongue may impede, selectively restrict, and channel the air

stream with precise contact against the teeth and palatal areas, thus articulating the

basic laryngeal sound, or the non-phonated air stream, into recognizable speech. If

oral structures such as the tongue, adjacent soft tissues, jaws or lips, are altered

surgically and / or neurologically, articulation may be compromised.

• NEURAL INTEGRATION: -

Speech is integrated by the central nervous system both at the peripheral and

central level. The sequential and simultaneous movements required throughout the

speech this complex demand precise co-ordination.

Neurologic impairments may compromise, a specific component of the speech

mechanism. Such as the vocal folds, soft palate or tongue, or it may indirectly affect

the entire speech system. A cerebro-vascular accident may compromise the ability of

the patient to comprehend and / or formulate meaningful speech, even though all

structures used to produce speech are anatomically within normal limits. In addition, a

neurologic impairment may produce a specific type of speech deformity. Example:

The loss of motor innervations to the soft palate may compromise elevation and

velopharyngeal closure.

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• AUDITION:-

Audition, or the ability to receive acoustic signals, is vital for normal speech.

Hearing permits receptions and interpretation of acoustic signals and allows the

speaker to monitor and control speech output. Compromised hearing can preclude

accurate feedback and hence, affect speech. Speech development and subsequent

speech therapy is hampered in-patient with hearing impairments.

NEUROPHYSIOLOGICAL BACKGROUND

A very complex neuro-physiological mechanism governs the production of

speech. A large number of oral mechano-sensitive receptors (tactile and kinesthetic)

are involved in its molar control. Therefore, all prosthodontic treatment will, more or

less, have an influence on speech performance because a great number of these

structures will be involved.

Speech production includes large number and sequences of innate and learned

motor acts produced in sequences of 12-16 sounds/sec in a rhythmic behavior. It has

been hypothesized that less cortex area is required for processing of skills as they

become automatic. Once automatized, speech control becomes localized in certain

areas such as the pre-motor and motor cortex. For the precise movements executed in

speech production the pyramidal motor system has the primary role.

Feedback plays a dynamic and flexible role in the control of most motor

events, including sequencing and timing of speech movements, there seems to be a

subconscious but learned type of pattern recognitions, or feedback, of afferent

information’s used to guide central pattern generator (CPG’s) and a central program.

The CGPs are thus important in the basic rhythm generation and timing of motor

activity. Other neural networks are also very active in the rapid transformations of the

shape of the oral cavity from one fixed configurations to another. Proprioceptive

mechano-sensitive afferents will establish the timing of certain aspects of the very fast

motor pattern and will, in synergy with cortical information, generate the final motor

output and rhythm. A precise co-ordination between different articulators is essential

for the final sound production.

A prerequisite for the satisfactory speech sounds and adaptation is an intact

general feedback system, that is orosensory and audio feed back with auditory

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feedback regarded as an every important mechanism. When impaired hearing is

present, speech production will deteriorate. Adaptation after an oral rehabilitation also

may create problems in the formation of new neuromuscular pathways.

It appears that adaptation to complete dentures may be explained by feedback

mechanical related to speech motor programming. Initially, a complete denture wearer

attempts to overcome problems related to the new prosthesis by the help of auditory

and oro-sensory feedback during function. After a while, only the patient will be

aware of remaining articulating difficulties, which often are related to certain specific

sounds. The listener (dentist) is, however, not able to detect any speech production

disturbances. At this stage, there are still sensory stimulations from orofacial

afferents to central areas. Finally, if the process of adaptation proceeds, the patient

will not be aware of any articulatory difficulties or distortional sounds due to the

prosthesis. New speech production central engrams have been established, and

adaptation and / or habituation to the complete dentures occur.

FIG 8: Speech production and communication

INNERVATION OF SPEECH

The principal motor nerves for the muscles of speech are the trigeminal

(Vth

cranial), facial (VIIth

cranial), glossopharyngeal (IXth

cranial), Vagus (Xth

cranial),

and hypoglossal (XIIth

cranial). These innervate the laryngeal muscles (vagus),

muscles of the soft palate (mandibular division of the trigeminal and vagus),

pharyngeal muscles (Glossopharyngeal and Vagus), muscles of the tongue

(hypoglossal), and muscles of the periphery of the mouth (facial) in order to obtain

mobility, to control tonus, and, in turn, to generate and withstand pressure.

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The speech mechanism is characterized by motility, by the capacity to exert

pressure, by the capacity to resist pressure, and by the ability of the talker to identify

through habitual pressures against familiar structures of the conditions for a particular

sound. The motor innervations involved derives from three pathways; the cortico-

bulbar pathway, extra pyramidal paths, and cerebellar paths. The first of these, the

corticobulbar-corticospinal, or pyramidal tract permits the conscious control of

precise movements required, e.g., in the articulation of speech sounds. This tract

becomes important in the relearning of speech habits to accommodate new intra oral

structures. The extra pyramidal tract also conveys some voluntary impulses as well as

the control of muscle tonus, the regulation and inhibition of opposing sets of muscles,

and the coordination of depth of breathing, tension of vocal folds, the lips, the cheeks,

the tongue, and the pharyngeal walls. The third pathway, from the cortex to the

speech muscles, is the cerebellar one, the route of the automatic coordination. This

one takes over much of speech after childhood until violent changes in the speech

mechanism or the functioning of the mechanism are introduced.

PHYSIOLOGIC VALVES IN SPEECH PRODUCTION

The primary functions of the respiratory and digestive tract in relation to their

secondary function of producing and modifying sounds may be understood by

recognizing that the speech mechanism includes three principal physiologic valves.

• Valve I , the glottis

• Valve II, the palato-pharyngeal region

• Valve III, the orifice of the mouth.

FIG. 9

Mechanism of Speech

40 | P a g e

• PHYSIOLOGIC VALVE I:-

True vocal folds of larynx :- The vibrating mechanism produces vocal tones,

and the true vocal folds serve as a valve only in connection with speech sounds that

have tone i.e., the voiced sounds otherwise, the outgoing stream of air passes through

the region of the vocal folds without interference as in normal breathing. The valve

mechanism serves to modulate the outgoing breath stream in instance of voiced

sounds only. It is a generator of sound waves which enables man to communicate at

a distance as contrasted to the short distance through which one might communicate

by whispering.

The larynx, containing the vocal folds that serve intermittently as valve I

during speech, is composed of three single cartilages and three pairs of cartilages.

They are connected by ligaments and moved by muscles, the larynx has a mucous

membrane lining that is continued superiorly with the pharynx and inferiorly with the

trachea. The cartilages and muscles offer the means for adducting (approximating)

and abducting (separating) the true vocal folds and for tensing them (shortening

antero-posteriorly) and relaxing them (elongating antero-posteriorly) as shown in

figure 3.

FIG. 10A, 10B: Movements of vocal cords. The broken outline shows the new

position of the vocal folds following muscle contraction.

Mechanism of Speech

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The true vocal folds are casually related to voice as opposed to whisper. The

folds are attached anteriorly to the thyroid cartilage and posteriorly to the arytenoid

muscles. When in a position of rest, as in quiet breathing, the free edges of the folds

form a triangular opening which has its apex located anteriorly and its base

posteriorly the opening or aperture between them when they are not approximated is

called rima glottidis. When voice is desired, the folds are approximated, and air is

pushed against them from below with sufficient force to blow the edges of these

elastic folds apart. The overload of air pressure is momentarily spent. Tension

restores the folds to a closed position. This cycle is repeated and becomes

quasivibratory. The acoustic output is called voice.

The muscles that control the vocal folds are divided into two classes:-

• Those within the organ itself (intrinsic) and

• Those that act upon it from out (extrinsic).

The intrinsic muscles have two main functions:-

• To adduct and abduct the folds

• To regulate the degree of their tension and length.

Intrinsic Muscles of Larynx

FIG11A, 11B

Mechanism of Speech

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The muscle that open the rimaglottidis are posterior Crico-arytenoids. They

are attached to the posterior surfaces of the arytenoid and cricoid cartilages. Thus,

they may rotate the arytenoid cartilages laterally and separate the true vocal cords.

Closure of rima glottides is effected by the arytenoid and lateral crico-

arytenoid muscle. They rotate the arytenoid cartilages medially and cause the true

vocal folds to be approximated. The arytenoids muscle extends from the posterior and

lateral surfaces of one arytenoid cartilage to the corresponding surface of the other.

These bring the arytenoids cartilage together, consequently narrowing the

rimaglottidis. The most important muscle used in lengthening and tensing the true

vocal folds is the cricothyroid.

The vocal folds are relaxed and shortened by the thyroaryteniod muscle.

The extrinsic (accessory) muscles act upon the larynx as a whole, connecting

the larynx with the hyoid bone, the sternum, the tongue and the pharynx. By means

of these muscles, the larynx may be elevated, depressed and tilted.

• PHYSIOLOGIC VALVE II:-

Palatopharyngeal region:-The pharynx is made up primarily of a constrictor band of

broad, flat muscles inserting into a median raphe along its posterior wall. The

pharynx may be divided arbitrarily into three parts (as shown in Fig. 5):-

• The nasal pharynx is a continuation of nasal cavity posteriorly; it is bounded

inferiorlyby the soft palate and terminates along the posterior pharyngeal wall

near the atlas (1st cervical vertebra). It’s only function is respiratory.

• The oral pharynx is a continuation, inferiorly, of the nasal pharynx to the

laryngeal pharynx, i.e. above the level of hyoid bone. Its function are respiratory

and digestive.

• The laryngeal pharynx is the inferior portions of the pharynx. It extends

inferiorly from the oral pharynx and terminates in the esophagus at about the level

of the VIth

cervical vertebra. Its function is strictly digestive. The palato-

pharyngeal valve is located in the region in which the respiratory and digestive

tracts cross each other (pharyngeal Isthmus). Both in the act of swallowing and in

speech, this valve divide the pharynx into naso-pharyngeal and oro-pharyngeal

cavities. The principal closure is affected by movement of the soft palate into

contact with the posterior wall of the pharynx...

Mechanism of Speech

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Schematic picture of the different valves and articulators

FIG. 12

• PHYSIOLOGIC VALVE III:-

The Mouth:-The mouth is a complicated valve, capable of making many changes,

both in capacity and in size of the orifices. It is modified by many articulators, the

chief one being the tongue.

The three physiologic valves serve to form a number of more specific articulatory

valves, such as:-

• Mandibular lip against the maxillary lip.

• Mandibular lip against the maxillary teeth.

• Tip of the tongue against the alveolar ridge etc.

These valves are formed by momentary intrusions of some segment of the

physiologic valves into the path of the outgoing stream.5

Description of Speech Sounds

In verbal communication we combine words to form sentences. The words are

formed by combining various syllabus / speech sounds. The speech sound production

is a complex process. In the process the speech organs move together in a coordinated

manner. During these movements various speech sounds such as vowels, consonants

and diphthongs are produced. The branch of linguistics that deals with the

characteristics of speech sounds is called phonetics. There are further subdivisions

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such as Articulatory phonetics, Acoustic Phonetics and auditory Phonetics. It is

Articulatory Phonetics which deals with the production of sounds by organs of

speech. Articulation is usually to be a joining of parts, however, speech articulation

takes place when any approximation or movement of the articulators constricts,

impedes, and diverts the air stream to produce a single sound. The single sound that

the physiologic airstream mechanism are capable of producing are varied and

innumerable. Many occur as noise and are unclassified, but those that are learned as

speech are called phones. Many of the phones are so similar in character that they

cannot be recognized as separate sounds by other than an expert or when pronounced

very slowly and carefully. These closely related phones have been combined to form

recognizable sounds and are classified as phonemes. The phoneme, then, is the unit of

speech by which we distinguish one utterance from another and which, collectively

(about 40) make up the phonemics of the language. Speech is further classified

according sonority into surds, sonants and consonants. The surd is any voiceless

sound and is produced by separation of vocal folds with no marginal vibration.

Consonants are articulated speech sounds and all require articulation to impede,

constrict, divert or stop the airstream at the proper place and time to produce the

desired sound.

Consonants

Consonants of speech sounds which are produced by closure or narrowing of the air

passage so that the air stream is blocked completely or partially in the mouth or come

out with an audible noise. In the production of consonants airflow out of the mouth is

completely blocked, greatly restricted or diverted through the nose. This gives

consonants a noisy, less melodic quality than vowels. Vowels are produced with an

unobstructed vocal tract .They are produced in a relatively open vocal tract, that is,

without any closure, or narrowing that will produce audible friction. The vowels

require laryngeal tone (voicing), and they provide the carrying power of voice. The

quality of a vowel depends on the shapes of the cavities of the pharynx, the mouth and

nose, which in turn depend on the positions of the soft palate, the tongue and the

lips. A diphthong is a vowel whose quality or timbre changes considerably during its

articulation. For example, the vowel of the word “my “is produced by starting with the

tongue in a low back position and then moving with the tongue up to high front

Mechanism of Speech

45 | P a g e

position ai. The combination of two sounds is known as clusters or blends, tr in train,

br in brown are few examples of blends.

Classification of consonants

Consonants can be classified by: (i) Place of articulation, (ii) Manner of articulation

(iii) Voicing.

(i) Place of articulation: the exact point in the vocal tract at which the air stream is

modified – that is the lips, teeth, alveolar ridge, etc.

(ii) Manner of articulation: the way the air stream from the mouth is modified

(blocked, restricted, diverted, etc.)

(iii) Voicing: whether vocal cords are vibrating or not vibrating. A segment is

described as voiced or voiceless.

Place of articulation

The place of articulation dimension uses the names of the various parts of the

vocal tract. The names are given according to the parts of the vocal tracts. The names

are given according to the articulators that take part in production of that consonant.

• Bilabial

• Labio-dental

• Linguo-dental

• Linguo-alveolar

• Linguo-palatal

• Linguo-velar

• Bilabial Sounds: - The sounds b, p and m are made by contact of the lips.

Insufficient support of lips by teeth and / or denture base can cause these sounds to

be defective. Therefore, the anterior-posterior position of the anterior teeth and the

thickness of the labial flange can affect the production of these sounds like wise an

incorrect vertical dimension of occlusion (VDO) or teeth positioning hindering

proper lip closure, might influence these sounds.

Mechanism of Speech

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Bilabial Sounds

FIG.13

Labio-dental Sounds: -

The labio-dental sounds f and v are made between the upper incisors and the

labio-lingual center to the posterior third of the lower lip. If the upper anterior teeth

are too short (set too high up), the V sound will be more like an ‘f’. If they are too

long (set too far down), the f will sound more like a v. If upper teeth touch the labial

side of the lower lip while these sounds are made, the upper teeth are too far back in

the mouth. In this situation, the relationship of the inside of the lower lip to the labial

surfaces of the teeth should be observed while the patient is speaking. If the lower lip

drops away from the lower teeth during speech, the lower anterior teeth are most

probably too far back in the mouth. If, on the other hand, imprints of the labial

surfaces of the lower anterior teeth are made in the mucous membrane of the lower

lip, or if the lower lip tends to raise the lower denture, the lower teeth are probably too

far forward, and this means that the upper teeth are also too far forward.

If the upper anterior teeth are set too far back in the mouth, they will contact the

lingual side of the lower lip when f and v sounds are made. This may also occur if the

lower anterior teeth are too for forward in relation to the lower residual ridge.

Mechanism of Speech

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FIG. 14

• Linguodental Sounds:-

Dental sounds are made with the tip of the tongue extending slightly between

the upper and lower anterior teeth. This sound is actually made closer to the alveolus

(the ridge) than to the tip of the teeth. Careful observation of the amount of tongue

that can be seen with the words – this, that, these and those will provide information

as to the labio-lingual position of the anterior teeth. If about 3mm of the tip of the

tongue is not visible, the anterior teeth are probably too far forward, or there may be

an excessive vertical overlap that does not allow sufficient space for the tongue to

protrude between the anterior teeth. If more than6mm of the tongue extends out

between the teeth when such sounds are made, the teeth are probably too lingual.

Mechanism of Speech

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FIG.15

• Linguoalveolar Sounds:-

Alveolar sounds (ex. t, d, s, z, v & l) are made with the valve formed by

contact of the tip of the tongue with the most anterior part of the palate (the alveolus)

or the lingual sides of the anterior teeth. The sibilants (sharp sounds) s, z, sh, ch& j

(with ch& j being affricatives) are alveolar sounds, because the tongue and alveolus

forms the controlling valve. The important observations when these sounds are

produced are the relationship of the anterior teeth to each other. The upper and lower

incisors should approach end to end but not touch. A phrase such as “I went to church

to see the judge” will cause the patient to use these critical sounds, and the relative

position of the incisal edges will provide a check on the total length of the upper and

lower teeth (including their vertical overlap).

A failure of the incisal edge to approach exactly end to end indicates a possible

error in the anterior of horizontal overlap of the anterior teeth.

Mechanism of Speech

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FIG. 16

THE ‘S’ SOUND

From a dental point of view, the S sound is the most interesting one. This is

the case because its articulation is mainly influenced by the teeth and palatal part of

the maxillary prosthesis Clinical experience suggests that s and t can cause most

problems suggests that s and t can cause most problems in a prosthodontic context. In

nearly all languages of the world, S is a common speech sound. The inter individual

variation in articulatory details may be great due to individual variation in teeth,

palate, lower jaw and tongue shape and size. However, the following phonetic

properties are common to all s sounds.

Mechanism of Speech

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FIG. 17

Linguopalatal and Articulatory characteristics:-

• The tip of the tongue is placed far forward, coming but never touching the upper

front incisors.

• The sagittal groove is made in the upper front part of the tongue, with a small cross

sectional area.

• The tongue dorsum is flat.

• Normally, the mandible will move forward and upward, with the teeth almost in

contact.

Auditory Characteristics

• The sound is fairly loud, with a light, sibilant (sharp) quality.

The S sound can be considered dental and alveolar speech sounds because

they are produced equally well with too different tongue positions, but there can be

some variations even behind the alveolus. Most people make the S sound with the tip

of the tongue against the alveolus in the area of the rugae, but with a small space for

air to escape between the tongue and alveolus. The tongue’s anterior dorsum forms a

narrow groove near the midline, with a cross section of about 10mm2. The size and

shape of this small space will determine the quality of the sound. Part of the sibilant

Mechanism of Speech

51 | P a g e

sound is generated when the teeth are being hit by a concentrated air jet. If the

opening is too small, a whistle will result. If the space is too broad and thin, the S

sound will be developed as sh, somewhat like a lisp. The frequent cause of undesired

whistles with dentures is a posterior arch form that is too narrow.

Creation of a sharp s requires accuracy of the neuromuscular control system,

for the creation of the groove and directing the air jet. Even small deviations of only

1mm will influence the quality. For example, if the tip of the tongue touches the

upper front teeth, the result will a lisped sound.

• Linguovelar sounds:-

The truly palatal sounds (example: year, she, insion and onion) present less of

a problem for dentures. The velar sounds (k, g and ng) have no effect on dentures,

except when the posterior palatal seal extension encroaches on the soft palate.2

FIG. 18

Manner of articulation

The manner of articulation refers to the description of how the sounds are

made i.e. the way in which the air stream is obstructed and how the air is released

from the vocal tract. Consonants can be grouped into the various categories.

Mechanism of Speech

52 | P a g e

• Stops :- Are characterized by stoppage and sudden release of the air stream and

require complete occlusion of the articulators involved ; the plosives P and B are

produced by closure of the lips to permit momentary buildup of the air stream,

followed by a sudden explosive release, and t & d are produced by tongue

contacting the hard palate to stop the air stream before suddenly releasing it; and

the K sounds are produced by tongue and soft palate closing the oral cavity at the

same time the soft palate and pharynx close the nasal cavity to stop the air stream

prior to plosive release.

• Fricatives:-Are produced by the air stream being forced through loosely closed

articulators or a narrow passageway. For the labiodentals f and v, the lower lip

articulates with the maxillary anterior teeth to constrict the air stream. The linguo-

dental ‘th’ is produced by incomplete articulation of tongue lip maxillary incisors

to construct the air stream. The sibilants s, z, zh, sh are produced by tongue blade

articulating with the lateral aspects of the hard palate, permitting the air stream to

be forced through the groove created in the tongue apex.

• The Affricatives: - “j” and “ch” are produced by a combination of stop and

friction, accomplished by articulation of the tongue and anterior hard palate.

• Diversions: -Of the air stream is characterized by stoppage at one point to permit

escape at another. The nasal m is produced by the lips occluding to seal the oral

cavity and permit emission through the nose. The nasal n is produced by

articulation of the tongue and hard palate closing the oral cavity while the sound

escapes through the nasal cavity. The nasal ng is produced by the tongue and soft

palate closing off the oral cavity to permit nasal emission. For the lateral “l”, the

tongue apex occludes the anterior portion of the oral cavity while sound escapes

through the lateral portions.

Voicing

This is the third dimension commonly used for classifying consonant sounds.

This is a binary dimension and refers to whether or not a consonant is accompanied

by laryngeal tone. Consonants that are produced with vocal fold activity are termed

voiced. Voiceless is the term applied to consonants that are not produced with vocal

fold vibration.

Review of Literature

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In order to produce articulate speech in complete denture patients, an effective

tongue to palate contact is an important factor. Unfortunately, very few attempts are

made to modify the palatal contours of maxillary dentures to produce the desired

normal speech. There are sporadic references in the literature identifying specific area

of tongue contact on the palate during pronunciation of various consonants in

dentulous, edentulous and denture wearing individuals. However, this information is

rarely used to modify the palatal contour of artificial maxillary denture. In 1958

Allen6 carried out a comparative analysis of the palatograms made by dentulous

subjects He developed the palatogram on thin methyl methacrylate artificial palate

dusted with unscented talcum powder .The tracings made by different subjects were

compared and analyzed. The study concluded that though there is a pattern of tongue

to palate contact in pronunciation of given consonant, no two patients contacted

exactly the same area of the palate in pronouncing it. He further concluded that the

thickness of the palatal vault is critical to speech only in the anterior region from

canine to canine also advised that thickening the area of the incisive papilla facilitates

proper enunciation and eliminates much of the post insertion practice period.

Palmer44

a speech pathologist, indicated that some patients develop problems

after the insertion of complete dentures because they experience a loss of tactile

location skills. He recommended that a non-anatomic papilla be placed on the oral

surface of the denture just posterior to the location of the incisive papilla to foster

normal speech also suggested to incorporate a transversely elongated rugae like

papilla to be identified by patient’s tongue.

History states the untiring efforts that numerous pioneers have taken for the

improvement of speech in the edentulous patient using complete denture. From the

olden times till this contemporary era, the literature reviews the significant studies and

research work that has been done.

The review of literature has been described separately under the following heads:

• Physiology and analysis of speech.

• Speech as used for designing of dentures.

• Studies to evaluate the denture in relation to speech.

• Incorporation of rugae


54 | P a g e

• PHYSIOLOGY AND ANALYSIS OFSPEECH

E. McDowell(1936)11

stated that overtones in speech are dampened by the

walls of the mouth but minimized the effect with fallowing statement ‘the size and

shape of the hard palate which acts as a sounding board, probably have much to do

with the quality of voice. Nevertheless, so many other factors more potential in

selecting frequencies are operating simultaneously that the degree of influence of the

textures of the lining of the cavities is probably very small.

C. Van Riper (1954)12

stated that there are various ways to make all speech

sounds, the compensatory activity of the tongue can substitute for anatomic

abnormalities of the lips and jaws. The outcome can also occur after the dentist has

interfered with habitual movements. There is however, an additional factor of

personal discomfort of the patient as he is called upon to make new movements and

difficult adjustment and to run the risk of uttering odd speech.

Barnett Kessler (1955)13

analyzed the tongue factor and its functioning areas

in dental prosthesis. He suggested that comprehension of the tongue function and its

operating area in both the buccal cavity and the vestibular space is a prerequisite in

achieving or approaching the ideal dental prosthesis. The tongue is a necessary part of

the instrument of articulate speech; and also moistens the lips to facilitate speech. It

acts like a reed in a wood-wind instrument to effect variations of sound qualities. It

has the transient and permanent power to change form in order to effect better speech

patterns or in general function of maturation. Tooth alignment should be effective

without encroachment upon the tongue functioning space. The base of the tongue is

frequently “hooked” by the lower second molars resulting in unstable lower dentures.

In cases of tongue enlargement the author has suggested to lessen the mechanical

irritation. The tongue use the upper and lower teeth as a spring board in capitulating

words. The tip of the tongue possess an extremely noticeable tactile sense. Thus the

authors has outlined the tongue factor in speech.

Alexander L. Martone (1962)14

wrote a series of eight articles on “An

approach to prosthodontics through speech science” titled as –„The phenomenon of

function in complete denture prosthodontics‟ described the physiology of speech to

provide a basis for a scientific approach to the phonetic factor in denture construction.

In Part I of the series he has described the „Anatomy of the mouth and related

structures‟. According to him, all the facial features act as diagnostic aids to the


55 | P a g e

dentist as he first sees his patient. But as the patient begins to relax and speak, the

dentist has an opportunity to observe the fleeting facial movements and mannerisms

characteristic of that individual. This has been termed the fourth dimension, the

vitality factor, or anatomy in action.

PartII15

of the series, Alexander Martone describes how the complex

interplay of bone and musculature is apparent in any facial expression. These complex

structures are responsible for the functions of speech, respiration, mastication, and

deglutition. Analysis of the facial expression and speech and the study of dissection of

the muscles of facial expression had indicated that these muscles, act as combined

units and are attached to fixed and movable bone, and play a role in mandibular

movements associated with the functions of speech and facial expression.

Part III16

of the series the author describes how the various parts of the oral

cavity that lie within the poly-functional pyramid carry out several functional

activities like speech, respiration, deglutition and mastication with miraculous

smoothness. The role of tongue, hard and soft palate has been explained that together

they act as a resonating sound board, and also serve as deflectors of airstream, thus

giving vocal colour to the speech sounds.

Part IV17

the author has discussed in detail the physiology of speech to

provide a background for the practical application of principles of speech science to

prosthodontic practice. The primary physiologic functions of respiratory and digestive

tracts in relation to their secondary function of producing and modifying sounds has

been explained by describing the role of three valves – glottis, Palatopharyngeal

valve, and the oral cavity in the speech mechanism.

Part V18

Alexander Martone highlights on how speech entails the use of

structures and muscles that shape and reshape the oral cavity from second to second.

The innervation of these muscles is such that habitual and rapid formation of sounds

is provided. The dentist who is constructing dentures for a patient has choices which

permit greater or less interference with the habits of speech. Construction of a denture

will preclude his forming new habits of articulation of speech sounds. Since the

quality of voice and speech is inherent and serves as a major area of identification of

an individual, the prosthodontic implication of maintaining this identity has to be

understood.


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Part VI19

In The diagnostic phase of denture construction describes how

detailed patient evaluation, clinical examination, and vitality factor of the patient and

his speech, functional patterns are significant while fabricating dentures. The benefits

of incorporating a fluid or progressive diagnostic approach in Prosthodontic treatment

need to be recognized, to study the functional performances of various structures

during speech and to apply the additional knowledge gained to the procedural steps in

denture construction in relation to phonetics.

Part VII20

described as The recording phases of denture construction in which

the development of impressions and the registrations of Maxillo-mandibular relations

have been discussed and the significance of each step in re-establishing the patient’s

speech habits.

Part VIII21“The final phases of denture construction” in which speech plays

an important role in this verification, in esthetic determinations, and in the critical

evaluation of the completed dentures. The muscles responsible for facial expressions

in the regions of the lips and checks must be properly supported by the dentures so

that natural movements of facial expressions should not get disturbed. He described

the unique complexity of the oral cavity and adjacent structures and their role in

performing various functions like respiration, deglutition, mastication, facial

expression and speech. This presents a continuous challenge to the prosthodontist.

This article focuses on how several factors such as respiration, phonation, resonance,

speech articulation, audition, neurologic function and emotional behavior are

responsible for the overall speech mechanism in its totality. All these parameters need

to be considered by the clinician while constructing dentures.

Hamlet SL, Geoffrey VC, Barlett DM. (1976)22

in the article effect of a

dental prosthesis on speaker specific characteristics of voice. Proposed that every

individual produce sound is different and person specific no similar pattern of

articulation has been observed in the patients wearing removable dental prosthesis

John M. Palmer(1974)23

in his article Analysis of speech in prosthodontic

practice has discussed in detail three baseline features of speech sound production that

include acoustic events, aerodynamic characteristics and anatomy and physiology of

the speech apparatus; thereby providing a basic rationale for speech evaluation by the

clinician. He has also illustrated various speech problems like omission, substitution,


57 | P a g e

and distortion that may occur in patients with dentures and has suggested general

approaches to alleviate these problems.

C. Andrew Burnett (1999)24

conducted a study to describe the mandibular

incisor positions for 24 consonant sounds of the English language. Incisal

relationships have been described in speech function at the S position and M position

while counting or recitation of any passage that simulate conversational speech. He

concluded from his study that the incisor position for each individual consonant was

unaffected by initial or final word placement of that sound. A sibilant sound always

produces the most anterior and superior position of the mandible.

The Rehabilitation Council of India1has provided a manual for patients with

speech and hearing difficulties titled “Fundamental of Speech and Speech Teaching.”

The structured literature consists of detailed description of mechanisms of speech

production, description of various speech sounds, their classification, development of

speech , habitual patterns, evaluation of speech , and defects or changes in speech

apparatus with age. Appendix for speech intelligibility rating scale that was

constructed by the National Teaching Institute for the Deaf, USA and followed by the

National Institute for the Hearing Handicapped in India have also been included.

Nitinkumar Agarwal and Ruchir Tripathi25

in their book “Complete

Denture Prosthodontics” have included an entire chapter on Speech Considerations

with Complete Denture Patients. According to them, speech production is an

autonomous unconscious activity. Hence, description of the various factors

responsible for its production has enlisted such as neural factor, muscular factor,

mechanical factor, aerodynamic factor, and auditory factor.

Fenn, Liddelow, and Gimsons26

in their book “Clinical Dental Prosthesis”

included an entire chapter on phonetics in which the mechanism of speech and factors

in denture designing affecting speech have been discussed in detail.

A. Ylppo (1954)27

in his article “The effect of dentures on speech” surveyed

the work of other authors and divided it into:

• Ordinary normal cases,

• Congenital and acquired cleft palate cases for the effect of dentures on speech. He

concluded that the best results were obtained by placing the upper incisors so that

edges hardly show below the lower border of the upper lip.


58 | P a g e

He also stated that during the articulation of the dentals i.e. t, d, l, s, z the tip of

the tongue either touches the hard palate or the back portion of the front teeth.

Any variations thus made in the palatal aspect of the upper anterior teeth leads

to different articulation from the original.

Anthony K. Kaires Part 1 (1956)28

in his article “Palatal pressures of the

tongue in phonetics and deglutition” quantitatively measured the variations in the

palatal pressures of the tongue at definite vertical dimensions:

• During pronunciation of palatolingual sounds

• During swallowing.

In addition to this, an attempt was also made to find out the change in the

phonetic values with a change in the vertical dimension. It was concluded that the

tongue was capable of adapting itself to the different predetermined vertical

dimensions of occlusion. However, it was noted that during the pronunciation of

certain sounds containing words – /t/, /d/, /m/, all the strain gauges were affected. It

was also stated that highlighting the effect of altering vertical dimension on the

various speech sounds was a difficult procedure. This was due to the adaptability of

the patient to the predetermined vertical dimensions. The patient, however, faced

certain amount of difficulty in the pronunciation of sibilants. He stated that co-

coordinated movements and an unrestricted tongue are dependents for the act of

speaking and swallowing.

II. SPEECH AS USED FOR DESIGNING OF DENTURES

Landa J.S. in (1935)29

suggested the use of the s sound to determine the

adequacy of freeway space and the m sound as a relaxing subject so as to establish a

desirable rest position while treating complete denture patients. He also used the f and

v labiodental sounds as an adjunct to the arrangement of maxillary teeth.

Sears V.H. in (1949)30

reported that clearer s pronunciation will result by

fashioning the area of the anterior median ridge according to the type of the tongue.

He recommended making a groove in this area of the maxillary complete denture for a

broad tongue with a slight median sulcus and building a ridge in this area for the

tongue with a deep median sulcus.


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Pound E.in (1951)7 made his patient pronounce s and he observed the

clearance of the anterior teeth. He stated that reproduction of a reverse curve in the

maxillary complete denture facilitated proper production of s and sh sounds.

Silvermann M.M (1953)8in his article "The speaking method in measuring

vertical dimension‟, had arranged the vertical height of complete dentures such that

they provided the “closest speaking space” of 1 to 2mm depending on the facial

appearance and comfort of the patient, thereby using speech as a physiologic phonetic

method for re-establishing the lost vertical dimension in the edentulous patient.

Kessler H.E. (1957)31

stated that dentistry and all its specialties play a leading

role both in maintaining normal speech and in helping to correct certain speech

defects that occur in complete denture patients. Some dentures are made phonetically

correct and in certain others, the patients compensate with their tongues or lips for the

phonetic shortcomings of their dentures. The author emphasized that a tape recorder

should be an important part of the prosthodontists equipment. A comparison should

be made between the recordings made before extraction, at wax try-in, practice

sessions and final recording. This procedure gives the patient a little needed ear

training and some understanding of where his tongue touches while he still has his

natural oral sensation. After experimentation, the author concluded that artificial

rugae are a hindrance to speech as they make the region thick. The largest share of

responsibility for the denture wearer’s speaking voice rests on the dentist. It can be

fulfilled by correct construction of dentures and giving each patient as much

education in phonetics as is needed.

For the purpose of speech therapy by the dentist. The author used anterior

teeth of many different brands of material for complete denture prosthesis treatment,

one after another, in the mouth of different patients and recorded the patients’ voices

each time on tape. He concluded that the dentist and the speech therapist both bear a

responsibility towards the phonetic considerations of the patients. This should be

overcome by a proper analysis of speech and education of the patient for a more

phonetically correct prosthesis.

Allen L.R (1958)6 carried out a comparative analysis of the palatograms made

by dentulous subjects. He developed the palatogram on a thin methyl methacrylate

artificial palate dusted with unscented powder. The tracings made by different


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subjects were compared and analyzed. The study concluded that although there is a

pattern in tongue-to-palate contact in pronunciation of a given consonant, no two

patients contacted exactly the same area of palate in pronouncing it. He further

concluded that the thickness of the palatal vault is critical to speech only in the

anterior section from canine to canine. He also advised that thickening the area of the

incisive papilla facilitates proper enunciation and eliminates much of the post-

insertion practice period.

Morrison (1959)2suggested the use of the words „sixty-six‟ and ‘Mississippi’

and several short poems containing many sibilants to determine the closest speaking

space and to establish an acceptable vertical dimension of occlusion in the denture.

Rothman R (1961)32

described the action of the lips, tongue, teeth and soft

palate in the production of speech as is related to denture construction. In his article

‘Phonetic Considerations in Denture Prosthesis’ described how for normal speech

production - The primary concern in phonetics is the change in the stream of air as it

passes through the oral cavity. The tongue plays a major role by changing its shape

and position for pronunciation of vowels and contacting a specific part of the teeth,

ridge or palate for each consonant. If these structures are replaced by dentures the

dentist must know where the tongue contacts them. Correct vertical dimension,

occlusal plane, contour of palate, and position of anterior teeth are the primary

requirements for speech sounds.

Mehringer E.J. (1963)33

adjusted the occlusal rims to provide an incisal

separation of 1- 1.5mm for sibilants, 2- 4 mm for nasal sibilants, and 5-10mm for

diphthongs. The author has quoted the recording of speech as the first and the most

logical step in recording functional positions. The neuromuscular pattern that controls

speech is not affected by the loss of teeth. This article discusses how the speech

patterns develop physiologically, illustrates graphically the basic phonetic formats

established by neuromuscular patterns in articulate speech and shows how such

patterns can be utilized under functional conditions for maling records.

Paul Gibbson (1963)34

in response to “The use of speech patterns as an aid in

prosthodontic reconstruction- by Edward J. Mehringer”, has appreciated how several

authors have become aware of the role of speech and have come to the consensus that

speech can be used as an aid in selecting and checking the vertical dimension of


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occlusion, height of occlusal plane, and position of teeth in relation to the lips, tongue

and cheek.

Silverman M.M.(1967)35

in his article titled “The Whistle and Swish Sound

in Denture Patients” explained how common abnormal sounds, such as whistling and

swishing, occur in speech of patients wearing fixed and removable restorations.

Etiology and treatment of these undesirable conditions were discussed in this article.

According to him, for proper enunciations of the “s” sound - the sides of the tongue

are pressed against the sides of the palate up to, but not including the central incisors

and air passes through a narrow groove; while for “sh” sound – the entire tongue is

drawn back and slightly broadened; for “s” & ”z” sounds - maxilla and mandible are

in their closest speaking relation; teeth are edge to edge in a horizontal relation and

sufficient vertical overlap is present. The whistle and swish sounds can be corrected

by maintaining a vertical overlap equal to the closest speaking space and by

incorporation of reverse curves in the processed denture. All abnormal sounds can be

avoided by using pre-extraction records in patients with normal speech and placement

of teeth in exact locations they previously occupied

Donald P. Erb (1967)36

attempted to provide information on various aspects

of speech effects of the maxillary retainer. According to his observations the thickness

of the maxillary retainer has to be as thin as possible in the anterior alveolar area (1-

1.5mm). Most patients adapted to speech with their denture within two weeks.

Adjusting the retainer, grooving it, and roughening it in the anterior alveolar area

appeared to improve speech. Roughening the region in the anterior alveolar area

seems to allow the patient to find the correct tongue placement for speech. The

grooving allows for a sharper quality to the sibilants. It helps correct a substitution of

“sh” or “th” for “s” sound. Patterns in articulate speech and shows how such patterns

can be utilized under functional conditions for making records.

W. Alan Lawson and E.K. Bond (1969)37

in their review article under

“Speech and its relation to dentistry and the effect of speech on variations in the

design of dentures” discussed the changes in the speech due to various denture shapes.

They pointed out the following changes:


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• If upper anteriors placed back palatally (centrals alone or centrals, laterals and

canines) it produces a total blockage of the air channel and affects /t/, /d/, /tsh/,

/dz/, /th/, /s/ and /z/ sounds.

• If there is thick gum present behind the upper anteriors, the air channel is blocked

again resulting in changes in the /t/, /d/, /th/ sounds.

They concluded that the elimination of speech defects of dental origin can be

possible by understanding general mechanism of speech and by knowledge of the role

played by oral structures in speech articulation.

Pound E (1970)38

attempted to utilize speech to simplify a personalized

denture service. Maxillary anterior teeth should be positioned so the incisal edges

make a definite seal against the lower lip, when the patient is pronouncing the "F" or

"V" sounds. This position sets the stage for the positions of all the remaining teeth.

The mandibular anterior teeth are set using the "S" sound, slightly lingual to the labial

edges of the upper incisors with a space of 1-1.5 mm between them. The "S" position

is also utilized for recording of the patient’s original class of occlusion, vertical

dimension, centric relation, and incisal guidance. A technique of progressive

refinement is outlined utilizing diagnostic treatment dentures, tissue treatment

material, and resin blocks on the posterior of the mandibular denture. After occlusion

is developed and tissues are in good tone, patient is comfortable, and esthetics are

satisfied these dentures are used as a mockup for the making of "continuance"

dentures.

George A. Murrell (1970)39

in his article occlusal considerations in esthetic

tooth positioning has put forth an opinion that to achieve protrusive balance, dentists

have minimized the horizontal and vertical overlap when positioning anterior teeth for

dentures. This factor increases denture stability but at the expense of natural tooth

position, esthetics and phonetics. The dentist should be concerned with developing the

following three functions in the dentures. First, the phonetic function is developed so

that the incisal edges of maxillary anteriors form a seal with the vermilion border of

lower lip when the patient says “f”. A soft block of wax is contoured as the patient

says “s” to determine the position of the lower anteriors. Second, a balanced occlusion

is developed on the articulator and a masticator function is incorporated by

eliminating the occlusal interferences during chewing and swallowing.


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Francis W. Shaffer, Robert A. Kutz (1972)40

in their article on Phonetics

and swallowing to determine palatal contours of dentures, suggested a method for

using soft wax to physiologically develop the palatal-rugae surface of a denture prior

to fabrication in acrylic resin. This technique is based on the movements and

pressures made by the tongue during swallowing and speech.

George A. Murrell (1974)41

has reviewed the positioning of anterior teeth for

esthetics and phonetics. The production of the “f” sound is used to determine the

positions of the upper anteriors. The procedure of using speaking wax placed on

stabilized lower base as used for the diagnosis of anterior occlusion is explained.

Using the established anterior stop, a procedure is described to record the occlusal

vertical relation and centric relation. The article also provides a brief review of the

atypical “s” sounds produced under classes I, II and III of occlusion and methods to

overcome these obstacles in recording the occlusal vertical and centric relations.

Pound E. (1977)42

stated that it is necessary to develop clarity of speech in

patients who wear dentures. The author reviewed the use of the sound /s / for

designing of dentures. The principles of using speech for designing of dentures

encompass two factors. The most forward, most closed position of the mandible is

assumed when the /s/ sounds are enunciated at conversational speed and another that

no teeth or denture parts should ever make contact during speech. Even after the teeth

are lost, the mandible is carried to the precise established relation during the

pronunciation of the /s/ sound. This position is as definitive and recordable as the

terminal hinge position of the condyles. The /s/ sound can be used to determine the

correct position of the maxillary and mandibular incisors along with the vertical

dimension of the patient. It is important, however, that the patient produces the sound

at conversational speed as slow speech creates larger incisal space during /s/ sound.

The posterior speaking space may vary with the skeletal jaw relation of the patient

being about 1 to 3mm for classes I and III occlusion and may be as much as 10 mm in

class II patients. The author has described a method of obtaining protrusive

registration after the anterior teeth have been set to the correct vertical and horizontal

overlap.

George Chierici and Lucie Lawson (1973)43

studied the clinical speech

considerations in prosthodontics, from the perspective of a prosthodontist and speech


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pathologist. They considered the various dimensions of speech production separately.

For this seven related functions and their importance were assessed.

• Respiration: The phenomenon of respiration is generated by the intercostal

muscles and the diaphragm. During speech the rate of air exchange per minute is

accelerated, the number of breaths per minute is decreased, breathing is deeper,

the rate of inspiration is slightly increased and rate of expiration is decreased.

A prosthetic treatment which interferes with the normal physiologic

process of respiration during speech should be avoided.

• Phonation: During speech the breath stream through the trachea initiates the

vibration of the vocal cords.

• Resonance: The sound produced at the site of the vocal cords is modified when it

passes through various chambers, example: pharynx, the oral cavity, the nasal

cavity. The excessive bulk of dentures alters the size of the oral cavity by reducing

it and may affect the resonance pattern.

• Speech articulation: The air column, thus produced is radiated outwards. It is

formed into meaningful elements of speech by the movements of the palate,

mandible, teeth, tongue and lips. This is referred to as “articulation”.

Precise articulation requires the tongue contact with the teeth, the alveolar

area, the hard or soft palate. Missing anterior teeth require the compensation for

linguodental or the labiodental sounds. Though intelligible speech can develop,

however, the precise articulation is rarely accomplished.

• Audition: It is important to recognize any form of hearing impairment in the

patients. This is to say that distortions in the speech articulations may be

associated with hearing disorders.

• Neurologic function: It is of utmost significance to distinguish speech defects

associated with neurologic disorders, from those related to prosthodontic

treatment.

• Emotional behavior: The emotional attitude of the patients towards the

prosthodontic treatment influences the patients. Such a situation requires

psychotherapeutic counseling.


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He concluded that each patient’s condition should be thoroughly evaluated so

that the prosthesis is able to provide an optimal environment for its accommodation

and acceptance towards a more natural speech.

John M. Palmer(1979)44

stated that in the absence of any clearly identifiable

pathologic condition, the prosthodontic patient demonstrating speech problems after

insertion of complete dentures must be having problems with loss of turbulence,

because of diminution of tactile location skills in speaking, or both. Potential aids to

improve speech are a non-anatomic papilla placed on the oral surface of the denture

just posterior to the location of the incisive papilla, a transversely elongated rugae-like

papilla at the same location, a roughened region at that spot, or an indentation

sufficient for the patient’s tongue to identify. The location and effectiveness of such

structural changes can be planned and judged with the cooperation of a qualified

speech pathologist.

G.M. Ritchie and Yusnidar T.Ariffin (1981)45

conducted a study on

sonographic analysis of speech sounds with varying positions of the upper anterior

teeth. This study was done to investigate the effect of the varying position of the

anterior teeth on the speech of denture wearers and the adaptability of the tongue to

altered intraoral dimensions. Complete dentures were constructed for each subject.

Six replica of upper dentures were constructed using a duplication technique and

fabricated to articulate with complete lower dentures. The position of the upper

anterior teeth was altered and these alterations were termed as conditions. The

different conditions were of seven types:

Condition I– subject without wearing dentures.

Condition II– upper central incisors 12mm from incisive papilla.

Condition III– same teeth positioning but thinning of rugae area.

Condition IV– upper central incisors 2mm anterior to the standard position as in

condition II.

Condition V– upper central incisors 4mm anterior to the standard position as in

condition II.

Condition VI– upper central incisors 2mm posterior to the standard position as in

condition II.

Condition VII– upper central incisors 4mm posterior to the standard position as in

condition II.


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Test sounds chosen were tee, chee, see and recordings were made in a sound

proof room with the mike at a distance of 40cm from the subject. Spectrographic

analysis was done subsequently. They mentioned that the tee sounds are formed with

the tip of tongue touching the lingual surfaces of the upper anterior teeth and leaving

with an explosive sound or “Burst”. A change in tee sound was noted in different

conditions during spectrographic analysis. The authors concluded that spectrographs

can be employed to analyze and interpret speech difficulties related to prosthetic

treatment.

J F McCord, H J Firestone, A A Grant (1985)46

in their article „Phonetic

determinants of tooth placement in complete dentures‟ - The provision of satisfactory

complete dentures requires that dentist, technician, and patient adequately fulfill their

respective roles in the provision of, and adaptation to, these dentures. The clinician

should combine clinical skills and appropriate patient management, in addition to an

appreciation of post-extraction resorptive changes in the alveolar ridges, if clinically

acceptable dentures are to be prescribed. An increasing number of replacement

dentures are being prescribed for older patients; thus, the need to utilize functional

factors to determine tooth placement has been reviewed.

Emily A. Tobey and Israel M. Finger (1983)69

put forth a view that since

anterior teeth play a major role in the production of certain sounds any prosthesis

placed near or replacing teeth alters speech production. According to the authors since

the volume of the oral cavity is changed on insertion of the prosthesis a variation in

the speech articulation is observed. For this purpose the authors carried out an

acoustic study of sounds produced with and without dentures and active versus

passive adaptation. A number of 10 subjects were selected and special target stimulus

words were recorded at two different intervals 1) without dentures and 2) Immediately

after wearing dentures. They concluded that passive acoustic affects are noted for

sounds produced with high-tongue to palate relationships; however active articulatory

changes were observed when there was a low tongue to palate relationship.

J.E Riski, E. DeLong (1984)47

conducted a study on articulation development

of children with cleft lip/palate and suggested that as the severity of clefting increases

the severity of the articulation deficit does also. Age and type of cleft were

statistically significant factors in the development of normal articulation skills.

Children with cleft lip appeared to be a homogeneous speaking group characterized


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by normal articulation development. However, children with palatal clefts remained at

a heterogeneous group with regard to their articulation test performance.

Samuel G. Fletcher (1988)48

investigated changes in the dimensions and

patterns of aticulation to compensate for different amounts of tongue tissue excised

during partial glossectomy and observed that place of articulation was shifted to parts

of the vocal tract congruent with the speakers' surgically altered lingual morphology.

Certain metrical properties of the articulatory gestures, such as width of the sibilant

groove, were maintained.

K.C. White, M.E. Connelly (1989)49

described a simple method of

duplicating natural palatal rugae to a complete denture has been described. For those

patients who have difficulty with their speech patterns accommodating to the

introduction prove helpful. This article describes methods of incorporating palatal

rugae in a newly fabricated and existing complete denture.

G.E.Turner, W.N.Williams. (1991)50

stated that optimal prosthetic

management of the palato pharyngeal part requires close interaction between the

prosthodontist and speech pathologist in the use of video fluoroscopy and video naso-

endoscopy for design, placement, and modification of the prosthesis. Function of the

palato-pharyngeal port during production of controlled samples of connected speech

can be observed from multi-view fluoroscopy, including lateral and frontal

projections. Like fluoroscopy, naso-endoscopy can be used to observe and record

function of the palato-pharyngeal port during speech.

C.A. Burnett and T.J. Clifford (1993)51

studied the closest speaking space

during the production of sibilant sounds and its value in establishing the vertical

dimension of occlusion. The purpose of their investigation was to determine whether

the production of sibilant sounds involved adapting a jaw position that corresponded

to the closest vertical speaking space. 30 young adult subjects had their closest

speaking space determined during three separate phonetic tests by using a

Kinesiograph and a Bio-pak jaw tracking software programme. It was concluded that

the subjects varied with the respect to the group of sibilant sounds produced and that a

single sibilant word sound does not give a reliable indication of the smallest speaking

vertical dimension.

Patrick A. Mattie and Rodney D. Phoenix (1996)52

have described a precise

method for fabricating metal denture base with appropriate placement and contouring


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of metal-resin finish lines, such that the resultant prosthesis should exhibit surfaces

that re-establish proper anatomic, physiologic and phonetic contours .

Vijay Prataph Singh, Girish Bharadwaj and K.Chandrashekaran Nair

(1997)53

conducted a clinical study to observe the tongue position in speech and

tongue position for four selected consonants, /s/, /k/, /l/, and /t/, through an opening in

the cheek of a patient and found that the variations in tongue position were negligible.

Although the patient had a large facial defect, speech clarity was also not affected.

D.W Farley, J.D Jones, R.J Cronin (1998)54

presented a review of the

mechanics of speech as well as common speech problems encountered with a

removable maxillary prosthesis. The use of a palatogram to aid the clinician in the

assessment and resolution of speech problems associated with a maxillary denture

were demonstrated.

T. Tachimura, K. Nohara, H. Hara, T. Wada (1999)55

conducted a clinical

study to evaluate the change in levator palatine muscle activity of normal speakers in

association with elevation of velum using experimental palatal lift prosthesis and they

concluded that the severity of velopharyngeal incompetence might be related in part

to change in levator activity in association with oral air pressure. The effect of a

speech appliance to correct velopharyngeal incompetence might consist not only of

mechanical obturation of the velopharynx but also of alteration of velopharyngeal

function to become similar to normal speakers. Moreover, it is likely that the

velopharyngeal system could be well regulated so as to exhibit a consistent outcome

of velopharyngeal function.

C. Andrew Burnett and Thomas J. Clifford (1999)56

in their study on the

mandibular speech envelope in subjects with and without incisal tooth wear described

a mandibular envelope of motion during speech for 2 subject groups. One subject

group with no tooth wear and the other with incisal tooth wear. The author concluded

that the envelope of mandibular movements during speech differed in dimension and

position for the two groups investigated.

Christina A. Gitto, Salvatore J. Esposito and Julius M. Draper

(1999)57

described how restoring patient’s speech is an important goal in complete

denture fabrication. For those patients who have difficulty with their speech patterns

accommodating to the introduction of a prosthesis, texture in the palatal region may


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prove helpful. This article describes methods of incorporating palatal rugae in a newly

fabricated and existing complete denture.

Eberhard Seifert, ChristophRunte, Michael Riebandt, Antoinette

Lamprecht-Dinnesen, and Friedhelm Bollmann (1999)58

stated that alterations to

the oral cavity caused by dental prostheses can affect speech articulation, whereas the

influence of dental prostheses on the voice is unknown. In their study they observed

that for 1 patient, the fundamental frequency rose by up to 5 semitones during speech

and his voice range was enlarged by up to 4 semitones when a thin denture was used

instead of his normal denture. This study evaluated the effects of changes in

phonation by varying the dentures of 20 subjects in line with those of the first patient.

They concluded that the variations of thickness and or volume of dentures and of the

vertical and horizontal dimension of occlusion may result in unpredictable audible

changes to the voice. Patients should be informed about possible effects of modified

or new dentures on their voice.

Stig.L.Karlsson (2004)4, in his chapter “Speech Consideration with Complete

Denture” as a contribution to the book “Prosthodontic treatment for the edentulous

patient: complete dentures and implant- supported prostheses” has described how the

various orodental morphological features influence and individual’s speech and the

role of prosthetic treatment on speech activity. He has also given an in depth

description of the neurophysiologic mechanism that governs the speech production

and how the various speech sounds are influenced by the variations in articulatory,

acoustic and auditory features/ characteristics of a person . The chapter also covers

methods for speech analysis and suggests simple and prudent ways to overcome /

minimize the speech problems that patients may encounter after prosthetic treatment.

G Schierano, M. Mozzati, F Bassi, G. Preti. (2001)59

conducted a clinical

study to evaluate the influence of the resin palatal vault on the closest speaking with

complete dentures and they concluded that thickening the resin palatal vault could be

a useful procedure to increase the VDO, in cases in which it is too low from the

aesthetic stand point.

Jana Rieger, John Wolfaard, Hadi Seikaly and Naresh Jha (2002)60

revealed that speech without an obturator is significantly different from the

preoperative stage, while speech with an obturator does not differ significantly from


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preoperative state, while speech with an obturator does not differ significantly poorer

nasalance values than individuals with involvement of the hard palate only and

concluded that rehabilitation with a maxillary obturator is successful in restoring

preoperative speech function. Rehabilitation of individuals with involvement of the

soft palate maybe more challenging.

Seiko Hongama, Masatoshi Ishikawa, Fumiaki Kawano and Tetsuo

Ichikawa (2002)61

described the fabrication of a complete denture with removable

palatal lift prosthesis and a clinical evaluation of the concluded that the dentures were

24.4% less stable when the palatal lift prosthesis was in place and were generally easier

to dislodge than were conventional dentures. This denture with removable palatal lift

prosthesis is useful for patients with dysfunction of the soft palate involving hypernasal

speech who have difficulty in retaining the prosthesis while eating.

B. Meier, O. Luck, W. Harzer (2003)62

concluded that the manual

registration method can be used only in connection with mm. consonants. Speaking

the word “Ohio” yielded excessively high values in all methods, so that this word has

to be rejected as a speech sample. Cephalometric registration produced values with

slight inter individual variations. In practice, however, this method is unsuitable for

use with orthodontic patients because of the additional radiation exposure involved in

producing an additional lateral cephalogram. For good reproducibility, practicing or

frequent repeating of the measuring method prior to definitive measuring is essential.

Mark A. Pigno, Jeff J. Funk (2003)63

described the prosthetic treatment of an

edentulous total glossectomy patient with an unconventional custom impression

procedure to develop and record proper lower lip and cheek support. They also discussed

some issues involved in the prosthetic management of the total glossectomy patient.

David M. Bohnenkamp, Lily T. Garcia, (2007)64

evaluated that the

fabrication, use, and wear instructions for complete dentures are often the factors

determining success. The dentist must help guide the mental attitude of the skeptical

patient to foster acceptance and success of complete dentures. A “feeling of looseness”

may be a condition experienced while patients learn to wear a new mandibular

complete denture. This type of patient requires more explanation, more advice, and

more instruction. A phonetic training technique, to demonstrate to the patient how to

retain and stabilize the mandibular denture, may be needed for some denture patients.


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This article reports the clinical use of phonetics and its effect on tongue position to

improve the retention and stability of a mandibular complete denture.

III. STUDIES TO EVALUATE THE DENTURE IN RELATION TO SPEECH -

Kaires AK. (1957)65

- in his article “Palatal pressures of the tongue in

phonetics and deglutition” ; conducted a study to measure quantitatively, by electronic

means, under predetermined vertical dimensions of occlusion, the palatal pressures of

the tongue in the pronunciation of selected palatolingual speech sounds and that

during the act of swallowing. Spectrographs were used to detect changes in phonetic

values in which the vertical dimension of occlusion was altered. A palatogram was

constructed for an old maxillary single denture wearer to determine the regions of

strain guage placement. Test maxillary dentures were made one with increased

vertical dimension and one with decreased vertical dimension. The results obtained

from the experimental dentures were compared with that obtained from the denture

that the patient had worn successfully for one year. The study concluded that in

speech and in swallowing, the compensatory tongue changes resulted not only in

changes of the magnitude of palatal pressures, but also in the time interval in which

those pressures were applied.

Agnello JG and Wictorin L (1972)66

conducted a study of phonetic changes

in edentulous patients to alter speech function following complete denture treatment.

The patients who have been completely edentulous for a minimum of six months prior

to making of dentures speech samples are taken

• In the edentulous state

• Immediately following denture insertion

• Two weeks following insertion of dentures

• Twelve weeks following the insertion of dentures.

They concluded that the voiced /th/ was least resistant to improvement after

the insertion of complete dentures and might need the attention of speech therapy.

Harley W.T. in (1972)67

in his article “Dynamic palatography - A study of

linguopalatal contacts during the production of selected consonant sounds. “Identified

areas of the palate contacted by the tongue during speech to assess the evidence of


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lingual laterality and to observe if a characteristic pattern linguopalatal temporal

sequencing exists. The speech material selected included the consonants /t /, /d /, /l /,

/n /, /s / and /k/ as control. The apparatus used for the study consisted of artificial resin

palates of uniform thickness (1.9 mm), which had twelve electrodes, embedded into

the lingual surface. It recorded the areas contacted by the tongue during speech. The

results of the study showed that the lateral aspects of the palate plus the incisive

papilla are the areas most commonly frequented by the tongue. The tongue appears to

function in a bilaterally symmetrical manner during speech and the dynamic manner

in which the tongue contacts and releases from the palate depends on whether an

“initial” or “ final” consonant is being articulated.

Hisatoshi Tanaka (1973)9studied the speech patterns of edentulous patients

and morphology of the palate in relation to phonetics. He made the following

conclusions-

• Most of the patients showed speech improvement when the dentures were first

inserted.

• With increased length of time of wearing new dentures, the speech intelligibility

was improved.

• Speech of patients can be improved by experience with their new dentures.

• Individuals showed difference in length of speech intelligibility and the level of

improvement with different lengths of denture usage.

• Acoustic distortions occurred more frequently in “s’, “sh”, “ch”, “zh”, “j” sounds

than in the “z”, “t”, “n”, “d”, and “l” sounds.

• “S” sound is a poor prognostic sound for speech intelligibility of speech.

• The palatal ridge formation of complete denture will affect the acoustic distortion

of affricative and fricative sound “s”.

Sandra Hamlet, Maureen Stone and Thomas McCartey (1978)68

studied the

feasibility of using conditioning prosthesis for speech adaptation. Seven subjects with

normal speech, hearing and no orthodontic treatment or experience in speaking with a

dental prosthesis formed the sample of the study. Each subject was given an artificial

palatal plate similar to an orthodontic appliance, with 1 mm base thickness and 4 mm

thickness at the alveolar region. A similar second prosthesis was constructed with 16


73 | P a g e

electrode contacts to be used during speech sample recording. Speech sample

consisted of a set of short phrases. Recordings were made at three intervals:

• Immediately with unfamiliar prosthesis

• After two weeks of adaptation

• Approximately 1 month after the second recording.

During this interval, the subject did not wear the prosthesis. The study

concluded that speech improved with adaptation and this adaptation pattern is stored

as memory. The third recording was a progress from the initial recording towards the

adapted speech.

Bal.K.Goyal and P.Greenstein(1982)10

conducted a study that was designed

to develop a method by which the palatal contour of the maxillary complete denture

could be modified according to the individual’s tongue-to-palate contact for

enunciation of normal speech immediately on insertion of the dentures. The dentures

were modified using auto polymerising resin. The speech was recorded in three

modes without the dentures, with conventional maxillary complete dentures and with

modified maxillary complete dentures, while the patient was asked to say aloud ten

stimulus sentences for contouring the palatal vault of the dentures. The immediate

speech achieved by modification showed on improvement since the modified palatal

surface of the denture offers a more physiologic and “natural” tactile sensation to the

tongue during speech production as compared to the smooth surface of a conventional

complete denture.

Tobey E.A. and Finger I.M. (1983)69

explored active verses passive

adaptation to orofacial reconstruction in relation to the speech changes that

accompany volume changes in the oral cavity during edentulous verses a denture-

speaking condition and to what extent the passive acoustic and active articulatory

effects contribute to these changes. The study was conducted on ten subjects, with

previous history of denture wearing prior to current treatment. New dentures were

made, all subjects reported satisfactory with esthetics and masticatory function of

dentures. Target words were given in a carrier sentence in which the initial consonants

consisted of /t/, /s/, and /sh/, medial vowels were /e/ as in "seat" and /a/ as in "sat".

Subjects were tested in a quiet room and recorded without dentures and immediately

following insertion of the new denture. Analysis was done of the recordings with a


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Kay Sonagraph machine and broad spectrograms were generated for each of the target

sound. They observed that –

• In the edentulous situation /a/ segments were longer than /e/ and increased in

duration with wearing of the dentures.

• The /sh/ sound was associated with the greatest % of change (3%), followed by /s/

(0.9%) and /t/ (0.7%).

• Speakers produce longer vowel segments when speaking with dentures than

without.

• Overall frequency relationships between vowels are achieved by variations in

tongue, position, and jaw opening.

• Lower frequencies during edentulous conditions may reflect subtle lengthening of

the oral cavity - a passive acoustic rather than active articulatory effect.

• Lower frequencies for /a/ may occur because speakers overcompensate for

dentures by using wider mouth opening or active articulation adjustment.

• Speakers actively change jaw position to accommodate the prosthesis if it may

potentially interfere with speech sounds like vowel production.

Thus, they concluded that examination of vowels, as well as consonants,

assists in delineating active articulatory versus passive acoustic changes to orofacial

reconstruction. Adjusting prostheses by listening to the changes in consonant sounds

may change only the passive acoustic characteristics of prostheses and may not

necessarily influence active articulatory accommodation by the patient.

Jeffrey M. Kestenberg (1983)70

studiedthe various types of speech tests such as

spontaneous samples, imitative samples, samples by reading, and deep samples have

been discussed. The clinical application of speech tests in relation to dentistry has also

been also outlined. A proposed speech articulation screening test for use in the dental

surgery has been suggested. The criteria to which the test was formulated are listed and

an analysis of the test is provided. It has been recommended that for difficult cases, that

a speech pathologist treats the patient in co-operation with the dentist.

A.Petrovic (1985)71

Evaluated the effects on speech sounds caused by

alterations of the oral cavity dimensions with complete dentures of different

morphology were analyzed. Different positions of upper incisors and different


75 | P a g e

thickness of the denture palatal plate were used as changeable factors in the

longitudinal and transverse dimensions of the oral cavity. The method was based on

sounds spectrograms as carriers of information about individual voice characteristics.

The effects of these changes on the relative duration of separate sounds in a word and

the patient adaptation period were also analyzed. From the results some conclusions

of pragmatic value were obtained useful in the clinical procedures of denture

construction.

Howell (1986)72

conducted an investigation in which the dimensions of

movement of the mandible during the reading of a standard passage of text were

measured using a bar magnet (affixed to the mandibular incisors), magnetometers,

and computer software. This enabled a speech envelope to be described. They derived

from this study that the relationship between closest speaking space and the vertical

overlap of the incisor teeth shows that there is a trend in this direction, but it is not as

definitive a correlation as has been previously assumed. The relationship between the

anterior speaking space and the horizontal overlap of the incisor teeth shows a similar

trend but with a much reduced correlation. There was often a small space of

approximately 0.2 mm between the mandibular incisor teeth and the palatal aspects of

the maxillary incisor teeth that, although a common finding in this study, was by no

means a constant feature for all subjects.

Alexander J. Hassel and Thomas Holste (2006)73

conducted a study to

compare the improvement in speech function of maxillary complete dentures with and

without sand blasting of the palatal surface of the denture. They observed a significant

improvement in the speech after sand blasting the palatal surface of the maxillary

denture, especially for stops and fricatives.

Hyung-Jun Kong and Carl A. Hansen(2008)74

described a technique for

customizing palatal contours of a maxillary complete denture. This technique uses a

palatogram as a diagnostic tool, dynamic impression of the tongue and auto-

polymerizing resin to reproduce the functional contours of the palatal vault of the

maxillary denture. After inserting a trial / processed denture, the patient is asked to

pronounce a series of sibilant sounds while recording the dynamic impression of the

tongue. Though this method does not cause any significant impact on mastication,

retention and comfort, it does help the patient to easily adapt to the denture and

shorten the adjustment period for achievement of enunciation


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Bortum Cristina,Leretter Marius, Sandu Liiana (2004)75

proposed the

phonetic evaluation of the edentulous patient co-related with the various settings of

the artificial teeth assessed the phonetic alterations in complete denture wearers

caused by position, size and material of the frontal artificial teeth. This was performed

using the static palatographies and spectograms.

Earl Pound (2006)76

in the article utilizing the speech to simplify a

personalized denture service, stated that the extent of downward and forward

mandibular movements made during speech automatically restores the patients

original horizontal and vertical overlaps which can be used to control seven factors of

occlusion. The values derived by progressive function refinement of this information

through the controlled use of diagnostic treatment dentures incorporating tissue

treatment material, and a free running occlusal scheme have been reviewed .

Manashvini S. Patil, Sanjaygouda B. Patil et al (2008)77

in the critical

review of palatine rugae and their significance in clinical dentistry reviewed that the

patients whose speech is sensitive to a changed relationship of the tongue to a palatal

prosthesis may require surface texture to orient the tongue. Because surface portion of

a complete denture can impede proper articulation, one solution is to add palatine

rugae. Unfortunately the addition of rugae to a prosthesis is not a foolproof method of

eliminating speech problems.

F.STelzie, B.Urginovic C. Knipfer et al (2010)78

assessed automatic,

computer –based speech assessment on edentulous patients with and without complete

dentures- preliminary results. Speech accessibility assessment was done by expert

listeners and the automatic rating of the word accuracy by computer based speech

recognition system (ASR). Speech production is significantly reduced after complete

loss of teeth. Reconstitution of speech production quality is important part of dental

rehabilitation and can be improved for edentulous patients by means of complete

dentures. The (ASR) has proven to be a useful and easily applicable tool for automatic

speech assessment in a standardized way.

Jean –LueSchwarfz,Louis-Jean Boe Pierre Badin et al (2011)79

evaluated

grounding stop place systems in the perceptuo-motor substance of speech on the

universality of the labial–coronal-velar stop series. Authors have used an articulatory

acoustic model of the vocal tract to examine stop consonant place in terms of both

articulation and formant values. This allows them to locate each place of articulation


77 | P a g e

in the F1-F2-F3 space and to demonstrate in “articulatory nomograms” how formants

evolve while closure is displaced from the front to the back of the vocal tract. Then

near universal labial-coronal-velar stop series i.e. (/b d g/or/p t k/) is a perceptually

optimal structure for stops just as /I a u/is for vowels, provided that it is embedded in

a suitable perceptuo-motor framework.

Victoria Artjomenko, Aldis Vidzis, Kristine Broka (2012)80

inthe problem

solving article. The assessment of speech quality and intelligibility after replacement

of lost teeth with removable dentures: review of literature .After analysis of data in

current literature conclude that alterations in oral cavity caused by tooth loss and

resorption of alveolar ridges can produce changes in speech quality and intelligibility.

Abdul-Aziz Abdullah Al Kherif and Ravikumar Ramakrishnaiah (2012)81

in the article ‘phonetics related to prosthodontics’ stated the correlation between

occlusion and speech, since there two factors are mostly not considered related to

each other , but during phonation the lower teeth function independently and there

should not be any constant with upper teeth. This article also highlights the utilization

of phonation as a tool for placement of upper anteriors in complete and partial denture

rehabilitation if pre extraction records have been lost. We us phonetics as a guideline

for proper placement of artificial teeth.

Vasmi Krishna, V. Vasmi Krishna Reddy et al (2012)82

performed the study

on dentures with phonetically contoured palate. A simple technique of adding

customized rugae and palate contours to the maxillary denture…..introduced this

technique for achieving normal speech after denture fabrication.

Rajya Laxmi Ravuri, Suchita Tella, Kiran Thota (2013)83

in their article

phonetics in complete denture- A prime concern stated that loss of teeth is through a

physiological process, many times it leads to psychological trauma to individuals due

to lack of confidence, esthetics and clarity of speech by fabrication of complete

dentures is always done but they consider it to be technique sensitive. They stated the

role of orodental structures in speech production so also denture thickness oral

peripheral outline , post dam area, vertical dimension, width of dental arches,

anterioposterior position of incisors relationship of upper anteriors to lower anteriors

and freeways play important role in speech production.


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Mariko Hattori, Yukal Smita, Hisaashi Taniguchi et al (2013)84

experimented the automatic evaluation of speech impairment caused by wearing a

dental appliance. The automatic test system detected a significant difference in speech

intelligibility, using the speech recognition score, in normal subjects with and without

placement of palatal plates. The results of the automatic test system and the

conventional evaluation system by human listeners were positively co-related their

findings suggest that the system can be used to evaluate speech intelligibility of

denture wearers.

Kristine Broka, Aldis Vidzis, Juris Grigorjevs et al (2013)85

reviewed the

influence of the design of removable dentures on patient’s voice quality. When

designing removable dental prosthesis it is important to evaluate the disposition of

artificial teeth (taking into account phonetic pronunciation) and to make a

phonetically beneficial construction of the base of dental prosthesis. It is necessary to

make the base of the prosthesis as thin as possible to improve good sound

pronunciation, however it is important not to change the resistance ability of dentures.

Spectrograms and palatograms are suitable methods of investigation to evaluate

phonetic quality of removable partial dentures.

Raghvendra Adki, Suresh Meshram, Shridevi Adaki (2013)86

performed a

study on Acoustic analysis and speech intelligibility in patients wearing conventional

dentures and rugae incorporated dentures. Reports of the acoustic analysis revealed

that pronunciation of S, SH, T, D. was clearer with rugae incorporated dentures than

conventional dentures. Amongst rugae incorporated dentures, customized rugae were

better than arbitrary rugae dentures. Intelligibility reports showed many substitutional

errors with conventional dentures. Special attention should be given to anterior palatal

region while fabricating the denture.

Hala M Abdel hameed and Mohamed E. El-Sayed (2014)87

studied the

effect of different techniques for palatal denture base configuration on speech quality

in complete denture wearer. The purpose of this study was carried out to evaluate the

effect of different techniques for palatal denture base configuration on pronunciation

of different speech sounds. Based on the results of this study, it could be concluded

that, with proper denture construction, the palatine rugae plays an important role in

speech pronunciation, as there should be some anatomical landmarks where tongue

can recognize and produce best particular sound.


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Ashish R Jain, M. K. Venkat Prasad and Padma ariga (2014)88

in the

article palatograms revisited describes a technique of obtaining palatogram and

customizing palatal contours of a maxillary complete denture with autopolymerising

acrylic resinto improve the clarity of speech.

Hamada Zaki Mahross and Kusai Baroudi (2015)89

did the spectrogram

analysis of complete dentures with different thickness and palatal rugae materials on

speech production. It is recommended to reproduce the rugae area in complete denture

because the phonetic quality of complete denture with rugae was superior to the

conventional denture. If the denture was too thick in the anterior region the result

would be a faculty /s h/d/z/ t /l/ sound .The dentures with metallic base can enhance

s/s h / t /d and z sound. The use of resilient acrylic to reproduce the rugae in complete

denture can enhance z/l/s/sh/t/ and d sounds.

Sleve Kelly, Alison Main, Graham Manley et al (2015)90

describes the

technique of electropalatography and the development of linguograph which is a user

friendly clinical instrument for measurement of tongue/palate contact, during speech.

Linguograph allows objective assessment of tongue function, appropriate targeting of

therapy is therefore possible. Visual feedback is also provided for therapy and an

objective measurement of occlusion is easily obtained. Technical aspect of linguograph

and of the trial results are presented here. These suggest that the investment will prove

useful in the assessment and management of many speech disorders.

Priya Vaswani, Pronob Sanyal, Ankur Prajapati (2015)91

demonstrated

comparison of speech articulation and intelligibility in palatally contoured dentures

using a novel rugae duplication technique stated that phonetics is better served by

keeping the posterior ridge area in the denture as thin as possible and confining the

palatal contour in anterior region. Irrespective of the depth of palatal vault, mucostatic

impression material is more appropriate as a material of choice for rugae duplication

and wax pattern fabrication.

Herman J.M. Steeneken92

wrote the chapter on the “Measurement of speech

intelligibility” suggesting that the present signal processing technologies, integrated in

personal computers, allows us to perform advance measurement on public address

system and telecommunication channels used for alert and warning messages,

professional use and entertainment


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Saurabh Chaturvedi, Narendrakumar Gupta, Ashok kumar Verma et al

(2015)93

in the article speech comprehension (prosthetic contemplation) is all the

steps of denture fabrication with its effect on speech which helps in construction of

perfect complete denture.

Christopher Jeannin et al (2016)94

did experiment on tongue pressure

recording during speech using complete denture. This describes an original

experimental procedure to measure mechanical interactions between tongue and teeth

during speech production .Using edentulous subjects, pressure transfuses are inserted

in their complete denture duplicate, physiology is respected during sound and pressure

recording as with standard complete denture original calibrations device is also

describe in order to know what kind of information can be extracted from the data.

The device permits the measurement of contact pressure without introducing any

additional perturbation other than the prosthesis itself. The preliminary results show a

well synchronization between the two signals.

Dr. Renu Gupta, Dr. R.P Luthra, Dr. Deepak Gautama (2016)95

in the

article Phonetics in complete denture- A review stated that replacement of missing

dentition with complete dentures is a major event in patient‘s life .This brings drastic

change to his /her activities. In complete denture the impressions accurate periphery

vertical dominions arch form posited of the anterior teeth etc. should be such that they

allow natural articulators such as tongue lips to work efficiently with the

morphological changes in the oral cavity thus results in each word to its fullest

perfection.

Martina Giovannetti, Alessio Casucci, Daniel Casucci et al. (2016)96

did

phonetic analysis and maxillary anterior tooth position signifies that clinicians take

care in determining the correct central incisor position in complete dentures in order

to avoid any undesirable phonetic distortions to patients complete dentures with

anterior teeth set too far palatally prevent many problems including aesthetic and

phonetic alternation ions sometimes result in whistle.

Anupama Neelakantan, Sunil Dhaded (2016)101

In the article rugae

duplication- different techniques of customizing palatal rugae in maxillary complete

denture to enhance phonetics discussed various techniques of customizing palatal

rugae in maxillary complete dentures to improve phonetics.

Material and Methodology

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The present study was undertaken in the department of prosthodontics, Sharad

Pawar Dental College to evaluate the effect of functionally contouring the palatal

vault of maxillary complete denture on the quality of speech sounds produced in two

group of patients.

G1- this group used conventional dentures without modification of palatal

vault of maxillary complete denture.

In G2-group of patients palatal vault of maxillary complete denture had been

functionally contoured with visible light cure resin. In both the groups same set of

sounds has been recorded by microphone and analyzed spectrographically in terms of

amplitude and frequency. Following equipment and materials were used to perform

this study.

MATERIALS USED –

1. Materials used for complete denture fabrication (Ph.1)


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2. Material used for functional contouring of palatal vault of maxillary complete

denture – Vocco’s visible light cure denture base resin. (Pink sheet) (Ph.2)

• Instrument used for fabrication of complete dentures (Ph. 3)

• Maxillary edentulous non perforated metal stock trays

• B.P. blade with handle

• Rubber bowl

• Plaster spatula

• Wax knife

• Lecron’s carver

• Camel hair brush


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• Enamel bowl

• Varsity flask and clamp

• Acrylic finishing burs

• Glass Slab

• Cement Spatula

EQUIPMENT USED -

1. Sony entertainment copyrighted Sound Forge Pro System software Version 11

for recording the speech samples. (Ph.4)

2. Portable Microphone (VHF) (Ph.5)


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3. Light Cure Unit (Delta India Ltd.) (Ph.6)


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METHODOLOGY -

A) Selection of patients -

• 60 edentulous subjects of both gender aged between 40 to 70 years, were selected.

• The patients were selected randomly from the out-patient department of

Prosthodontics at Sharad Pawar Dental College, Sawangi (Meghe), Wardha.

• The subjects chosen were Co-operative in nature.

• They had no hearing disabilities.

• The subjects had basic education and could speak and read the local language

(Hindi or Marathi) fluently.

• All the subjects were informed about the procedure of the study and a written

consent was obtained. (Annexure 1)

B) Fabrication of complete denture by conventional method (Ph.7)

The selected patients were clinically thoroughly evaluated and relevant medical and

dental history was obtained. Complete dentures were then fabricated for the selected

subjects by conventional method .The preliminary impressions were made using

impression compound and this was poured into a plaster model. A special tray with

spacer was fabricated using autopolymerising resin. Border molding procedure was

performed using low fusing compound. Secondary impressions were made using Zinc

Oxide Eugenol impression paste. An accurate master cast was obtained in dental

stone. The occlusal rims were placed in the mouth and the jaw relations were

recorded. A face-bow transfer was done using waterpik spring bow face bow and

maxillary cast was mounted on to the articulator. Mandibular cast was mounted

against the maxillary cast using a centric relation record.


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The anterior teeth were arranged based on guidelines marked on the maxillary rim and

the angulations of the adjustable incisal table. An anterior try in verification was done

with esthetics and phonetics principles. Then, protrusive records were made and the

articulator was programmed. The lateral condylar inclination was calculated using

Hanau’s formula.

L= H/8 + 12 where, H = Horizontal condylar inclination

L = Lateral condylar inclination.

The posterior teeth were arranged and the protrusive and lateral balance was obtained.

In the waxing stage the thickness of maxillary denture was kept 1 mm so as to

facilitate easy adaptation of light cure resin without altering the thickness of the

denture. Try-in verification was done and denture was fabricated with a heat

polymerized acrylic resin

C) Stimulus speech sounds used in the study (Ph.8)

Linguopalatal sounds were used for functionally contouring the palatal vault of the

maxillary complete denture. For this, the speech sounds used in local language (Hindi

/ Marathi) are as follows – T, TH, D, L, CH.. (ट, ठ, ड, ल, छ)

The classification for consonants in both Hindi and English languages is given in

Annexure II.

D) Recording of Speech Samples –(Ph.9)

The recording of speech for all the subjects is done in a sound proof room using a

portable microphone (VHF) and MP3 recording system (Sony entertainment’s

copyrighted Sound Forge Pro System software Version 11). The subjects were


87 | P a g e

askedto wear portable microphone where the distance of the microphone from the

mouth was kept constant. Training was provided to each patient with the help of

pictorial representation of the sounds (ph.8) and speech sound samples of various

linguopalatal sounds were recorded. Each speech sound was recorded thrice to ensure

proper recording of each sound.

E) Recording Speech Sounds without Modification of Palatal Vault of Maxillary

Complete Denture(Ph.10)

The first speech sound sample (group G1) was recorded by instructing the subject to

speak the 05 stimulus speech sounds with the maxillary complete denture without any

modifications on the palate. The sound spectrograph obtained is as follows


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F) Recording Speech Sounds after functionally contouring the Palatal Vault of

Maxillary Complete Denture using visible light cure material (group G2)(Ph.11)

Visible light cure acrylic resin was adapted on the complete palatal surface of

maxillary complete denture.

The subject was then instructed to speak the 05 stimulus speech sounds to

functionally contour the palatal vault of the maxillary complete denture

(Ph.12)


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After recording the various tongue–palate contact positions, the resin was

cured using light source. The sound spectrograph obtained is as follows (Ph.13)

spectrograph after functional molding

(G) Assessment of the sound samples -

The recorded sound samples of each subject post-denture insertion were analyzed by

using –

Quantitative analysis - Spectrogram – The software (Sony entertainment’s

copyrighted Sound Forge pro System software Version 11) used for recording the

sound samples displays each sample in the form of a spectrograph (sound waves)

(Fig. 14a, 14b,). The spectrograph provides the details of the mean frequencies (pitch

of sound) and mean decibel (intensity / loudness of sound) of each of the recordings.

A spectrograph is defined as a graphic representation of the sound in terms of their

component frequencies, in which time is shown on the horizontal axis, frequencies on

the vertical axis and intensity of each frequency at each moment in time by the

darkness of the mark.

Fig 14 a Fig 14 b

Observation and Results

90 | P a g e

The present study was undertaken to evaluate the effect of functional

contouring of palatal vault of maxillary complete denture on the quality of speech

sounds produced. Sixty edentulous patients were selected as per the criteria laid down

.Complete dentures were fabricated by conventional method for all these patients.

Samples of linguo-palatal sounds were then recorded and then grouped as fallows

1. G1--Samples of speech sounds recorded without modification of palatal vault of

maxillary complete denture.

2. G2—Samples of speech sound recorded by functionally contouring the palatal

vault of maxillary complete denture using visible light cure resin.

Table 1: Baseline characteristics

Speech Sound Without

Modification

With

Modification t-value p-value

T in dB 15.31±2.87 20.36±4.09 7.82 0.0001,S

T in Hz 128.76±15.86 134.10±14.12 1.94 0.054,NS

Th in dB 17.28±2.97 19.83±4.07 3.91 0.0001,S

Th in Hz 136.51±12.51 136.63±13.09 0.05 0.96,NS

D in dB 20.55±3.52 17.10±3.06 5.71 0.0001,S

D in Hz 135.76±11.88 134.86±10.34 0.44 0.65,NS

L in dB 21.13±4.01 20.48±3.99 0.89 0.37,NS

L in Hz 129.38±16.62 132.96±12.44 1.33 0.18,NS

Ch in dB 16.10±3.60 20.01±4.01 5.61 0.0001,S

Ch in Hz 131.75±15.42 134.53±13.33 1.05 0.29,NS


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Graph 1: Baseline characteristics

15

.31

12

8.7

6

17

.28

13

6.5

1

20

.55

13

5.7

6

21

.13

12

9.3

8

16

.1

13

1.7

5

20

.36

13

4.1

19

.83

13

6.6

3

17

.1

13

4.8

6

20

.48

13

2.9

6

20

.01

13

4.5

3

0

20

40

60

80

100

120

140

160

T in dB T in Hz Th in dB Th in Hz D in dB D in Hz L in dB L in Hz Ch in dB Ch in Hz

Me

an V

alu

e

Speech Sound

Without Modification With Modification


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Table 2: Age wise distribution of patients

Age Group(yrs.) No of patients Percentage (%)

31-40 yrs 3 5.00

41-50 yrs 10 16.67

51-60 yrs 16 26.67

61-70 yrs 21 35.00

>70 yrs 10 16.67

Total 60 100

Mean ± SD 60.46±11.55(31-84 years)

5% of the patients were in the age group of 31-40 years, 16.67% in the age

group of 41-50 years, 26.67% in 51-60 years, 35% in 61-70 years and 16.67% were in

the age group of more than 70 years.

Graph 2: Age wise distribution of patients

31-40 yrs, 5%

41-50 yrs, 16.67%

51-60 yrs, 26.67% 61-70 yrs, 35%

>70 yrs, 16.67%


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Table 3: Gender wise distribution of patients

Gender No of patients Percentage (%)

Male 35 58.33

Female 25 41.67

Total 60 100

58.33% of patients were males and 41.67% were females.

Graph 3: Gender wise distribution of patients

Male, 58.33%

Female, 41.67%


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Table 4: Comparison of speech sound T in dB in two groups

Group N Mean Std.

Deviation

Std. Error

Mean

t-

value p-value

Without Modification 60 15.31 2.87 0.37

7.82 0.0001,S

With Modification 60 20.36 4.09 0.52

Mean speech sound T in dB in without modification was 15.31±2.87 and in

with modification it was 20.36±4.09. By using Student’s unpaired t test statistically

significant difference was found in speech sound T in dB in two groups (7.82, p-

value=0.0001)

Graph 4: Comparison of speech sound T in dB in two groups

15.31

20.36

0

5

10

15

20

25


Me

an s

pe

ech

so

un

d T

in d

B


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Table 5: Comparison of speech sound T in Hz in two groups

Group N Mean Std.

Deviation

Std. Error

Mean t-value p-value


1.94 0.054,NS


Mean speech sound T in Hz in without modification was 128.76±15.86 and in


no significant difference was found in speech sound T in Hz in two groups (1.94, p-

value=0.054)

Graph 5: Comparison of speech sound T in Hz in two groups

128.76

134.1

124

126

128

130

132

134

136


Me

an s

pe

ech

so

un

d T

in H

z &

SD


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Table 6: Comparison of speech sound Th in dB in two groups

Group N Mean Std.

Deviation

Std. Error



3.91 0.0001,S


Mean speech sound Th in dB in without modification was 17.28±2.97 and in


significant difference was found in speech sound Th in dB in two groups (3.91, p-

value=0.0001).

Graph 6: Comparison of speech sound Th in dB in two groups

17.28

19.83

0

5

10

15

20

25


Me

an s

pe

ech

so

un

d T

h in

dB

an

d S

D


97 | P a g e

Table 7: Comparison of speech sound Th in Hz in two groups

Group N Mean Std.

Deviation

Std.

Error

Mean

t-value p-value


0.05 0.96,NS


Mean speech sound Th in Hz in without modification was 136.51±12.51 and

in with modification it was 136.63±13.09. By using Student’s unpaired t test

statistically no significant difference was found in speech sound Th in Hz in two

groups (0.05, p-value=0.96).

Graph 7: Comparison of speech sound Th in Hz in two groups

136.51 136.63

134

134.5

135

135.5

136

136.5

137

137.5

138


Me

an s

pe

ech

so

un

d T

h in

Hz

and

SD


98 | P a g e

Table 8: Comparison of speech sound D in dB in two groups

Group N Mean Std.

Deviation

Std. Error



5.71 0.0001,S


Mean speech sound D in dB in without modification was 20.55±3.52 and in


significant difference was found in speech sound D in dB in two groups (5.71, p-

value=0.0001).

Graph 8: Comparison of speech sound D in dB in two groups

20.55

17.1

0

5

10

15

20

25


Me

an s

pe

ech

so

un

d D

in d

B &

SD


99 | P a g e

Table 9: Comparison of speech sound D in Hz in two groups

Group N Mean Std.

Deviation

Std. Error



0.44 0.65,NS


Mean speech sound D in Hz in without modification was 135.76±11.88 and in


no significant difference was found in speech sound D in Hz in two groups (0.44, p-

value=0.65).

Graph 9: Comparison of speech sound D in Hz in two groups

135.76 134.86

0

20

40

60

80

100

120

140

160


Me

an s

pe

ech

so

un

d D

in H

z &

SD


100 | P a g e

Table 10: Comparison of speech sound L in dB in two groups

Group N Mean Std.

Deviation

Std. Error



0.89 0.37,NS


Mean speech sound L in dB in without modification was 21.13±4.01 and in


no significant difference was found in speech sound L in dB in two groups (0.89, p-

value=0.37).

Graph 10: Comparison of speech sound L in dB in two groups

21.13 20.48

0

5

10

15

20

25


Me

an s

pe

ech

so

un

d L

in d

B &

SD


101 | P a g e

Table 11: Comparison of speech sound L in Hz in two groups

Group N Mean Std.

Deviation

Std. Error



1.33 0.18,NS


Mean speech sound L in Hz in without modification was 129.38±16.62 and in


no significant difference was found in speech sound L in Hz in two groups (1.33, p-

value=0.18).

Graph 11: Comparison of speech sound L in Hz in two groups

129.38

132.96

125

126

127

128

129

130

131

132

133

134

135


Me

an s

pe

ech

so

un

d L

in H

z &

SD


102 | P a g e

Table 12: Comparison of speech sound Ch in dB in two groups

Group N Mean Std.

Deviation

Std. Error



5.61 0.0001,S


Mean speech sound Ch in dB in without modification was 16.10±3.60 and in


significant difference was found in speech sound Ch in dBin two groups (5.61, p-

value=0.0001.

Graph 12: Comparison of speech sound Ch in dB in two groups

16.1

20.01

0

5

10

15

20

25


Me

an s

pe

ech

so

un

d C

h in

dB

& S

D


103 | P a g e

Table 13: Comparison of speech sound Ch in Hz in two groups

Group N Mean Std. Deviation Std. Error Mean t-value p-value


1.05 0.29,NS


Mean speech sound Ch in Hz in without modification was 131.75±15.42 and

in with modification it was 134.53±13.33. By using Student’s unpaired t test

statistically no significant difference was found in speech sound Ch in Hz in two

groups (1.05, p-value=0.29).

Graph 13: Comparison of speech sound Ch in Hz in two group

Statistical Analysis: Statistical analysis was done by using descriptive and

inferential statistics using Student’s unpaired t test and software used in the analysis

was SPSS 22.0 and p<0.05 is considered as level of significance.

131.75

134.53

128

129

130

131

132

133

134

135

136


Me

an s

pe

ech

so

un

d C

h in

Hz

& S

D


104 | P a g e

STATISTICAL FORMULAS

Statistical analysis of assessment “Evaluation of the effect of functional

contouring of the palatal vault of maxillary complete denture on clarity of speech

sounds in edentulous patients “Analysis of the data was done by using descriptive and

inferential statistics both.

Descriptive statistics are used to describe the basic features of the data in a

study. They provide simple summaries about the sample and the measures. Together

with simple graphics analysis, they form the basis of virtually every quantitative

analysis of data.

Descriptive statistics are typically distinguished from inferential statistics.

With descriptive statistics you are simply describing what is or what the data shows.

With inferential statistics, you are trying to reach conclusions that extend beyond the

immediate data alone. For instance, we use inferential statistics to try to infer from the

sample data what the population might think. Or, we use inferential statistics to make

judgments of the probability that an observed difference between groups is a

dependable one or one that might have happened by chance in this study. Thus, we

use inferential statistics to make inferences from our data to more general conditions;

we use descriptive statistics simply to describe what's going on in our data.

The software used in the analysis were SPSS 17.0, EPI-INFO 6.0and Graph

Pad Prism 5.0 version and p<0.05 is considered as level of significance.

The statistical tests used for the analysis of the result were:

1. Student’s unpaired t test

Descriptive Statistics:

1. Arithmetic Mean: The arithmetic mean, or average, is the sum of the

values divided by the number of values.

Formula:

http://www.socialresearchmethods.net/kb/statinf.php


105 | P a g e

Where:

2. Standard Déviation(SD) =

Inferential Statistics:

3. Student’s unpaired t-test:

Assumption:

1. The samples (n1 and n2) from two normal populations are independent.

2. One or both sample sizes are less than 30

3. The appropriate sampling distribution of the test statistic is the t distribution

4. The unknown variances of the two populations are not equal

To compute the two-sample t-test two major computations are needed before

computing the t-test. First, you need to estimate the pooled standard deviation of the

two samples. The pooled standard deviation gives a weighted average of the standard

deviations of the two samples. The pooled standard deviation is going to be between

the two standard deviations, with greater weight given to the standard deviation from

a larger sample. The equation for the pooled standard deviation is:


106 | P a g e

In all work with two-sample t-test the degrees of freedom or DF is:

The formula for the two sample t-test is:

Discussion

107 | P a g e

Speech is an integral part of human communication, which makes the human

species superior to other life forms. Although every prosthodontist aims at providing

excellent complete denture prosthesis in terms of esthetics, functional efficiency and

comfort, a thorough evaluation of phonetics is too neglected with greater emphasis

placed on other three components. Loss of teeth is usually accompanied by eventual

loss of oral morphology responsible for the articulation of certain speech sounds.

Some patients do not experience any speech problems because it appears that tongue

makes compensatory adjustments for the absence of teeth. Allen had stated that

patient fitted with complete dentures generally adjust his speech pattern to the new

appliance and thus improves6.Mortone reported that older patients with complete

dentures show a resistance to speech improvement.18,19,20,21

Speech consists of

Respiration, Phonation, Resonation, Articulation, Neural integration and

Audition43

.Of these components articulation is mostly affected by construction of

complete dentures.

Articulation by definition is resonated sound formed into meaningful speech

by the movements of the mandible, lips, tongue, soft palate, hard palate and teeth. The

tongue, lips and soft palate are dynamic structures that control and direct the air

movement. Rapid and precise movements of tongue and lips occur across the static

structures. Their approximation to the teeth, hard palate and the alveolar processes

create valves for the production of specific sounds of speech like lingual-dental,

lingual-alveolar and palatal consonants. Tanaka H. (1973) reported that a reverse

curve exist in the sagittal and frontal sections of dentate patients9. This convexity is

important for the pronunciation of the sibilant sounds such as S and SH. If the anterior

palatal area is over contoured such that the air stream is excessively impeded, an S

sound may be heard as central or frontal lisp. However if this area is under-contoured,

resulting in an insufficient impeding of the air stream, “S” sound may be perceived as

whistle.91

Complete loss of teeth can cause a persistent speech disorder by altering dental

articulation areas. This severely reduces the quality of speech particularly the alteration

of frontal maxillary morphology leads to impairment of speech production. Removable

complete dentures can partly solve this problem. However, they disturb speech

production themselves as they restrict the flexibility of tongue, narrow the oral cavity

and alter the articulation areas of the palate and teeth. Speech production plays a

Discussion

108 | P a g e

significant role in patient’s general satisfaction with dentures. The patient’s contentment

co-relates with the acceptance of the denture therefore, speech production quality is an

essential feature for success or failure of dental rehabilitation.9

A phonetically correct articulation after a prosthodontic treatment in the form of

complete denture prosthesis is an important desideratum for a socially comfortable,

meaningful, and high quality of life. Moreover, the ability of correctly articulating the

phonemes and words, with no impediment in realizing the proper prosody is an

essential requirement in numerous professions, such as public relations- related

professions, law, teaching media, speakers. In all these fields of activity, normal natural,

fully modulated pronunciation is a crucial requirement. Researchers in dentistry and

psychology are aware of these facts. Dental treatment and prosthetics contribute to the

preservation of the normal speech ability, beyond contributing to the preservation and

re-establishing of the masticatory and esthetic functions. While the last two roles of the

dental treatment and prosthetics are well instituted and understood, the phonetic

recovering is still poorly comprehended and rather unvalued 103

Correction of faulty speech is the primary task of the speech specialist but the

complexity of the voice producing mechanism implores the services of the allied

health sciences .Successful treatment of the defective speech usually requires close

co-operation between the speech therapist and the practitioner in some branch of the

medical or dental profession.

This co-operation would be greatly enhanced if the medical and dental

practitioner were more aware of the fundamentals of the phonetics. Early and proper

diagnosis of speech abnormality is important for successful treatment and favorable

prognosis.

Articulation is usually considered to be a joining of parts however speech

articulation takes place when any approximation or movement of the articulators

constrict, impedes or diverts the airstream to produce a single sound.

The single sound that the physiologic airstream mechanism are capable of

producing are varied and innumerable. Many occur as noise and are un-classified, but

those that are learned as speech are called phones. Many of the phones are so similar

in character that they cannot be recognized as separate sounds by other than an expert

Discussion

109 | P a g e

or when pronounced very slowly and carefully. Those closely related phones have

been combined to form recognizable sounds and are classified as phonemes.

The Phoneme then is the unit of speech by which we distinguish one utterance

from another and which collectively (about 40) make up phonemics of the language.

Each phoneme has been given a phonetic symbol which represents its specific

sound in any language. The symbols of all phonemes together with their variance are

published by the International phonetic Association (IPA) as the Phonetic ‘Alphabet’.

Knowledge of this alphabet is an invaluable aid in learning different languages and it

is likely that phonetics will be better understood when it is mastered, because to learn

the alphabet it is necessary to learn the sounds which are universal and basic to any

language2.

Speech may be defined as formalized oral communication. It consist of four

components which are: 1-linguistic (conversational). The underlying thought and

grammatical form used in expression, 2-phonatory, the breath support as well as

laryngeal vibration in articulate speech, 3-articulatory, the neuromuscular controls

used to alter the oral and pharyngeal architecture to make definitive phonetic sounds,

and 4-auditory,the aural monitoring of one’s own speech.34

Speech is a very complex, sophisticated and autonomous activity.4 It is a

complex and highly coordinated process involving several systems of the body like

the respiratory system, phonatory system, articulatory system and resonatory system.1

Of these the articulatory system is of particular interest or significance to the dentist,

owing to the fact that the various components of the articulatory system consist of

structures of the oral cavity. The unique complexity of the oral cavity and adjacent

area presents a continual challenge to prosthodontic point. Functional movements

include those associate with respiration, deglutition, mastication, facial expression and

speech

Hence, knowledge of the phenomenon and mechanism of speech production is

an essential feature of comprehensive dental treatment.

Speech in matured man is a learned habitual neuromuscular pattern. The loss

of teeth and supporting structures alters the main articulator cavity and produce a

marked effect on the speech pattern.

Discussion

110 | P a g e

An empiric approach to the phonetic factor in denture construction frequently

place the burden for compensating for speech changes on the adaptability of the

tongue. While it is true that the tongue is very adaptable, it must be recognized that

this quality is far more significant in patients of orthodontic age than those who are

within a prosthodontic age range. In the latter group, functional patterns have been

established, and ability to adapt has decreased. Additionally significant is the fact that

the speech mechanism is highly susceptible to degenerative diseases. If dentures are

to contribute effectively to the function of speech, dentist should utilize studies in the

speech science field to augment their clinical knowledge of the phonetic factor in

denture construction.18

As Bloomer said, “surgeons and dentists who have labored carefully and

skillfully to fashion or restore anatomical form are frequently disappointed to find that

anatomical form is no guarantee of function” more important , of course , is the fact

that patient is sometimes equally or more disappointed when function does not equal

structure. Here, the function we will consider is speech –specifically, articulation or

phonetics.

For some time, prosthodontics main attention has been placed upon the patient’s

skill in talking after dentures have been made and fitted. Schlosser and Gehl said that”

correction of speech defects due to the partial or complete loss of natural teeth in

compliance with phonetic requirements was the third major objective for the fabrication

of a denture prosthesis. These authors were suggesting that a speech problem existed

before the patient had his dental treatment. It is perhaps equally important to identify

any speech problems which might develop after the denture has been fitted .The patient

will probably suspect that the denture itself is the cause of the speech problem.23

Patients usually maintain acceptable speech if the dentures satisfy the

requirements of function and esthetics however, some patients encounter difficulties,

and their speech becomes major concern. Accurate diagnosis of the speech problem is

essential in order to determine the appropriate clinical response. Of paramount

importance is the differentiation between 1) those speech defects which are associated

with changes in oral form and structure and2) those produced by other co existent

conditions in denture wearing patients. Since dentures constitute an obvious “reality”,

the patient with the speech defect may readily assume that all components of the

problem are ascribable to the dentures. However other concomitant conditions may be

Discussion

111 | P a g e

contributory to the speech defect or may be of major etiological significance. Older

patients, in particular, frequently have physical problems which are temporarily

overshadowed by their concern regarding the dentures.

Though the totality of the speech process should be emphasized for purposes

of differentiation, the various dimensions basic to speech production will be

considered separately. To clarify areas of mutual concern for prosthodontists and

speech pathologists, the following seven functions will be assessed: 1) respiration 2)

phonation 3) resonance 4) speech articulation 5) audition 6) neurologic function 7)

emotional behavior.22

The primary concern in phonetics is with the changes in the stream of air as it

passes through the oral cavity. Therefore, the enunciators or articulators are of

greatest interest to us. Of these, the tongue plays a major role. The tongue is the

principal articulator of the consonants and changes position and shape for the

pronunciation of each of the vowels. In pronouncing each consonant, the tongue

contacts a specific part of the teeth, alveolar ridge or hard palate. These structures are

covered or replaced by the denture, and the dentist must know where the tongue

contacts them so that they may be appropriately restored in the prosthesis.32

In as much as the neuromuscular patterns for speech are least affected by the

loss of the teeth, it follows that the recording of the speech, positions would be the

first and most logical step in recording functional positions. The study of phonetics

provides much useful information in formulating a treatment plan for the prosthetic

patient. In addition, knowledge of how the speech patterns develop, how they operate,

and what they are, is a most enlightening factor in understanding the performance of

all the oral functions.

The phonetic formats to be described are normal and average formats which

will physically produce the proper and intended speech sounds, and do not hold true

for retrognathic, prognathic, or any other. Although speech patterns are universal,

there are minor and individual variations, just as there are in the human gait for

walking. For this reason, functional positions assumed during speech can be recorded

only on an individual basis.33

This is true, especially, in case of the complete or partially edentulous patient,

wherein the loss of teeth and supporting structures alters the main articulatory cavity

Discussion

112 | P a g e

and produces a marked effect on the speech pattern. Wad M.A. and associates have

described the importance of speech for patient satisfaction with new dentures.97

They

showed that incorporation of dentures affects speech and familiarization may be a

protracted process. Quite often patient Complains about their inability to pronounce

certain sounds following insertion of complete dentures.

Such a complaint is more significant, especially for those engaged in a

profession where oration is an important entity like teachers, orators, singers, famous

personalities, politicians etc.

Superior speech performance was found to be related to a denture with better

fit.99

More emphasis has always been placed, by the clinician, on other key elements of

denture success like esthetics, function and comfort as compared to phonetics. Several

authors100,44,72

suggested that missing proprioceptors , change in sensory stimulus,

altered tooth positions , change in oral cavity dimension, gradual loss of hearing

(ageing process) might be responsible for problems in speech sound production

immediately post denture insertion.

The role of lips, teeth, tongue, hard palate, alveolar ridges and soft palate, in

production of speech sounds has been described eloquently by several

authors.14,15,16,17,18,19,22

Rothman32

termed these structures as "enunciators" and described

the mechanism of speech and how these structures added distinctness and clarity to

speech sounds. These structures act in unison to produce consonant sounds. Thus

consonants are articulatory speech sounds that require the articulatory structures of the

oral cavity to impede, construct, divert or stop air stream at the proper place and time

either actively or passively1 The production of consonant sounds have multiple

dimensions based on place of articulation (bilabial, dental, linguopalatal, velar,

labiodental), manner of articulation (plosives, fricatives, affricatives, flap, retroflex) and

voice (voiced / voiceless). Of these the tongue has been universally accepted as the

principal articulator for the consonants speech sounds which contacts the anterior,

middle and posterior portions of the hard palate in pronouncing many of them (t,d,n,s,l)2

A few have recognized the importance of palatal contour of the denture for

better phonation. Snow, as early in (1899) recommended restoring the anterior lingual

alveolar area to improve phonetics, particularly the pronunciation of S and SH.

Prendergast 1935 pointed out that proper thickening of the lingual alveolar area was

important for proper speech. Sears in (1949) recommended making a palatogram on

Discussion

113 | P a g e

cases where the median sulcus of the tongue does not coincide with the midline of the

palate. He recommended grooving of the palate just above the median sulcus for

patients who had little or no tongue sulcus and thickening this area for the patient who

had a deep tongue sulcus. Pound in (1951) was successful in improving phonetics by

contouring the entire lingual aspect of the maxillary denture to stimulate the normal

palate. In 1958 a method for restoring the lingual alveolar area by use of palatography

was published, and, in essence, that method together with several refinements found

to be advantageous.2

The precision of tongue palate contact relationship for a given sound has long

been a subject of interest, the use of palatograms has been well documented for this.54,

67Tanaka

9 studied the relationships between palatal contours and speech intelligibility

in both dentulous and edentulous subjects. He noted that in a sagittal section, the

natural anterior portion of the palate exhibits a reverse curve. This curve is crucial for

production of linguopalatal consonant sounds like t, d, n, l, s, sh, ch, jh. When

compared between dentate subjects and complete denture patients, Tanaka found that

this curvature was missing in most of the prostheses.

The role of palatal rugae as a land mark which the tongue recognizes in speech

has long been a point of contention. The palatal rugae contribute to a sensory input

which also serves as a bio feedback unit along with the tongue and the auditory

system, in production of various sounds. As this is surface is covered by an artificial

material, the feedback mechanism is weekend. The speech sound distortion might be

the result of substitution of plastic material against natural tissues in the palatal

region. Hence, the controversy as to whether or not to replace or reproduce the rugae

has been long standing.

Slaughter7 believes that the smoothness of the denture is disturbing, and

without the rugae, the tongue loses its capacity for local orientation. However,

Landa29, 33

states that the rugae are useless or even detrimental to most patients

because of the unnecessary additional thickness of the denture. When plataolingual

sounds t, d, s, n, l54

are produced, the excessive thickness causes phonetic difficulty

due to the premature contact of the tongue with the denture base. As there is no loss of

tissues on the palatal surface, the denture should be thin so tongue space will not be

reduced,6believed that entire lingual aspect of the maxillary denture should be

Discussion

114 | P a g e

contoured to simulate the palate, if phonetics is to be attained. Hence, many authors

recommended the reproduction of rugae as an adjunct to proper phonetics.

The simplest procedure involves hand carving the palatal surface of the

denture.49

However, this method is difficult to correct if improperly done and is

difficult to polish. Another more precise procedure uses electroplating to form a metal

plate that duplicates the form of the patient’s palate.49,52

K.C.White, M.E. Connelly

advocated the use of prefabricated palatal veneers and also described a technique for

making an individualized palatal pattern made of acrylic resin to duplicate the

rugae49

Alexander Hassel73

conducted a study and observed that there was a

significant improvement in the speech after sandblasting the palatal surface of the

maxillary denture, especially for stops and fricatives. Christina et al57

described a

method for incorporating rugae by the use of tinfoil trimmed and adapted to a cast

with prominent rugae. Shaffer and Kutz40

suggested a method of using soft wax to

physiologically develop the palatal rugae surface of a denture, based on the

movements and pressure made by the tongue during swallowing and speech.

Raghvendra Adaki, Suresh Meshram86

conducted study to evaluate the impact of

rugae on phonetics. Evaluation of speech was done by acoustic analysis and

intelligibility analysis. Reports revealed that pronunciation of s, sh, t, d, was clearer

with rugae incorporated denture than conventional denture. Amongst rugae

incorporated dentures customized rugae dentures were better than arbitrary rugae

dentures. Bit of modification in the anterior part of palate gives the better results

regarding pronunciations, thus enhancing patient’s confidence. We can do better

justice by inculcating this into our routine practice. In the past some investigators

stated that metal denture base can improve the quality of speech as it can be used in

thin sections. So tongue can adapt the oral environment easily as compared to acrylic

but fabrication of metal denture base is time consuming and costly. It cannot be

relined and cannot be contoured with any functional method. Sandblasting of the

palatal vault of denture was also performed to create the irregularities on the surface

to mimic the natural tissue morphology. These irregularities will entrap the food

particles which would be difficult to keep clean.

This aroused the need for the concept of customized palatal surface or

functional molding of the palatal vault with various materials like auto-polymerizing

resins, tissue conditioners, and physiologic wax74

. However, none of the methods is a

Discussion

115 | P a g e

direct method and can be put to use in routine clinical practice. Thus, though initial

experiences in speech disturbances are transient, the treatment objective should be to

make the dentures confirm to the individual patient's existing neuromuscular pattern.

The dentist should therefore recognize the role of prosthetic treatment on speech

activity. However there has been very few studies in the literature that use sound

spectrographic analysis to analyses the changes that use of dentures would produce.

Hence the present study is conducted to assess the changes in the speech sound

production in edentulous patients after rehabilitation with complete dentures where

functional contouring of the palatal vault of maxillary complete denture was done by

visible light cure resin.

In the present study, an attempt was made to improve the quality of speech

sounds produced immediately post denture insertion by customizing / functionally

contouring the palatal vault of maxillary complete denture using visible light cure

material and assessed if it can be put to use in routine clinical practice.

Immediately after insertion of dentures, the tongue is in a new environment

usually has to function against a highly polished palatal surface of the denture,

resulting in an altered speech pattern.10

It is possible the tongue might be able to adapt

to the new environment, and might even produce normal speech with the practice in

time. However, the approach in this study is to functionally contour the palatal surface

of the maxillary complete denture so that at the time of insertion and afterwards the

tongue does not have to adapt itself to the changed environment to produce normal

speech.

So in this study, sixty edentulous patients were selected who satisfied the

criteria laid down. Complete dentures were fabricated by standardizing the clinical

and laboratory steps for all these patients to avoid influence of variations. At the

denture insertion appointment, speech sounds were recorded with and without

modification of palatal vault of maxillary complete denture. The complete palatal

portion was functionally contoured by carefully adapting visible light cure resin

material. In the various studies conducted in past other materials had been used to

contour the palate functionally like waxes, reversible hydrocolloid, tissue

conditioners, auto polymerizing resins. Each has its own drawbacks, so the material

selected in this study is visible light cure resin, Light -activated resins are supplied as

premixed sheets or rope in light proof pouches which has fallowing advantages

Discussion

116 | P a g e

1-available in thin sheet forms

2-good working time

3-can be easily adapted manually by finger pressure

4-chemical bonding with the existing denture

5-no extra equipment required

6- biocompatible with pleasant colour

7- Easily moldable by tongue pressure

8- easy to polish. Repeatable procedure

9- cost effective, readily available

10-can be done chair side no lab procedure required

11- Changes are identifiable and visible

12- Light weight, less porosity, nontoxic

13- Reduced polymerization shrinkage

This palatal area was chosen because the tongue makes direct, firm contact

with the denture in this region and the normal anatomy of this area shows unevenness

due to presence of rugae.74

After adaptation of the material on the complete palatal

vault patient was asked to pronounce certain linguopalatal and linguoalveolar sounds

thrice so that proper molding should takes place. Denture was removed from the

patient’s oral cavity and cured. Again the sound recording been done which was

recorded in the form of spectrographs of that particular sound and analyzed in the

terms of frequency (pitch) and loudness. During the adaptation procedure there were

chances to increase the thickness of denture area in palatal region which would

adversely affect the quality of speech. So care has been taken while fabrication of

denture during wax-up stage. Thickness of the wax in the palatal region has been kept

1 mm, so that after addition of visible light cure resin thickness of denture should not

increase

In the previous studies the anterior area of the palate had given much more

importance than the posterior region in the production of speech sounds. As presence

of rugae in the anterior region became the major factor when compared to posterior

area, Duplication and incorporation of rugae has been done by many investigators but

Discussion

117 | P a g e

the results are controversial. Majority of them stated that rugae improved the quality

of speech by orosensory mechanism when compared with smooth glossy surface of

denture. Some investigators found the presence of rugae disturbing the quality of

speech.

As the hand carving and duplication of rugae from the other patient model

and transferring it to the denture require extra laboratory time and it is not matching

with the natural morphology of the palatal vault of that particular patient. So the

results achieved are not promising. This emphasized the need to contour the palate

functionally both in anterior and posterior region. Tongue makes contact in posterior

region in lateral sounds like labeling the principle articulator of the speech tongue

makes contact in both the anterior as well as posterior regions, so in this study

material has been adapted on the complete palatal vault.

Actual molding of palatal surface by patient by pronouncing certain

palatolingual sounds used in the study molded the palate uniquely and true for that

particular patient and improved the quality of sound in terms of frequency and

loudness measured in Hertz and Decibels respectively on the spectrograph. Even the

patient can be involved in the procedure and the change in the quality of speech can

be witnessed by the patient which improves the psyche of the patient dramatically and

gives confidence to patient. The palatal area was chosen because the tongue makes

direct, firm contact with the denture in this region and the normal anatomy of this area

shows unevenness due to presence of rugae.74

Hence, the speech sounds analyzed in this study were restricted to

linguopalatal sounds like t, d, ch, l, th in which the tongue made active contact with

the palate thereby functionally molding it. Other linguopalatal sounds s, dh, sh, jh,

were not included as they are formed by passive contact of tongue with the palate and

are also influenced by the position of the teeth. The subjects were trained prior to

recording and the records were made in local language Hindi. The polymerization was

done in the light curing unit

The sound recording and spectrographic analysis was done with the help of

Sony Entertainment Ltd. copyrighted Sound Forge Version 11.0 Sound Forge is a

two-track digital audio editor that includes a set of audio processes, tools, and is

compatible with any Windows sound card to create, record, and analyze audio files.

The speech sound samples of each subject were recorded immediately post denture

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insertion without any modification of the palatal surface of the denture. The recording

was repeated again after functional molding of the palatal vault of the maxillary

complete denture with visible light cure material. Spectrographic analysis of the

sound samples was done using the same software, for both frequency and decibel

comparison. This spectrum analysis allows user to perform FFT analysis and displays

the resulting data in a spectrum graph or sonogram display. The spectrum graph

allows real time monitoring of input and make it easy to navigate data and read audio

frequency and position. In the spectrum graph the horizontal axis represents frequency

and vertical axis represents amplitude in decibel (dB.)

The descriptive analysis of comparison of decibels between group G1 and,

group G2 showed that the mean value and standard deviation of the decibels of the

sound samples of "t" in group G1 was 15.31±2.87dB, and in G2 was 20.36±4.09 dB.

In "th” sound group G1 shows 17.28±2.97dB and G2 shows 19-83±4.07dB.Sound"d"

in G1 shows20.55±3-52 dB and G2 shows17.10±3.06dB.In sound "d' group shows

20.55±3.52 dB and G2 shows17.10±3.06 dB. In sound 'l" G1 shows21.31±4.01dB and

G2 shows20.48±3.99 dB. Sound "ch" in G1 shows16.10±3.60 dB and G2 shows

20.01±4-01 dB.

The descriptive analysis of comparison between decibels of group G1 and

group G2 showed that the mean value and standard deviation of sound samples in

group G1and G2 by using Student’s unpaired t test statistically significant difference

was found. All the sounds recorded after modification of palatal vault with visible

light cure material showed increase in dB. The scale for measuring intensity/loudness

of sound is the decibel scale. It was observed that group G2 had a higher decibel as

compared to group G1 indicating that the tongue had active contact with the

contoured palate to produce clear sounds as compared to group G1.

The frequency of a sound wave is measured as the number of complete back-

and-forth vibrations of a particle of the medium per unit of time. The sensation of a

frequency is commonly referred to as the pitch of a sound. A high pitch sound

corresponds to a high frequency sound wave and a low pitch sound corresponds to a

low frequency sound wave. The descriptive analysis of comparison of frequencies

between group G1 and group G2 showed that the mean value and standard deviation

of sound samples in GI for sound "t” was 128.76±15.86 Hz and in G2 it was

134.10±14.12 Hz. The sound "th" in group G1 it was136.51±12.51Hz and in G2 it

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was136.63±13.09Hz.Sound "d' in group G1 it was 135.76±11.88Hz and in G2

134.86±10.34 Hz. The sound "l" in G1 was 129.38±16.62 and in G2 it was

132.96±12.44 Hz. Sound 'ch" was 131.75±15.42 and in G2 it was 134.53±13.33 Hz.

The results showed that samples of group G2 had a higher frequency than group G1

indicating that functional contouring of the palatal vault resulted in an improvement in

the pitch of the speech.

Observing the combined results of frequency and decibels, it can be seen that

there was improvement in the pitch of speech and intensity/loudness of sound after

functional molding of palatal vault of maxillary complete denture.

When the tongue, a soft muscular structure, makes firm contact with relatively

smooth, glossy surface of the acrylic there is dampening of the sound as compared to

the relatively hard, rough / uneven surface of the set resin which simulates the

unyielding nature of tissues in that region. Thus, it can be concluded that the

orosensory feedback as well as the type of material, both, are responsible for

improvement in the pitch (frequency) and intensity (decibels), hence quality of the

speech sounds.

The improvement noticed may be due to the orosensory feedback by the

tongue-functional palate contact relation, leading to better adaptation and hence,

improvement in the quality of speech. Thus, the quantitative results affirmed that

functional contouring of the palatal vault of maxillary complete dentures significantly

improves the speech intelligibility.

There is a need for further studies with a larger sample size to investigate the

effect of alterations in dentures on other parameters. There is a necessity to evaluate

the effects of a longer duration of adaptation on all parameters. The study has proved

that functional contouring of the anterior portion of the palate is one of the major

factors that contributes to the clarity of speech but other factors like vertical

dimension, tooth position, arch form etc. have not been considered. Hence, there is

need for further investigation in this area.

PALATAL CONTOUR OF THE DENTURE

A few have recognized the importance of palatal contour of the denture for

better phonation. Snow (1899), recommended restoring the anterior lingual alveolar

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area to improve phonetics, particularly the pronunciation of s & sh. Prendergast

(1935) pointed out that proper thickening of the lingual alveolar area was important

for proper speech.

Sears (1949) recommended making a palatogram on cases where the median

sulcus of the tongue does not coincide with the midline of the palate. He

recommended grooving the palate just above the median sulcus for the patient who

had little or no tongue sulcus and thickening this area for the patient who had a deep

tongue sulcus. Pound (1951) was successful in improving phonetics by contouring

the entire lingual aspect of the maxillary denture to simulate the normal palate

PROSTHODONTIC CONSIDERATIONS OF SPEECH

The impact of denture on speech has been studied since 1950s in the papers of

pound42

and by Allen6and continued sporadically in 1960 by Rothman32

Martone

and Black17,18,19,20,21

and silverman35

during the last two decades, several groups

started investigating methodically the relationships between speech on one side and

dental treatment and prosthetic denture, on the other. These researchers were helped

by the new technologies of speech processing that flourished between 1990 and

2000.103

• Speech problems are usually identified immediately following phonetic treatment.

• After denture insertion, it is sometimes difficult to receive speech habits

immediately, but gradual process of retaining tongue positions good compensation

can be achieved in later periods.

• Speech adaptation to new complete dentures normally takes place within 2-4

weeks after insertion.

• During fabrication of denture, certain guidelines have to be followed in order to

achieve clarity of speech.

1) Effect of denture thickness and peripheral outlines

If the thickness of the denture base covering the palatal area is more, then lisping of

the sounds will occur.

Allen (1958) found that an additional thickness of 1mm in the anterior palatal area

made speech awkward and indistinct.

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The denture base thickness in the post dam area will irritate the dorsum of the tongue

which will impede the speech and there is a possibility in producing feeling of nausea

and denture may be unseated during sounds, which requires sudden repositioning of

the tongue to control and stabilize it.

The upper denture base in posterior region must be kept thin and the posterior border

should be merge with soft tissues.

If the lingual flange of the lower denture is too thick in the anterior region, will

encroach the space needed by the tongue and this results in faulty production of ‘s’

sound.

It can be corrected by arranging the artificial teeth, in same position as the natural

teeth will occupy and shaping the lingual flange so that there will be enough tongue

space to establish.

2) Effect of tooth position on speech

If the lower anterior teeth are arranged too lingually, the tongue is forced to arch itself

up to a higher position and the airway is to be too small and there will be faulty

pronunciation in ‘s’ and ‘z’ sounds.

If upper anteriors are too short of occlusal plane the word ‘v’ will more likely

pronounce as ‘f’. If upper anteriors are arranged below the occlusal plane the word ‘f’

will be pronounced like ‘v’.

The labiodental sounds like ‘f’, ‘v’ are helpful in determining the anteroposterior

positioning of the upper incisors and the occlusal plane.

3) Effect of dental arch form on speech:

If the arch is narrow, which will crumple the tongue which affects the size and shape

of the air channel results in faulty articulation of the consonants like ‘t, d, l, n, s, t’

where lateral margins of the tongue makes contact with palatal surfaces of the upper

posterior teeth.

The correction can be done by the slight thickening of the denture base in the center of the

palate, so that tongue does not have to extend up as far as into narrow palatal vault.

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With the Every effort should be made, consistent with the general mechanical

principles, to place the lingual and palatal surfaces of the artificial teeth in the position

previously occupied by the natural dentition03

4) Effect of vertical dimension on speech:

Fymbo (1936) pointed out that defective speech is most frequently associated with

increased vertical dimension which may result in difficulty in pronouncing sounds

like ‘b, m, p, f, and v’.

Landa (1947) recommended various phonetic tests to determine proper vertical

dimension using sounds such as ‘s, c, z’.

Silverman (1956) stated that sibilient sound‘s’ as a mean for determining the correct

vertical dimension. He established the “closest speaking space” and used this as

clearance area between the dentures.

The bilabial sounds like ‘m’ is helpful in determining the vertical dimension, when

this sound is pronounced there will be passive contact between the upper and the

lower lip, which aid in obtaining the correct vertical dimension.

Seifert e, Runt C et al (2000) concluded that variations of thickness and or volume of

the dentures and of the vertical and horizontal dimension of occlusion may result in

unpredictable audible changes to the voive93

5) Whistle and Swish sounds:

Silverman (1967) stated that the Whistle and Swish sounds are produced during

speech due to air abnormally passing over the tongue and through the interincisal

space. These sounds may be caused due to decreased over jet.

6) Effect of denture esthetics on speech:

Speech is sometimes related to patient’s emotional attitudes towards the denture

esthetics.

Lawson (1973) stated that when there is any change in patient mouth, then there will

be anxiety reaction will occur some patients dissatisfied with their teeth appearance in

denture and to overcome this problem they shows abnormal movement of lip, jaws,

and tongue during speech.

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The Tongue Factor

The tongue, which is the most versatile of the articulators, is involved in the

production of all vowels and the vast majority of consonants. The versatility of the

tongue allows different sounds to be produced; these require different tongue

configurations .By altering tongue position and shape' the size of the oral cavity, and

therefore the resonating characteristics, are changed the tongue can also acts as a

place of closure, in the production sounds, where a buildup of intra oral air pressure is

required. Furthermore, by using the tongue to create a narrowing against the hard

palate or teeth, fricative sounds are produced90

The tongue is the principle articulator for speech, and learning its position for

a given sound is the key to speech learning. To divide its role in speech the dorsum of

the tongue is divided into a back portion, which approximates the soft palate, and a

front portion, which approximates the hard palate, and the sides are referred it’s as the

tongue blade and the apex is called the tongue tip, or apex.

To pronounce ‘a’ the dorsum of the tongue is arched and the blade contacting

the alveolar ridge and the tip resting behind the lower incisors. The position for ‘e’ is

essentially the same, except the dorsum is arched a little higher, with the blade in

heavier contact with the alveolar ridge and the tip raised slightly. To pronounce ‘i’,

the tongue is pulled back with the dorsum flattened at the beginning of the sound, but

raises to the ‘e’ position for the completion. To pronounce ‘U’ the tongue first

assumes the ‘e’ position then fills back with the dorsum flattened for the second part

of the sound. For the ‘o’ tongue is in its flattest and lowest position with no palatal

contact.

Functional Tongue Classification

The working range of the mobile tongue varies with the individual. Therefore,

classification and knowledge of the conditions that cause variations are indicated.

The degree of activity and the variation in functional type suggest the

following classification:-

• The occupational tongue.

• The still tongue

• The normal tongue

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• The habitual tongue.

The term “occupational tongue” was selected to apply to those people whose

activities require increased tongue action. This includes jurists, teachers, lecturers and

preachers.

The developed increased muscular positioning force will herein after be

designated “tongue power movements”.

The “still tongue” is at the opposite end of the classification. In these patients,

as a result of limited activity, due to injury, deformity, or undue timidity, a passive

tongue exists. An example is ankyloglossia.

The “normal tongue” exists between these two extreme ranges and refers to

the type of tongue function in people exhibiting a normal or average development.

These cases are welcomed by the prosthodontist, as they give a range within limits in

effecting desirable rehabilitation.

PALATOGRAMS

A palatogram is a graphic representation of the area of the palate contacted by

tongue during a specified activity, usually speech-GPT 8

Palatograms are the area of tongue contact for a given sound displayed on an

artificial palate through a medium of non-scented talcum powder.

Pre-Requisites of Making a Palatogram

1. The artificial palate must be accurately adapted and refined so that it can be worn

comfortably without an adhesive until speech is normal and natural. The subject who

does not accommodate or who gags after a 15 minutes practice speaking period

should not be used, because palatograms of faulty speech would be of dubious value

and gagging makes palatography impossible.

2. The subject should be trained to pronounce the sound distinctly, and then to open

his mouth with the tongue flat (out of contact with the palate) and not to attempt to

swallow until after the palate is removed. Several trials should precede the making of

the palatogram to ensure that the patient can pronounce the sound distinctly and

immediately open his mouth without a gain contacting the palate with the tongue.

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3. The tracing medium should not be distasteful in flavors or appearance and should

be of a consistency that will permit ease of application and removes from the artificial

palate. The colour of the medium should contrast with the palate sufficiently to

display readily the area of tongue contact.

4. The palate must be dried thoroughly before dusting with talc, and care must be

taken in inserting and removing the dusted palate to avoid finger contact, which

would smudge the tracing. In pronouncing the phoneme, the moist tongue removes

the talc from the contact area, leaving a clear tracing.

A palatographic study of all the vowels revealed tongue palatal contact for all

except ‘O’. The similarity of the tongue contact area on the palatograms is because

phenomes are usually composed of more than one phone and that each phone requires

separate articulation. The phone with, occurs singly in pronouncing the vowel ‘e’ and

is prevalent in a, i and u. It occurs as the initial sound in u (ee – o) and as the second

sound of a and i (i-ee)

Consonants cannot be used in making palatograms, because the vowels included

in the pronunciations involve tongue palatal contact, which would obscure the tracing

of the articulation for the stop or affricative. Example: in pronouncing t and d, the

occlusive articulations is made first followed by ‘e’, ‘a’ follows the affricative

articulations for J and the affricative articulation for K. In pronouncing S, n or l, the

mid-vowel ‘e’ precedes the articulations for the sibilant s, the nasal n, or the lateral l.

To make the palatographic study of consonantal articulation, the ‘O’ was used in

conjunction with the consonant to be studied, even though the combination did not

result in a standard English work as in pronouncing ‘O’, the tongue naturally drops

back out of contact with the palate and flattens, making it easy for the subject to

open his mouth without raising the tongue.

Speech Tests

The phonetic aspect of denture construction at least deserves equal

consideration with esthetics and mechanics and should be checked at the time of the

waxed try in when it is possible to alter palatal contour to accommodate speech

articulation. The trial denture evaluation should not be considered complete until a

phonetic test has been made and enunciation proved satisfactory to both the patient

and the operator.

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Waxing of the palatal portions of the trial denture should be confined to the

area adjacent to the teeth, with just enough wax added to ensure a smooth surface

between the base tray and collars of the teeth. It is presumed that the base trays are

comfortable, well adapted and approximate the tissues with nearly the same fidelity as

anticipated for the completed denture bases. Before the speech tests are started, the

mandibular trial denture should be secured with denture adhesive.

• The first test is of random speech and is best accomplished by engaging the

patient in conversation and obtaining a subjective speech analysis by asking the

patient how the dentures feel, how his speech sounds to him, and which words

seem most difficult to pronounce.

• The second test is to specific speech sounds. This is best accomplished by having

the patient pronounce six or eight words containing the sound and then combining

these words into a sentence. The following is a list of the sounds to be tested;

opposite the sounds are the words to be pronounced and a sentence composed of

these words :-

s and sh Six, sixty, ships, sailed,

Mississippi, sure, sign, sun,

shine.

Sixty-six ships sailed the

Mississippi. Sure sign of sunshine

t, d, n, and

l

Locator, located, tornado, near,

Toledo

The locator located the tornado near

Toledo.

Ch and j Joe, Joyce, Joined, George,

Charles, church

Joe and Joyce joined George and

Charles at the church.

K Committee, convened, political,

convention, Connecticut

The committee convened at the

political convention in Connecticut.

f and v Vivacious, Vivian, lived, five,

fifty-five, fifth, avenue

Vivacious Vivian lived at five fifty-

five Fifth Avenue.

In the third test, the patient is asked to read a short paragraph containing an

abundance of s, sh, and ch sounds.

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If the patient can complete the speech test distinctly, with no difficulty, and if

his random speech satisfies him and the operator, it would be unwise to contour the

palate to solve a speech problem that does not exist. If, however, problems are

encountered in one or more of the areas tested, then palatal contour is indicated and

can effectively be accomplished by palatography.

If the palate is to be altered, the entire palate should be contoured to

accommodate tongue contact for all palatal consonants. This is best accomplished by

systematically displaying each contact area with a palatogram and establishing normal

tongue contact.

Palatography for Proper Palatal Contour

The only additional equipment necessary for palatography is some non-

scented talc, in inexpensive soft bristle brush for dusting the talc on the palate, and a

glass marking pencil to outline the contact area. Palatograms can be easily and

quickly made on the trial denture if the following steps are recalled:-

• Use o with the consonant to be studied, even though the combination is not a

word; i.e., to study k, use KO; to study ch; use cho.

• Train the patient to pronounce the sound and open the mouth without again

contacting the palate.

• Dry the palate thoroughly before dusting on non-scented talc (do not use regular

or surgical talc) and shake off the excess powder.

• Avoid touching dusted palate with the fingers during insertion, but ensure that the

denture is well seated before the sound is pronounced.

• Be sure the patient makes definite palatal contact in pronouncing the sound, but

avoids palatal contact after opening the mouth.

• Avoid contacting the palate with the fingers when removing the denture.

• Outline the contact area with a wax carver where wax is present, and with a glass-

marking pencil where the base tray is exposed.

To avoid overlapping the tracing and recontouring one contact area to

accommodate another, a sequence of palatograms should be followed, and waxing of

the palate should be accomplished in steps. First, s and sh palatograms are made and

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outlines on the base trays. Where wax is present, the palatogram is outlined with the

carving end of the wax spatula; where the base tray is exposed, the outline is made

with a glass marking pencil. Before waxing is commenced, the patterns for s and sh

should be reviewed. The tongue contact for s is always higher and more anterior on

the palate, so that the outline for the s palatogram is the high line and includes some

of the anterior teeth, and the sh line is always lower and includes fewer anterior teeth.

The sh line (low line) is used as a guide in waxing the posterior alveolar area, and the

s line (high line) is used as guide in waxing the anterior alveolar area. The anterior

portion of the “sh” tracing is not waxed until last.

Waxing is started around the first molar by adding enough wax to provide a 1-

mm margin at the collar. Next, the low tracing line on the palate is sighted directly

below this tooth, and enough wax is added to the palate to permit an even contour

between this line and the margin of the molar. Then wax is added around the anterior

teeth delineated by the s tracing to provide a ½ mm margin at the collars. Enough

wax is then added between the tracing line and teeth to present an even contour.

Waxing in the bicuspid area is accomplished by using the anterior and molar regions

as a guide for adding wax around these teeth to complete for smooth, even contour

between these waxed areas and the palatal tracing line.

Waxing around the second molar consists of adding enough wax around this

tooth to complete the contour between palatal tracing line and the waxed first molar

area. After waxing on the other side of the palate is completed, a palatogram should

be taken to cheek to contour. If the area is properly contoured, the tongue tracing line

should be even and about 2mm above the original. If the tracing line rises abruptly in

a specific area, that area is too thick and should be reduced until the tracing line is

even. If the tracing line drops abruptly in a specific area, that area is not thick enough

and additional wax will be needed to provide an even tracing. If the entire tracing

rises markedly, the area has been over contoured and should be reduced.

The photographs of the waxing procedure of a case with considerable alveolar

ridge resorption, and using the palatogram to outline the area and waxing in steps as

described should aid the beginner in establishing normal tongue contact for these

cases. After some experience, the entire outlined areas can be waxed in one step.

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The palatogram can be used effectively for any case, including the immediate

denture, if the pattern for normal tongue contact is kept in mind and if sensible

observation is employed.

The line on the palate outlining the palatogram represents the lowest point of

tongue contact in pronouncing s, and the area between this line and the artificial tooth

should be of even contour and gradual slope without excessive convexity or concavity.

The amount of wax needed to complete this contour is dependent upon the extent and

degree of alveolar resorption, and wax should be added only where necessary to

compensate for alveolar deficiency. Many times it is not necessary to add wax as far

down as the tracing line to complete the contour, and sometimes, as in the case of slight

resorption or the immediate denture, it is not necessary to add wax at all, because

enough of the alveolar ridge remains to provide proper contour to the base tray.

After lateral tongue contact for s has been established on the trial denture, the

speech tests should be repeated, and if speech is satisfactory, further contouring is

unnecessary. However, it is usually necessary to contour the anterior aspect of the

palate to facilitate proper s pronunciation.

By using the palatogram to establish normal tongue blade contact in

pronouncing s, appropriate portions of the lateral aspects of the anterior alveolar area

are included in the contour, leaving only the region between the lateral contact areas

to be considered. The area of this region, which is the most critical to proper s

pronunciation, is the area midway between the lateral contacts and directly above the

median sulcus of the tongue. In pronouncing s, the tongue contacts the alveolar area

to occlude the lateral portion of the oral cavity and form a channel for the air stream

between the median sulcus and the palate. This channel narrows to a groove at the

tongue apex to constrict the air stream, so that is escapes as a hiss. Normally, this jet

of air exits at the incisal edges of the teeth to be heard as the typical s, but on the

denture, where tooth arrangement has been altered to accommodate mechanics and

esthetics, it is usually necessary to provide a path of exit on the palate in the area

directly above the groove in the tongue apex. This is best accomplished by inserting

the trial denture and instructing the patient to pronounce ess (not so) and hold it so

that the groove in the tongue apex can be observed. The chair should be tilted back

and slightly raised so that the operator can look up and into the oral cavity to

determine the character of the groove and its proximity to the palate. It is the area

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directly above the groove that must be altered according to the fault in pronunciation.

If the patient whistles and hisses when pronouncing s, the area between the groove

and denture base is excessive and will need to be thickened. For the patient with a

deep groove ,a slight elevation is usually required. If the patient lisps substitutes th

for s or has a muffled, indistinct s, there is not enough space between the groove and

the denture base, and the area will need to be thinned. If the groove in the tongue is

broad and shallow, a depression in the denture base may be required, and if there is no

groove in the tongue, a groove on the denture base directly above the median sulcus,

as recommended by Sears, will be necessary. If the patient substitutes sh for s, the jet

of air is probably escaping toward the vault and the area above the groove will need to

be extended toward the tongue. This extension must be made with care, because

overextension will occlude the air stream and it will occlude the air stream and sh will

be substituted for s.

There is no simple way of correcting faulty s pronunciation. The fault must be

analyzed the area contoured, and the sound tested, then reanalyzed, re-contoured, and

retested until satisfactory pronunciation is attained. The words best suited for testing

are short words containing the ess sound, such as “hess,” “guess,” “less,” “mess”.

The time required to correct an error in s pronunciation is time well spent, because it

is the commonest and most persistent oral inaccuracy of the denture patient and the

one that may remain as a characteristic denture whistle.

Proper palatal contour is the key to proper s pronunciation, or all other

pronunciation for that matter, and that the palate can be contoured to accommodate

phonetics for any sensible tooth arrangement, including the bizarre class II and severe

class III jaw relation cases. There is little doubt that the character of the air stream

directed between the upper and lower incisors in pronouncing s will be affected by the

relationship of these teeth at the time of exit therefore, it is possible to soften or

sharpen the s by increasing or decreasing the amount of over jet. However, the

direction of exit can be controlled by palatal contour to permit considerable leeway in

anterior tooth arrangement and still provide good quality to this sound.

Contour of the anterior palate is completed by adding the minimum amount of

wax between the low tracing line for sh and the lateral and mid-palatal contoured

areas to make a smooth junction. Care should be taken not to thicken the lateral

contact areas or alter the median contour. To ensure that enough wax was added to

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provide tongue contact for the occlusive t, d, and n, a palatogram of t, to should be

made. After completing the anterior palatal contour, usually no further contouring is

necessary, but the speech tests should be repeated with particular attention given to

the pronunciation of ch and j, because occasionally, in contouring the mid anterior

alveolar region, wax builds up on the palate below and will interfere with the

pronunciation of these sounds. If this happens, a palatogram should be made for ch,

cho to outline the area of tongue contact so that alteration can be confined to that area.

The use of palatograms for contouring the entire alveolar area will be useful to

those who adhere to the philosophy of placing the artificial teeth in the same relative

position as the dentition. If the posterior teeth are arranged near the center of the

alveolar ridge and the anterior teeth arranged to occupy approximately the same

position as the originals, then a palatogram on the trial denture is an aid in contouring

the palate for normal contact. If, however, the philosophy of arranging teeth

according to mechanical advantage is adhered to, then the palatogram would be of

limited value in contouring the posterior alveolar area, because the posterior teeth will

occupy a position lingual to the center of the ridge on this denture. A palatogram of

the s on the trial denture in this case would reveal limited tongue contact in the molar

alveolar area, progressively increasing to normal contact in the anterior region, and

adding wax to simulate a natural alveolar contour in the molar area would be a grosser

insult to phonetics then not adding wax to complete alveolar contour in this area on

the denture with center of the ridge tooth arrangement. Phonetics is better served in

these cases by keeping the posterior alveolar area as thin as possible and confining

palatal contour to the anterior region. Thickening the vault to narrow the channel for

the air stream, facilitate s pronunciation in this type of denture, but before wax is

added to the vault, a palatogram of k, KO should be made to delineate the area of

posterior palatal tongue contact so that this area can be excluded from the waxing.

Satisfactory phonetics can be accomplished with a constricted posterior tooth

arrangement so long as the anterior teeth are arranged to permit normal palatal

contact. However, if the anterior teeth are arranged lingual to the natural tooth

position, they will interfere with the tongue in making palatal contact and impede or

occlude the air stream after contact has been made in pronouncing s. For this reason,

in cases with severe resorption, where the anterior ridge affords no clue to natural

tooth position, a palatogram can advantageously be used in arranging the teeth to

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ensure that tongue palatal contact is not jeopardized. Considerably more leeway is

permitted in arranging teeth toward the labial, because tongue contact is unhampered

and the palate can be contoured to accommodate the arrangement.

Complete loss of teeth can cause a persistent speech disorder by altering dental

articulation areas. This severely reduces the quality of speech

1-Particularly’ the alteration of frontal maxillary morphology leads to impairment of

speech production

2-removable complete dentures can partly solve this problem.

3- However, they disturb speech production themselves as they restrict the flexibility

of tongue, narrow the oral cavity and alter the articulation areas of palate and teeth.

Speech production has a significant effect on patient’s general satisfaction with

dentures. The patient’s contentment correlates with acceptance of denture. Therefore

speech production quality is an essential feature for success or failure of dental

rehabilitation.78

The influence of design of removable dentures on patient’s voice quality

The voice of each person is unique and is generally determined by size of the

resonatory system (oral cavity. Larynx, pharynx, vocal folds and nasal sinuses) which

vibrates at different frequencies, producing different sounds .The voice quality is

characterized by speech intelligibility (relationship between the voice pitch, volume,

timbre and speech speed).One of the most frequent phonetic distortions is lisping,

omission, substitution, distortion, addition and nasality are also possible when

improper and functionally low quality dentures have been made. Restrictions or

alterations of the normal mandibular may impede the transmission of acoustic energy

through the oral cavity, thereby affecting both oral resonatory characteristics and oral

/nasal balance. The phonetic adaptation of the patients with complete dentures

depends on selection and placing of artificial teeth, the thickness, size and placement

of maxillary denture base, the optimal space of the tongue, Individual adaptation

capacity and patient’s sound recognizing capacity.85

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The changes of resonance and the methods of research

Resonance is one of the most important characteristics of human speech, the

resonance depends on the age, gender spoken language, and phonetic environment of the

phonetic sound, models and speech conventions. Dental prostheses can alter resonance,

resulting in increase or decrease of nasalance. It is not known if or to what extent

complete maxillary dentures alter the resonating characteristics of the oral cavity. There

exits two hypotheses. The first claims that the base of prosthesis which covers the entire

hard palate and extends on to the soft palate, could impede the passive transmission of

sound waves into the nasal cavity, thus reducing the overall nasal energy, resulting in

decreased nesalance. The second hypothesis claims that the presence of dental prosthesis

would decrease the volume of oral cavity and increase impedance thereby reducing the

oral energy component, what results in increased nasalance. Thus dental prosthesis can

alter resonance but the passive acoustic effect on the oral/nasal resonance balance, related

to the presence of dentures, is not fully understood.

Spectrograms and palatograms are non-invasive research and evaluation methods

to estimate voice quality. For the best analysis of the phonetic spectral characteristics in

the spectrogram. However, the palatography is a rather conditioned method to evaluate

speech quality. There are no definite norms to evaluate the results that are obtained with

palatography. Palatograms of the announcers and speech artists were used to determine

the parameters of palatography. These norms of palatography were compared with the

parameters of palatography of patients of the patients with dental prosthesis inserted.

Speech production has a significant effect on the patient’s general satisfaction with the

dentures. Different studies revealed that the quality of speech production increases after

some period of habituation, the functional quality (retention, stability support) of

prosthesis is the main pre condition for good sound pronunciation85

Effect of different techniques for palatal denture base configuration

Metals and metal alloys used in denture bases display excellent strength- to-

volume ratios may be cast in thin sheets maintaining rigidity and fracture resistance.

Thinner metallic denture bases decrease interference with phonation and ensure proper

palatal contours. Failure to achieve unobtrusive palatal contours may produce noticeable

changes in phonation. Metal bases also display desirable dimensional characteristics and

may be cast accurately. Little concern has been given to the perfection and optimization

Discussion

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of the phonetic quality of denture users. However, insertion of prosthetic restorations may

lead to speech defects. Most of such defects are mild but, nevertheless, can be a source of

concern to the patient. For the dental practitioner, there are few guidelines for designing a

prosthetic restoration with maximum phonetic success one of these guidelines involves

the palatal configuration of the maxillary denture bases.87

The artificial palatal vaults of

maxillary denture often have a concave shape .In contrast, natural palatal vaults are of

convex shape in the alveolar region. So the palatal vaults of the maxillary complete

denture should be shaped like natural ones to facilitate correct pronunciation and the

quality of speech.89

The most important instruments for the investigation of speech and

sound production are the trained hearing of speech and language professional, spectral

analysis and palatography89

. Studies on speech sound production may have a clinical

impact because many patients attach great importance to undisturbed speech sound

production after dental treatment and Heylink et al found 21% of denture wearing

individual had speech problems.89

Dentures should be made to enable the patient to

produce voice and speech without deficiencies. About 25% of patients in clinical

dentistry are considered to suffer from temporary or permanent changes in articulation

due to the application of removable dentures. Articulatory errors may be due to denture

factors like altered vertical dimension, size, and position of the teeth thickness and the

contour of the denture base. Accurate approximation of the palatal contours of a maxillary

complete denture to a patients tongue can improve speech if other factors are

satisfactory.89

Pound in 1950 stated that anterior palatal portion plays an important role in

pronunciation of consonants. He termed it as "playground" of tongue because 90% of

tongue’s rapid manipulation while talking was restricted to this area and are lingual to

lower anterior teeth.89

Speech problems are frequently reported after complete denture placement

mainly expressed as problems with consonants, especially linguopalatal sounds. So

the linguopalatal sounds were selected and analyzed in the present study. Some

patients have remarkable adaptive capacity after repeating 5-6 key words. Analyzed

spectrograms are different by frequency of emitted sounds related to denture changes

and oral resonance cavity. Specific letters were selected because not all the letters can

be verified. According to Sinescue some sounds such as t, d, ch, z l, sh are more

sensible and more often compromised due to the changes of the oral structures and

demand for more precise articulation movements. Therefore, these sounds were

studied in this work89

Allen stated that the most widely used procedure to improve

Discussion

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denture phonetics is the random thinning of the entire maxillary palatal surface to

create more space for the tongue. Such arbitrary removal of acrylic resin from the

palatal surface ignores the critical importance of correct palatal contours in the proper

formation of the sounds. The results of this study coincide with the results reported by

Ravishankar and Singh as they reported that the linguopalatal sounds like t, d, n, l, z,

th are formed by contact of the tip of the tongue with the most anterior part of the

palate called palato alveolar or palato lingual sounds.89

If the denture base in rugae

area is too thick the ‘t’ sounds like ‘d’ and ‘d’ sounds like ‘t’.

Speech Analysis:

Assessment of speech defects is initially subjective, relying on the clinical

judgment of the Speech and Language Therapist. This will involve both assessment of

the intelligibility and quality of the patient’s speech, and observation of the visible

aspects of articulation. However majority of the articulators are not visible during

speech. Additionally there is a growing need for evidence based intervention. The best

approach is to use perpetual assessment, to highlight potential areas of difficulty, then

objective, instrumental assessment of these areas, to confirm the nature and severity

of their involvement.90

Spectrographic analysis of speech is one of the most widely used techniques

for studying the acoustic- phonetic characteristics of different phonems in language. It

is an extension of the short term spectral analysis ,and primarily involves

representation of the 3- D spectral information obtained by computing the magnitude

spectrum over the short overlapped window segments, that is 2-D spectral content

varying with respect to time. The 3-D spectral information is represented on a 2-D

plane with the X- axis representing time, Y-axis representing frequency, and the third

dimension denoting the long- magnitude of the sinusoidal frequency components is

converted to a proportional intensity or grey value. The resulting representation is

referred to as a spectrogram.107

A spectrogram is a visual representation of the spectrum of frequencies in a

sound or other variable. Spectrograms are sometimes called spectral waterfalls, voice

prints or voice grams. Spectrograms can be used to identify spoken words

phonetically and to analyze the various calls of animals. They are used extensively in

the development of fields of music, sonar, radar, and speech processing, seismology

Discussion

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Speech Instrumentation:

Studies on speech sound production may have a clinical impact because many

patients attach great importance to undisturbed speech sound production after dental

treatment and Heyink et al found that 28 (21%) of 131 denture wearing individuals

had speech problem.89

Important investigations of speech sounds are based on the Fourier spectrum

and on the short time Fourier spectrum (spectrogram) the most accurate

measurements methods were, as this study suggested, by Jindra et al, Kobayashi et al

and Outmen- Toller who choose speech sounds analysis by using standard signal

processing methods. The method with the best result was the Fourier method. Its

evaluation of the studied phenomena is both qualitatively and quantitatively valuable

making the reproducibility of the analysis applicable. The Fourier method for the

phonetic evaluation has been used because its graphic correspondence is simple and

facile to translate. The phonetic alterations are considered classic for the human voice

and could also be represented even for the higher spectrum. In the present study, the

spectrogram was used.89

Two popular spectrographic representations used for analysis

are wide band spectrogram and narrowband spectrogram, depending on the spectral

and temporal resolution preserved in the final representation in the frequency domain.

The measurement of tongue movement during speech is not easy, for the

simple reason that, for the majority of sounds, the tongue is obscured by lips or teeth.

Several methods of accurately determining the movement have been used. Tongue

strength can be measured by tongue force transducers. A flexible rubber bulb,

connected to a pressure transducer. The amount of pressure put on the bulb gives

measure of strength of movement .This gives no indication of mobility and movement

patterns, however both computerized tomography and Magnetic resonance imaging

MRI scans allow tongue placement for speech sounds to be accurately visualized. But

these cannot measure dynamic tongue movement.90

X-ray micro beams use a narrow beam of radiation to track the movement of

small gold pellets attached to various articulator, including the midline of the tongue.

Also Videofluroscopy gives a two dimensional moving image of the articulators.

Electromagnetic Articulography (EMI) gives similar as X-ray microbeams but without

radiation. The pellets are transducers and the subject is placed within the magnetic field. It

is invasive as transducers are to be glued to the articulators under investigation. The

Discussion

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equipment is also extremely expensive and the images recorded are again two

dimensional. It has been used therapeutically, in the treatment of dyspraxia.90

Electromyography (EMG) is a system that detects the electrical activity in

muscle fibers. The more active a muscle is, the greater the signals which will be

recorded. Therefore the degree of involvement of different muscles during different

articulatory gestures can be measured and compared. EMG is invasive, since it

involves either surface electrodes or the insertion of needle electrodes into the

muscles

Ultrasound uses the reflection of ultrasonic energy from tissue in its path. It

therefore enables the calculation of distance and speed of movement. Images from the

transducer, mounted below the chin, and does not use ionizing radiation. However,

the image provided is not detailed, and skilled transducer placement and image

interpretation are required.90

ELECTROPALATOGRAPHY:

Electopalatography is an instrumental technique for determining tongue/

palate contact during speech. The subject is provided with an artificial palate, in

which electrodes have been embedded. Generally, these palates are custom made,

from dental impressions. They are made of thin but rigid acrylic, which clips to secure

them to the subjects teeth. The plate extends from the front incisors to the junction of

the hard palate and velum. Individual wires from each electrode emerge from the

palate in two bundles, which leave the subject s mouth, one on each side. While

electropalatography measures dynamic movement of the tongue during speech,

precise tongue placement, and the part of the tongue which makes contact with

electrodes, can only be inferred. IT is generally accepted that, to maximize the

usefulness of electropalatography, it should be used in conjunction with other

instruments. A number of different electropalatography systems have been

developed.90

RION DP-01 ELECTROPALATOGRAPH SYSTEM

An electropalatography system was developed in Japan in the 1960s mainly

for phonetic research. From this early research, the Rion system has been developed.

The original system was not PC based, but instead relied on direct activation of Light

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Emitting Diodes (LEDs).Each corresponding to a palate electrode, on a single, one-

palate display.

KEY PALATOMETER SYSTEM

This is the American system, developed by Fetcher. It is PC based, with a

sampling rate of 100 frames per second, Data can be recorded, replayed and analyzed

For the KEY palatometer, several palate configurations have been described, and each

utilizes a thin, flexible acrylic palate, custom made for each individual, THE

PALATE FITS over the teeth. The palatometer can be linked to Kay’s computerized

speech lab, allowing comparison of tongue/palate contact with other speech outcome

data, like spectrum analysis.

READING SYSTEM

This system was developed by the speech Research Laboratory at reading

University, initially as a phonetic research tool, which came to be used in Speech and

Language Therapy Clinics.....EPG2,EPG3 can be used for the analysis of recorded

data. Tongue palate contact patterns, and spectral information can be obtained by

moving a cursor along the displayed acoustic wave form.

LINGUOGRAPH

Linguograph was developed to meet the need for a clinical, user and patient

friendly, portable low cost electropalatography system .It was developed by a multi-

disciplinary team, comprising Engineers, SPEECH AND LANGUAGE THERAPIST,

and PLASTIC SURGEON AND DENTAL SURGEON. The system comprises an

artificial palate, a small electronics unit, and interfaces to a standard PC. Custom

software, running under MS-DOS, PROVIDES VISUAL DISPLAYS AND

ANALYSIS.

PALATE

To provide compatibility with the other system in use in Europe, the Palate

developed at the University of READING has been adopted for use with Linguograph

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LINGUOGRAPH UNIT

The palate connector plugs into the Linguograph unit, which hangs around the

neck of the patient's by means of the adjustable strap.

INTERFACE CARD AND SOFTWARE

The linguograph electronics unit connects to an Amplicon PC14AT

DIGITALI/O card housed within the PC, Data from the Linguograph unit is displayed

and analyzed by custom software running under DOS.

Conclusion

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Speech difficulties as sequelae of oral rehabilitation with complete dentures

are generally a transient problem when encountered the difficulties may not be easily

solved. Therefore efforts should be made to avoid them by pretreatment records or

assessment of speech and provision of information to patients about likely initial

deviation from normal speech, immediately following oral rehabilitation. Hence a

prosthodontist play a pivotal in understanding the basic mechanism involved in the

various speech pathology and provide prudent treatment for the same to enhance an

individual's personality. More research needs to be carried out in this field to make

our rehabilitative treatment complete. With ideal esthetics and optimum function.88

AS defined several objectives and specific study methods and means for a new field

that called phonetic dentistry. Several plausible mechanisms that affect the phonetic

quality of prosthetic result have been derived based on articulatory mechanisms and

on morphologic factors resulting. The relationships between the articulatory facts and

the acoustic features have been emphasized and discussed in order to derive acoustic

methods and acoustic quantitative indices for assessment of speech.

Within the scope and limitations of this experimental study, the following conclusions

were established-

1) The speech quality immediately after denture insertion was found to be fair i.e. the

consonants can be appreciated but the acoustic quality of sounds was unclear.

2) Significant improvement in phonetics and acoustics was observed with complete

dentures made by functionally contouring the palatal vault using visible light cure

denture base resin.

3) Compared to the samples of group 1, there was significant improvement in the

clarity of the speech sounds after functional contouring of the palatal vault of

maxillary complete dentures using visible light cure material.

4) Since visible light cure denture base resin can be cured immediately after

functional molding, it has proved to be a direct method and can be used in routine

clinical practice for providing improved phonetics to edentulous patients in need

of complete dentures.

Conclusion

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Implications of study

This study has attracted the attention of professionals towards the neglected

aspect of phonetics in complete denture. Which can be taken care off by incorporation

of this simple step in routine clinical practice. Use of spectrographic analysis for

quality of speech is proposed and recommended

This study anticipates the improvement in the quality of speech after

functional contouring of palatal vault of maxillary complete denture by visible light

cure resin which may reproduce the original oral morphology. This reduces the

training and waiting post insertion period which may improve the quality of life.

.

Conclusion

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Limitations of the present study

1. In this study only the palatal aspect or surface of the maxillary complete denture

has been taken into consideration.

2. Only palato lingual speech sounds were studied.

3. “Z” sound was excluded in the study.

Scope

Some of the correlations between the acoustic features and the dentition

deficiencies are already documented in literature, but much remains to be done for

establishing corpus of knowledge and tools that could constitute the solid foundation

of the emerging domain we call phonetic dentistry.

The use of indices such as SQI, SII and of the distances and indices suggested

in this study provides the practitioner with the grounds of an automated method for

assessing the quality of the performed prosthetic act. From the speech rehabilitation

perspective, this is a major step ahead in the current technology and solves a

fundamental problem in dentistry. At the same time. This assessment method lays

solid ground to the new field of phonetic dentistry.

1. There is need for further studies to investigate effect of alterations in other

parameters on quality of speech produced by such dentures

2. Evaluation of the effect of adaptation period on the quality of speech

3. Relating acoustic analysis to the characteristics of the prostheses and to their

design.

4. Study on linguo-palatal passive sounds.

Summary

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Speech is critical and essential human activity that affects personal

communication and self-representation. Together with mechanics and esthetics,

speech is cardinal factor contributing to the ultimate success of a dental prosthesis.

The loss of teeth and supporting structures alters the main articulatory cavity and

produces a marked effect on speech pattern87

. An empiric approach to the phonetic

factor in denture construction frequently places the burden for compensating speech

depends on the adaptability of the tongue. While it is true that the tongue is very

adaptable, functional patterns have become firmly established, However , by

customizing palatal contours of a maxillary denture to the tongue, the patient may

easily adapt to the definitive denture contour, which in turn shortens or eliminates the

adjustment period for the achievement of proper pronunciation.87

There are persons

whose speech is sensitive to the changed relationships between lips, tongue, soft

palate, hard palate, alveolar ridge and teeth and have difficulty accommodating. These

patients often require a tactile sense to orient the tongue. The palatal rugae can often

serve as a cue because the lack of texture on the palatal portion of a complete denture

can impede proper articulation. There are some methods to duplicate palatal rugae,

one of the simplest method is to capture the patient's palatal rugae is by tin foil.

Beyond the unaesthetic acoustical appearance of the speech deficiencies

induced by imperfect dentition and by imperfect prosthetic denture, the decrease of

the linguistic expressive capacity is a significant social hurdle, even impairment. The

decrease in speech intelligibility may hinder the communication and may increase the

probability of confusion between words to levels that may require the abandon of a

profession and may even impose social quasi-isolation.

While progresses have been made in the analysis of the speech quality and in

understanding some of the involved mechanisms, the domain is still in its infancy.

The main needs are for relating acoustic analysis to the characteristics of the

prosthesis and to their design

The development of appropriate concepts, measuring method, and relevant

quantitative characteristics for assessing the changes in the vocal signals (speech) due

to imperfect prosthetic act remains a desideratum.

Summary

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Correlation of the vocal signal changes with the characteristics of the

prosthesis and the specific types of errors in the prosthetic act would be an essential

achievement in the way of improving the outcome of the prosthetic action.1

The present study was conducted to evaluate the effect of functional

contouring of the palatal vault of maxillary complete denture on speech quality

without functional molding of palatal vault and with functional molding of palatal

vault of maxillary complete denture with visible light cure resin material. The

advantage of visible light cure denture base resin is that functional molding of the

palatal vault of the maxillary complete denture can be achieved at the stage of

insertion and can be cured immediately. The speech achieved immediately after

modification is much more clear and sharp, thereby eliminating the waiting and

training period after denture insertion.

Since the modification of the palatal vault is achieved by the functional

contact of the tongue during articulation, the tongue does not have to adapt to the

presence of the denture in order to achieve „normal speech‟. The advantage of this

method is the ease with which it can be performed in a clinical set up, so no special

skills are needed to achieve successful results in improving the quality of speech

sounds. It is the responsibility of the prosthodontist to construct dentures as accurately

as possible, so as to improve speech sound production with dentures, minimize the

period of adaptation and thereby, increase the self-confidence of the patient.

Therefore the objective of the present investigation is to develop a procedure

in denture construction which would unable the patient to speak clearly at the time of

insertion of denture.87

Speech difficulties as sequelae of oral rehabilitation with complete dentures

are generally a transient problem. When encountered the difficulties may not be easily

solved. Therefore efforts should be made to avoid them by pretreatment records or

assessment of speech and provision of information to patients about likely initial

deviation from normal speech, immediately following oral rehabilitation. If persistent

difficulties to pronounce certain sounds or other speech disorders persist for more

than 2 to 4 weeks, the following protocol is recommended –

Summary

145 | P a g e

1. If the patient has the previous complete denture experience, compare the new set

with the old one to diagnose possible design differences of significance for speech

production.

2. Make the necessary modifications; soft wax might be helpful.

3. Have the patient’s hearing checked. An auditory deficit will prolong the

adaptation period and render it more difficult.

4. If the reported/ perceived problem cannot be resolved by dental methods, the

patient should be referred to speech pathologist.

Not only the face but speech also reflects an individual’s inner being. Any

abnormality or defect in the same can affect his/ her psychology and social behavior.

Hence a prosthodontist play a pivotal role in understanding the basic mechanisms

involved in the various speech pathology and provide prudent treatment for the same

to enhance an individual’s personality

References

146 | P a g e

1. SadhanaRelekar, UshaDalvi, Anjali Kant. Manual on „Fundamental Of

Speech AndSpeech Teaching‟; Rehabilitation Council Of India, Kanishka

Publisher.

2. John J. Sharry. Complete denture Prosthodontics, 3rd edition, McGraw Hill

Book Company , 1962, pg130-148.

3. SaryuArora, Manpreetwalia, Shushantgarg-“phonetics its role in

Prosthodontics Indian Journal of Dental Sciences June 2011 Issue 2 Vol.3 Page

No. 36-40

4. Zarb and Bolender. „Prosthodontic treatment for the edentulous patient:

Complete dentures and Implant- supported prostheses‟, 12th edition , Elsevier

publication, 2004,pg 370-388.

5. Phonetics in complete Denture

6. Allen L.R. „Improved phonetics in denture construction.‟ J Prosthet Dent 1958;

8(5): 753-763.

7. Pound E. „Aesthetics and phonetics in complete denture construction.‟ Dent J

Australia 1951;23:126-134.

8. Silverman M.M. „The speaking method in measuring vertical dimension.‟ J

Prosthet Dent. March 1953; 3(2): 193-199.

9. Hisatoshi Tanaka. „Speech patterns of edentulous patients and morphology of

the palate in relation to phonetics.‟ J Prosthet Dent 1973;29(1):16-28.

10. BalK.Goyal, P.Greenstein. „Functional contouring of the palatal vault for

improving speech with complete dentures.‟ J. Prosthet Dent 1982; 48:6:640-646.

11. McDowell E: The role of speech training in a program of orthodontic

treatment,Int. J. Orthodontia 22:105-113, 1936.

12. Van Riper, C: Speech correction: Principles and Methods, ed. 3, New York,

1954, Prentice Hall, Inc.

13. Kessler B. “An analysis of the tongue factor and its functioning areas in dental

prosthesis”.J. Prosthet. Dent. 1955; 5(5): 628-635.

References

147 | P a g e

14. Martone, A. L. „Clinical Applications of Concepts of Functional Anatomy and

Speech‟: Part I – “Anatomy of mouth and related structures.” J Prosthet Dent

1962;11:1009-1018.

15. Martone A. L. „Clinical Applications of Concepts of Functional Anatomy and

Speech.‟ Part II – “Musculature of expression." J Prosthet Dent 1962;12:4-27.

16. Alexander L. Martone, Linden F. Edwards. „Anatomy of the mouth and related

structures.‟ Part III –“Functional anatomic considerations.” J Prosthet Dent 1962;

12(2):206-212.

17. Alexander L. Martone, John W. Black. „An approach to prosthodontics through

speech science.‟ Part IV – “Physiology of speech.” J Prosthet Dent 1962; 12(3):

409-419.

18. Martone A.L. and Black J.W. “The phenomenon of function in complete

denture prosthodontics.” Part V – „An approach to prosthodontics through speech

science. Speech Science Research of Prosthodontic significance‟. J Prosthet Dent

1962; 12(4): 628-636.

19. Alexander L. Martone. „Clinical applications of concepts of functional anatomy

and speech science to complete denture prosthodontics.‟ Part VI – “The

diagnostic phase.” J Prosthet Dent 1962; 12(5):817-834.


and speech science to complete denture prosthodontics: Part VII- “ Recording

phases.” J Prosthet Dent 1963; 13(1):4-33.


and speech science to complete denture prosthodontics‟: Part VIII – “The final

phases of denture construction.” J Prosthet Dent 1963; 13(2):204-228.

22.Hamlet SL, GeofferyVC,Barlett DM. -Effect of a dental prosthesis on speaker

specific characteristics of voice Jr Speech Hear Res 1976;19; 639-50

23. John M. Palmer. „Analysis of speech in prosthodontic practice.‟ J Prosthet

Dent1974; 31(6):605-614.

24. C. Andrew Burnett. “The Mandibular Speech Envelope in Subjects with and

without Incisal Tooth Wear.” International Journal of Prosthodontics, December

1999 ; 12(6):263-271.

References

148 | P a g e

25. Nitinkumar Agarwal, RuchirTripathi. „Complete Denture Prosthodontics‟, 1st

edition, Arora Medical Book Distributor.

26. Fenn, LiddelowAndGimson. „Clinical Dental Prosthetics‟-A. Roy McGregor,

3rd edition, Varghese Publishing House.

27. Yippo A, Dr. Odont “The effect of dentures on speech”. 1954; 5(2): 224-241.

28. Kaires A.K. “Palatal pressures of the tongue Kessler H.E. “Phonetics in denture

construction”. J. Am Dent. Assoc. 1957; 54: 347-351.

29. Landa J.F. „The Importance of phonetics in full denture prosthesis.‟ Dent Digest

1935;41 :154-160.

30. Sears V H. 1949. “Principles And Techniques For Complete Denture

Construction”, The C.V.Mosby Co., St.Louis, pg 312-319, 324-325.

31. H.E. Kessler. „Phonetics in Denture Construction.‟ J Am Dent Assoc 1957;54:

347–351.

32. Rothman R. “Phonetic considerations in denture prosthesis”. J Prosthet Dent.

1961; 11(2): 214-223.

33. Mehringer E.J. “The use of speech patterns as an aid in prosthodontic

reconstruction.” J Prosthet Dent 1963; 13(5): 825-836.

34. Paul Gibbson. Discussion of “The use of speech patterns as an aid in

prosthodontic reconstruction” by Edward J. Mehringer. J Prosthet Dent 1963;

13(5):837-838.

35. Silverman M.M. „The Whistle and Swish Sound in Denture Patients‟. J Prosthet

Dent 1967;17(2):144-148.

36.Donald P. Erb. „Speech effects of the maxillary retainer.‟ J Am Dent Assoc,

October1967; 37(9):298-303.

37. Lawson W.A. “Speech and its relation to dentistry”. Dent. Prosthet. 1969; 19(5):

150-157.

38. Earl Pound. “Utilizing speech to simplify a personalized denture service.” J

Prosthet Dent 1970;24(6):586-600.

39. George A. Murrell. „Occlusal considerations in esthetic tooth positioning‟. J

Prosthet Dent 1970; vol23, no5, 499-502.

References

149 | P a g e

40. Francis W. Shaffer, Robert A. Kutz. “Phonetics and swallowing to determine

palatal contours of dentures.” J Prosthet Dent October 1972; 28(4): 360-362.

41. George A. Murrell. “Phonetics, function, and anterior occlusion .”J Prosthet Dent

July 1974 ;32(1): 23-31.

42. Pound E. „Let /S/ be your Guide.‟ J Prosthet Dent 1977;38:482-489.

43. Chierici G. and Lawson L. “Clinical speech considerations in prosthodontics:

Perspectives of the prosthodontist and speech pathologist”. J. Prosthet. Dent.

1973; 29(1): 28-39.

44. John M. Palmer. “Structural changes for speech improvement in complete upper

denture fabrication.‟ J Prosthet Dent 1979, vol.41,5,507-510.

45. Ritchie G.M., Ariffin Y.T.45 “Sonographic analysis of speech sounds with

varying positions of the upper anterior teeth”. J. Dent. 1981; 10: 17-27.

46. J F McCord, H J Firestone, AA Grant. “Phonetic determinants of tooth

placement in complete dentures.” J Quintessence international 1985; 25(5):341-5.

47. Riski JE. Delong E.: Articulation development in children with cleft lip/palate.

Cleft Palate J. 1984 April. 21(2):57-64.

48 Fletcher S.G. “Speech production following partial glossectomy”. J Speech and

Hearing Disorders, 1988; 57: 232-238.

49. K.C. White D.D.S., M.E. Connelly. “Duplicating natural palatal contours in

acrylic resin complete dentures.” J Prosthet Dent April 1989;61(4): 508-510.

50. Turner G.E., Williams W.N. “Fluoroscopy and nasoendoscopy in designing

palatal lift prostheses”. J Prosthet Dent 1991; 66: 63-71.

51. Burnett C.A. and Clifford T.J. “Closest speaking space during the production

of sibilant sounds and its value in establishing the vertical dimension of

occlusion”. J Dent Res 1993; 72(6): 964-967.

52. Patrick A Mattie, Rodney D Phoenix . “A precise design and fabrication

method for metal base maxillary complete dentures.” J Prosthet Dent 1996;

76(5): 496-499.

53. Singh V.P., Bharadwaj G., Nair K.C. “Direct observation of tongue positions

in speech – A patient study”. Int J. Prosthodont 1997; 10: 231-234.

References

150 | P a g e

54. Farley DW, Jones JD, and Cronin RJ:Palatogram assessment of maxillary

complete dentures: J. Prosthodont. 1998 Jun; 7(2):84-90.

55. Tachimura T, Nohara K, Hara H, Wada T.: Effect of placement of a speech

appliance on levatorvelipalatini muscle activity during blowing. Cleft palate

Craniofac. . 1999 May: 36(3):224-32

56. Burnett C.A. and Clifford T.J. “The mandibular speech envelope in subjects

with and without incisal tooth wear”. Int J Prosthodont 1999; 12: 514-518.

57. Christina A. Gitto, Salvatore J. Esposito, Julius M. Draper .“A simple method

of adding palatal rugae to a complete denture.” J Prosthet Dent 1999;81(2):237-9.

58. Eberhard Seifert, ChristophRunte, Michael Riebandt, Antoinette

Lamprecht-Dinnesen, and FriedhelmBollmann. “Can dental prosthesis

influence?” J Prosthet Dent 1999; 81(5):579-585.

59. Schierano G, Mozzati M, Bassi F, Preti G. Influence of the thickness of the

resin palatal vault on the closest speaking space with complete dentures. J. Oral

Rehabil. 2001 Oct.28 (10)903-8.

60 Rieger J., Wolfaardt J., Seikaly H., Jha N. “Speech outcomes in patients

rehabilitated with maxillary obturator prostheses after maxillectomy: A

prospective study”. Int J Prosthodont 2002; 15: 139-144.

61. Hongama S., Ishikawa M., Kawano F. and Ichikawa T. “Complete denture

with a removable palatal lift prosthesis: A case report and clinical evaluation”.

Quintessence Int 2002; 33: 675-678

62 Meier B, Luck O, Harzer W: Interocclusal clearance during speech and in

Mandibular Rest Position A comparison between different measuring methods. J.

OrofacOrthop. 2003 Feb; 64(2):121-34

63 Pigno M.A., and Funk J.J. “Prosthetic management of a total glossectomy

defect after free flap reconstruction in an edentulous patient: A clinical report”. J

Prosthet Dent 2003; 89: 119-22.

64. David M. Bohnenkamp, Lily T. Garcia. “Phonetics and tongue position to

improve mandibular denture retention: A clinical report.” J Prosthet Dent 2007;

98(5): 344-347.

References

151 | P a g e

65. Kaires AK. Palatal pressures of the tongue in phonetics and deglutition. J Prosthet

Dent 1957; 7:305-317

66. Joseph G Agnello, LennatWictorin. “A Study of Phonetic changes in edentulous

patients following complete denture treatment.” J Prosthet Dent 1972; 27:133-139.

67. William Harley “Dynamic Palatogrpahy - A study of linguopalatal contacts during

production of selected consonant sounds” J ProsthetDent 1972;27:364-376.

68. Sandra Hamlet, Maureen Stone and Thomas McCartey. “Conditioning

Prostheses viewed from the standpoint of speech adaptation.” J ProsthetDent

1978;40:60-66.

69. Tobey E.A. and Finger I.M. “Active vs. Passive Adaptation: An Acoustic Study

of Vowels Produced with and without Dentures.” J Prosthet Dent 1983; 49:314-

320.

70. Jeffrey M. Kestenberg. “Speech Assessment In Dentistry.” Dent

JAustralia1983; 28(2):98-101.

71.. A. Petrović. „Speech sound distortions caused by changes in complete denture

morphology.‟ J Oral Rehabil 1985;12:69-79.

72. Howell PG.T. „Incisal Relationships During Speech.‟ J Prosthet Dent 1986;

56:93-99.

73. Alexander J. Hassel and Thomas Holste. “Improving the Speech Function of

Maxillary Complete Dentures: A Pilot Study.” Int J Prosthodontics

2006;19(5):499-503.

74. Hyung-Jun Kong and Carl A. Hansen. “Customizing palatal contours of a

denture to improve speech intelligibility.” J Prosthet Dent 2008 ; 199:243-248.

75. Bortun Cristina, LeretterMarius,Sandu Liliana et al-- phonetic evaluation of

the edentulous patient correlated with the various settings of the artificial teeth

Serbian Dental Journal 2004, 51

76.Earl Pound Utilizing speech to simplicity a personalized denture service JPD

2006 ; (1) Vol. 95:1-10

77. Manaswini Patil, Sanjaya gouda B Patil-- Palatine regae and their significance

in clinical dentistry- A review of literature JADA Nov. 2008 ;Vol.139: 1471-

1478.

References

152 | P a g e

78. F.Stelzie ,B Ugrinovic,CKnipffr et al -- Automatic , Computer based speech

assessment on edentulous patients with and without complete dentures-

Preliminary results. Journal of Oral Rehabilitation (2010);37:209-216

79 Jean-Lue schwartz Louis Jean Boe Pierre Badin et al Grounding stop place

systems in the perceptible-motor substance of speech :on the universality of the

labial-coronal velar stop series. Journal of phonetics2012:40:20-16

80. Kyo Nomura Akemi Utsumi,Kaori Tomita et alInfuence of command on

tongue elevation during swallowing examination of tongue pressure and

ultrasound imaging. Journal of Disability and oral Health 2011: 149-158

81. Abdule-Aziz Abdullah al kherit and RavikumarRamakshnaih Phonetics

Realated to Prosthodontics Middle –East Journal of Scientific Research

2012:1,31-35

82.Vasmikrisna,V, VasmkrishnaReddy,N Praveen Kumar et al“Denture with

phonetically contoured Palate: A Simple technique of Adding Customized Rugae

and Palatal Contours to the Maxillary Denture The Journal Comtempoaray

Dental practical 2012-March-April ;13(2):216-218

83. RajyaLaxmiRavari ,SuchitaTelaKiranThotaPhonetics in Complete Denture –

A Prime Concern Indian Journal of Dent Adv. 2013:5(3) Suppl 1:1341-1343

84. Mariko Hattori,YukaISmitaHisaashi Taniguchi Automatic evaluation of

speech impairment caused by wearing a dental appliance open Journal of

stomatology 20133) :365-369

85. KristineBrokaAldisVidzis Juris Grigorjevs el- The influence of the Design of

Removable Dentures on Patients Voice Quality Stomatologija, Baltic Dental and

Maxillofacial Journal 2013;(15) No.-120-25

86. RaghvendraAdaki, Suresh Meshram,ShrideviAdaki-Acoustic Analysis and

Speech Intelligibility in Patients Wearing Coventional Dentures and Rugae

IncarporatedDenruresJr Indian Prosthodont Soc. 2013 Dec 13 (4); 413-420

87. Hala M abdelhameed and MohnamedE,El –syed‘Effect of Different

Tecniques for palatal Denture Base configuration on Speech Quality in compelte

denture wearer Med.J.Cairo unvi,2014(1)Vol-82 :657-664

References

153 | P a g e

88. Ashish R. Jain M.K. Venkat Prasad and Padma Ariga Palatogram

RevistedContcmporary clinical Dentistry 2014Jan-March,5(1):138-141

89.HamadaZaki‘Spectogram analysis of complete Denture with different thickness

and palatal Rugae Materials on speech production .International Journal of

Dentistry volume 2015,Artide 606834

90. SleveKelly ,allsionMain,Graham Manley et al ‘Electopalatogfraphy and the

Logograph system 2015

91 PriyaVaswani, PronobSanyl, AnkurPrajapati-- Coparison of speech

articulation and Intelligibility in Pallatalt Contoured dentures using a novel rugae

duplication technique:A clinical study International jr of dental research, 3 (2)

(2015) 15-20

92 Hemen J.M steenkenTno Human factors, Soe‘The measurement of speech

Intelligibility

93. SaurabhChaturvedi, Narendra Kumar Gupta ,Ashok Kumar Verma et al

“Speech Comprehension (Prosthetic contemplation) IOSR-JDMS

July2015(7)Vol.14:34-36

94. Christophe Jeannin,Pascalperrier,YohanPayan et al Tongue Pressure

recodings during speech using complete denture 2016

95. Dr. Renu Gupta Dr. R.P. Luthra, Dr. Deepak Gautam‘Phonetic in complete

denture –A Rewire ‘International Journal of Heath care sciences Apri2016 (1)

Vol4:373-377

96. Martina GiovawnettiAlessiocasucci, Daniele Casucci et al ‘Phonetic Analysis

and maxillary anterior tooth position :a pilot study on preliminary outcomes

International Dentistry SA 2016,Vol11No5 32-39

97. Awad MA, Feine JS. “Measuring Patient Satisfaction with mandibular

prostheses.” Community Dent Oral Epidemiol 1998;26:400-405. Cited from:

98 Alexander J. Hassel and Thomas Holste.“Improving the Speech Function of

Maxillary Complete Dentures:A Pilot Study.” Int J

Prosthodontics2006;19(5):499-503.

References

154 | P a g e

99. Garrett NR, Kapoor KK, Perez P. “Effects of improvements of poorly fitting

dentures and new dentures on patient satisfaction” J ProsthoDent 1996;76:403-

413.

100. Pound E. „Controlling Anomalies of Vertical Dimension and Speech.‟ J

Prosthet Dent1976; 36:124-135.

101, AnupamaNeelkantan, Sunil dhaded Rugae Duplication -Different techniques

of custamizing palatal rugae in Maxillary complete denture to enhance

phonetics-Karnataka prosthodontics jr 2016 vol (1) 1-7

102. Christopher Runte, DjfarTawana, Dieter Dirksen, BettiniRunte, Antoinette

Lamprecht-Dinnesen, FriedhelmBollmann, Eberhard Seifert and

GholamrezaDanesh. “The influence of maxillary central incisor position in

complete dentures on /s/ sound production.”J Prosthet Dent 2001;85(5):485-495.

103.Sherman H. „Phonetic capability as a function of vertical dimension in complete

denture wearers- a preliminary report.‟ J Prosthet Dent 1970;23:621-632 .

104. Glossary of Prosthodontic terms.

105..R C. Goyal Research Methodology FOR health ProfessionalsMethods in .

Jaypee Publication,2013.

106. Kanji Gopal. Hundred Statistical Test, 1995, SAGE Publications Ltd., London.

107.Sterberg the Netherlands 2015

108AnupamaNeelakantan Sunil Dhaded Rugae Duplication-Different techniques of

customizing palatal Rugar in Maxillary complete denture to Enhance Phonetic

Karnataka Prosthodontics Journal 2016.Vol.(1) 1-7

109.S K, Lwanga,S. Lemeshow--Sample Size Determination In Health Studies--

W.H.O.Geneva 1991

110. Spectrogram From Wikipedia

111. H. N. L Teodorescu Voice analysis in dentistry; Journal of Romanian Medical

Dentistry, vol 14, issue 3, July/Sep 2010- Pg 171-186

Annexure

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ANNEXURE – I

Annexure

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ANNEXURE – II

Sharad Pawar Dental College & Hospital, Sawangi (Meghe), Wardha

Department of Prosthodontics

Consent Form

I, ____________________age ________resident of _________ hereby give my

willingness to be a subject (patient) for the study entitled:

“Evaluation of the effect of functional contouring of the palatal vault ofed

palatal maxillary complete denture on clarity of speech sounds in edentulous

patients- An in Vivo- study conducted by Dr Surekha .Godbole.

I have been given detail information about my involvement as a subject in the

study. I am personally satisfied with the protective measures taken. For this I

am ready to give my consent to participate in the recording my speech sample

as required.

I assure best of my co-operation during the period of study. I offer myself as a

subject voluntarily.

Sign of Researcher Sign of subject with Name

-------------------------- -------------------------------

Sign of Guide Sign of witness with Name

-------------------------- -------- ----------------------

Date:

Place:

Annexure

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ANNEXURE – III

Classification of Consonants in English Language

Annexure

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ANNEXURE – IV

Sr.

No. Name of the patient Age Sex OPD No.

Recording of speech sounds

Without modification With Modification

T Th D L Ch T Th D L Ch

dB Hz dB Hz dB Hz dB Hz dB Hz dB Hz dB Hz dB Hz dB Hz dB Hz

1 SangramLambe 42 M 1511170042 12 108 14 129 21 129 22 108 15 129 20 151 15 129 10 129 22 129 18 129

2 SuhilabaiMasathe 50 F 1512220131 11 110 13 132 22 131 18 112 18 129 19 129 14 132 12 131 19 130 21 129

3 RekhaJipkate 52 F 1601040096 15 108 17 136 24 135 26 118 19 131 22 132 18 136 14 135 28 129 22 131

4 Vinod Tiwari 40 F 1511270086 13 129 15 129 26 129 18 139 17 139 21 136 16 129 13 129 20 139 20 139

5 GautamKumbhare 60 M 1509080058 12 108 13 132 18 132 17 129 14 129 20 129 14 132 18 132 19 129 18 129

6 Priti Shukla 31 F 1511130011 16 151 18 180 17 129 14 151 15 132 24 132 19 180 14 129 16 151 17 132

7 Ramesh Sirsikar 65 M 1601040035 10 108 12 129 14 129 19 159 13 134 22 180 13 129 10 129 16 159 15 134

8 Ram Projen 45 M 1601040002 13 129 15 132 19 132 21 129 12 129 20 129 16 132 18 132 21 129 13 129

9 Nilkantporbat 67 M 1512040099 12 111 15 131 21 131 22 129 21 151 21 132 16 131 19 131 22 129 22 151

10 Ashok Panchbhai 64 M 1511020084 19 101 21 121 22 121 18 130 27 159 22 131 22 121 20 121 24 130 29 159

11 TulsiGosavi 55 F 1601040041 21 105 20 132 16 132 22 121 24 141 24 121 21 132 17 132 24 121 26 141

12 ShaziyaTabassum 68 F 1512110169 16 109 18 129 19 129 21 111 23 139 21 132 19 129 21 129 23 111 25 139

13 MadhuriPiprande 78 F 1411030030 13 129 15 149 21 149 31 151 21 129 28 149 16 149 16 149 33 151 22 129

14 KanhaiyaPrasapati 67 M 1506110074 11 127 16 147 14 147 21 156 18 129 29 131 17 147 18 147 24 156 21 129

15 SushilaBhalkar 52 F 1512110190 16 108 18 128 15 128 22 131 19 142 31 169 19 128 20 128 22 131 22 142

16 BhagwantThombare 58 M 1508070105 12 129 13 139 16 139 25 139 14 159 20 129 14 139 17 139 18 139 16 159

17 Baburao More 61 M 1512290066 15 129 12 149 18 149 18 149 18 151 23 131 13 149 19 149 21 149 20 151

18 Vijay Jaiswal 51 M 1512040155 18 108 20 129 19 129 19 120 19 129 26 132 21 129 21 129 22 120 21 129

19 Kalavati Hole 62 F 1601070029 15 151 18 132 21 132 12 101 21 142 15 129 19 132 22 132 15 101 23 142

20 DharmajiBabhulkar 55 M 1601010191 12 141 19 131 22 131 18 108 22 149 20 129 20 131 21 131 22 108 24 149

21 AmbadasNishan 62 M 1511050120 14 129 15 129 20 151 22 129 12 108 20 129 21 129 18 129 22 121 19 131

22 DevidasPatharkar 45 M 1510060133 13 132 14 132 19 129 19 130 11 110 18 132 22 131 15 149 21 132 15 129

23 VithbaiPethe 80 F 1601040053 17 136 18 136 22 132 28 129 15 108 19 131 24 135 16 147 19 129 14 132

24 MadhuriPiprande 55 M 1510050131 15 129 16 129 21 136 20 139 13 129 15 129 26 129 18 128 16 149 18 136

25 Kisan Chauhan 65 M 1601090024 13 132 14 132 20 129 19 129 12 108 14 132 18 132 13 139 17 147 16 129

26 BaliramRathod 66 M 1801200102 18 180 19 180 24 132 16 151 16 151 18 136 17 129 12 149 19 128 14 132

27 VitthalGawande 84 M 1601110065 12 129 13 129 22 180 16 159 10 108 16 129 14 129 20 129 14 139 19 180

28 SindutaiBhoge 70 F 1601130124 15 132 16 132 20 129 21 129 13 129 14 132 19 132 18 132 13 149 13 129

Annexure

159 | P a g e

29 SeetabaiBendre 75 F 1601090074 15 131 16 131 21 132 22 129 12 111 19 180 21 131 19 131 21 129 16 132

30 NasayahPohane 52 M 1601130967 18 121 22 121 22 131 24 130 19 101 13 129 22 121 15 129 19 132 16 131

31 BimraoShende 72 M 1512140056 19 132 21 132 24 121 24 121 21 105 16 132 16 132 14 132 20 131 22 121

32 JangaluChavhan 70 M 1601200105 18 129 19 129 21 132 23 111 16 109 16 131 19 129 18 136 21 129 21 132

34 Asha Chaudhari 60 M 1601200517 15 149 16 149 28 149 33 151 13 129 22 121 21 149 16 129 22 131 19 129

35 Fakri Chauhan 65 F 1601200106 16 147 17 147 29 131 24 156 11 127 21 132 14 147 14 132 24 135 16 149

36 SomeshwarPunewar 56 M 1601280097 18 128 19 128 31 169 22 131 16 108 19 129 15 128 19 180 26 129 17 147

37 Suleman Khan 58 M 1601210086 13 139 14 139 20 129 18 139 12 129 16 149 16 139 13 129 18 132 19 128

38 AshubaiBhagat 45 F 1509070033 12 149 13 149 23 131 21 149 15 129 17 147 18 149 16 132 17 129 14 139

39 Asha Chaudhari 50 F 1801200157 20 129 21 129 26 132 22 120 18 108 19 128 19 129 16 131 14 129 13 149

40 Suresh Ghodkhande 40 F 1306030091 18 132 19 132 15 129 15 101 15 151 14 139 21 132 22 121 19 132 21 129

41 Vilas Shrikhande 55 F 1601250058 19 131 20 131 20 129 22 108 12 141 13 149 22 131 21 132 21 131 19 132

42 Asha Hingave 45 F 1512170191 18 109 21 149 23 129 21 129 14 129 21 129 20 151 19 129 22 121 20 131

43 ShrikantWalake 62 F 1601270073 16 129 19 147 21 149 22 129 13 132 19 132 19 129 16 149 16 132 22 129

44 SindhuWani 55 F 1601270072 15 127 18 128 20 147 24 130 17 136 20 131 22 132 17 147 19 129 24 130

45 ApurvaKhadse 58 M 1602100001 12 108 15 139 18 128 24 121 15 129 22 129 21 136 19 128 21 149 24 121

46 Subhandrasidam 60 F 1601290034 13 129 17 149 19 139 23 111 13 132 24 130 20 129 14 139 14 147 23 111

47 NilkanthVyenrghe 78 M 1602030088 16 129 19 129 21 149 33 151 18 180 24 121 24 132 13 149 15 128 33 151

48 wasudevDarne 81 M 1601190123 18 108 21 132 22 129 24 156 12 129 23 111 22 180 21 129 16 139 24 156

49 vinodChaudhari 48 M 1601300071 21 151 20 131 21 132 22 131 15 132 33 151 20 129 19 132 18 149 22 131

50 Haribhav Bhil 65 M 1620100042 20 141 24 129 23 131 18 139 15 131 24 156 21 132 20 131 19 129 18 139

51 LalitaChaubey 65 M 1602010062 12 129 15 132 16 151 21 149 18 121 22 131 22 131 21 149 21 132 21 149

52 BebitaiBwane 50 F 1601120050 13 132 18 136 19 129 22 120 19 132 18 139 24 121 19 147 24 130 22 120

53 YadavBehanre 65 M 1602040112 14 136 16 129 17 132 15 101 18 129 21 149 21 132 18 128 24 121 15 101

54 kamlesh Mishra 69 M 1602040095 16 129 18 132 18 136 22 108 15 149 22 120 28 149 15 139 23 111 22 108

55 Prakash Padade 49 M 1602040109 11 132 12 180 13 129 22 131 16 147 15 101 29 131 17 149 33 151 22 131

56 LilabaiDarange 74 F 1602050083 20 180 22 129 24 132 18 139 18 128 22 108 31 169 19 129 24 156 18 139

57 NazmaKureshi 65 F 1602090141 15 129 17 132 20 180 21 149 13 139 22 131 20 129 21 132 22 131 21 149

58 FakiraKuputkar 80 M 1602100103 16 132 20 149 21 129 22 120 12 149 18 139 28 171 20 131 18 139 22 120

59 BabanDurbude 72 M 1602040091 18 131 21 147 22 132 15 101 20 129 21 149 21 158 18 129 21 149 24 129

60 Manjulabaizade 70 F 1602100124 19 121 22 128 24 131 22 108 18 132 22 120 22 129 12 108 22 120 26 131

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