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CONTENTS AUSTRALIAN ORTHODONTIC JOURNAL

ISSN 0587 -3908

VOLUME 12, NUMBER 3 OCTOBER 1992

ORIGINAL ARTICLES

138 The Association Between Occlusion and Attrition Anthony Rircliard M.D.S.(Sydney), Alan H . Welsh B.Sc.iHons) (Syd),

P h . D . ( A N U ) , and C h r i s t i n e Donnel ly B . S c . ( H o n s ) ( T a s ) M.Sc.( A N U ) , Grad.Dip.Cump.Studies(CCAE), Canberra, Australia.

143 Dentofacial Orthopaedic Corrections of Maxillary Retrusion with the Protraction Facemask - a literature review

GekKiow Goh G.D.S., M.D.Sc., and Sheung K. Kaan B.D.S., M.Sc., D.D.O.. M.D.O., R.C.P.S., Singapore.

151 A Soye1 Method of Sterilizing Orthodontic Instruments Jo-Ann Miller A.D.B.L.T. B.App.Sci.(CIAE), Keigh M. Harrower

B.Sc.(Hons)St.And., M.Sc.(Exon), Ph.D.(Exon), M.A.S.M. and Maurice J. Costello B.D.Sc.(Qld), M.D.Sc.(Syd), F.R.A.C.D.S. Rockhampton, Australia.

153 A New Concept in the Begg Technique: The Separate Arch System Yoshinari Ashikari D.D.S., Ph.D., Japan.

166 A Procedure for Attachment of Gold Chain for Traction of Impacted Teeth

Sheung K. Kaan B.D.S., M.Sc., D.D.O., M.D.O., R.C.P.S. and GekKiow Go11 B.D.S., M.D.Sc., Singapore.

CASE REPORTS

169 Swallowed Piece of Archwire B.W. Lee M.D.Sc.(Melb.), Victoria, Australia

EDITORIAL 137

REVIEWS 171

NEWS AND NOTICES 175

OBITURIES 181

AUSTRALIAN ORTHODONTIC JOURNAL The publication of the Australian Society of Ortho- dontists Inc

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e Q for articles Taylor AT Orthodontics in Australia Aust Orthod J 1960 5 95-119

e g for books Graber TM Swain BF eds Orthodontics Current Principles and Techniques St Louis CV Mosby 1985 370-404

e g for text Dworking SF LeResche L Von Korff M Studying the natural history of TMD epimiologic perspectics on physical and psychological findings In Vig KD Vig PS eds Clinical research as the basis of clinical practice Ann Arbor The Centre for Human Growth and Development University of Michigan 1991 39-60

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FURTHER READING ON MATTERS OF STYLE: Uniform Requirements for Manuscripts Submitted to Biomedical Journals (International Committee of Medical Journal Editors) British Medical Journal Vol 284 1988 Style Manual for Authors Editors and Printers (4th Edition) Australian Government Publish- ing Service Canberra Australia 1988 The Elements of Style Strunk W White â‚ New York Macmillan 1979

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EDITORIAL Australian orthodontics has developed from sound traditions. Since the Aus- tralian Society of Orthodontist's incep- tion in 1928, when four of the five founding members were trained by E.H. Angle, innovative techniques and high standards have been the trademarks of its members. Research, always one of the Society's great strengths, was given added impetus in the 1960's when the limitations of preceptorship training were recognised and dental schools were able to increase their teaching role.

In the past many of us have looked, and many still do look overseas for the leads in our field. Of course, this scrutiny should continue, but, at the same time developments going on in our own country should not be overlooked as they were at our last Congress where there were no Australian lecturers and the allocation of space for silent clinics was meagre. Despite those fearful of original thought who have earned us the "cultural cringe" label, the traditions referred to above are still being upheld by the many innovative Australian orthodontists who are actively engaged in research and development. One of our great thinkers, Professor Elsdon Storey whose landmark research led the change to the use of lighter force and titanium alloys, was once asked how he conceived the idea of his early research: he replied that he nad never been made to feel guilty of the sin of original thought!

Lack of a forum is only one of the problems which have recently beset researchers in orthodontics. Reduced funding in these difficult economic times has meant that fewer opportunities are available even to commence a project or

purchase necessary equipment. Funds are available through the Society, the Founda- tion, the Begg Research Fund, and the Rocky Mountain Sam Bulkley Award and they must be urged to continue support- ing post graduate research and education in Australia. However, government policy has led to the Therapeutic Devices Branch of the Commonwealth Depart- ment of Health (formerly the Bureau of Dental Standards and a once very strong supporter of orthodontic research) moving away from dental research. It still has staff and facilities available at the rate of $500 a day on a "user pays" basis which is all very well but it does limit access to only those who can afford it or those funded from outside sources. As most research tends to be done at the start of an orthodontic career when personal funds are limited, this surely limits the scope and extent of research. The $500 a day rate is prohibitive for young post E graduate students and has the added dis- -

advantage that research may have to be hur r ied , and so chances of e r r o r increased.

Another problem which has beset the researcher in Australia is the lack of a forum in which to publish research material. In recent times Australian orthodontists have been encouraged to publish overseas both on advice and by the lack of regular publication of this journal. It is up to us all to remedy this situation. This journal in particular has a stated policy to foster the interests of all members of the Society, especially those upholding the tradition of research and innovation, and the young members in whose hands the future of orthodontics in Australia lies.

THE ASSOCIATION BETWEEN OCCLUSION AND ATTRITION AUTHORS Anthony Ritchard M.D.S.(Syd) Alan H. Welsh B.Sc.(Hons) (Syd) Ph.D.(ANU) Christine Donnelly B.Sc.(Hons) (Tas) M.Sc.(ANU) Grad. Dip. Comp. Studies (CCAE)

study was to identify variables of rnalocclusion that might be associated with attrition and then to quantify the relationship between these variables and attrition. The results of this study indicate that,

138 with all other factors held constant, a patient's attrition score tends to: increase with age, increase with bite depth, decrease initially with overjet until a critical value and then increase, and be unaffected b y sex, interincisal angle, U1 to NA angle, Angle

cu classification, posterior en

D- LU or anterior cross bites. m P Further, we discuss the v 0 statistical treatment of a E data of this kind and 2

Â¡ emphasize the v

importance of a professional approach to

0 analysis. a 0 z

Key Words 0- I- Occlusion, attrition, W 2 a statistical modelling.

Introduction Orthodontic clinicians who determine appropriateness of treatment on risk to the untreated dentition may be basing their decisions on unproven assertions. The notion that orthodontic correction of deep, shearing anterior bites characteristic of Class I1 division 2 malocclusions would be ultimately beneficial for the patient, eliminating a dental trigger to bruxism by providing freedom in anterior and excursive movements, may not be correct. Similarly, reducing those vectors of force generated on closure which may cause posterior condylar displacement [Thompson (1986), Farrar and McCarty (1983)] may not lessen the risk of internal derangement of the temporomandibular joint (TMJ).

Researchers [Stringert and Worms (1986), Pullinger er a1 (1987), Seligman e t a1 (1989), Gianelly e t a1 (1989), Pullin- ger and Seligman (1991) and Gianelly e t a1 (1991)l have been unable to confirm the existence of any association between occlusal factors and temporomandiublar joint dysfunction. McLaughlin (1988) and Tallents e t a1 (1991) in extensive reviews of the literature confirm these views.

Others have found associations but have been unable to quantify the relationship. Riolo e t a l (1987) in a study of young adults and children found a statistical association between TMJ symptoms and "certain features of occlusion" which did not include the minimum-overjet/ deep-overbite characteristics typical of Class I1 division 2 malocclusions. In young adults at autopsy, Solberg e t a1 (1986) found statistically significant associations between malocclusion and morphologic changes in the TMJ, particularly combined with age, and that longer exposure to malocclusion may be

associated with more extensive TMJ changes. However, the authors caution "it is premature to justify orthodontic treatment to prevent changes in TMJ morphology." Seligman er a1 (1988) consider "bruxism as a centrally induced phenomenon common to all people and unrelated to local factors (Angle class, deflective occlusal contacts, centric- relation to centric-occlusion slides)" and failed to associate discernible attrition through bruxism with signs and symptoms of TMJ disorders.

Evidence for a statistical association between occlusal irregularities and signs and symptoms of dental or dento-facial disorders would provide clinicians with a justification of treatment as a preventive measure, and a means of assessing whether a patient would be functionally disadvantaged by an untreated malocclusion. A limited study was therefore designed to attempt to quantify associations between anterior attrition and various features of malocclusion.

The Study The study was designed to challenge those conclusions of Seligman e t a1 (1988) which claimed that attrition was unrelated to occlusal factors and age, by duplicating that part of the study which could be carried out by the examination of available histories, study models and headfilms. The subjects for study were selected randomly from current records. In the absence of a formal sampling scheme, it is difficult to categorise the population of which these data are representative. However, it is reasonable to argue that they represent the population of people who seek orthodontic assistance. (This difficulty is common to all other studies in this area.) N o intraoral examination was performed for

these patients to identify functional occlusal occlusal discrepancies (deflective occlusal contacts, centric relation-centric occlusion slides).

The models were examined and scored for the highest level of attrition of the lower incisor segments using the methods of Seligman et a1 (1988) modified to more realistically represent degrees of incisor attrition. The scores were, in order of severity:

0 =none

1 =slight (small incisal edge wear facet)

2 = noticeable flattening within planes of contour (partial flattening of the incisal edge, without loss of shoulder contour, the rounded contour from interproximal surface to incisal edge)

3 = flattening of cusps or grooves (flattening of the entire incisal edge without complete loss of shoulder contour, or in the case of oblique wear, unilateral loss of shoulder contour and partial flattening of the incisal edge)

4 =total loss of contour and/or den- tinal exposure

The median age group of our sample was younger than that of Seligman et a1 (1988) and had a high percentage of patients without notable posterior attri- t ion (scores 2,3,4). Our study was restricted to attrition of incisor segments because the chances of inaccuracy in differentiating between the first three levels of attrition (scores 0,1,2) of posterior teeth are high.

To explore the association between attrition and occlusal influences, we need to select variables which together reflect the occlusal pattern. There is no morpho- logical measurement yet devised which when taken on its own is capable of describing dental pattern even in its static sense let alone the effects that pattern will exert o n closure o r in excursive movements. Angle's classification describes in a general sense the anterior-posterior and vertical relation of upper to lower sets of teeth, but does not provide any worthwhile description of individual or group tooth contact. The only "effect-specific" Angle malocclusion class is Class I1 division 2, which indicates the character of deflective tooth contact on closure causing posterior displace-

m e n t of t h e m a n d i b l e [ F a r r a r a n d M c C a r t y (1983)l.

None the less , mos t of the characteristics that contribute to the nature of tooth contacts, such as overbite and overjet, molar relation, presence and location of cross-bites and tooth angula- tions are visibly or radio- graphically detectable and numerical ly recordable. These variables are usually noted at examination and recognised in formulating treatment plans. If these simple measurements are shown to be related to attrition, they will prove to be more clinically useful than Fig. 1 - Age distribution of subjects. recordings dependent on higher technology e.g. strain gauges, computer -ana lysed electronic bi te wafers. The exact mechanism by which these occlusal factors may account for the variability in attrition score will not be indicated by our investigation.

Specifically, the variables measured were:

from the subjects' history:

age (years) at the time the models were taken.

gender

from the subjects' headfilm:

interincisal angle (degrees)

U1 to N A angle (degrees)

from the models:

Angle classification classes 1,11/0, 1111, 1112, 111

presence or absence of anterior X-bite

presence or absence of posterior X-bite

overjet as distance between the closest dental surfaces lingual of the upper incisor to labial of lower incisor (mm)

bite depth as a % - measured as the position of lower incisor edge along the length of the lingual surface of the upper incisor.

A total of 393 study models were examined. Those subjects with no headfilm or with Class I11 malocclusions with reverse overjets were discarded, leaving a total of 298 subjects. The age distribution of the subjects is shown in Figure 1.

Statistical Methodology There are several ways of determinging a n d l o r characterising relationships between attrition and the variables associated with the occlusal pattern. These can be categorised as follows:

Method (a) extract two subgroups from the sample on the basis of some variable such as sex which leads to a group of females. Test the hypothesis that the response (that is attrition score) distribution for the two populations from which the samples arise are identical. If they are not, then there is a relationship between the response (attrition score) and the paritioning variable (sex). The partition- i n g var iab le m u s t be categorical although, at the expense of some information, it can be constructed from a continuous variable. Examples of tests actually used in this strategy in the orthodontic literature include:

- t-test (with pooled estimate of variance)

- Wilcoxon Rank-Sum tes t o r Mann-Whitney U-test

Method (b) Calculate a measure of association between two variables. An association indicates a relationship between the two variables. Methods used in the orthodontic literature include:

- Correlation coefficient

- Spearman's rank-order correlation coefficient

Method (c) Build a model relating the response distribution to the other variable. Regression is a classical

example of this approach which is described in detail in Draper and Smith (1981). In the present context, more general methods are needed to treat the ordinal response.

Method (a) is simple though tedious, particularly if, as is required, the assumptions for each test are checked. This is usually ignored or overcome by applying tests with less stringent assumptions. The rank based methods have been developed for ranks derived from continuous data rather than ordinal data. The identification of ordinal scores with ranks is often acceptable but seems prob- lematic in the present context where the scores take only a few values and so produce predominantly ties when inter- preted as ranks. The particular tests used are usually designed to detect specific differences in populations and whatever their power against these alternatives, they tend to have no power against other alternatives. For example, the Mann- W h i n e y U-test is designed to detect differences in the locations of the two populations and may fail to detect other differences.

140 The main weakness of approach (a) is that creating the subgroups can result in loss of power (making the method less likely to detect real relat ionships) through decreasing sample size, convert- ing continuous variables to categorical and through unfortunate category choice. What appear to be quite sufficient numbers in the total sample group, may not be so once the total sample is subdivided into sub-groups. For example, Seligman e t a1 (1988) examined a total group of 222 but when the sample was partitioned into sexes and then into malocclusion class, the male sub-group with Class I1

g< division 2 rnalocclusions comprised a mere 4 individuals. See also Gianelly e t a1

oc # (1989). Finally, when a relationship is

2 detected, this approach is silent about its 0 nature, magnitude, etc. 1

T h e second method is also fairly U 3 straightforward to implement and avoids

arbitrary partitioning. Its main dis- 0 advantage is that measures of association z 0 detect limited classes of relationships and

0 not others, and may be sensitive to structures in the data. For example, the correlation coefficient detects linear z

5 relationships, may fail to detect non- J

linear relationships and is highly sensitive to cluster effects. Also, while the

3 a method may detect a relationship, it is

again silent about its precise nature or magnitude.

Method (c) is more complex than the previous methods but, when properly applied, offers considerably more flexi- bility. Moreover, the result of the analysis is an explicit formula giving the nature and magnitude of the relationship between the response distribution and the other variable. This formula provides a precise description of the relationship and can also be used to predict likely outcomes. This ability to forecast likely outcome if proposed orthodontic treatment is declined, can be of immense value to the practising clinician.

The above descriptions concentrate on relationships between two variables. It is fairly obvious but widely under- appreciated that a finding of no relationship between pairs of variables does not imply that there is no joint relationship between the variables. Thus there may be no relationship between attrition score and age or sex taken separately (ignoring all other variables) but a strong joint relationship between these variables.

Since there is no single measurement capable of describing dental pattern, it is clear that we need to study the joint effects of several variables acting simultaneously on attrition. For example, it is not sensible to consider the influence of vertical overlap and horizontal overlap separately in relation to TMJ dysfunction but their combined effect (along with that of other variables) may be substantial. The method of singular treatment -

of variables is commonly employed [Stringert and Worms (1986), Pullinger e t a1 (1987), Seligman er a1 (1989), Gianelly e t a1 (1989), Pullinger and Selig- man (1991) and Gianelly et a1 (1991)l. More subtly, considering a single variable while ignoring others may enable cancel- lation effects to occur. For example, the variable "presence/absence of deflective occlusal contacts" was chosen by Selig- man e t a1 (1988) as a "local factor" in their study. Here the contacting of teeth produces a resultant force which may be " re t rus ive-brac ing" o r " re t rus ive causing"; one will tend to deflect the condyle mesially, the other distally, and being opposite effects may tend to cancel across the sample. ("Tend" is empha- sised as mitigating or exacerbating factors interpose between the influencing and the dependent variables.)

Thus it is vitally important to be able

to incorporate a number of variables simultaneously into the analysis. The third approach of building a statistical model provides by far the simplest and most powerful methodology for doing so. In addition, it provides a way to avoid the proliferation of tests and the consequent multiplicity problems which occur with the other two approaches. Finally, modelling indicates the relative importance of each variable which is useful diagnostic information (Rio10 e t a1 1987).

Statistical Analysis The ordinal nature of the categorical response limits the type of model we can consider. We begin by fitting a proportional odds model with linear terms for all the covariates. The software available to us included PLUM and GAIM. The data is in the ungrouped form (i.e. at the single subject level) so PLUM is unsuitable for this data. GAIM can handle ungrouped ordinal data but does not provide standard errors for the coefficients. Model fitting can however still be carried out using the analysis of deviance technique. The deviance does not strictly have a chi-squared distribution when the data is ungrouped but we still use the chi-squared distribution to calibrate the deviances. The null deviance was 8980.642 on 1188 df.

We began by including all nine covariates in the model using indicator variables to code the nominal variables (sex, presence or absence of anterior cross-bite and presence or absence of posterior cross-bite) and the ordinal variable classification. The deviance was 772.029 on 1177 df. Since we did not have standard errors to examine, we dropped each covariate in turn to see how the deviance changed. Only age, bite depth and overjet appeared significant so we fitted a new model with only these covariates. The deviance was 782.634 on 1185 df. The difference is of the order of the difference in degrees of freedom so we omitted the dropped covariates.

We then proceeded to address the question of whether subjects with crossbites are different from those without, by including crossbite interactions. (The effect of the interactions is to fit separate models for patients with crossbites and those without in such a way that the models can be compared directly.) Our version of GAIM is restricted to a maximum of twenty covariates so we could not simply include all possible inter-

actions simultaneously. We therefore fitted all nine covariates and a number of groups of interactions. None of these groups of interactions contributed anything to the model so we concluded that patients with crossbites do not need to be treated separately from those without.

To explore the quality of the model with age, bite depth and overjet, we fitted a nonparametric additive model. This model suggested that overjet may enter quadratically rather than linearly. W e therefore included a quadratic term in overjet in the model. The resulting deviance was 778.627 on 1184 df so this term is worth including. As a final check, we fitted a nonparametric additive model with all nine covariates. This only affects the fit for the remaining continuous covariates, namely the two angles. Aside from a single discrepant point, this analysis suggests that the treatment of these effects as linear is reasonable.

The residual mean deviance was less than one for all models fitted so there is no evidence of over-dispersion. Diag- nostics with ungrouped data are problem- atical so we have therefore restricted ourselves to expanding the model to explore the quality of fit. The available software does not permit the fitting of non-proportional odds models. Finally, we noted the possibility of but did not try grouping subjects with similar covariates so we could use PLUM to obtain approxi- mate standard errors or grouping the response into only two categories corres- ponding to high (attrition score 3 or 4) or low (attrition score 0,1,2) attrition so that we could apply logistic regression methods. Both of these possibilities would involve a loss of information.

Results

The proportional odds model fitted in this analysis is parametrised by the probabilities

yo = PjAttrition score equal to O}

7 , = PjAttrition score equal to 0 or l}

y2 = PjAttrition score equal to 0, 1 or 2}

y3 = PjAttrition score equal to 0, 1, 2 or 3}

and

7 4 = l.

The final model relates the cumulative probabilities 7 0 , yl, y2, y3 to the covariates age, bite depth and overjet. Explicitly, we obtained

log (5 1.2600 - p

log (3 2.3108 - p

log (5) = 3.8468

and

where p = 0.1563 Age + 0.0196 Bite Depth -

0.4018 Overjet + 0.082 0verjet2.

The residual mean deviance is 0.653. (Recall that our software is unable to provide standard errors for the coefficients.) The probability of each attrition score as a function of age, bite depth and overjet is obtained as:

PjAttrition score equal to 4} =

exp(5.5254 - p) 1 -

l+exp(5.5254 - p)'

PjAttrition score equal to i} =

exp(ei - p) e x ~ ( 0 ; - ~ - p)

l+exp(Oi - p) l + e x ~ ( 0 , - ~ - p)

i = 1, 2 or 3,

and

PjAttrition score equal to O} =

exp(l.2600 - p)

l+exp(l.2600 - p)'

where 0, = 2.3108, 0, = 3.8468 and e3 =

5.5254.

The model is straightforward to inter- pret and use. W e see that with all other factors being held constant, a patient's attrition score tends to:

increase with age,

increase with bite depth,

decrease initially with overjet until a critical value and then increase,

be unaffected by sex, interincisal angle, U1 to N A angle, angle classification, posterior or anterior crossbites.

Suppose by way of illustrative example that we apply the model to a 13 year old male patient with 100% overbite and no overjet. Then if the overbite and overjet reamin the same, at age 15 the model predicts that the chances he will have:

Attrition score of 0 = 4.5%





That is, with high probability, he will have an attrition score of two or worse. However, if overbite and overjet remain the same, at age 30 the model predicts that the chances he will have:






which shows a high probability of deterioration to an attrition score of four by age 30.

Discussion Our results support clinical observations that there is a realtionship between occlusal variables and attrition. This finding is in conflict with the results of Selig- man et a1 (1988) and others who found no relationship between these variables. W e argue that while differences in the study populations may be important, the different results may also be due to differences in statistical analyses. The widely used method of studing the relationships between two (or at most a selected few) variables at a time using two-sample techniques is inferior to our approach in that it is more likely to fail to find relationships when joint relationships exist. Moreover, the emphasis in these studies o n hypothesis testing means that even if relationships were to be found, they would not be quantified.

Recommendations in the literature which advise against orthodontic treatment for the prevention of pathology are grossly premature. Firstly, irrespective of the methodology used, a failure to find evidence of relationships between the variables does not imply that such relationships do not exist. Secondly, when our critique of the statistical methodology on which these findings are

based is taken into account, it is clear that the conclusions are overstated. W e should be aware of overstatement in the opposite direction. Our analysis does not establish that the relationship between age, bite depth, overjet and attrition is necessarily causal and therefore cannot on its own establish that orthodontic treatment will prevent attrition. That this is the case can, in principle, be un- ambiguously decided but only by a controlled clinical trial in which attrition for treated patients is compared to that in untreated patients.

Finally, there are many subtleties in the appl icat ion of s tat is t ics t o the analysis of data. These are properly dealt with by statisticians with specialist knowledge of modern methodological developments and experience in their i m p l e m e n t a t i o n work ing in close co-operation with clinician-researchers to produce high quality collaborative research.

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GIANELLY, A.A., PETRAS, J.C., BOFFA, J. (1989) Condylar position and Class I1 deep-bite, no- overjet malocclusions. Am.J.Onhod.Dentofac.0rthop. 96428-432.

GIANELLY, A.A., ANDERSON, C.K., BOFFA, J. (1991) Longitudinal evaluation of condylar position in extraction and non-extraction treatment.

m p Am.J.Orthod.Dentofac.0rthop. 100:416-420. 0-

McLAUGHLIN, R.P. (1988) 0 Malocclusion and the temporomandibular

g joint - an historical perspective. Angle Orthod. 58:185-191. 1 PULLINGER, A.G., SELIGMAN, D.A.

3 0 (1991) g Overbite and overjet characteristics of refined

diagnostic groups of temporomandibular dis- g order patients.

Am.J.Orthod.Dentofac.0rthop. 100:401-405. IÃ 0- 0 PULLINGER, A.G., SOLBERG, W.K. ,

HOLLENDER, L., PETERSSON, A. (1987) 5 Relationship of mandibular condyle position

E to dental occlusion factors in an asymptomatic population. Am.J.Orthod.Dentofac.0rthop. 91:200-206.

RIOLO, M.L., BRANDT, D., TENHAVE. T.R., (1987) Associations between occlusal characteristics and signs and symptoms of TMJ dysfunction in children and young adults. Am.J.Orthod.Dentofac.0rthop. 92:467-477.

SELIGMAN, D.A., PULLINGER, A.G., SOLBERG, W. K. ( 1988) The prevalence of dental attrition and its association with factors of age, gender, occlusion, and TMJ symptomology. J. Dent. Res. 67:1323-1333.

SOLBERG, W.K. , BIBB, C.A., NORD- STROM, B.B., HANSSON, T.L. (1986) Malocclusion associated with temporomandibular joint changes in young adults at autopsy. Am.J.0rthod. 89:326-330.

STRINGERT, H.G., WORMS, F.W. (1986) Variations in skeletal and dental patterns in patients with structural and functional alter- ations of the temporomandibular joint: A preliminary report. Am.J.Orthod. 89:285-297.

T A L L E N T S , R . H . , C A T A N I A , J . , SOMMERS, E, (1991) Temporomandibular joint f indings in pediatric populations and young adults: a critical review. Angle Orthod. 61:7-16

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Dr. A.J. Ritchard 1002 AMP Building Hobart Place CANBERRA CITY ACT 2601

Received forpublication,June 1992.

DENTOFACIAL ORTHOPAEDIC CORRECTION OF MAXILLARY RETRUSION WITH THE PROTRACTION FACEMASK - a literature review AUTHORS GekK~ow Goh BDS, MDSc and Sheung K Kaan BDS, MSc, DDO, MD0 RCPS, Singapore.

1 he retruded maxilla in the Class I11 skeletal pattern could be effectively corrected with the protraction facemask in selected cases. A review of the different types of orthopaedic appliances used in Class I11 treatment, the rationale for facemask therapy, the ef treatment and affecting stabi presented.

Key Words

feet of this the factors lity is

facemask, orthopaedic force, maxillary retrusion, protraction, maxillary rotation.

Short Title The protraction facemask - A literature review.

Department of Orthodontics, Government Dental Clinic, First Hospital Avenue, Singapore 0316 Fax. No. 2242521

Introduction The use of mandibular protraction and extraoral maxillary restraining devices, such as functional appliance and headgear, have been widely practised in the treatment of Class I1 skeletal discrepancies. It is the contrary for the Class 111 skeletal pattern, which often presents the orthodontist with a dilemma.

At present, clinicians tend to treat Class 111 skeletal patterns with definitive orthognathic surgical correction upon skeletal maturation" rather than with early interceptive orthopaedic^.^ Much controversy and uncertainty surround the effect and stability of early treatment of the Class I11 skeletal dis-

pancy, l X . l ~ ~ , 2 > , i l , ~ 8

Questions have been raised regarding the mode of correction, whether true maxil lary advancement o r d e n t o - a l v e o l a r c o m p e n s a t i o n has been a~hieved . '~ This article will review the dentofacial correction of maxillary retrusion with the extraoral protraction facemask.

Treatment of Class I11 malocclusion There are various treatment modalities for the correction of the Class 111 skeletal pat tern. Trea tment of the younger patients have included various orthopaedic appliances to restrain grown of t h e mandible a n d / o r protract the maxilla.'-'^ In the adults, orthognathic surgery is usually indicated.

Classification of Class I11 orthopaedic devices 1. Maxillary protraction devices

( i ) facemask/reverse pull head- gear2-

Fig. 1. An wimple of a mimdibitlur restraining device, the c h i p 1 cup.

( i i ) rapid palatal expansion, where a n t e r i o r d i s p l a c e m e n t of maxilla is an advantageous secondary effect" ' I

( i i i ) in combination"" "

2. Mandibular restraining devices a c u p ~ c , ~ ~ , 2 ; (Fig. 1 )

( i i ) mandibular extra-oral traction on molars'

3. Combinations of 1 and 2 ( i ) face~nask/reverse pull

headgear ( i i ) intraoral functional

appliances2'

Aetiology T h e frequency of mandibular prognathism and Class 111 n~alocclusion is relatively small , about 59 in t h e Caucasian population,^" but a higher incidence exists in the Japanese population because they are observed to be more bracl~yfacial.'~

I orthognathic surgery

KEY

no normal

c l 111 David 6 M F

Fig. 2. Familypedigree of the boy in Fig. 4 showing a familial tendency of the Class III malocclusion.

There have been report^'^'^'^^ of familial tendency (Fig. 2) in mandibular prognathism and the Class 111 malocclusion. Litton e t a1 20 reported genetic influence in the transmission of Class 111 malocclusion and their results do not support a monogenic mode of transmission but points to a multifactorial expression. Envi ronmenta l factors i n c l u d i n g t h e p o s i t i o n of t h e t0ngueio,~;,26,27,34 are also believed to be

responsible for the development of Class Ill skeletal pattern.

Components of Class I11 skeleton The clinical presentation of the Class I11 discrepancy is very much affected by the direction of mandibular growth, dental compensation and soft tissue masking. Various Class I11 skeletal patterns exist due to different combinations of deficiency and excess of the maxilla and mandible.6 They can result from a large and/or anteriorly positioned mandible, a small and/or retropositioned maxilla and their c o m b i n a t i ~ n . ~ , ~ ~ Contrary to common clinical impression, maxillary retrusion or deficiency has been observed to be the prevalent feature of Class 111 malocclusions. Maxillary retrusion is present in 62%-63% of the popula- tion9'> in combination with various sizes of the mandible (Fig. 3). The Class 111 malocclusion is often associated with a more obtuse gonial angle and increased lower anterior facial height.z,6s9 This latter characteristic has been observed to be present in 41% of a group of Class 111 patient^,^ t h e r e f o r e , t r e a t m e n t mechanics of these patients should

ideally avoid extrusion of posterior teeth. A diagnosis of Class 111 malocclusion at an early age would allow for the institu- tion of orthopaedic treatment to alter maxillo-mandibular growth and development,3,6~14'20~22 but Guyer eta1 found indications that Class 111 growth is not fully expressed in the younger age group. The Class 111 skeletal pattern grows progressively worse with time as maxillary growth tapers off earlier compared to mandibular growth,; increasing the proportion of the Class III skeletal pattern from childhood to adulthood? Early detec- tion is difficult as different cephal&netric analyses have demonstrated different cephalometric diagnoses of the Class III skeletal patterm3> Therefore, experienced clinical judgement backed by cephalometric findings is still required in the diagnosis and staging of the Class I11 malocclusion.

Rationale for maxillary protection

Mandibular protrusion has often been blamed as the cause of Class 111 skeletal dis~repancy,"~ hence, attempts at interceptive Class 111 malocculsion therapy have been based on mandibular growth retardation or redirection using mandibular headgear, chin cup and intraoral functional appliance^.^^^^"^"^^',^^

However, inhibition of manidibular growth with chin cup therapy is difficult to a c h i e ~ e * ~ , ~ ~ ~ ; ~ because of the shape of the condylar head in relation to the glenoid f ~ s s a . ~ ' In addition, a chin cup which is not well adapted to the chin to avoid riding up the dentition would only produce undesirable dentoalveolar changes with lingual tipping of lower incisors. Treatment with the chin cup has been found to be ~ n p r e d i c t a b l e ~ ~ . ~ ~ and correction was not maintained because of the unalterable inherited growth direction of the Class III skeletal pattern.36 The literature5536 has shown that results of such interceptive orthopaedics is dependent upon accurate diagnosis of the Class 111 malocculsion and the treatment approach.

The retruded maxilla as a significant component is often ignored in treatment planning and management of the Class I11 skeletal pattern, and is only specifically addressed during orthognathic surgical ~ l a n n i n g . ~ , ~

These studies suggest the need to look directly into correcting the retrusive maxilla by means of protraction.

Sanborn Dietrich Jacobsen Ellis Guyer

Pro Md/Norm Mx Norm Md/Retr Mx

Pro MdIRetr Mx Norm Md/Norm Mx

Q. 3. Components of Class III malocclusion by various authors.

Case selection Selective LISC ofthe protraction facemask would help achieve stable orthopaedic changes.

Indications (Orthopaedic) l M~xi lkry retrusion4 ' ' """' 2. Craniofacial deformities associated

with maxillary deficiency" ( i ) Cleft palate patients".' ' '' "'

( i i ) Achondroplastia patients, post(~peratively"

3. Combination of maxillary hypoplasia and mandibular prognathism"

4. Post Surgery ( i ) Correction of Class 111 post-

surgical relapse after orthognathic surgery"~"'

( i i ) Protraction of maxilla tra~~matically retruded during RTA in an adult patient'

As teeth and alveolus are used to transmit traction forces from the appliance to the maxilla, there is, invevitably, an accompanying orthodontic effect.

Therefore, facemasks can also be used for o r t h o d o n t i c space c losure in the maxilla with forward nlovement of posterior teeth in cases of maxillary hypodontia or where residual extraction spaces2"-'-' * exist.

Limitations of facemasks as orthopaedic devices The efficiency of the facemask as an orthopaedic device depends very much on the control of undesirableorthodontic movements as well as the following factors.

Growth potential The timing of facemask therapy is critical i f skeletal orthopaedic movement is to be achieved. Treatment at a younger age would ensure maximum exploitation of the maxillary growth potentia14"5'9'14 as maxillary growth is known to peak off earlier than mandibular The age of commencement of facemask treatment varies across case reports published and is often related to phases of dental development. Treatment may commence as early as the age of 4 y e a r s ' . ~ $ , % 3 or with the eruption

of the first permanent maxillary molar^.^' Ideally, protraction should begin prior to the attainment of the pubertal growth spurt because the

greatest amount of skeletal anteroposterior maxillary development was found in younger patients who have not reached puberty.^ Hand- wrist radiographs'5,",'j '4 would be able to predict the amount of growth expected. There is a variable amount of growth at different times in the development of the child and between therefore, timing of treatment should vary accordingly. Where secondary sexual characteristics and radiographic evidence of skeletal maturation are present, less orthopaedic result can be expected. The result attained is by dental compensation with the underlying skeletal discrepancy ~ ~ n r e s o l v e d . ~ ' ~ ' '

Growth direction Maxillary protraction would help stimulate and redirect growth of the m a x i l l a . ' Facemask t r e a t m e n t produces maxillary conterclockwise rotation and maxillary molar extrusion, resulting in backward mandibular rotation; increased lower anterior facial height and bite opening.:' This makes facemasks unsuitable for vertical growers when used alone.""'Limited control of these undesirable effects may be achieved with auxiliaries.

The Class 111 pattern due to true mandibular prognathism, would not respond favourably to facemask therapy as the mandible will eventu- ally outgrow the maxillary protraction," although Petitr maintains that mandibular prognathism is treat- able with accelerated facemask therapy.

Patient con~pliance Facemask therapy is totally dependent upon patient cooperation for both the daily and longterm wear required,3.21.25.+X~

While growth potential can be maximised at very young ages, there is o f ten poor cooperat ion and motivation.

The facemask The earliest report of facemask treatment was documented by Potpeschnigg in 1875 according to P e ~ i t . ' ~

Delaire" was responsible for its regain in popularity with the Delaire-Verdon facernask design.

Components of the facernask All facemasks have the similar basic components2~"

I . chin cup 2. forehead rest 3. hook bars for the attachment of pro-

traction elastics 4. connectors consistingof a wire frame-

work 5. with or without accessories such as

nose rollers, nose rubbers, front cup gliders. chin cup gliders"

Facemasks are either custom made or available as preformed models. The custom made facernask proposed by T ~ r l e y ' ~ necessitates a face r n o ~ l l d ~ " ~ to be taken and adequate laboratory facilities, resulting in better fit of the chin cup and forehead pad. Some of the currently preformed models available are:

l Delaire facernask (RMO) open face design (Fig. 4)

Fig. 4. The Detain' faccmask.

2. Petit facemask (Salt Lakes) central rod design

3. Tubinger facemask (Dentaururn) paranasal rods design (Fig. 5)

4. Grummons facemask with cheek pads instead of the chin cup

Despite manufacturers' claims, several auth0rs2.?~.'n found that much chairside

time is required to fit the preformed mask to each patient.

Rapid Maxillary Expansion The effects of rapid maxillary expansion are optimised when used in conjunction with facemask therapy to obtain the

Fig. 5. The Ti(/?ir;ger facemask.

following result^.'^ Rapid maxillary expansion (RME) (Fig 6):

disarticulates the maxilla It was felt that loosening of the maxilla would -

facilitate easier protraction. researchers12,1~,15.16,21,~~,~~:S

recommend the use of rapid palatal expansion with facemask therapy to disrupt the circummaxillary sutures.

RME should preferably begin 7-10 days before delivery of protraction headgear.?'

However, experiments carried out on primates without maxillary expansion obtained similar r e s ~ ~ l t s . ~ ~ ~ ~ ~ " ' ~ ~ "

helps correct the antero-posterior skeletal discrepancy by anter ior repositioning of the maxilla during expansion."

3 . increase the lower facial height by opening the bite. The anteroposterior discrepancy is reduced by backward rotation of the mandible.''" "'. This would help correct overclosure commonly found in the brachyfacial Class I11 malocclusion.

4. corrects posterior crossbite that often accompanies the Class 111 skeletal pattern because of deficient trans- verse maxillary growth" 1 2 ' ^ " and retropositioning; and enhances vertical maxillary development.'*

5 . splints the maxillary dentition during protraction and helps transmit forces from teeth to the maxilla, thus, limit- ing unwanted tooth r n o ~ e m e n t . ~ ~ "

6. resists construction of the anterior part of the palate which often occurs with maxillary advancement."

However, with the use of RME, there is a need to control adverse dentoalveolar changes and minimise backward rotation of the mandible in many cases."

RME has been den~onstrated to show niidpalatal and circum-maxillary sutural separation which results in anterior- inferior displacement and lateral expansion of the maxilla.'u"fl~y"

In addition, hanging of palatal cusps of upper molars during expansion also produced backward rotation of the mandible,"~'" '" although recovery has been reported in some cases.'9

Attempts to counteract this mandibular rotation and maintain the lower anterior facial heighth include modifications to the RME device to prevent molar extrusion. An acrylic splint with full

Fifi. 6. H}rcix appliance with hooks at the region of the &/CS.

occlusal and dental cover- ii g e ' ~"'~""' which exceeds the freeway space has been re~ommended . '~ Thi'i occl~~s:~l bite plane serves as a functional appliance with intrusive forces against the mandibular teeth'"" and frees the occlusion."

A high pull headgear attached to a chin cup which carries hooks for forward elastic application'""" has also been suggested to prevent the mandible from rotating backwards.

Mechanics Proper application of biomechanical principles is required in facemask therapy to achieve maximum orthopaedic movement and minimal dentoalveolar compensation.

Centre of resistance The centre of resistance of the midface of the human skull is located between the first and second preniolars antero- posteriorly and between the lower margin of the orbitale and distal apex of the first molar vertically.'" Ideally, the protraction force should pass through this centre of resistance, to produce a translatory forward movement of the maxilla. Considering that the maxilla is an irregularly shaped and attached three- dimensional bone, it is difficult to apply a force through the centre of resistance in the human being to obtain true translatory anterior advancen~ent. '~

The protraction force applied to the maxillary dentition usually results in movement of the maxilla and its dentition around a centre of rotation. The centre of rotation of the maxilla has been observed to vary according to the direction and location of application of force,?' thus generating various displacement patterns of the maxilla."

Direction of force Investigations2'~" have recommended force directions to be either horizontal and parallel to the occlusal plane or downward and forward (Fig. 7).

According to N a n d ~ ~ , ? ~ a horizontal direction of force produces a more superior centre of rotation resulting in a more horizontal rather than vertical maxillary displacement. On the other hand , horizontal forces have been blamed for causing counterclockwise maxillary rotation and an anterior open

Fig. 7 .Various directions o fforces applied/rom irztr~i-oralhooks at the canine region.

bite, 1 - 3 l,\7 This is confirmed by Itoh'- using photoelastic analysis and Tanne et 2~1,~' employing the finite element method.

They demonstrate that a parallel protraction force could induce larger forward as well as larger vertical maxillary displacement; more extrusion of maxillary molars and greater rotation of the palatal plane.

Conversely, a downward force approximately 20'- 30' to the occlusal plane would reduce this r ~ t a t i o n , ~ ' but also extrude molars.I7 In spite of a forward and downward force vector, anterior rotation still occurs unless a heavy downward vector is applied.''

Differing findings reported in these 1724.37 may have arisen because of

the different points of application of force.

To achieve pure translatory movement of the maxilla, titanium implants were placed directly onto various bones of the nasofacial c~rnplex . '~ Protraction forces directed anteroinferiorly were found to reduce or eliminate counterclockwise rotation of the maxilla.

However, these forces were applied directly to the facial bones, while results of other ~ t u d i e s ' ~ ~ " utilize tooth borne anchorage. Application of forces directly to bones would minimize adverse dentoalveolar changes which often accompany orthopaedic advancement, but so far, skeletal anchorage has yet to be performed on human beings.

There have been attempt^^',-'^ to achieve skeletal anchorage clinically by

intent ional ly ankylosing maxillary primary canines to improve anchorage. Any force system applied to the ankylosed tooth would produce skeletal rather than dental movement. However, root resorpt ion of these canines occur. Despite the problems with force directions, c ] i n i c i a n s 1 7 . ~ l , 3 ~ 38 a t t e m p t to minimise undesirable counterclockwise rotation of the maxilla and its anchor teeth with a combination of a horizontal and slightly anteroinferior force. The degree of the direction of pull depends on the bite opening required.I2,l6

Point of application of force Elastics (Fig. 8) have been applied to maxillary molars d i r e ~ t l y ~ " ~ ~ " ~ ~ ~ or onto hooks extending to the distal of lateral incisors,l9.2~,34.3a Forces applied directly to

molars produced more forward movement of the maxilla. This maxillary forward movement was accompanied by an upward and forward rotation of the nasal f l ~ o r ~ ~ c o r n p a r e d to the effect of the first pren~olar site of force applies tion. '

Upper molar extrusion also occurs. Extension hooks should be applied as far forward as possible'" to produce downward and forward movement of the maxillary complex without excessive rotation.'. However, selection of the intraoral site of elastic application should also be determined by consideration of the vertical dimension and by the amount of forward advancement required.'"

The use of elastics intraorally for protration purposes, however, does not allow for a change in the point of application or direction of force delivery to attain predictable results."

In an effort to produce more favourable protraction, forces were applied to various vertical points in the dry ~ k u l l . ' ~ This experiment demonstrated that the point of application higher or lower relative to the centre of resistance produced a posterior or anterior rotation together with forward movement of the maxilla respectively. A true advancement of the maxilla was accomplished by applying a force of 5 mm. above the maxillary arch, although this is difficult to accom- plish in the human being.

Dissatisfaction with unfavourable effects produced by the facemask has led to many modifictionsl'"^ to the protraction devices to control these variables better.

Fig.. 8. Tim different sites o f application of intraoral elas'tics. Attac/~?ne?zt could be - -

either to molars or to hooks at the canine region

Nanda Mermingos Turley Hickham Subtelny Cozzani Delaire

Fig 9 The different range offori.a for maxzlkir}~protraction

Magnitude of force Orthopaedic force levels are mandatory for maxillary protraction to occur. Anteriorly directed orthopaedic force l e v e l s a d v i s e d b y v a r i o u s a u t h o r s 3 , ~ , ? 1 , 2 2 , 2 > , ~ 1 , 3 8 range from 500 to 2000gm. (Fig. 9).

The force magnitude needed to break t h e c i r c u m m a x i l l a r y s u t u r e s f o r maxillary advancement would have to be greater than the force applied to restrain maxillary growth with Class 11 headgear therapy.''

Several clinician^^^^^^^^ have advised increasing force levels progressively for patient adaptation. The magnitude of force essential for orthopaedic advancement of the maxilla is not related to the amount of maxillary rotation.2^

Duration of force Full time wear is recommended by most

21 2 5 m to achieve rapid and op t imal skeletal changes. Turleyi8 suggests 24 hour per day wear to correct the rnaloccl~~sion within 2 to 6 weeks, and within 3 to 4 months, according to Cozanni.'

An acceptable result can also be obtained with 14 hour per day wear but requires longer treatment time.'"

Nanda3 claims that continuous force in the range (if 16 to 24 hours, is desirable to produce disarticulation of facial bones. McNaniar:~~' advises fulltime wear until ..in overjet of 4 mm. is obtained, thereafter. the patient is put on night wear for another 6 months. The protraction heaci- gear may have to be woi'n for year'i to

improve maxillary advancement'" and control subsequent mandibular growth. A maintenance phase where a chin cup could be worn in the place of the protraction facemask has been reported."

Effect of protraction device The mode of action of the maxillary protraction device is debatable. The result is often achieved by various combination of dentofacial changes.^

1. Effect on the maxilla Animal studies18.192~f,3i demonstrated a significant forward repositioning of the maxillary complex and remodelling not only of the sutures but also the surfaces of facial bones. Remodelling occurs in greater amount in sutures in closer proximity to the applied force,"."

e.g., the zygo~~iacicom~ixillury, piilato- maxillary, pterygopalatine and zygo- maticotemporal sutures.''

Deep cranial structures such as the synchondroses of the sphenoid bone also undergo re~nodel l ing. '~ However, ortlio- peadic changes in primates are more dramatic than clinical changes24 possibly because of controlled internal variability involved with animal research. Case

2 ? 2 5 , 4 l show that besides significant point A advancement, the whole maxilla is protracted forwards and down- w a r d ~ . ' ~

An increase in the effective midface length is also observed .^ ' -^ 0 ther authors16.2?,48 have reported counter-

clockwise rotation of the maxilla, that is, a forward and downward movement of the posterior part of the maxilla and of the dentition (Fig. 10). Despite this, the vertical effect of facemask therapy is less when compared to the use of Class I11 intermaxillary elastics." Narrowing of the anterior part of the maxillary arch has also been ob~erved. '~-"

2. Effect on the mandible While an orthopaedic force is used to protract the maxilla, the chin cup serves as anchorage and at the same time redirect mandibular growth downward and backward.?' i ' 'aThis vertical displacement together with mandibular rotation from RME,""O'" strongly suggest that precautions have to be taken in the vertically growing patients.

The effective mandibular length may continue to increase,?? but the effect of downward and backward mandibular

rotation'~,2i,;s reduces the SNB angle,I6

the prominence of the pogonion2' and increases facial convexity." Inhibition of mandibular growth may also occur.2n8

3. Effect on the maxillary dentition Utilization of maxillary teeth for the application of force to advance the maxilla often leads to adverse tooth movement.'' There is an extrusion and mesial tipping of molars and proclination of incisor^,"^'.^-^^ thereby causing counterclockwise rotation of the occlusal plane. ' To overcome anterior tipping, a heavy rectangular wire with labial root torque has to be placed early in treatment."" T h i s wire also uni tes all maxillary teeth together as one unit, allowing even force distribution to the midface structure." The protraction device also has the effect of moving the entire maxillary dentition over skeletal base, increasing the risk of dehi~cence. '~

4. Effect on the mandibular dentition Lingual tipping of incisors and vertical eruption of lower molars have been rep~rted." ,~

Incisal tipping occurs as a result of the pressure of the chin cup on anterior teeth,21 25 3 1 A well adapted chin cup fitted

to the inferior contour of the chin could reduce this adverse effect.?'

5 . Effect on the profile Generally the lower anterior facial height increases2"j8 with facemask treatment, although the mandibular plane and gonial angles are reduced or main-

However, several clinician^'^'^^ found an increase in the mandibular plane angle14 because of maxillary molar extrusion. Although the above result is favourable in improving the facial profile, I t o h ' warns that excessive displacement of the mandible during treatment alters the intermaxillary relationship and will affect stability after treatment.

Retention and long term stability Stability of the Class I11 correction is of great concern to the orthodontist in order to avoid the need for surgery. In addition, the Class 111 malocclusion is not resolved until cessation of facial growth.' This has lead to various suggestions to enhance treatment results

Relapse of Class I11 correction has been reported to occur in 2 phases:

( i ) dental changes following the protraction

( i i ) post treatment rotation of the maxilla which can occur within l month after cessationof facemask wear

Dental tipping has to be avoided or minimisedI8 to obtain long term stability as dental changes after facemask treatment undergoes four times as much relapse as facial bone change^.'^ Where significant skeletal changes have occurred, minimal relapse appears after discontinuation of facemask wear. 80% of skeletal movement was observed to be maintained twenty-two weeks after removal of protraction forces.I8

S t ~ i d i e s " ~ ~ on animals reveal that the stability of correction is also proportional to the length of retention. As a result, cliniciansv4 have advo- cated continual facemask wear possibly even until completion of mandibular growth. Retention is often carried out with a Class 111 bionatori8 or FR I11 a p p l i a n ~ e ~ ' " ~ for a period of three to six months.

Some a ~ ~ t h o r s ' ~ . ~ ' warn that results will be unstable unless the aetiology of the malocclusion is removed. Tonsil- lectomy, adenoidectomy, partical glos- sectomy and re-education of the tongue have been recommended. On the other hand, Delaire4 observed that treatment will permit the establishment of a normal equilibrium and prevent relapse of the corrected facial skeleton.

Overcorrection of the overjet?' and achieving optimal occlusion in the permanent dentition will help control any further disproportionate growth between the maxilla and the mandible.

Increasing the overbite would resist relapse of the maxillary retrusion. This can be accomplished \virh labial root torque of the incisors which, a t the same time advances A point and improves the stability of the correction.

References l B'inks P, , Bogus (1988): Traumatically

induced maxillary retrusion - a case report of orthodontic management with the protraction headgear. Br. J. Orthod. 14:l 1-16,

2. Cook M.S.; Wreakes G. (1977): The face mask: A new form of reverse headgear, Br. J. Orthod. 4: 163-168.

3. Cozzanie G. ( 1981): Extraoral traction and Class I11 treatment, Am. J. Orthod. 80:638-650.

4. Delaire J. (1971): La croissance maxi[- laire, Trans. Eur. Orthod. Soci. pp8 1 - 102.

5. Dunbar J.P.: Goldin B.; Subtelny J.D. (1989): Correction of Class I crowing in an achondroplastic patient, Am. J . Orthod. Dentofac. Orthop. 96255.263.

6. Ellis, E . ; McNamara J .A. (1984) : Components of adult Class 111 malocclusion, J Oral Maxillofac. Surg. 42:295- m.

7 Graber L.W.: Chung D.P.B.; Aoba J.T. ( 1967): Dentofacial orthopaedics vs orthodontics, DADA 75:1145-I 165.

8. Graber L.W. 1 1977): Chin cup therapy for mandibular prognathism, Am. J. Orthod. 72: 23-41,

9. Guyer, E.C.; Ellis E.E.; McNamara J.A.; Behrents R.G. (1986): Co~nponents of H Class I11 malocclusion in juveniles and adolescents, Angle Orthod. 56:7-30.

10. Haas AJ. (1970): Palatal expansion: Just W the beginning of dentofacial ortlio- 2

peadics, Am. J. Orthod. 57219-255. ?5 C1

11. Haas A.J. (1973): Rapid palatal expan- 2 sion: A recommended prerequisite to 5 Class I11 treatment, Trans. Eur. Orthod. t-

soci. pp 3 11. 3 S 12. Hata S.; Itoh T.; Nakagawa M.; Kamoga- Q_

shira K.; Ichikawa K.; Matsumoto M,; g Chanconas S.J. (1987): Biomechanical

IÃ effects of maxillary protraction on the 3

z craniofacial complex, Am. J . Ortliod. Q

v> Dentofac. Orthop. 91:305-3 11. 2 ec

13. Hickman J. (1991): Maxillary protraction therapy: Diagnosis and Treatment, J . Clin. Orthod. 25:102-113. 2

14. Hocevar R.A. (1988): Face frame anchor- 2 age for closing spaces by protraction - A & solution for missing teeth. Ani. J. Orthod. 9 Dentofac. Orthop. 94:') 16-524. 0 IÃ a

15. Irie M,; Nakamura S. (1975): Ortlio- a, peadic approach to severe skeletal Class g I11 maloccl~ision. Am. J. Oerttiod. 67: 377- g 9 2 . U

-sC Q_

16. Ishii H.; Morita S.; Takeuchi Y.; Naka- 9 mura S. (1987): Treatment effect of g combined maxillary protraction and chin 2 cup appliance in severe skeletal Class I11 2 cases, Am. J. Orthod. Dentofac. Orthop. 2 z 92:304-U?. W

0

7 Itoh T.; Cllaconas S.J.; Caputo A .A; Matyas 1. (1985): Photoelastic effects of maxillary protraction on the craniofacial complex, Am. J. Orthod. 88: 117-1 24.

18. Jackson G.W.; Kokich V.G.; Shapiro P.A. ( 1 9 7 8 ) : Expe r imen ta l and pos t - experimental response to anteriorly directed extraoral force in young Macaca nemestrina, Am. J. Orthod. 75:3 18-333.

19. Kambara T. ( 1977): Dentofacial changes produced by extraoral forward force in the Macaca ims. Am. J. Ortl~od. 7 1 :249- 277.

20. Litton S.F.; Ackermann L.V.; Isaacson R.J.; Shapiro B.L. (1970): A genetic study of Class I11 malocclusion, Am. J. Orthod. 58: 565-577.

21. McNamara J.A. (1987): An orthopedic approach to the treatment of Class 111 malocclusion in young patients, J. Clin. Orthod. 2 1 :598-608.

22. Mermingos J.; Full C.A.; Andreasen G. (1990): Protraction of the maxillofacial complex, Am. J. Orthod. Dentofac. Orthop. 98:47-5 5.

23. Mitani H.; Sakarnoto T. ( 1984): Chin cup force to a growing mandible, Angle Orthod. 54:93-122.

24. Nanda R. ( 1978): Protraction of maxilla in rhesus monkeys by controlled extraoral

150 forces, Am. J. Orthod. 74:121-141

2s). Nanda R. (1980): Biomechanical and clinical considerations of a modified protraction headgear, Am. J. Orthod. 78: 125- 139.

26. Paz M.E.; Subtelny J.D.; Iranpour B. 1989): A combined face mask - orthog-

nathic surgical approach in the treatment of skeletal open bite and maxillary defiency, Am. J. Orthod. Dentofac. Orthop. 95:l-11.

27. Petit H. ( 1983): Adaptation following accelerated facemask therapy, Clinical Alteration of the Growing Face, pp 263.

28. Proffit W.R. ; Fields H . W . (1986): CM m Contemporary Orthodontics. CV Mosby CT) 0-

pp 208-21 1,242-243. W m 29. Roberts C.A.; Subtelny J.D. (1988): Use

of facemask in the treatment of maxillary 0 0 skeletal retrusion, Am. J . Or thod. <c Dentofac. Orthop. 93:388-394. z 5 30. Sarver D.M.; Johnston M.W. (1989):

0 Skeletal changes in vertical and anterior 0 displacement of the maxilla with bonded l- z rapid palatal expansion appliances, Am. g J. Orthod. Dentofac. Orthop. 95:462-466.

2 31. Shapiro P.A.; KokichV.G. (1984): Treat- U 0 nient alternatives for children with z severe maxillary hypoplasia, Eur. J . 5 <c Orthod. 6:141-147.

a:

32. Sheller B.; O~nnell L. f l991 1: Therapeutic ankylosis of primary teeth, J. Clin. Orthod. 26:499-502.

3 Smalley W.M.; Shapiro P.A.; Hohl T.H.; Kokich V.G.; Branemark Per-Ingvar ( 1988): Osteointegra ted t i tanium implants for maxillofacial protraction in monkeys, Am. J. Orthod. Dentofac. Orthop. 94:285-295.

34. Subtelny J.D. ( 1980): Oral respiration: Facial maldevelopment and corrective dentofacial orthopeadics, Angle Ortliod. 50:147-166.

35. Sue G.; Clianoca S.J.; Turley P.K.; Itoli J. 1987) : Indicators of skeletal Class 111 growth, J Dent. Res. 66 (special issue) pp 343.

36. Sugawara J.; Asano T.; Endo N.; Mitani H. (1990): Long term effects of chincup therapy on skeletal profile in mandibular prognathism, Am. J. Orthod. Dentofac. Orthop. 98:127-133.

37. Tanne K.; Hiraga J.; Kakiuchi K.; Yama- gata Y.; Sakuda M. ( 1989): Biomechanical effect of anterior directed extraoral forces on the craniofacial complex: A study using finite element method, Am. J. Orthod. Dentofac. Orthop. 95:200-207.

38. Turley P.K. (1988): Orthopeadic correction of Class 111 malocclusion with palatal expansion and custom protaction headgear, J. Clin. Orthod. 22:314-325.

39. Wertz, R.; Dreskin M, (1977): Midpalatal suture opening: A normative study, Am. J. Orthod. 71:367-381.

Receired forpublication, June 1992

A NOVEL METHOD OF STERILIZING ORTHODONTIC INSTRUMENTS AUTHORS Jo-Ann Miller A.D.B.L.T., B.App.Sci.(CIAE)* Keith M. Harrower B.Sc.(Hons) StAnd., M.Sc.(Exon), Ph.D(Exon), M.A.S.M.4 Maurice J. Costello B.D.Sc.(Qld.), M.D.Sc.(Syd), F.RAC.D.S.**

range of orthodontic instruments was artificially inoculated with a mixed culture of representatives of the oral microflora and a marker bacterium and subjected to dry heat sterilization using a glass bead sterilizer. The shortest time which would guarantee total sterilization of the functional parts of the instruments was thirty seconds.

Key Words instrument, sterilization, dry heat.

Technologist, University College of Central Queensland, Rockhampton. #Lecturer in Microbiology, University of Central Queensland, Rockharnpton. **in private practice at 80 High Street, Rockhampton.

Introduction For many years orthodontic instruments have been chemically or heat sterilized between use with different patients. A range of chemicals have been used including ethanol and small sterilizers or autoclaves suitable for the small private surgery have also been routinely used.

This paper describes a little known method of rapidly sterilizing instruments using dry heat in a 'glass bead sterilizer' (Fig. 1). Such units consist of a heating element in association with a steel bowl containing glass beads. In some models the temperature is set by the manufacturer to 250nC and in other models it is adjustable. The steel bowl is approximately 4 c m in diameter and about 7cm deep and contains a loose mass of glass beads. The beads are 1- 2 mm in diameter. A T U L P D E N T ' model was used in this study.

The principle of the apparatus is simple. The beads and interstitial spaces are allowed to heat to the prescribed temperature and the instrument to be sterilized - or, more precisely, the functional part of the instrument - is inserted into the bead mass. Residual liquid on the surface of the instrument is rapidly heated to 250Â° and the very nature of the bead matrix arrests sputter- ing thus avoiding generating aerosols of bacteria.

In order to dispel concern that such units were not effective a typical unit was submitted to a series of simple experiments involving members of the oral microflora and also a 'marker' bacterium - S ( f ~ t ~ t / a marcescet 1.s

Materials and Methods Four representative instruments were selected for this study. They were a :

Fig. 1

(a ) Matheiu needleholder (RMO), (b) ligature cutter (RMO), (c) distal arch cutter (ETM), and d ) a bird beak plier (RMO).

Each i n s t r u m e n t i n t u r n w a s immersed in a broth derived from several mouth rinses using plain tapwater. This was topped up with distilled water in a beaker to a depth of 6cn1. The handles of each instrument were not submerged in the broth and were used to open and close the jaws of the instruments several times. Excess liquid was allowed to drain from the surface of each instrument which was then subjected to the heat treatment as described above. The following time periods were used, in order: -OS (control), LOS, ?OS, 30s, 1 min. 2 min. and 4 min. The instrument was then allowed to cool t o room tempera ture and attempts were made to isolate viable

bacterial cells from the jaws and hinge area of each instrument. The process was repeated twice for each of two different methods of isolation.

Firstly, the treated end of the instrument was soaked in a solution of glucose broth with bromocresol purple p H indicator. The instrument was then agitated to loosen viable cells from its surface. Each instrument was treated twice at each treatment time and the vials were then incubated at 25' for 48h. At the end of the incubation period vials which had received viable inoculum contained a cloudy bacterial suspension and the colour of the broth had changed from redlpurple to yellow. Vials which were still sterile were red/purple.

One set of vials constituted the con- trols. They were shaken with an untreated instrument which had been dipped in the inoculum.

Secondly, after the end of the treatment process the jaw areas of each instrument were rolled in soft Nutrient Agar in

a Petri plate. Where the agar had been breached clear outlines of the jaws and part of the hinge areas could be seen. All plates were incubated inverted a t 25Â° for 4811. A negative result, i.e. non- sterilization of the instrument was taken as the presence of one or more colonies of bacteria around the impression zone in the plates. These zones were checked using incident and transmitted light using a Wild stereomicroscope at X150 magnification.

All of the above trials were repeated using an axenic culture of Serratia ruascescefis as the source of inoculum and peptone gylcerol agar (PGA). This bacterium, when grown on PGA produces intense red pigmented colonies due to an abundant production of the pig- ment prodigiosin. Such colonies, even when very small, could readily be seen under the stereomicroscope whereas the hyaline colonies of some members of the oral microflora were sometimes hard to see.

Results

Presence of viable bacteria after heat treatment on all instruments tested.

Duration of Oral Sen'atia treatment microflora marccsc cns

nil X X X X

10s X X X X

20s X - - - Ws - - - -

1 mm - - - 2 mm - - - - 4 min - - - -

( X = viable colonies isolated, - = sterile)

Discussion T h e chemical sterilization of dental instruments is a comon practice with a range of chemicals being used. Aqui.'oiis benzcilkoniuni chloride is widely used but it has severe limitations in penetrat- ing organic debris, is easily inactivated and lacks t~iberc~ilocidal and broad vir~i- cidal activity. Other agents sugh as gluteraldehyde and hypochlorite solutions also have disadvantages although they are still commonly used. Alcohols are generally much more reliable but still must be replenished regularly to maintain an effective concentration.

Instruments are readily sterilized by autoclaving or by dry heat in an oven. The method reported here is essentially ii small compact 'oven' which will effectively sterilize the surfaces of instruments in a short time. Since it is not necessary to heat all of the instrument to the required temperature a period as short as 30 seconds effectively sterilizes the functional parts of instruments. A period of one minute would give extra assurance of sterility and, in trial, did not heat the handles of the instruments sufficiently to cause discomfort.

General References CRAWFORD J.J. ( 1983) Sterilization, Disinfection, and Asepsis in Dentistry, in, 'Disinfection Steriliza- tion and Preservation', ed. BLOCK S.S., Lea and Febiger, Philadelphia.

Rewired for publicatior/, J I 1992

A NEW CONCEPT IN THE BEGG TECHNIQUE: THE SEPARATE ARCH SYSTEM

AUTHOR Yoshinar~ Ashikar~, D.D.S., PhD, Nagoya, Japan.

he author reports on the Separate Arch System (SAS) he has devised by adapting basic Begg Technique concepts in the light of his clinical experiences. SAS, a multi-bracket arrangement using reverse light wire brackets, is a method of initiating orthodontic movement in the anterior and posterior segments separately, but completing them at the same time. The method's features include: a) use of thinner wire in segments and in multiple strands, as needed, maximis- ing benefits of light force and differential anchorage; b) one-point rigidity in the wire-bracket relation; c) the method can be applied in both extraction and non-extraction cases; d) the patient's home care is simplified; e) the method is quick, simple, and systematic (thus making estimation of a therapy goal possible).

Key Words Light wire, reversed bracket, Separate Arch System SAS.

Introduction From the time the Begg technique was introduced to Japanese orthodontists by Enoki,'" it has occupied a special niche in orthodontic practice; as far as technique is concerned, it has established itself as the basic theoretical method.3 There have been modifications of the pure Begg technique itself, by, fo r example , Kesling4 and Kameda.> In spite of this, there can be no doubt that the value of the original pure Begg technique has not been diminished thereby, and, generally speaking, it stands even today as something of an absolute (see Fujimoto6 and Sakai7).

This article reports a refinement that the author has devised after years of practising the pure Begg technique: a refinement that he calls the Separate Arch System, or SAS. The Separate Arch System takes into account the goals of orthodontic treatment, standardises and stabilises anchorage at each and every stage, and pinpoints where the anchorage should be. It can be used in either extraction or non-extraction cases. The use of lighter, thinner wires results in less painful, and yet more effective, orthodontic movement. Results over several years have confirmed SAS's efficacy.

Technique 1. Definition

The Separate Arch System is a system of conducting orthodontic treatment by partitioning the dental arch into an anterior segment and a posterior segment. The movement period is normally divided into three stages (sometimes after-Stage I11 treatment is required):

a) Stage I

1) Improvement of the overbite of the anterior teeth;

2) E l i m i n a t i o n of c r o w d i n g in anterior teeth;

b) Stage I1

1) Elimination of displacement in posterior teeth;

2) Establishment of occlusal relationship in posterior teeth;

c) Stage I11

1) Harmonizing of maxillary and mandibular dental arches;

2) Uprighting of all teeth.

2. Materials

a) Brackets

T h e brackets a re reversed, that is, attached "upside down", with the bracket slots opening incisally. Their positions are calculated from the incisal edges of the relevant teeth, normally as follows: upper central incisors, 4.0 mm; upper lateral incisors, 3.5 mm; lower incisors, 4.0 mm; canines, 4.5 mm; and premolars, 4.0mm.9 Mesio-distally they are centred, except for the lower canines, which can be positioned 0.5 mm me~ia l ly .~ High profile type brackets are used for the upper lateral incisors, and normal brackets for the rest.

Brackets are set upside down for the following reasons: a) even under biting pressure, the wires will be held firmly in place by the brackets; b) the brackets and wires can be tightly ligated and locked in place; and c) the operations of setting and removing wires, as well as mounting auxiliaries. are made easier.

b) Buccal tubes

For the first molars 5-mm-long flat oval tubes with hooks are used, while round or rectangular tubes are used for the second molars. They are positioned 4.0 m m from cusp points.

=+-===+ +-+=+1

Fig 1.1, 11, and 111 wire pes . I is one wire, 11 is two wires, IIIis three wires: ' ~ l n s x " is+ I in this instance.

c) Wires

T h e wires used are: anterior wires (0.012- 0.014-, and 0.016-inch Aus- tralian wire of at least special plus hardness; posterior wires (0.016-inch Aus- tralian wire of at least extra special plus hardness); anterior k-type wires (so called because of their shape) (0.016-inch Australian wire of at least extra special plus hardness); and plain arch wires 0.012-, 0 .014- and 0.016-inch nickel titanium wire, and 0.014-inch Australian wire of at least extra special plus hardness). From one to four wires are used in each segment at each stage. Basic wire combinations are identified as types I, 11, and 111, each with a "plus X" factor to allow for additional wires (Fig. 1)

154 d) Coil springs

Used to connect the an te r io r and posterior wires, open or closed coil springs are chosen, depending on the diameters that result when anterior and posterior wires are placed one on top of the other.

e) Pliers used for wire bending

Ohno-type arch-forming pliers (Mitsuba O r t h o Supply Co.) (Fig. 2 ) ; arch- contouring pliers; Tweed arch-bending pliers; light pliers (with side groove).

Fig. 2. O h o arcb-formi?zgpliers. Because they are light wirepliers at the tips and can also be used as arch-contouring pliers lonw dozi'ti, they an' coinvriiefit; other wires with thesame /1/tictions can, however, be substituted. With these it ispossible to make an arc and hook at the same time.

Fig 3 Wire bending of the anterior and posterior wires

3. Wire Bending

a) Anterior wires (Fig. 3)

The distance between the distal ends of the canine brackets is measured, and to this is added 24 mm; this is taken as the tentative length of the wire. When crowding is present, length is determined by estimating what the length will be after the crowding has been eliminated.

The arch form is bent to match the ideal arch form desired at thecompletion of orthodontic treatment. An arch symmetry chart (e.g., Forestadent, Unitek) may be used for reference (Fig. 4). Ohno arch-forming pliers are suitable.

b) Posterior wires (Figs. 3, 5 )

Light wire pliers are applied about 3 cm from the distal end of a straight 11.5-cm wire, the wire is bent back, then another bend is made 6 m m from the first, so that the wire crosses over itself. Here it is wound one turn round, to produce a hook, and cut. At the mesial end the wire is cut 7 cm from the double-back end.

One wire is wound clockwise, the o t h e r counterclockwise. T h e y a r e adjusted to the buccal tubes in such a way that, as much as possible, play is eliminated. The doubled-back wire end section is given a horizontal curve with

% 4. Arch s\'tnmetr\' chart. There are differ etices in arch form, depending on the maker, so one h a s to choose the chart that is suitable.

Ohno arch-forming pliers (to give it toe-in).

c) Anterior k-type wires with AK hooks

Use is made of 0.016-inch extra special plus or 0.016-inch premium plus wire that has been bent in conformity to an arch symmetry chart (Fig. 4). After the distal end (C point) of the canines and the mesial end (M point) of the buccal tubes of the first molars are measured, a wire size chart is made (Fig. 61, and the wires bent in accordance with this chart. A "wire bender" (Green Cross; see Fig. 7) is convenient at this time.

To form an anterior k-type wire with hooks (Figs. 8, 9), put the flat surface of Ohno arch-forming pliers onto C point and bend the wire at a right angle; then, using the step in the pliers, bend it into another right angle, distally. From that position rotate the wire up and around along the round surface of the pliers, to form a circle hook.

Pig. 5. Double-back arch wire I'posteriorwird with a hook. Fig. 1 7shoirs aphotograph of this wire.

Fig 6. Wire size chart

Fig 7 "Wire bender"and antertor k type wire hare been adpisted Marks have been made for length measurements

Fig. 8. Method of making anterior k-We wire andAKhook Thephotograph s h i i ~ ~ an anchorage arc (Fig. 24) added.

Next, 5 mm from the first right angle, bend the wire horizontally to be on a line with the rest of the straight wire.

The conventional routine calls for the hooks to be inserted in front of the canine brackets, but better results are achieved by inserting the hooks as AK hooks bent distally from the canines. The advantages of using AK hooks are: they can be matched up accurately with the distal ends of the brackets at the time they are being made; it is easy to hang elastics onto them and to mount and remove the wires from the brackets; and the elastics do not slip off, hence can be left on even when eating.

When an intermaxillary elastic is used in conjunction with an AK hook (Figs. 19, 23), the added effect of the elastic is that, between the upper and lower wires in the posterior segment, the adduction of the part being pulled works to offset buccolingually the eversion of the part pulling. As a consequence, the anterior k-type wire just needs to be made so that it matches the ideal dental arch.

4. Wire Retention

Various methods of wire retention are used. These are:

a) Lock pin: conventional lock pins are used to retain the wire in the brackets.

b) High hat 0 ring (Fig. 10): high hat safety pins are inserted into the brackets in reverse, and the wire is held in place with 0 rings (Lancer, 0.0125 inch). It is possible to hold the wire in place very tightly, so that there is no play in the wire and slot. These rings are used mainly for the incisors. The arrangement is particularly effective for joining adjacent surfaces of individual teeth.

c) (Super) high hat ligature (cross) (Fig. 11): retention is effected by means of a ligature (0.011 inch) in place of the 0 ring.

d) Tpin uprighting (Fig. 12): involves use of a Tpin in conjunction with an uprighting spring. (A hook pin can also be used instead of a T pin.)

e) Twist-torque (Fig. 13): used for torque on individual teeth.

f) High hat (rotation) Tpin (Fig. 14): involves use of Tp in in conjunction with a high hat pin; easy to attach intermaxillary elastics and vertical elastics. The high hat pin is adjusted slightly.

Fig. 9. Two t}pes ofAK book.

Fig. 10. High hat 0 ring.

Fig. 11. Left: high hat ligature; centre and right: high hat ligature (cross). The upperpart o f the photograph shows a super high hat pin being used.

F&. 12. Tpin uprightitig.

Fig. 13. Twist-torque

e

Fig 14. High hat (rotation Tpin.

F&. 15. Bypcm ligature

Fig 16 Tpin l<qatzire

g) Bypass ligature (Fig. 15): used for retaining type I1 wire.

h) Tpin ligature (Fig. 16): used for retaining type I1 wire. A lock pin can also be used instead of a Tpin.

i) Retention of posterior wires (Fig. 17): a double-back end is inserted into an oval tube with a hook and held in place by an Oring (Tomy, separating module).

5. Elastics (Fig. 18)

A variety is used, including Class I1 and Class I11 elastics, check elastic^,'^ and vertical elastics (Fig. 19).

6. Stage I

Commence by using a type 111 wire or I11 + 1 wire (Fig. 20). Brackets are attached to incisors and canines. For the anterior wires 0.014-inch Australian wire (special plus or higher) is used. Sometimes 0.012-inch nickel titanium wire is added. For the posterior wires 0.016-inch Australian wire (extra special plus or higher) is used.

The double-back ends of the posterior wires are inserted into the buccal tubes on the first molars, and adjusted so that the hooks end up on the buccal side, with the round loops of the hooks close to the cervices, and the tips of the hooks point- ing crownwards.

One must note where the straight lengths of wire cross the distal ends (C points) of the canine brackets, and judge whether one wants intrusion or extrusion of the canines, or simply to leave them as they are; when one decides on the C points that will produce the ideal occlusal surfaces, one bends the wires to the calculated degree, giving them anchorage beds vertically at a place slightly mesial of the hooks on the doubled-back wire ends, using pliers within the mouth (optical pliers or intraoral adjustment pliers, double-sided) and making sure the left and right sides have the same angle. (Normally, when trial testing is done within the mouth, anchorage often works effectively even without an anchorage bend, and in such cases no bend is needed. Two to three months after the wires are fitted the movement of the teeth can be checked, and, if anchorage is weak, additional bends of 5' each time can be made.)

The posterior wire is removed from the mouth and joined to the anterior wire with 0.030-inch-diameter closed coil

Fig 17 Method of retainzngposterzor zi1ire

Fig. 18. Ways of using elastics. Photograph shows Class II elastic in Stage I.

springs. Two closed coil springs of 1-mm length are used for each connection (8, therefore, for the whole mouth).

The distal ends of the anterior wires and the mesial ends of the posterior wires are bent into round loops, using light wire pliers. The finished type I11 wires are placed into the mouth, lining the posterior wires up with the canines and first molars, and the anterior wires with the incisors and canines, and then fastened. The distal ends of the anterior wires are rolled into circles and cut (roll- up cut). A length ofthree to five mm. of

Fig. 19. Various ways of putting on elastics. Photograph shows Class II elastic in Stage

posterior wire is left at the mesial ends of the canines, cut (M cut) and bent inwards.

When crowding is severe, the wires are doubled by adding 0.012-inch nickel titanium wire to the anterior wires. Nothing is added to the closed coil springs, however. Later, when crowding has been removed, the anterior wire

Fig. 20. Basic form of type III wire; used in Stage I.

alone is used. In non-extraction cases, the mesial ends of the posterior wires are cut longer, after estimating how much length will be needed once crowding is removed.

At the time the wires are fitted in the mouth, the closed coil springs are brought to the distal part of the canines, but as occlusion improves it is better to move one of the two closed coil springs toward the mesial side of the canine brackets. In the beginning ordinary lock pins are used, but it is good to gradually replace the incisor lock pins with high hat 0 rings, and the canine lock pins with high hat ligature (cross) or rotation Tpins. The roll-up cuts and the M cuts must be checked and adjusted at every visit of the patient.

Intermaxillary elastics are attached to the circle hooks at the distal ends of the anterior wires and to the buccal tube hooks on the first molars. The elastics do not require removal during meals.

The above routine is followed until there is improvement in the overbite and overjet. In cases in which the canine occlusal contact has improved but with insufficient improvement in the incisors, either a bend is added ("anterior bend") vertically between the upper lateral incisors and canines and between the lower lateral incisors and canines, or the anterior wire is changed to 0.016 inches. Normally the anterior bend can be added directly within the mouth.

There is no change in the occlusal relationship of the molars during this stage.

In non-extraction Class I1 or I11 cases, it is advisable to have the coil springs used for connecting the anterior and posterior wires equal in length to the distance between C point and the mesial end (M point) of the oval tubes on the first molars. One can then pass the anterior and posterior wires through the spring one over the other, make a hook at the mesial end of the posterior wire, and use it to hook up an intermaxillary elastic; this makes it possible to move the first molars distally.

A trial test of the Stage I wire within the mouth is needed only once, when the posterior wire is given an anchorage bend.

Fig. 21. Basic form of type II wire; used in Stages II and III.

7. Stage I1

Stage I1 is alignment of the posterior teeth and begins after alignment of the anterior teeth is completed.

Type I1 wire is used (Fig. 21).

Normally a 0.016-inch anterior k-type wire of extra special plus grade or higher is used, together with a plain arch wire of nickel titanium wire, normally 0.016 inch, which can be activated with a tip- back bend and molar offset as required, Special plus or higher grade 0.014-inch Australian wire can also be used. When displacement in the posterior teeth is severe, treatment can begin with 0.012- inch wire for both the anterior k-type wire and plane arch wire.

Both wires are checked against the wire size chart (Fig. 6), the lengths are measured, and then they are mounted and fastened with lock pins. The lock pins used are: for the canines, rotation Tpins or high hat ligatures; for the incisors, rotation Tpins or high hat 0 rings; f o r ~ h e premolar section, a Tpin at 90' fastens the plane arch wire. Even when the wire must be extended to the second molar, only a plain arch wire is used.

In extraction cases, differential orthodontic force is used to advantage. When it is desired to move the posterior teeth forward, the canines are connected with the second premolars by means of elastomeric modules and the teeth are moved

one at a time. When it is desired to move anterior teeth distally, the second premolar and the first molar are made to provide the anchorage (Fig. 22). Slightly stronger intermaxillary elastics than those used in Stage I are used in this stage (Fig. 23).

Stage I1 ends when the extraction spaces close up, d i sp lacement i n the posterior teeth is eliminated, and the occlusal relat ionship is firmly established.

One activates the anterior k-type wire by the addition of an anchorage arc (Fig. 24) , which is made at the distal end of the AK hook. In non-extraction cases, a 10' arc is produced by pressing and bending with Ohno arch-forming pliers. In cases where a premolar has been extracted, a

M 10' arc is produced by using arch- contouring pliers. With this serving as a guide, adjustments can be made so as to obtain the angle desired (Fig. 25).

Because the anchorage arc makes it possible for anyone, at any time, to give the same shape to a wire, uniform effects can be expected. It is also possible to record and keep the wire sizes. Some basic research remains to be done regarding the mechanism involved, but it seems clear there is a proportion between the

length of distance of the wire and the strength or weakness of the anchorage. As far as manipulativeness goes, one of the features of this arc is that, once the wire is mounted, there is little need for removal and adjustment.

8. Stage I11

Commence this stage with the type I1 wire. By the end of Stage 11, overjet, overbite, and the occlusal relationship have been corrected. When a greater torque to the nickel titanium wire is desired, a twist-torque technique (Fig. 13) is used. Molar offsets are incorporated. Lock pins can be changed from 90' T pins to 10' T pins in order to achieve overuprighting, and invidividual teeth can be adjusted.

9. After Stage I11 (if required)

Type I wire (either round or rectangular) is used and the conventional Begg method is followed. The anchorage bend is increased by 15'.

Annealed wire can, if desired, be cut and passed through the first-molar oval tube and fastened, so as to reduce the size of the lumen to that of a single tube.

10. Cases

1) Extraction case (Figs. 26,27,28,29-1,29-2, and Chart 1).

Angle Class I, maxillary protrusion, deep overbite, extraction.

Age at first visit: 15 years 3 months (male).

Chief complaint: maxillary protrusion and crowding.

Family history: nothing significant.

Facial impressions: impression of protrusion in upper lip when lips closed.

Occlusal impressions: severe protrusion of upper front teeth, producing deep overbite; lower front teeth touching the lingual cervical area. On both sides the first molars had Angle Class I occlusal relationships, while the canines exhib- ited an Angle Class I1 relationship. Over- jet was 6.5 mm, overbite was 4.5 mm, and midline deviated 1 mm. to the left side. Slight crowding in both jaws.

Panoramic x-ray photograph impressions: all teeth vital, except third molars, which were imbedded.

Roentgenopgrahic cephalometr ic analysis impresseions: SNA +lS.D. , ANB +2S.D., maxillary protrusion with

Fig. 24. Anchorage arc. Photograph shows an anchorage arc and an arc made in a wire, 'superimposed.

L Fig. 25. Graph showing combinatiot~s of anterior k-bipe wire and various sizes of anchorage arc (unit = mm). When the start- ing point of the AK hook is taken to be 0, the formula for finding the midpoint of each arc":

6

(x is vertical axis, j3 the horizontal axis). X= 9 or less in extraction cases, X= l0 or more in ~onextractiofi cases, X= 9 comes out as an arc of the same size as that formed b } ~ bending with arch-contouringpliers; X = 10, as an arc of the same size as that formed b\' bending with Ohno arch-formingpliers.

Fig 26 l'pper row before treatment, lower row after treatment

maxillary overgrowth, mandibular under- growth; mandibular plane to S N was + lS.D., with appearance of posterior rotation. U1 to L1 was -3S.D., U1 to AP was +2S.D., L1 to SN was -2S.D., accompanied by protrusion of upper front teeth and proclination of lower front teeth.

Diagnosis: crowding; skeletal maxillary protrusion accompanied by wide gonial angle and underdevelopment of mandible; Angle Class I malocclusion.

Treatment policy: upper first premolars and lower second premolars to be extracted; because occlusal relationship of first molars was Class I, treatment of overlapping and protrusion of the front teeth was aimed at improving occlusal plane and tooth axes of front teetch.

Course of treatment:

Stage I (eight months)

Brackets were set in reverse position on incisors and canines. Type 111 wire was chosen; for the anterior wires 0.012-inch special plus was used, for the posterior

wires 0.016-inch extra special plus; for the closed coil springs eight 1 -mm 0.028 inch (RM) were used. Class I1 elastics (75 gm) were used for the elastic threads; when after three months crowding was eliminated, a change was made to 0.014-inch special plus for the anterior wires and 0.030 inch (RM) for the closed coil springs. After a further three months 0.016-inch special plus was used for the anterior wires and 0.032 inch (RM) for the closed coil springs, and an anchorage bend was put in the anterior wires.

Prior to the completion of Stage I an anchorage bend was added without removing the appliance from the mouth.

Stage I1 (eight months) For the first four months 75-gin Class I1 elastics and 75-gm horizontal elastics were used. The extraction spaces in the lower jaw closed, and the extraction spaces that remained in the upper jaw were closed by using e las tomer ic modules.

Stage I11 (six months)

Reverse brackets were set on the upper second premolars and lower first premolars. Type I1 wire was used; 0.016-inch extra special plus wire was used for the anterior k-type wire, and 0.016-inch nickel titanium wire (Lancer, Titanal XR) was used for the plane arch wire; 40' was added to the anterior k-type wire (see Fig. 24) in two steps: first, the end of the wire was given a 30' bend, then this bent section was given a 10' arc. Class I1 elastics and horizontal elastics, all of 75 gm, were used.

Results of treatment

Dynamic treatment period: 23 months.

Facial impressions: both front and side views were improved. Retrogression of both lips was seen, as well as mitigation of overclosure of the lower lips.

Occlusal impressions: after treatment the occlusal relationship of the first molars remained Angle Class I, but the

159

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Fig. 28. @per row: before treatment; lower row': after treatment.

overjet was 3.0mm, and the overbite 1.5 mm.

Panoramic x-ray photography impressions: paralleling of teeth axes, and impaction of third molars.

Roentgenographic cephalometr ic analysis impressions: skeletal changes were few, though there was some diminu- tion in SNA; malocclusion was improved through changes in the occlusal plane and axial inclination.

2) Nonextraction Case (Figs. 30,31,32,33-1,33-2, andchar t 2)

Angle Class 111, crowding.

Age at first visit: 12 years 7 months (female).

Chief complaint: crowding and mandibular protrusion.

Family history: nothing significant.

Facial impressions: facial centre slightly recessed, but still symmetrical.

Chart 1. Roentgenographic cephalometric ana(11sL~ values. Left: before treatment; right: after treatment.

1 Mean S.D. Before After

SNA SNB ANB SN-MP U1-L1 U 1 -SN Ll-MP Ll-AP

Occlusal impressions: crowding accompanied by upper-right canine infra- labioversion. The occlusal relationship with the first molars was an Angle Class I11 on both sides; overbite and overjet were 0 . 0 m m , and the median line deviated 1 mm.

Panoramic x-ray photography impressions: all teeth vital except for third molars, which were imbedded.

Roentgenographic cephalometr ic analysis impressions: ANB -S.D., mandibular plane to S N + lS.D., gonial angle +2S.D.; U1 to S N was + 1S.D., L1 to S N was -2S.D.; also, there was overgrowth of mandible and lingual tipping of lower front teeth.

Diagnosis: crowding accompanied by overgrowth of mandible; Class 111 malocclusion.

Treatment policy: expansion of upper and lower dental arches; encouragement of Class I1 tendencies; acquisition of ample overjet and overbite, as well as establishment of intercuspation.

Course of treatment:

Stage I (ten months)

Begg technique brackets were set in reversed positions on all incisors and canines. Type I11 wires were selected. For the anterior wires 0.012-inch special plus was used, and for the posterior wires 0.016-inch extra special plus; for the closed coil springs eight 1-mm-long 0.028- inch wires were used. By leaving the anchorage bend at 0 Â and using only the first molars for anchorage, the intrusion of the anterior teeth was inhibited. Extremely weak (50-gm force) Class I11 elastics were used, with a view to improvement of overjet and overbite. As crowding was eliminated a change was made in the lock pins to high hat 0 rings for the incisors; the anterior wires were replaced by 0.014-inch special plus wires, and the closed coil springs were changed to eight 1-mm 0.030-inch springs. This procedure was followed until the crowd- i n g a n d a n t e r i o r - t e e t h o v e r b i t e improved.

[ N o Stage 111

Stage I11 (four months)

Reverse brackets were set on the premolars. Type I1 wire was used: for the anterior k-type wires, 0.016-inch extra special plus; and for the plane arch wires, 0.016-inch nickel titanium wire. The

Fig. 29-1. Sl$eri~~It)ositioii of cvphalograms. Solid line: before treatment; broken lino: after treatment.

intermaxillary Class 111 elastics were strengthened for the final three months, from 50gm to 75gm.

Results of Treatment

Dynamic treatment period: 14 months. 161

Facial impressions: frontal left-right asymmetry was improved

Fig 29-2 Snt)(.nmposztzot~ of t~~a~dlar-}' and mandiblilar cephalogmms. Solid line: k fore treatment: broken line: after treatment.

Occlusal impressions: after treatment the occlusal relationship of the first molars on both sides was Angle Class I, with an overjet of 3.0 mm and an overbite of 2.5 mm.

Fig. 30. Upper row: before treatment; lower row: after treatment.

162 Panoramic x-ray photograph impressions: paralleling of all teeth up to second molars; impaction of third molars.

Roentgenographic cephalometr ic analysis impressions: though there were no great skeletal or odontogenic changes, the overbite relationship of the anterior teeth improved as a result of the increase in SNA and changes in the axes of individual teeth.

Summary Experiences with the Begg technique since 1973 and the practical problems

C\J encountered in the course of clinical 0-l

?2 treatment have led to experimentation E with a separate arch system that has m 0 proved capable of satisfactory applica-

g tion. The system is characterised by:

i 1) use of thinner wire, divided into seg- a ments or doubled or tripled as suit- 3

0 able, using to maximum advantage U L

light force and differential anchorage;

2) importance attached to maintaining g one point contact between bracket 0 l- and wire; a 0 3) equal applicability to extraction and z 5 non-extraction cases, and the poten-

2 tial for predicting treatment goals; l- CO 4) the ease with which patients can take Ã‘ a care of the appliance at home.

Concerning clinical practice At Stage I1 it is better to move directly into type I1 wire. At Stage I it happens more often than not that one can begin with type 111 + 1 wire (Fig. 1) -that is, with an anterior wire of 0.014inch plus an additional wire of 0.012 inch - rather than with an anterior wire of 0.012-inch special plus.

Closing of extraction spaces is done with elastomeric modules. For intermaxillary elastics the weakest possible elastics are used. Sometimes, though in- frequently, interdental spaces and extraction spaces can be produced in the course of treatment; in such eventualities, the spaces are closed by using elastomeric modules and ligature 8 ties for the incisors and canines, and ligatures for the canines and premolars.

The angle that was given to the anchorage bend in Stage I is carried over in Stages I1 and I11 by giving the same angle to the anchorage arc. During Stages I1 and 111, any anchorage insufficiency is remedied by adding a V bend to the plain arch wire (without removal from the mouth).

Wire rationale In Stage I, when type 111 wire is used, making a hook at the distal side of the

canines reduces the antagonistic action against the intrusive force of the anterior teeth when Class I1 and Class I11 elastics are used. That is, the more the hooks on which one hangs the elastics are placed on the mesial side of the canines, the more the reciprocal actions of vertical and hor izon ta l o r thodont ic forces decrease (Fig. 34).

By having the anterior and posterior wires of different thickness, advantage can be taken of the vertical-oriented force acting on the anterior teeth, using it as a differential force. That is, the force of the molar segment can be applied to the anter ior teeth individually and separately. Thus, one can change, very effectively, the force applied to the canines, the lateral incisors, and then the central incisors, in order. Also, the teeth can be moved with a weaker force.

By separating the wires into anterior and posterior segments, the orthodontic force of the anchorage bend towards the distal end of the molars and the orthodontic force resulting from the expansion of the anterior teeth do not counteract each other.

Because the position of the anchorage bend remains unchanged and fixed, the anchorage bend is effective.

A NE

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fig 32 ipper rout before treatment lower row after treatment

Fig. -33-1. Supt>rifnposition o f cephalugrams. Solid line: Iwfore treatment; broken line: after a treatment before treatment, broken line after

treatment

5 Fig. 34. [pp(-r left: iiztriisiiv Jorce of anchorage bend a'lorie. Lower left: irztrnsuvforn' of miivntiorial intvmiaxi!!ar\! elmttc, m e 1 0

2 ii'ire. 'pper centre: analysis of operations o f i wtical and horizontal forces when type 111 wire (split wire) is used. Lower centre: graph o f operations o f the various orthodontic forces. oc

2

0 ksiitning it takes about 20gm to bare EFdisplaced to IF, then for GF to more to HF ~i~o; / ld require about 60gm, and the forces 2 i.c~cluired to bring about U displcicetrzetzt o f EF atpoint G as far as CD a s we'll as AB would be f O p a n d 3 0 p , re\pectidy 11n other l- z wo~ds. with separate uires, both irztr;isive Jorce andpu~lling forces arc increased. 0

Chart 2. Roeutpcigr~q~L~ic cephaloinetric analysis rubies. Left: before treattt~c~~zt: r ifbt:

after treatment.

Mean S.D. Before After

SN A SNB ANB SN-MP U1-L1 U l -SN L1 -MP L l -AP

By using double wire from Stage I1 on, it is possible to divide the functions of drifting between the anterior and posterior teeth. In addition, use of type I1 wire makes it possible to maintain the labiolingual position of the front teeth.

Conclusion The above is a report on the Separate Arch System devised after several years of practising, and reflecting upon, the fundamental concepts of the Begg Tech- nique. SAS involves a multi-bracket appliance that makes effective use of reversed light-wire brackets, and follows a method of beginning orthodontic migration by dividing the teeth into an anterior and a posterior section, and then of completing both sections at the same time. The author is confident that SAS is a method of orthodontic treatment that can be satisfactorily applied in daily clinical practice in addition to the conventional, established Begg Technique.

References 1. Enoki K. Notes on Begg's light arch wire

technique. Shigaku [Odontologyl 1962; 49(4): 225-50. [in Japanese]

2. Enoki K. On Begg's light arch wire technique. Shikai Tenbo [Dental Out- look] 1964; 23(1): 1-27. [in Japanese]

3. Enoki K. et al. Beggu-ho - sono kihon jutsushiki to rinsho [The Begg technique: Its basic technique and clinical practice]. Tokyo: Ishiyaku Shuppan, 1980.

4. Kesling, PC. Begg technique guide with ribbon arch type appliances. Westville, Indiana: Swan Advertising, 1987.

5 . Kameda A. Beggo-ho no subete I, kairyogata Beggu-ho [All about the Begg technique, I: An improved Begg technique model]. Kyoto: Nagasue Shoten, 1988.

6. Fujimoto M. Two cases of adult orthodontic treatment. Beggu Kyosei Shika Janaru [Japan BeggJ Orthod] 1990; 1:27- 38. [in Japanese]

7. Sakai N. Reappraisal of the Begg technique. Beggu Kyosei Shia Janaru (Japan Begg J Orthod] 1990; 1:5-10. [in Japanese]

8. Ashikari Y . Cases of treatment based on the Begg technique: Thoughts about overcorrection. Kyosei Rinsho Janaru [I Orthod Practice] 1989; 5(7): 59-69; 5(8): 59-74. [in Japanese]

9. Sakai N. The Begg technique IV. Kyosei Rinsho Janaru [J Orthod Practice] 1988; 4(6): 41-50. [in Japanese]

10. Cannon JL, Thompson WJ. Combination anchorage technique: A manual of philosophy, diagnosis, design and technique.

Reprint requests Reprint requests to:

Dr Yoshinari Ashikari Toyota Dental Clinic 2-88 Kitamachi, Toyota City Aichi Prefecture, 471 Japan. Phone (from Australia): 0011-81-565-32-6568

Councillor, The Japanese Begg Society; member, Japan Orthodontic Society; regular member, North American Society for the Study of Orthodontics

Received for publication, March 1992.

A PROCEDURE FOR ATTACHMENT OF GOLD CHAIN FOR TRACTION OF IMPACTED TEETH

AUTHORS Sheung K Kaan BDS, MSc, DDO, MD0 RCPS and GekKiow Goh BDS, MDSc, Singapore.

improve the strength of the attachment of the gold chain to impacted teeth. Dislodgement of the gold chain requires a second surgery for reattachment. Failures have been observed to occur at two interfaces. The authors have devised a method of attaching the gold chain to the mesh pad securely, by ligating them together. This article describes the method and discusses other factors which enhance the retention of the gold chain to the impacted tooth.

Key words Impaction, canines, incisors, active traction, gold, bonding.

Short Title Attachment procedure.

Department of Orthodontics, Government Dental Clinic, First Hospital Avenue, Singapore 031 6,

Introduction The palatally impacted maxillary canine and the ectopic incisor often require some form of guidance or traction in their eruption into functional occlusion. In the management of impacted teeth, a correct diagnosis of the 1ocation'~j and angulation is essential for their successful eruption. This, together with their rela- t ionship to surrounding teeth and o b ~ t a c l e " ~ will determine the direction of approach and traction.

Literature Review Active traction of unerupted teeth has been indicated in the following situations:

1. teeth in a high palatal location 2. teeth developing in a n ectopic

position 3. teeth impacted by odontomes, mesio-

dens, cysts and ankylosed decidious teeth, where it is convenient to place a traction device during the surgery for the removal of the obstruction.

In all of the above examples, there is a need for active traction, rather than relying on residual eruptive force, once past the normal age for eruption of the impacted tooth.

Radiographs are required to establish t h e a e t i ~ l o g y ' ~ ~ ~ ~ and t h e accurate location1^ of the impacted tooth. Various methods of management of the impacted tooth, namely, surgical exposure of the crown: transplant, excision, removal of o b s t r u c t i o n , fol lowed by pass ive eruption7 or active traction into position of functional occlusion,6 have been documented.

C The earliest reports on traction employed eyelet wiring inserted into amal- gam fillings in the impacted tooth; pins or screws with hooks attached embedded

into the tooth6; silver caps cemented on to the crown; and stainless steel ligature lassooed around the cervical margin of the tooth. Lassooing is often associated with excessive removal of bone during surgical exposure of the crown and resorption around the area of tension.' Traction method included stainless steel ligatures, gold and elastomeric chains.'

With the introduction of BisGMA composites, bonding was incorporated into the procedure of attaching the traction devices to the unerupted tooth using mesh pads.'.5 Failures associated with the gold chain procedure often occur at two interphases.

1. between the mesh pad and the enamel surface, i.e., bonding failure

2. at the joint site between the gold and stainless steel mesh pad.

Bonding failure could be effectively reduced with adequte isolation of the field and complete polymerization of the adhesive.

On the other hand, joint site failure is usually due to attempts to weld or solder two dissimilar metals. During welding, gold, which has a lower melting point than stainless steel, tends to melt around the mesh pad forming a purely mechanical bond. Fusion between these two metals seldom occurs. Weakening of this joint may result from corrosion and excessive manipulation. Attempts at improving joint strength by soldering gold chain to the mesh pad brings about its own problem of poor histocompati- bility between tissue and corrosion products of the silver solder used. Union by heating also tends to anneal the s u r r o u n d i n g metals , c h a n g i n g its physical properties.'

The author has devised a technique to securely s t rengthen the mechanical

attachment between the gold chain and the mesh pad, without soldering or affecting the mechanical strength of the two materials.

Procedure 1. Attaching the gold chain t o the stainless steel mesh pad. The objective is to create a secure but less stress-prone joint between the gold chain and the mesh pad. A 2cm length of at least 18K gold or gold-plated chain, - 1 . 5 m m thick, is required. The chain is composed of complete individual links, rather than just being pinched together, but the links should be sufficiently wide to permit passage of a 0.25 mm ligature wire. The author uses an open mesh pad manufactured by Dentaururn (799-102C) measuring 3 mm by 2.5 mm.

To avoid the problem of joining two dissimilar metals, the gold chain is ligated to the mesh pad instead of being welded or soldered on to it. Two holes are pricked in the centre of the mesh pad about 1 mm apart with a probe to allow for passage of an 0.25 mm ligature wire (Fig. 1). One end of the gold chain is

ligated to the mesh pad and secured by twisting the ligature ends into a short pigtail (Fig. 2). The end is secured to the mesh pad by welding to one corner of the mesh pad (Fig. 31, leaving the central area intact. To facilitate threading of the free end of the gold chain through the surgical site, a 3 cm long ligature pigtail is fashioned (Fig. 4). T h e attachment device is then sterilized chemically in preparation for the surgery.

2. Effective bonding of mesh base t o surgically exposed enamel. The objective is to ensure a more complete polymerization of the adhesive and reduce the bulk of the bonded mesh pad.

Thorough irrigation with distilled water to clear the etched enamel surface of salt deposits prior to bonding, is recommended. However, this must be done carefully and slowly, with a syringe, as hypotonic solutions can cause tissue damage. Precise positioning of the suction tip would ensure sufficient dry- ness of the etched surface and prevent exposure of tissues to the distilled water.

Ul t ra - sure* l igh t cure b o n d i n g adhesive is used to bond the mesh pad

Fig. 1. Dentaurum 799-102C meshpadprepared with 2 holes 1mm apart. Closed links 1.5mm thick 22Kgold chain.

Fig. 2. 0.25rnm SS ligature is used to secure gold chain to the mesh pad.

to the etched enamel surface. The mesh paid is adapted to the curvature of the exposed tooth surface just prior to bonding. The material is added in small precise amounts with all excess removed between light curing intervals, especially around the links of the gold chain.

The bonding is tested with a good tug prior to suturing up of the operation site. The excess links are cut, leaving 4-5 links free for subsequent traction. Traction is not advised until after the removal of stitches.

To date, this procedure has been used on fifteen patients and there have been no detachment failures reported.

Discussion There are several advantages with this technique:

1. The Dentaurum mesh pad is preferred because its mesh is finely woven leaving the edges well trimmed and smooth. It is sufficiently small for bonding on to the small area of exposure on the impacted tooth and soft enough to allow for on-site adaption to the area of tooth exposed. T h e open mesh permits light cure

- Fig. 3, Tag of ligature welded to a corner of the mesh pad. 6

z

<.-)

Fig. 4. A3cm long ligature pigtail attached to the free end o f the g Q-

gold chain as a threader. Â¥s

Fig. 5. A 3cm long ligature welded to a corner of the Fig. 6. The ligature joints allow free movement o f the mesh pad

adhesive to be used. It also allows for ligation of the gold chain, thereby obviat- ing the need for high temperature welding or soldering as when compared to using rigid backed base. The gold chain is mechanically tied to the mesh pad and welding occurs only between the stainless steel mesh and the ligature tag. The mechanical strength of the mesh pad is not affected as welding isdone only at the corner of the mesh pad, away from the ligation site.

2. The stress-breaking structure of the ligature joint and gold chain links, together with more complete polymerization, allows for a smaller mesh pad to be used. Thus, only a small surface area of the buried tooth need to be exposed and tissue disturbance is kept to a minimum. By not securing thegold chain too rigidly to the mesh pad, adaptation for a different direction of traction is permitted, even after bonding (Figs 5 , 6). Ligating rather than soldering the gold chain to the mesh eliminates histocytoxicity of silver corrosion products from the solder, which could cause staining of gingival tissue upon eruption.

3. The use of low-filled light-cure resin, *Ultra-sure light-cure bonding adhesive, is recommended for three reasons.

Firstly, the rapid polymerization during light curing reduces the risk of contamination from blood and tissue fluid from t h e surrounding tissue. Secondly, a more complete polymerisa- tion of the light-cure resin is enhanced," if applied in relatively thin layers and when the illumination time is i n ~ r e a s e d . ~ The material can be applied in precise amounts with minimal excess. Thirdly, the absence of free residual monomer and the smooth contour is more histocompatible with oral tissues. This low-

gold chain

filled light-cure composite leaves a smooth and glossy surface over the mesh pad when it sets with complete polymerization. This has a distinct advantage over the chemical-cured composite which may cause adverse soft tissue reaction as a result of reported leaching of its residual m o n ~ m e r . ~ The lower abrasion resistance of the low-filled resin is not a clinically significant factor in this situation. Although it is difficult to sterilize the light source unit to ensure asepsis, disposable sterile sleeves should eliminate this problem.

Conclusion This method of ligating gold chain to the mesh pad enhances its attachment to the tooth.

It allows for a small thin pad to be effectively attached to the tooth with a flexible direction of traction. The use of a low-fillled light-cure resin promotes a s t ronger and more histocompatible bond.

* Ultradent Products Inc.

References Bishara S., Kammer D.D., McNeil M.H., Montagano L.N., Oesterle L.J., Young- quist H.W. (1976): Management of impacted canines, Am. J. Orthod. 69:371- 387.

Cook W.D. (1980): Factors affecting the depth of cure of UV polymerized composites, J. Dent. Res. 59:800-808.

Coupland M.A. (1984): Localization of misplaced maxillary canines. Ortho- pantomograph and posteroanterior skull views compared, Brit. J. Orthod. 11:27-32.

Heys R.J. (1981): Biologic considerations of composite resin, Dental Clinics of N America 25:257-270.

Hunt N.P. (1977): Direct traction applied to unerupted teeth using the acid- etch techniaue, Brit. J Orthod. 4:2 11-2 12.

Kettle M.A. (1958): Treatment of the unerupted maxillary canine, The Dent. Pract. 8:245-255.

Oliver R.G., Hardy P. (1986): Practical and theoretical aspects of a method of orthodontic traction to unerupted teeth illustrated by three cases, Brit. J. Orthod. l3:229-236.

Phillips R.W. (1982): Skinner's scienceof dental materials, WB Saunders Co. 8th edition.

Shapira Y., Kuftinec M.M. ( l 983): Treat- ment of the impacted cuspids. The hazard lasso, Angle Orthod. 5 1:203-207.

Tirtha P,, Fan P.L., Dennison J.B., Power J.M. (1982): In vitro depth of cure of photo-activated composites, J. Dent, Res. 61:1184-1187.

Received forpublication, June 7-9-92

CASE REPORT - SWALLOWED PIECE OF ARCHWIRE AUTHOR B. W. Lee M.D.Sc., Bendigo, Victoria.

I fifteen year old healthy, male patient contacted our office stating that whilst eating a bread roll he had swallowed a piece of orthodontic archwire. He complained of stomach pain and was advised to contact his local medical practitioner who had the area radiographed. The radiographic examination revealed the piece of archwire to be lodged in the pylorus. The patient was then referred to a consultant physician who, using a gastroscope and with the orthodontist present, to assist with supervision of the orthodontic appliance during gastroscopy and to determine that the piece removed had not undergone further fracture, removed the piece of broken archwire.

The piece of wire was forwarded to the Therapeutic Devices Branch of the Department of Community Services and Health for analysis.

Comment The operator has been in orthodontic practice for thirty six years and had not had this happen before. A scanning of the orthodontic literature of the last ten years revealed no other reports of this nature. As the Therapeutic Devices Branch report states, the longitudinal mode of fracture is probably due to the drawing process used in manufacture and not to any defects in the wire. The drawing process increases the elastic limit or yield point of the wire. The wire diameter was 0.014" and the grade was Premium Plus, one of several grades produced by the AJ. Wilcock Company. The break occurred at a point 10 mm. distal to the cuspid hook and therefore was not affected by manipulation. The patient had been advised not to eat any hard or sticky foods requiring heavy mastication, including crusts. This advice had been given in the expectation that it would avoid arch distortion rather than arch wire breakage. The archwire had been in place for ten months and the case was treated non-extraction so that no long spans of unsupported archwire existed which might have facilitated breakage during mastication of hard or sticky foods.

The previous history of this patient's co-operation was relatively favourable for males in their mid-teens but in this instance the patient had bitten on a crusty bread roll against instructions. This patient had had one other breakage of the appliance three months previously - a relatively good record when compared to other males in their mid-teens. However in this instance stresses set up by the forces required to masticate the pieces of bread roll were too much for the a rchwire . T h e choice of a rchwire material and grade should not only be

dictated by the forces required for tooth movement but also by the ability of the wire to withstand masticatory stresses

Report Therapeutic Goods Administration Therapeutic Devices Branch Department of Community Services and Health

Reference: Sample delivered to TDB 14 Febr~1'1t-y 1991 for examination and report.

Product: Wilcock orthodontic stainless steel wire, 0.365 mm diameter.

Sample: A 25 mm length of wire, being part of that recovered by gastroscope after inges- tion by a patient following breakage of an orthodontic appliance.

Test Methods: The fractured ends of wire were examined with an optical binocular rnicro- scope at 40 X magnification and the scanning electron microscopy at up to 2000 X magnification. T h e metallo- graphic cross-sections were examined using an optical microscope by reflected light at up to 1000X magnifications.

W E 3 = U

Observations: U= 4 L 0 1. The binocular microscope did not W

show any useful detail. g m

2 . SEM examination indicated that the o d e cif fracture of each of the two 3 ends was substantially different. One 3

cn end showed evidence of combined -a:

bending with the application of blunt cutters, which produced some splitting of the wire as can be seen in Figure 1.

The other end contained stepped fracture markings consistent with progression of the fracture in small increments by successive applications of bending in the one plane of action. The origin of the fracture cannot be reliably d e t e r m i n e d because of damage to some areas of the fracture surfaces, but the most likely position is seen in the lower

FiQiire 1 Cut end o f wire sample.

portion of Figure 2, adjacent to a

worn region.

3. The splitting of the wire at both ends suggests that there may be longitudinal defects in the wire. Metallo- graphic cross-sections were taken 5mm from each end of the wire sample. Microscopic examination of the sections both as-polished and after subsequent etching did not indicate any cracks or non-metallic defects that would contribute to splitting or longitudinal fracture. Figure 3 shows the structure of the etched cross-sections of the wire. The longi-

tudinal mode of fracture is probably a consequence of the anisotropic properties of the wire produced by a drawing process used in its manufacture.

4. N o evidence of corrosion was found on the wire.

Conclusion: The tests carried out on the sample submitted do not indicate that fracture was due to defects in the wire.

21 March 199 1

Kecezi~d fen- publication, March 1992

Figure 3. Micrographs of etched cross-section of the wire. Figure 2. Fractured end of wire sample. Etchant - acetic//ndrocbloric/'nitric acids with g[ycerol.

REVIEWS

1 I N C 110\1.1 4 P P l U M t S IN OR I HOI~OM'K r R t \ l M I - M

Orton H S

FUNCTIONAL APPLIANCES IN ORTHODONTIC TREATMENT. An atlas of clinical prescription and laboratory construction.

Published by: Quintessence Publishing CO Inc Chicago Available from: Quinessence Publishing CO Inc, Australia Division 209-21 1 Burke Street, Sydney 2000 Australia Price: SUS68

The task of the book reviewer is facilitated by a summary on the back cover. It is headed "About the book", and it reads. .

'This atlas will show clinicians how to prescribe and manage orthodontic functional appliances that will work for their patients and technicians howto make orthodontic functional appliances that will work well for the clinician The atlas explains how clinicians (who may have been trained principally in the use of fixed appliances) can significantly widen the scope of their orthodontic treatments The atlascovers the blending of functional appliances into a fixed edgewise treatment to produce not only good occlusal results but also optimal facial improvements in both moderate and

severe Class II malocclusions. The information given has been harvested during a decade and a half of experience in the busy orthodontic clinic at Kingston Hospital, Surrey, England. During this period many orthodontic trainees have tested both previously described and also newly evolved functional appliance systems against many serious occluso-facial problems The refined treatment techniques that are described in detail, are known to work for average clinicians on average patients on 'blue Monday mornings" as well as "rosy Friday afternoons". Where there are potential clinical problems these are outlined frankly, so that the clinician who reads this atlas can avoid these pitfalls. The atlas also details how each system works, so that the clinician can see which functional appliance is appropriate for the particular Class II problem that is being planned for treatment Specific guidance on appliance design is shown in the extensive and detailed diagrams, and also in easily read note format. Functional appliances can only work well in the clinic if they are made well in the laboratory. The detail of appliance construction is described in an easy to follow, step-by-step fabrication guide. In particular the technician will be able to see what the clinician wants to do and how the technician can make this happen. There is an easy to read wire conversion chart so that the construction diagrams can be used internationally in Europe, The Americas and Pacific countries. This atlas of clinical prescription and laboratory construction of orthodontic functional appliances is intended to improve cooperation and information flow between the clinic and the laboratory, for the benefit of any patient with a substantial Class II malocclusion.

The atlas is appropriate to:

- All experienced orthodontic clinicians seeking to improve their treatmentcapa- bility,

- All postgraduate orthodontic students. - Dental practitioners wanting to under-

stand orthodontic functional appliances. - All dental technicians in training. - Any experienced dental technician who

makes an orthodontic appliance."

In short, the book is Harry Orton's "How to do it my way". It presents, in an abrupt note form with an abundance of should"^ and 'must'k and in the rather dogmatic fashion of a British consultant, what, how, why, and when orthodontic treatment iscarried out in his orthodontic department at Kingston Hospital

The introduction by Professor William Profitt accurately and tactfully summarizes the currently accepted role of functional appliances and informs that Harry Orton has contributed significantly to the

' componentsapproach' to functional appliances

There are five main chapters covering The Frankel System, Expansion and Labial Segment Alignment Appliances Activators Intrusive ' Functional Appliances and The Herbst Acrylic Splint

Each chapter commences with some introductory text which gives an overview of the place of the appliance system within the spectrum of orthodontic treatment The detail of each appliance is shown in clear diagrammatic form and above each set of diagrams the functional component objec- tives of that appliance are listed The opposite page lists the clinical guidelines on the prescription of theappliance as well as the design the clinical records needed and the visit by visit treatment expectations and requirements On the same page the construction guidelines for the technicians are given

No doubt Harry Orton has successfully corrected a large number of severe class I1 malocclusions over the years However one could presume that the treatment techniques described which are claimed to work for the average clinicians on average

patients would on average produce average results Average results might be acceptable in a busy orthodontic department in a British Hospital but they might not be accepted by the average idealist in private orthodontic practice In private orthodontic practice in North America and Aus- tralia for example treatment is usually carried out in two distinct stages When the teeth are irregular and the arches are not coordinated then orthopaedic correction of the skeletal disharmony with a functional appliance is followed by arch alignment and coordination with fixed appliances Occasionally a preliminary stage of upper arch alignment is necessary

Although the title would suggest that the book is about functional appliances a size- able section of the book is devoted to the expansion and alignment appliances used at Kingston Hospital in preparation for functional appliance treatment On the other hand there is relatively little discussion on tooth alignment with fixed appliances despite the author's claim that half of the class II cases treated with functional appliances have the occlusion detailed with fixed appliances

To be critical several of the appliances described in the bookare not true functional appliances For example with respect to the correction of a class II antero-posterior disharmony, the "Maxillary intrusion splint with 'concorde' whisker and Clark type lower traction plate" relies on exactly the same force system as does fixed appliances In both cases the corrective forces

are derived from headgear and intermaxillary elasticsi It could be argued that conventional fixed appliance treatment is

a simpler alternative which offers the additional benefits of arch alignment and level- ling

The layout is rather cluttered and dis- jointed and asection of colour plates which refers to text throughout the book is included at the front of the book The repeti- tion of many design cards on consecutive pages isannoying On a more positive note the key reference list is comprehensive and up-to-date

Being an atlas no attempt is made to explain the theory behind the various components of functional appliances As such this really isn t a suitable book for someone who wants to learn about functional appliances from first principles Nor does the book offer anything particularly new or exciting for clinicians whoalready use functional appliances in conjunction with fixed appliances However the book does fulfill one stated intention by addressing the ways in which communication and understanding between clinicians and technicians can be improved The book is 'a must ' for any clinician or technician about to start ajob in the orthodontic department at Kingston Hospital

David Fuller

Isaacson KG, Reed RT, and Stephens CD FLNCTIONAL ORTHODONTIC APPLIANCES. Published b y Blackwell Scientific Publica- tions Availablefrom' Blackwell Scientific Publica- tions Ltd, 54 University Street, Carlton, Victoria 3053 (03) 347 0300 Price $1 26

This new textbook explains the action of functional appliances and gives guidance on the selection and clinical management of cases

The first chapter outlines the role of func-

tional appliances, reviews their history, and introduces the debate that surrounds their use and mode of action,

Toappreciate the changes which may be brought about by functional appliances, it is necessary to have an understanding of the normal mechanisms of growth The second chapter considers the nature of the human growth pattern and particularly the pubertal growth spurt as it affects the face. The authors recommend serial height measurements and the use of charts to help select the best time to commence functional appliance treatment,

The third chapter examines the mode of action of functional appliances. The authors acknowledge that the precise mode of action of functional appliances is not fully understood. They use the "component approach" to functional appliances, which was promoted by Vig in 1986, to simplify the explanation. The three broad methods of action discussed are tooth tipping movements, eruption guidance, and mandibular reposturing. The controversy surrounding the so-called orthopaedic effect of mandibular reposturing is presented in asimple, scientific, and unbiased manner.

The fourth chapter discusses the importance and the limitations of cephalometry in the accurage diagnosis and successful execution of functional appliance treatment. The Eastman analysis, the Harvold analysis, and the Bjork analysis are presented.

Chapter five looks at case selection and the management of functional appliances in general. The cases presented are well- illustrated and well-treated and the general guidance on the management of functional appliances is practical and uncomplicated.

Chapter six details the design, indications, clinical consideration, and management of specific appliances including the Andresen appliance, the activator, the bion- ator, the function regulator of Frankel. and the twin block. Oral screens, positioners, the Bimler appliance, the Herbst appliance, and the lip bumper are also discussed in brief,

A functional appliance will seldom provide acomplete solution toan occlusal problem. Chapter seven presents the modern approach which involves the use of functional appliances in combination with other forms of treatment such as removableappli- ances, headgear, and fixed appliances.

The authors feel that it is important for the reader to be aware of the difficulties and pitfalls surrounding research into the effec- tiveness and mode of action of functional appliances so that the reason for the present controversy about the mode of action of functional appliances can be appreciated and in order to be better

equipped to evaluate new research as this becomes available. In the final chapter the authors present the problems of research- ing the topic and summarise the content. generally accepted conclusions which have been drawn from recent research.

The first part of the Appendix presents a review of selected papers covering research into functional appliances. The reviews are succinct and the list is up-to- date, relevant, and comprehensive.

The second part of the Appendix covers the laboratory procedures involved in con- structing some of the functional appliances mentioned in the text

This book is refreshingly unpretentious It has a good balance of theory and relevant clinical information It is clearly written well-illustrated comprehensive and prag- matic It is highly recommended for students interested general dentists and orthodontic specialists

David Fuller

l A Color Alias

Reyneke JP, Evans WG and McCollum AGH INTRODUCTION TO ORTHOGNATHIC SURGERY - A Colour Atlas. Published by: Ishiyaku EuroAmerica, Inc. 1991 Available from: McGraw Hill Book Com- pany, 4 Barcoo Street, East Roseville 2069 Price: $300 (AUD)

This book has been written by a maxillofacial surgeon and two orthodontists associated with the University of Witwatersrand in Johannesburg, South Africa.

The book is intended to be used by general dentists and specialists to help explain the concepts and treatment possibilities of orthognathic surgery to patients.

The introductory chapter describes diagnostic procedures (including a simple

explanation of some important cephalometric measurements used to assess the face), presurgical orthodontics, the concept of "decompensation", preparation for aseg- mental osteotomy, final surgical planning, the surgical phase, and postoperative orthodontics.

This chapter presents the general principles of the orthodontic and surgical aspects of orthognathic surgery in asimple, clear and logical way. The text is pitched at a general practitioner level but contains technical terms and concepts which are probably beyond the comprehension of an un- informed reader.

In the next three sections facial deformities are discussed as they affect the anteroposterior, the vertical, and the trans- verse planes of the face.

The final chapters cover "Facial asym- metries", "Prosthodontics and orthognathic surgery" and "Cleft clip and palate and orthognatic surgery".

The cases used to represent the various deformitiesare generally well-treated. How- ever, for an expensive atlas, the standard of photography is poor and the illustrations, which have been drawn by one of the authors, are rather "amateurish". The extraoral photographs vary in depth of exposure and often have shadows in the background. The intraoral photographs are worse. Too often, they are poorly framed, poorly exposed, too yellow, and out of focus.

The layout of case photographs is dis- concertingly inconsistent. Some sets of photographs are laid out horizontally, some are stepped diagonally across the page, and others seem to be randomly scattered over the page. The first few cases are presented clearly and the pretreatment and postreatment photographs can be compared without turning a page. However, in the third chapter, and often thereafter, the postoperative photographs of one case are opposite the pretreatment photographs of the next case. Such a layout makes comparisons and the explanation to patients more difficult.

There are several typographical errors and incorrect references to figures in this first edition.

The concept of this book is excellent, the text is well-written, easy to read, and easy to understand, but, unfortunately, the accompanying photographs and illustrations are not of a high enough standard to make this book a classic,

Nevertheless, this book is recommended as introductory reading for general practitioners and, until something better comes along, as a patient guide for orthodontists and maxillo-facial surgeons.

David Fuller

Ide Y and Nakazawa K ANATOMICAL ATLAS OF THE TEMPOROMANDIBULAR JOINT. Published by: Quintessence Publishing CO Inc Chicago Available from: Quintessence Publishing CO Inc. Australia Division 209-21 1 Burke Street, Sydney 2000 Australia Price: $US1 42

In the foreword to this atlas is it noted that the temporomandibular joint is becoming an increasingly important target of treatment and yet many dentists are not familiar with it.

This seems to be a reasonable observa- tion. Whilst the book claims that the treatment of occlusion should be closely coordinated with the temporomandibular joint and that disorders of the temporomandibular joint are being noticed more frequently, to many practitioners the temporomandibular joint is a mysterious, nebulous structure which should be treated with respect but given a "wide berth".

With the need for a comprehensive temporomandibular joint handbook in mind, Dr lde, Professor of the Department of Anatomy of Tokyo Dental College, and Dr Nakazawa, a noted temporomandibular joint specialist in private practice in Tokyo, have written a clinically orientated text in conjunction with the medical illustrator, Mr Kamimura.

The first part of the atlas considers the anatomical structures of the temporomandibular joint. This section consists of five chapters which cover the embryology, growth and development of the joint, the bony structures, the muscles, the soft tissue components, and the arterial and nerve supply of the temporomandibular joint.

The second part of the atlas covers the anatomical function of the temporomandibular joint. This section consists of three chapters which cover "functional considerations", mandibular movements, and the muscles of mastication.

This atlas explains the structure and functions of the temporomandibular joint with the aid of detailed illustrations. The illustrations, which are superb, are the outstanding feature of the book. With the aid of minute

detail, colour, shading, and transparent over- lays, the joint can be clearly visualised in all three dimensions.

The text accompanying the section on anatomical structures is the unavoidably mundane, descriptive text typical of anatomical textbooks. The excellent illustrations in this section unfold the mysteries of the temporomandibular joint and confirm the adage that a picture IS worth a thousand words.

Unfortunately, the text accompanying the section on functional anatomy is fundamental, clumsy, long-winded, and, at times, vague and wishy washy. This section isn't particularly well-written or well-translated and it would seem to be more sensible to refer to the original articles by Posselt on the movement of the mandible, by Gibbs on masticatory movement, and by Hannam on masticatory muscle activity, rather than to wade through this section. Normal function is described in detail but there is very little discussion of clinical implications or of temporomandibular joint disorders.

In summary, this atlas admirably depicts the anatomy of the temporomandibular joint and the movements of the mandible. At times, the accompanying text is disappoint- ing. The book is recommended for students and for practitioners who wish to update their knowledge of this mystic region.

David Fuller

Stephens C and Isaacson K PRACTICAL ORTHODONTIC ASSESSMENT. Published by: Heinemann Medical Books June 1990 Availablefrom: Butterworths Pty Ltd, PO Box 345, North Ryde 21 13 Price: $75 (AUD)

This book was written by CD Stephens, Professor of Child Dental Health at the Uni- versify of Bristol, and KG Isaacson, a Con- sultant Orthodontist, to fulfil the constant

demand on them by undergraduate and postgraduate orthodontic students for more practice in treatment planning.

The book is divided into four sections.

The first section is titled "Case assessment and treatment planning".

The first chapter of this section details the orthodontic case assessment recommended by the authors Because of the layout of the book, the reader is virtually obliged to follow the examination scheme as outlined in this chapter (and summarized in the inside cover for ready reference) The examination scheme is traditional, practical logical simply and clearly explained fairly comprehensive and useful However it is clinically based and cephalometricanalysis barely rates a mention

The second chapter explains how to plan orthodontic treatment. The authors have a typically British (but realistic) outlook on the need for orthodontic treatment. They feel that, in cases of mild malocclusion, it is acceptable to advise that no treatment be undertaken as real improvement requires an ideal occlusion to be obtained (and this is only possible if fixed appliances are used competently, the patient co-operates fully during treatment, and nothing relapses after

174 appliances are withdrawn). A useful list of situations where orthodontic treatment is indicated on dental health grounds is provided. The chapter also discusses timing of treatment, the stages of treatment, the principles of removable appliance design, and retention

The second section contains the pretreatment records of twenty cases These records consist of a front view of the patients face a cephalometric tracing a front view side views and occlusal views of study models and an OPG x-ray The reader is instructed to use a guide on the inside front cover to carry out an "examination and to use a guide inside the back cover to formulate a treatment plan for each

m case z The third section presents the authors

CD

0 assessment of each of the twenty cases o The amateur is thus able to compare his

assessment with those of the experts

The fourth section presents and comments on the treatment carried out In the 0

<_) introduction to this section the authors admit that in retrospect not all treatment

g plans were correct and that, even if they

9 were not all cases went entirely to plan

Many Australian orthodontists would 0

agree with the authors' admission. Most cases are treated with removable appli-

2 ances and the results are sometimes less !Z than ideal. Of the cases which are success- 3 a ful, one cannot help wondering whether the

results are truly representative or excep- tional For example, the first patient was the daughter of a dentist and the second was a dental student who adjusted her removable appliance herself throughout treatment'

The authors concede that some of the cases are not typical with comments on treatment such as, "during treatment the growth pattern was almost purely horizontal", "the alignment in the lower arch was truly remarkable", "rather surprisingly, the lower left canine moved distally around the back of the upper lateral incisor and then moved mesially again in its correct buccolingual relationship", "an excellent occlusion has been obtained by spontan- eous tooth movement", "treatment proceeded far more quickly and achieved a much better result than expected . . . treatment took just two months", "the superimposed tracing shows remarkable forward growth of the mandible and lower face", and "much to everyone's surprise there was no detectable change following the discarding of appliances",

One might question whether cases which seem to have gone unusually well and which are examples of the exception rather than the rule should be presented in an elementary text on orthodontic assessment and treatment.

Several cases have Class I I buccal relationships at the end of treatment, in some cases second molars seem to have been extracted needlessly, and in other cases spaces are left unclosed. The authors justify these and other compromises with statements such as, "ideally an upper fixed appliance with headgear support should have been used but the patient was not prepared for this to be carried out", "there were no post-treatment changes apart from further extraction space closure", and "by this time the upper second molars were erupting very distally inclined and rather bucally displaced and it was decided that these should be removed".

The concept of this book is good but the treatment philosophy and standard of case treatment has a level of compromise which would be unacceptable to many Australian orthodontists.

The book is a practical guide to case assessment but the treatment plans are often less than ideal and, given the appliances used, the treatment results are better than what might be expected. As such, there is a danger that this book might foster unrealistic expectations in orthodontic novices.

David Fuller

(SA Branch) Inc is pleased to host this Prof J I M MOSS

NEWS & NOTICES

The Australian Society of Orthodontists (SA Branch) Inc.

Preliminary Advice for

A SYMPOSIUM ON COMPUTERISED

symposium of international and national presenters We are also enthusiastic about the opportunity of entertaining interstate and overseas delegates

Dr Bruce Haskell. through the sponsor- ship of Rocky Mountain Orthodontics, has agreed to present at the meeting, His reputa- tion is outstanding and he is well qualified to speak,

Professor Jim Moss will present his latest findings relating to the use of 3-D laser and CT scans of facial structures to assess growth and the outcome of surgical inter- vention

To supplement this material local and interstate presenters will demonstrate and critically evaluate a number of currently available software packages such as Dento- facial Planner JOE, Quickceph and Ceph- mate

We are fortunate that Rocky Mountain Orthodontics have generously offered a Computer-aided Cephalometric Evaluation for each registrant This is to be carried out by RMO Diagnostic Services, on their main- frame computer at no charge to delegates at the time of their registration This will allow those attending the symposium to objectively evaluate the system prior to the November meeting

Professor Moss also has an extensive curn- culum vitae and is well known to many in Adelaide He is currently furthering his research in the field of 3-D computer imaging of facial structures at the University College Hospital London

His presentations will include state of the art use of laser scanning for measuring facial qrowth in three dimensions as well as assessing the 3-D restuls of various surgical procedures He will also present on the use of CT scanning to predict surgical outcome and its use as an adjunct to the production of prostheses used in surgical reconstruc- tions

His extensive knowledge and detailed presentation will be of great interest to all and suitably augment the other presentions at the meeting

Softwaredemonstration and evaluation will be undertaken by various practitioners including:

Dr BILL WEEKES Dr Weekes graduated from the Adelaide Postgraduate Orthodontic Programme in 1982 and has been using Dentofacial Plan- ner for five years He not only works in private practice but is a lecturer with the Department of Orthodontics at the Univer- sity of Sydney His private practice experience toaether with his Universitv back- .,

CEPHALoMETRICs Dr BRUCE HASKELL ground ensure that he is ideally suited to appraise the Dentofacial Planner Software

'Making the right decision' Dr Haskell is currently Clinical Professor at at the Department of Orthodontics at the Uni- Dr CR-AIG DREYER

Mt Lofty House on

November 26th-27th, 1992

In recent years an increasing number of computer programmes for quantifying cephalometric radiographs have been developed.

Generally, these programmes have orgin- ated in North America, making it difficult for orthodontists practising outside the United States and Canada to objectively evaluate, or keep up to date with the available software. Many practitioners remain uncertain as to the benefits of computerised cephalometrics and the advantages and limitations of individual software packages.

With an increasing demand for greater details of this diagnostic tool it is timely to assess the clinical relevance of computerised cephalometrics, review any short- comings of the current technology and appraise further development.

The Australian Society of Orthodontists

versity of Louisville, Kentucky

He achieved his orthodontic qualifications at the University of Pittsburgh in 1972 and completed his Ph D in 1978 This he followed with Post Doctoral studies from 1983 until 1986

During the last 20 years, he has contributed at numerous meetings at the regional national and international level His presentations have encompassed a wide variety of topics including the Application of Computer Aided Diagnostic Systems in Orthodontic Practice

Dr Haskell currently lists more than 20 publications on avariety of topics including Computer Aided Modelling. In 1990 he was awarded the B.F. and Helen Dewel Award for the best article of the year appearing in the American Journal of Orthodontics and Dentofacial Orthopedics,

Dr Haskell has previously travelled to Australia and presented in both Sydney and Melbourne His interests are varied, his curriculum vitae exhaustive and he is well placed to provide an informative and interesting foundation for the meeting.

Dr Dreyer graduated from Adelaide in 1981 and similarly spends part of his time in private practice and part as a lecturer and tutor at The University of Adelaide He too is well placed to objectively evaluate a number of software packages including the Rocky Mountain 'JOE program and Oliceph'

Dr GRAVT DLNCVS Dr Duncan graduated from the University of Manitoba in 1982 and has used the Apple Macintosh Quickceph software for the past five years His thoughts are to be respected and should be of interest to us all

Places for this course are being offered initially to A S 0 members However interest has also been expresssed by overseas Orthodontists and Oral and Maxillo- facial surgeonsalike Early registration prior to a general notification later in the year is encouraged as both the number of registra- tionsand accommodation at Mt Lofty House is limited

Proceeds from this symposium will be directed fo fund orthodontic research at The University of Adelaide.

AUSTRALIAN SOCIETY OF ORTHODONTISTS WESTERN AUSTRALIAN BRANCH OFFICE BEARERS FOR 1992 PRESIDENT: Dr John R Owen 8 The Avenue MIDLAND WA 6056 PH 09 274 6861 FAX 250 2406

VICE PRESIDENT: Dr Peter Southall 8 The Avenue MIDLAND WA 6056 pH092746861

SECRETARY: Dr Keith R. Huxtable 52 Farrington Road LEEMING WA 61 49 PH 09 310 1159

TREASURER: Dr Peter I, Dillon Exchange House 68 St Georges Tce PERTH WA 6000 PH 09 321 5571

STATE BRANCH PROGRAM 176 FOR 1992

WESTERN AUSTRALIAN BRANCH February 10th General Meeting at ADA House West Perth Management of Cleft lip and Palate Patients at PMH - Dr S Singer

May 12th General Meeting ADA House West Perth Members to participate in Workshop covering various topics of interest in Orthodontic Practice

August 12th General Meeting ADA House Titanium Wires - Which Type, When and

Â¤ How - Dr M Goonewardene OT1

November 20th LU m Annual General Meeting and General 2 Clinical Day. 0 Venue and Lecturer to be advised. 2 E NEW SOUTH WALES

BRANCH - JUNE 1992

l- z The New South Wales Branch held its g Clinical Day on 19th June 1992 at the Novotel, Darling Harbour

U 0 - Guest speakers were L

a Dr J Mclntyre (Dean Faculty of Dentistry g Adelaide University) &5 Assoc Prof K Godfrey (Head Depart-

ment of Orthodontics, Sydney University)

Dr T Jayasekera (Specialist Orthodontist Private Practice Victoria)

a MS Justine Hemmings (Speech Patholo- gist - Speech Pathology Unit West- mead)

a Dr R Cherny (Specialist Orthodontist Private Practice Newcastle)

a Dr R Chapman (Specialist Orthodontist Private Practice Newcastle)

Case presentations by:

a Dr J Geenty (Specialist Orthodontist Pri- vate Practice Wollongong)

a Dr H Wasilewsky (Specialist Ortho- dontist Private Practice Sydney)

a Dr S Duncan (Recent Graduate Ortho- dontist Private Practice Sydney)

The AS0 Annual Dinner followed

TABLE CLINICS At the next Clinical Day to be held on 13th November 1992 -to which General Practi- tioners have been invited - we are fortunate to have Professor Jim Moss from University College, London, as the principal speaker. Dr. Moss has also been invited to be the External Examiner to the Universities of Sydney and Adelaide post graduate students this year.

NEW SOUTH WALES ORTHODONTIC FOUNDATION COMMITTEE REPORT The Committee has received regular en- quiries as to whether donations will be required this financial year,

It was anticipated that the Constitution would have been ratified by the University of Sydney at this time, and that the NSW. Orthodontic Foundation would have been formally acknowledged at its inaugural meeting Disappointingly, this has not been the case. The Committee has been led to believe that the ratification of a Constitution was a formality as there were numerous foundations within the University. To date there have been four drafts of the Constitu- tion.

The Committee will not ask members for any money until it can be assured that it will be used in the manner indicated by the resolutions passed almost twelve months ago. To date it has not been able to ensure that this will be the case.

The Committee has been pleased by the response to requests for contributions. It allowed the Committee to approach the University with serious intent and to feel that afive year Chair was within its means. Once established the Foundation would have five years in which to ensure enough money be raised to continue the Chair.

In January 1992 the Committee approached the University with a proposal and explained that it would like to begin

raising money this financial year with aview to advertising and filling the position by January 1994 at the latest Before Easter it was felt that time was running out and the support of the Dean Professor Iven Kline- berg, who had been involved in establishing the newly formed Foundation for Dentistry was enlisted

At a meeting held in early April the University informed the Committee that the quickest way to begin collecting donations was to set up a Trust Fund for a Chair in Orthodontics administered by the University and jointly controlled by the Faculty and the Australian Society of Orthodontists N S W Branch The goal of a Foundation was a much longer term proposition and not merited at this time

The Committee was also informed at this meeting, for the first time, that the position would only be advertised when all the money had been collected This wasa body blow because it appears that members will have to be approached to decide on a course of action should a Foundation not eventuate.

In summary all avenues are being explored at this time including the forma- tion of a Foundation outside the University A trust fund agreement is being negotiated with the University and the Faculty and the intended goal of an Orthodontic Foundation is still being pursued The Committee will have more definite newsat the end of July at which time it will report again

Asssociate Professor Keith Godfrey has recently returned from North-eastern Thailand where he worked in the Faculty of Dentistry at Khon Kaen University. The Faculty has recently been expanded as a result of Government policy to improve the present dentist-to-population ration of 1:15,000 It is envisaged the Khon Kaen University will also lend assistance to neigh- bouring Laos and Cambodia.

Khon Kaen Faculty Library is trying to fi l l the gaps in its various Journal titles from 1980 onwards To this end Keith has asked for our help. It would be a great help to the Faculty allowing it to use much needed funds elsewhere. So please have a look through your shelves and boxes and if you can spare any of the listed Journals contact Professor Godfrey at the United Dental Hospital, Telephone 2820280, to arrange delivery

MISSING JOURNALS 1. Advances in Dental Research -

before 1 99 1 2, Archives of Oral Biology - 1989-90

nclusive 3, British Dental Journal - 1980-81 4. Caries Research - before 1991 5 Compendium - before 1988

Dental Materials - 1985-86 Endodontics and Dental Trauma- tology - before 1991 International Journal of Oral and Maxillofacial Surgery - before 1991 International Journal of Periodontics and Restorative Dentistry - before 1991 International Journal of Prosthodontics - before 1991 Journal of Clinical Orthodontics - before 1987 Journal of Dental Education - 1988-90 Journal of Oral Medicine - since 1987 Journal of Pedodontics - before 1985 Journal of Public Health Dentistry - 1988-present Journal of Western Society of Periodontology before 1988 Pediatric Dentistry - before 1987 Quintessence International - before 1991

VICTORIAN BRANCH NEWS AND NOTES The programme for 1992 consists of five evening meetings and two clinical days,

The Annual Golf Day was held in April in foul weather at Victoria Golf Club. An 18- hole Stableford competition was conducted and the Ormco perpetual trophy was won by John Armitage on a countback from David Ellett, Scores were low in the appal- ling conditions and everyone who finished the course deserved a prize even if they did not receive one. Having won, John Armitage now has the task of organizing the 1993 competition and members will no doubt be hearing from him in due course

The programme and contributors to the evening meetings are listed below,

Wednesday, February 12th, 1992 General Meeting. 'Aesthetic Brackets - Love them, hate

them". Drs Paul Buchholz, Alan Pollard, Anne- Maree Vincent, Micahel Woods,

Wednesday, April 8th, 1992 General Meeting, "Infection, Risk and Control". Dr R. Doherty, Deputy Director, Macfarlane Burnett Centre of Medical Research,

Wednesday, June 17th, 1992 General Meeting, "Orthodontic Aspects of Restorative Den- tistry". Dr Bruce Squires.

Wednesday, August 12th, 1992 General Meeting 'Endodontics for the Orthodontist" Dr Geoffrey Heithersay

The programme this year was designed to be strongly clinically oriented and to include interaction with other specialities

The Clinical Days at Portsea on Friday November 13th and Saturday, November 14th will be the jewel in the crown' with three major lecturers addressing the problem of retention and ten younger members giving short presentations on clinical topics

VICTORIAN BRANCH OFFICE-BEARERS 1992 PRESIDENT: Andrew McDonald PO Box 700 190 Foster Street DANDENONG VIC 31 75 PH 03 791 6230

VICE-PRESIDENT: James Curtain

SECRETARY: Anne-Maree Vincent Suite 2, Second Floor 2 Collins Street Melbourne 3000 pH036546092

TREASURER: Patrick Hannan

COUNCILLORS: Samara Amari Michael Shearer

HAMILTON ISLAND ORTHODONTIC RESEARCH FOUNDATION MEETING 28th-29th SEPTEMBER 1992 Dr. Patrick Turley was the guest speaker. He delivered the Don Spring Memorial Lecture.

SOUTH AUSTRALIAN BRANCH NEWS 1. State Branch Programme for 1992

February 11 th General meeting at the Edinburgh Hotel An Introduction to Tip Edge Dr Colin

Twelftree Short Presentation Dr M Reichstein

April 14th General meeting at A D A House Combined presentation from representatives of three Health Funds Short Presentation Dr A Toms

June 15th General meeting at the House of Chow An Update on Orthodontic Materials Dr

John Fricker Short Presentation Dr G Duncan

August 11 th General meet ing Bradman Room Adelaide Oval T h e Extraction Debate" panel discussion

September 22nd General meeting, Lenzerheide Restaurant "My Life in Orthodontics", Dr Milton Sims.

November 26th -27th Annual Clinical Days Mount Lofty House A Workship on Computer Cephalo- metrics Dr Bruce Haskell and Professor J P Moss with presentations by Dr W Weekes Dr C Dreyer and Dr G Duncan The workshop will be followed by the Annual General Meeting and the Annual Dinner

PRESIDENT: Dr Helen McLean

VICE PRESIDENT: Dr Steve Langford

SECRETARY: Dr Craig Dreyer

TREASURER: Dr Steve Farrer

COUNCILLOR: Dr Simon Freezer

FEDERAL AS0 SECRETARIAT: Dr lan Watson

2. Courses

The Australian Begg Orthodontic Society held a new course of Continuing education in the use of the Begg Appliance in Adelaide, South Australia, July 9th, 10th and I l t h , 1992. Plans are well advanced for another Basic Begg course to be held in conjunction with the national Australian Begg Orthodontic Society annual meeting in Sydney during July 1993

3. Notable Events

(a) Dr Milton Sims is due to retire from the Department of Denstistry The Univer- sity of Adelaide at the end of 1992 He has served with great distinction as Reader in Orthodontics since 1963

b The Department of Dentistry The Uni- versity of Adelaide, in association with the South Australian Foundation for Dental Education and Research has announced the release of a named Chair in Orthodontics to be known as the P Raymond Begg Chair in Ortho- dontics It is hoped the position will be filled in 1993 to coincide with the 10th anniversary of the death of Dr Begg

m (c) The 14th A S 0 Congress will be held in g

Adelaide September 19th- 23rd I- 0 1993 The scientific programme will

7 feature Professor B Melsen Professor 2 B Ingervall Associate Professor P Sinclair and Professor D Woodside

with able support from local and interstate speakers. A pre-Congress Tip- Edge course has been organized and is certain to be highly successful - early registration would be advisable! Contri- butions to silent clinics, table displays and poster presentations are urgently encouraged. The social programme and Trade Display are set to be most memorable, Registration details can be obtained from Dr Steve Langford, Sec- retary, 14th AS0 Congress Scientific Committee, 198 North Terrace, Adelaide, South Australia, 5000.

AUSTRALIAN SOCIETY OF ORTHODONTISTS 14th CONGRESS The 14th Congress of the Australian Society of Orthodontists will be held in the magnifi- cent facilities of the Adelaide Convention Centre from Sunday 19 September until Thursday 23 September 1993.

The Congress Committee, which meets on a monthly basis, hopes to make the 14th Congress as successful as the previous Adelaide Congress which was held in Hong Kong in 1982.

By changing the format of "Congress Week" the Committee trusts that all participants have a better opportunity to absorb technical and scientific information and socialize under more relaxing circum- stances,

Registration as usual is on Sunday afternoon This will coincide with the opening of the Trade Exhibition In the evening the Stanley Wilkinson Oration will be held in St Peter's College Memorial Hall An academic procession will precede the Oration which will be delivered by the Chancellor of the University of Adelaide, Mr Bill Scammell The Governor of South Aus- tralia Dame Roma Mitchell has been invited to Open Congress The Presidents Wel- come Reception will follow

The Scientific Programme will be held on Monday, Tuesday and Thursday. Wednes- day will be the day to relax and the Social Committee has an interesting day planned,

The Congress Committee is conscious of the importance of local input into the scientific programme and eight Australians have been invited to deliver lectures and add support to the four International Speakers. Roundtable Luncheon discussions and Silent Clinicswill provide an informal setting for the exchange of scientific knowledge.

The Changeover Dinner is scheduled for the final night of Congress -Thursday 23 September.

At the time of this report the response from the Trade has been excellent It is

will open on Sunday 19 and close on Tuesday afternoon 21 September.

The Annual General Meeting of the Society will be held on Tuesday afternoon 21 September

The Committee of the 14th Australian Society of Orthodontists has appointed the University of Adelaide Office of Continuing Education as its Congress Organiser

Finally, I askthe co-operation of Members of Council to promote the outstanding scientific programme of the 14th Congress at state level Success is dependent on the goodwill and co-operation of all

Keith Grave Congress Chairman

QUEENSLAND BRANCH NEWS In 1992 all branch meetings were held at the United Services Club Wickham Terrace Brisbane

February 12 Some Perspectices of the Begg Tech-

nique Dr A P Weir a recent Adelaide postgraduate

April 8 An Outline on AIDS Hepatitis B and C

Dr Michael Whitby Director of Infectious Diseases at the Princess Alexandra Hospital

June 10 The Importance of Soft Tissue Profile Dr Demetrios Patrikios a private practitioner in Brisbane

August 19 Business meeting only no guest lecturer

October 14 Speaker to be announced

November 20 Annual Clinic Day followed by the Annual General Meeting and Dinner at the Hilton Hotel Brisbane

Speakers are local pracitioners

Dr T J Freer Modern Concepts of Anterior Retraction

Dr Don 0 Donoghue Current Cross Infection Control in Our

Practice

Dr Peter McMahon A Retrospective Assessment of Treatment

with Functional Appliances

Dr Rick Olive Orthodontic Anomalies

Dr Colin Nelson Mandibular Changes in Functional Appli-

ance Treatment

2 a important to note that the Trade Exhibition

NEWS & NOTICES FROM OVERSEAS

SIXTH BRITISH ORTHODONTIC CONFERENCE 24 - 27

THE PEMBROKE HOTEL, BLACKPOOL A return visit to the Pembroke Hotel in Blackpool provided the venue for the 1991 British Orthodontic Conference Although a bit windswept this year the hotel provided excellent lecture and tradeexhibit facilities

Overseas speakers included Dr R G (Wick) Alexander who outlined his philosophy on treatment weith particular reference to non-extraction treatment Professor J A McNamara presented the annual North- croft memorial lecture "Orthodontics and Orthopaedic Treatment in the Mixed Den- tition' This included rapid maxillary expansion for the class I crowded case, functional treatment for the skeletal II discrepancy, and an orthopaedic approach with face masks for the class Ill malocclusion A masterly dissertation on the temporomandibular joint in normal function and in disfunction was presented by Dr A Isberg from Scandinavia - a subject rarely shown with such clarity and well illustrated with film of the joint in action

Advocates of different appliance systems were well represented, Andy Parker discussed the uprighting mechanisms and advantages of Begg and Edgewise systems. Richard Parkhouse compared the Tip Edge bracket with the Edgewise and Straight Wire bracket and concluded that differential forces offer significant advantages in class II deep overvite cases, and the Tip Edge improves on the previous Begg appliance. Chris Gait discussed the use of removable appliances with headgear prior to functional appliance therapy in class l1 division I malocclusions. Linsay Winchester reviewed the development and present status of aesthetic brackets in the

Belle Maudsley lecture. Jonathan Sandler explained his philosophy on the use of magnets to encourage eruption of buried teeth, and David Tidy examined the current usage of arch wires and arch wire progression, and presented practical recommendations for optimising arch wire changes,

As usual a session was devoted to ten minute abstracts on current research pro- jects given by thirteen younger participants - topics including video imaging, laser scanning, comparisons of tooth size and arch form, and dental material studies.

Round table lunch groups on many topics provided lively discussion and con- current clinical demonstrations and a trade exhibit with twenty-one participants provided ever popular and impressive stands.

The excellent attendance of this year's conference included for the first time a much appreciated orthodontic dental surgery assistants programme.

The social programme including the annual golf competition sponsored by Forestadent proved a great success. The traditional conference banquet took place on the Thursday evening with our own John

Muir as the speaker in his inimitable witty style. The 1992 British Orthodontic Confer- ence will take place in Manchester from the 22-25 September.

Details from BOC Office, Orthodontic De- partment, Eastman Dental Hospital, 256 Gray's Inn Road, London WCIX 8LD, UK.

W G WEBB

Dr Isberg delivering her lecture Dr R G (Wick) Alexander delivering his lecture.

Professor McNamara receiving his commemorative certificate from Mr /an Crossman 15 W

following his Northcroft memorial lecture. z

THE EUROPEAN BEGG SOCIETY OF ORTHODONTICS 16th CONGRESS

19th TO 24th MAY 1993

AT SAN SEBASTIAN, SPAIN

The Scientific Programme headed by Dr. H. Booy includes papers given by Drs. Sims and Mollenhauer (Australia), Thornpson and Morres (U.S.A.), Moss, Parkhause, Parker (U.K.), Anne ten Hoeve Mulie, Booy, Levin, Ackerman. Bijlstra (Netherland), Pancherz (Germany), Jimenez (Spain), Beck-Nielsen (Denmark) and Bolender (France).

A Pre-Congress Course will be held the 18th and 19th May 1993 given by Dr William J. Thompson on the Combination Anchorage Technique (CAT.).

PRESIDENT: Dr Jose Echeverria, Zubieta 8 - 20007 San Sebastian (Spain).

SECRETARY: Dr. Ove Beck-Nielsen, Fisketorvet 4-6, 5000-Odense C, Denmark.

TREASURER: Dr. H Gerken, 23 Viersenerstr. 4050- Monchengladbach I, West Germany,

ORTHODONTIC PRACTICE FOR SALE

We are currently seeking interested parties with Orthodontic Qualifications who have an expressed interest in purchasing one of Melbourne S finest Orthodontic Practices

Beautifully equipped in modern profes- sionally designed premises computerised and fitted out with every modern aid to perform at an optimum level of professional service to the motivated patientsattending

A situation such as this rarely presents itself in a fully operational, high activity level practice of this calibre with the vendor effecting personal introductions and con- tributing to a continuing level assuring con- tinuity of the practice growth

Genuine inquiries will be expected and will be treated in strictest confidence

For more information on this highly desirable practice please write in confidence to -

The Practice manager Clo PO Box 109

Brunswick, Victoria 3056 or phone (03) 822-61 65

3-year Postgraduate Programme in Orthodontics:

Clinical programme leading to a Master of Science degree upon completion of a research thesis. The programme constitutes the major part of the Danish requirements for the specialty in Orthodontics.

Start of programme: September 1, 1993

Deadline for applications: December 1, 1992

Short-term Postgraduate Course in Orthodontics:

The aim of the course is to give the participants relevant information on orthodontic diagnosis as well as therapy, based on an understanding of the development of the craniofacial skeleton and occlusal development and physiology The course consists of a number of theoretical and practical modules. Formalized teaching takes place on a full-time basis for a duration of 9 weeks.

Start of programme: January 18, 1993

Deadline for application: October 1, 1992

Short-term Postgraduate Course in Orthognathic Surgery:

The aim of the two-week course 1s to present with details the up-to-date knowledge in the field of combined surgical-orthodontic treatment of dentofacial deformities and to guide the orthodontist towards differential diagnosis and treatment planning.

Start of programme: September 28, 1992 & September 27, 1993

Deadline for applications: June 1 , 1992 &June 1,1993

The Department of Orthodontics can also provide upon request courses suitable to individual needs of small or large groups of dentists or orthodontists in nearly all topics relevant to the specialty fields.

For further information and forms of application, please contact:

Department of Orthodontics, Attn. Dr. A.E. Athanasiou, Royal Dental College, Faculty of Health Sciences, University of Aarhus, Vennelyst Boulevard, DK-8000 Aarhus C. Denmark, FAX: 45 - 86 - 196029.

ORTHODONTIST Orthodontist required for a modern

New South Wales country group practice.

View to future associateship.

Reply with resume to: Advertiser,

P.O. Box 206, Maitland N.S.W. 2320

OBITUARY

Hugh died peacefully in February after bravely enduring his illness for more than two years He was born and grew up in Dunedin New Zea- land and followed afamily tradition in the practice and teaching of dentistry for his father Neville was a dental surgeon too Neville had a private practice and in addition taught at the Otago Dental School Dental connec- tions also exist on his mother's side for Hugh S maternal grandfather (W H Naylor) founded the firm that

ROBERT HUGH AITKEN B.D.S.(Otago), M.D.Sc.(Melb.)

16.1.1944 - 16.2.1992

constructed the Otago Dental School Hugh had a wonderful pair of hands he was a masterful wire-bender An early indication of his hand steadiness was evidenced in secondary school where he was a member of the shooting team that won the Victory Challenge Shield competed for by South Island Schools Embossed on the shield were the words 'England expects that every man will do his duty prophetic words in Hugh S case for he did fulfill his responsibilities to his profession He attended Mornington Primary School followed by John McGlashan College He studied at the Otago Dental School from 1963- 1967 and during the university vacations engaged in avariety of jobs including employment in a paint factory and as a builder S labourer After graduation Hugh worked for two years in the dental department of Lower Hutt Hospital Wellington He then went to Melbourne to study orthodontics

After obtaining his M DSc in 1972 Hugh became a fulltime member of the Orthodontic Department of The Royal Dental Hospital of Melbourne until 1982 when he established a private practice in Ringwood He continued part- time work at The Dental Hospital until his illness became too restricting in March 1991 at which time he also sold his practice Hugh taught the post-graduate students in orthodontics for many years and was selected as an examiner on several occasions an indication of the esteem in which he was held In addition he was a regular presenter at continuing education orthodontic courses for general practitioners

He was a member of the Australian Society of Ortho- dontists from 1973 and Table Clinics Co-ordinator for the

10th Congress of the AS 0 in Mel- bourne in 1984 He was a founding member of the Melbourne Edgewise Study Group which existed from 1975- 1986 His time as Assistant Editor of the Australian Ortho dontic Journal (1 980- 1992) was one of Hugh S major contributions to his speciality He brought to that position a comprehensive knowledge of the literature, an ability to focus on the essentials of a subject immediately, succinct expression and intellectual

integrity. Orthodontics was kind t'o Hugh. Not only did it provide him with stimulation and a livelihood but he also met his wife, Berris, when he was a post-graduate student and she was working in the Faculty Office.

Hugh was a gentle man modest but not easily impressed and rare ly overawed He never made exaggerated statements especially about his achievements If Hugh was annoyed or disagreed he would make his feelings known However he never complained whether it wasabout work-related issues or his illness Even during his illness he was always cheerful I saw him seven days before he died He was smiling and writing clever quips even then There was a group of dentists present some of whom as is natural with any occupation were saying that perhaps other profes- sions were superior to dentistry I asked Hugh whether he had ever regretted doing dentistry Immediately he wrote - NEVER Hugh had numerous interests which included food and wine classical music (particularly Mozart Haydn Bach and Vivaldi) reading vegetable gardening photography and carpentry He enjoyed travelling and visited Europe frequently His favourite countries were Scotland France England and the South Island of New Zealand

This accomplished human being will be sadly missed by his friends and colleagues Berris his wife and loyal com- panion made him happy all his married life and looked after him devotedly during his illness We all extend our sincere condolences to Berris Hugh S mother Grace and his sister Margaret

STANLEY JACOBS

OBITUARY

DAVID ROBERT DUNLOP Saturday 30 May 1992 was a tragic day for family friends and colleagues of DAVID ROBERT DUNLOP His death on that day marked the end of an exciting, short yet full life of a great man

David was born in Kalgoorlie on 5 November 1946 but grew up in Brisbane He was educated at Brisbane State High School then attended the University of Queensland for his B S Sc qualification After spend- n g two years in the Royal Australian Navy, David moved overseas toattain his Fellowshipthen Diploma in Orthodontics

After acolourful, exciting life in the United Kingdom, David commenced orthodontics in Brisbane in 1978 and formed afull partnership with Peter Ferguson up to the time of his death. Julie Creagh and later, Bruce Trusler joined the "Dunlop and Ferguson" team.

David contributed much to the Australian Society of Orthodontists by being Secretary for two years, then President of the Queensland Branch He volunteered many hours lecturing to various dental and orthodontic groups Apart from this David was a postgraduate clinical demonstrator with the University of Queensland

David leaves a young family of three children Alastair Chloe and lain and his beautiful wife Clare

Who was this person David Dunlop? Those who were unfortunate not to have met Dave have missed out on knowing a very spirited kind and generous man David had an overwhelming personality His smile his stories (sometimes exaggerated to add

spice and wit), his height, his wit, his fitness and physique, all added a special ingredient that made poeple, meeting him for the first time, instantly remember his as their friend - this was David.

Many of David's friends and colleagues will remember him for his favourite sayings, when on a run - "It's only just around the corner" when it wasa long way to go. While skiing - "I know an easy way down". This was usually a black diamond run with rocks. And when you crashed, he would give that famous laugh and say "Yard sale". While fishing - "Let's not go yet, the fish are ready to come on the bite". As you can see, David loved sports, especially snow-skiing, running, windsurfing and fishing with his friend, Craig Trenfield.

Apart from his loving family, David's other love was Nature. "Isn't that fantastic!" was his favourite expression to describe all different flora and fauna in any part of the world. While working, if a nurse was feeling stressed he would say "Go hug a tree".

One of David's dreams was to buy a large sailing boat and cruise the islands of the Pacific. He loved sailing, he loved the sea. Sometimes in quieter moments, while dreaming of his future life, he would quote one of his favourite poems, Tennysons's ''Crossing the Bar" -

"And may there be no sadness of farewell when I embark I hope to see mypilot face to face when I have crossed the bar!"

Goodbye, David!

PETER FERGUSON

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