British Journal of Orthodontics
ISSN: 0301-228X (Print) (Online) Journal homepage: http://www.tandfonline.com/loi/yjor19
A study of adult orthodontic patients and their treatment R. S. Khan B.D.S., F.D.S.R.C.S., M.Sc., M.Orth. & E. N. Horrocks B.Ch.D, F.D.S.R.C.S., M.Orth. To cite this article: R. S. Khan B.D.S., F.D.S.R.C.S., M.Sc., M.Orth. & E. N. Horrocks B.Ch.D, F.D.S.R.C.S., M.Orth. (1991) A study of adult orthodontic patients and their treatment, British Journal of Orthodontics, 18:3, 183-194, DOI: 10.1179/bjo.18.3.183 To link to this article: http://dx.doi.org/10.1179/bjo.18.3.183
Published online: 21 Jun 2016.
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Date: 15 October 2016, At: 18:21
British Journal of Orthodontics/Vol. 18/ !99 I /183-194
A study of adult orthodontic patients and their treatment R. S. KHAN, B.D.S., F.D.S.R.C.S., M.Sc., M.ORTH. E. N. HORROCKS, B,CH.D, F.D.S.R.C.S., M.ORTH.
Eastman Dental Hospital, 256 Grays Inn Road, London WCI Received for publication July 1990
Abstract. This retrospective epidemiological study was undertaken to assess factors related to adult orthodontic treatment and to identify any associated trends. Case records of all patients (676) aged 18 years or over at the start of active orthodontic treatment at the Eastman Dental Hospital, London were examined. Variables associated with patients and their treatment (age, sex, source of referral, malocclusion, type of appliance, and interdisciplinary treatment including orthognathic surgery) were studied and the data analysed statistically. Findings revealed that the number of adult patients undergoing orthodontic treatment has increased significantly, especially since 1985. The age of the patients treated was also found to increase in recent years. The percentage of female patients (72 per cent) Class Ill malocclusions (21·6 per cent) and Class Ill skeletal bases (26·2 per cent) was higher than found in studies on children. Most of the treatments required fixed appliances and over half involved interdisciplinary treatment, with an increase in the percentage of orthognathic surgical cases. Surgery was significantly more common in males (P < 0·0 1) and highly significantly associated with Class Ill malocclusions and skeletal Ill bases (P < 0·001). Twenty-five per cent of adult patients were found to have had a previous course of orthodontic treatment though .these patients were not significantly different from adult patients presenting for the first course of treatment. Index words: Adult Orthodontics, Malocclusion, Treatment, Survey.
Introduction Adult orthodontics is a rapidly growing field and over the past two decades there has been a noticeably increased demand for orthodontic treatment from adults. This may be attributed to improved dental services and a greater dental awareness amongst adult patients. This increase will be reflected in both adjunctive and comprehensive procedures, and is likely to continue in the future as more aesthetically acceptable appliances are developed and less social stigma is attached to adults Wearing visible orthodontic appliances. Despite this recent exponential rise in adults seeking and undergoing orthodontic treatment, an extensive search of the literature shows that most of the published work on the subject is subjective and speculative in nature, and certainly prevalence data for British populations are lacking. This epidemiological study was undertaken to bridge this gap. The adult patients treated in the orthodontic 030I-228X/91/000000+00S02.00
department at the Eastman Dental Hospital would provide a large data base for analysis. The aims of this retrospective investigation were to study: (1) general factors relating to the adult population undergoing orthodontic treatment, their mal occlusion and treatment undertaken; (2) changes in trends in the type of adult patients treated over a period of time; (3) whether the adult patients undergoing orthognathic surgery differed from the remainder (non-surgical group) in any of the factors studied; (4) whether the adult patients who have had previous orthodontic treatment differed from those presenting for their first course of treatment. In the current climate of financial constraints on the health services, any differentiating factors may be useful in planning treatment, and in the allocation of resources for adult treatment. © 1991 British Society for the Study of Orthodontics
184 R. S. Khan and E. N. Horrocks
Review of the Literature Orthodontic treatment for adult patients is by no means a recent idea. The first reference to it was made by Pierre Fauchard, author of the first known scientific book on dentistry, Le Chirurgien Dentiste in 1723, when he observed that the teeth of young people were easier to move than those of older persons (Goldstein, 1953).
BJO Vol. 18 No. 3
(1981) found the mean age at onset of treatment within a private practice had increased from 11 years in 1964 to 13 years in 1978, whereas Thilander (1979) noticed an increase in the number of adult referrals from 1970 to 1978. The fact that these surveys were completed over l 0 years ago highlights the need for more up to date studies.
Previous adult surveys Prevalence
Several authors have commented on the general trend in the increase in adult orthodontics and have attributed this to many reasons (Fine, 1972; Baum, 1975; Chiappone, 1976). With the success of preventative dentistry over the past 20 years, more patients are retaining their teeth into adulthood and more attention is now being given to the orthodontic treatment needs of adults who were not given the opportunity to receive orthodontic treatment when they were young (Muir et al., 1986). The Adult Dental Health Report of England and Wales (Todd et al., 1978) noted that in the hfghly selected adult population that finds its way into orthodontic practice, there appear to be two increasingly evident traits. I. An overall improvement in general dental health. 2. An increased interest in and expectation of orthodontic treatment. In North America, the increased interest in adult orthodontic treatment is as a result of increased public advertizing and dental education, coupled with insurance benefits and an increased general dental awareness among the population (McGonagle, 1981). , The prevalence of adult orthodontic treatment is difficult to ascertain since the term 'adult' is taken to mean different age groups by different authors. Watson (1979) estimated the number of adults treated in American orthodontic practices constituted 10-25 per cent of the average patient load. More recently, Norton (1988) stated that there is a predominance o(adults in retirement communities in North America, such as Florida where adults may comprise between 60 and 70 per cent of the practice, and in urban business centres with a large adult white collar worker population where some practices consist of almost 100 per cent adults. Very few statistics are available for the i1umbers and trend of adult orthodontic treatment in Europe. However, two studies have shown that the age of orthodontic patients is increasing. Cousins et al.
Tayer and Burek (1981) surveyed adults' attitudes towards orthodontic therapy since they noted a relative paucity of articles on the subject. Their overall results concluded that adult patients, properly motivated and educated, were excellent candidates for orthodontic treatment and had a great appreciation of the results achieved. Muir et al. (1986) questioned 45 orthodontists in specialist practice in New Zealand about personal details of the adult patients treated, their malocclusion, and the orthodontists' attitude to treating adult patients. The percentage of adult patients was found to vary between I and 12 per cent with a mean of 6 per cent; the female to male ratio being 71 per cent to 29 per cent. 74 per cent of the patients were referred by their general dental practitioner and 70 per cent of the adults who sought treatment did so for cosmetic reasons; the principle conditions requiring treatment being excessive incisal overjet and dental crowding. Eighty-six per cent of the orthodontists who returned the questionnaire did not discourage adults from receiving treatment and considered that adults were more appreciative of the treatment provided for them than children. Seventy-five per cent of the orthodontists, however, felt that it took longer to treat adults than children and the result was more compromised. A number of more objective studies into the demand for adult orthodontic treatment have been carried out in the Scandinavian countries. Thilander (1979) looked at the main indications for orthodontic treatment in adults. She reported that between 1970 and 1978, 1186 adults aged between 18 and 77 years were referred to the orthodontic department at the Faculty of Odontology in Gothenburg, Sweden, and that the numbers increased annually during this period. As expected she found a greater demand for treatment in women (63 per cent); the reason for wanting treatment expressed by almost all the patients was a desire for improved appearance of the upper front teeth. The mean age was 31 years and 65 per cent of the patients were referred by their general dental practitioners. Mohlin ( 1982) interviewed 272 randomly selected
Adult patients orthodontic treatment 185
BJO August /991
women from Gothenburg aged between 20 and 45 years. Nine per cent of that sample desired orthodontic treatment and again the expectation of a cosmetic improvement seemed to be the main motivating factor. Breece and Nieberg (1986) surveyed by questionnaire 180 adult patients treated in private practice and 24 in hospital. The principle findings were that two-thirds of the patients were in the 18-27-year age group. Seventy-five per cent were referred by their general dental practitioner, 76 per cent were female, and just over half were married. The main reasons for deferring treatment until their present age was financial since 41 per cent could not afford treatment earlier, whereas 19 per cent had never been recommended or were unaware that anything could have been done earlier. Only 7·6 per cent were retreatment cases. The main motivating factor was aesthetic improvement which is in agreement with the findings of several workers (Muir et al., 1986; Thilander, 1979; Shaw et al., 1975). This is in contrast to children undergoing orthodontic treatment where the mother's desire for treatment is more influential (Baldwin and Barnes, 1965). Comparison of orthodontic treatment between adults and children
There are several similarities that exist between adults and children in terms of orthodontic treatment, but the major difference between the two is the presence or absence of growth (Bond, 1972). The other special considerations that have to be taken into account when treating adult patients include motivation, co-operation, limitations of treatment, biological factors, adjunctive treatment, and the periodontal and restorative condition of the teeth. As the main motivating factor for adults seeking treatment is aesthetic, the patient's perception of the dental appearance is of considerable importance in determining treatment demand and patient cooperation (Shaw, 1981 ). Dentists' and orthodontists' perception of malocclusion and the individual's own views on the acceptability of his dental appearance differ considerably with the professionals operating a more critical dental/aesthetic scale than society in general (Shaw et al., 1975; Prahl-Anderson et al., 1979). Adult orthodontics prior to the 1970's was mainly of an adjunctive nature, i.e. tooth movement was carried out to facilitate other dental procedures necessary to control disease and restore function, and the literature contains many case study reports (Andreason, 1972; Seide, 1970; Levitt, 1971 ).
Although comprehensive orthodontic treatment for adults is increasing, a high proportion of adult orthodontic treatment still requires adjunctive treatment. In a survey by Musich (1986a) of 1370 consecutively examined adult patients treated by the same orthodontist in two private practices, over two-thirds had undergone adjunctive treatment. Several authors have stressed that close cooperation with other specialists is essential (M usich, l986a; Carastro and Moshiri, 1987; Williams et al., 1982). Not only should the various specialists be aware of the orthodontic possibilities but the orthodontist himself should be fully aware of the scope and capabilities of the other specialists since, in many cases, adult orthodontics can be avoided altogether or treatment time reduced by solutions incorporating prosthetic (Seide, 1970) or restorative (Fine, 1972) care. Materials and methods
The material for this investigation was taken from all available records of adult patients treated, or currently under treatment, in the Orthodontic Department of the Eastman Dental Hospital, London up to December 1988. The term 'adult' in this context referred to any patient aged 18 years or over at the start of active orthodontic treatment. The material obtained fell into two broad categories: Completed cases
These were obtained from the 'Findex System' which is a retrieval system that records all completed orthodontic cases with full records at least I year out of retention or 1 year post-active treatment if there was no retention period. A total of 305 names of adult patients was obtained from this system and the original orthodontic notes of these patients were traced. However, nine sets of notes were unobtainable, leaving 296 available for study. Current cases
These consisted of cases undergoing active treatment or in retention or which were still within the first year post-retention and therefore not yet officially recorded as complete. These were obtained by requesting each treatment operator to make a list of all patients over the age of 18 years at the start of active treatment, who were at that time under their care. By this method a total of 382 names was obtained, the notes of two of them being unavailable for study. Overall there were 676 sets of notes out of a
186 R. S. Khan and E. N. Horrocks
BJO Vol. 18 No. 3
possible 687 (98·4 per cent) available for examination, which were deemed to be representative of the orthodontic adult population treated at the Eastman Dental Hospital. These comprised 296 completed cases and 380 cases which were still under treatment at the time of study. Information collected for each patient included: (I) date of start of treatment, to the nearest month; (2) sex; (3) age at start of treatment, to the nearest month; (4) source of referral; (5) presenting malocclusion, according to Angles incisor classification, as stated in the notes and verified on the L.S. radiograph; (6) presenting skeletal pattern, as stated in notes and checked radiographically (this was classified according to the Eastman Analysis using the corrected ANB value); (7) type of appliance therapy, in terms of fixed or removable appliances; (8) interdisciplinary treatment involving other departments within the hospital; (9) orthognathic surgery-including site of surgery; (10) previous orthodontic treatment. This information relating to the patients and their malocclusion was coded into well defined categories and computerized. The S.P.S.S. (Statistical Package for Social Sciences) program was used in this study to store, assimilate and analyse the data, on an IBM AT compatible computer.
The information obtained was used to determine the frequency distribution of all the variables studied in the population as a whole, which provided some baseline data of adult orthodontics for comparison with other studies and future research. The same data were then grouped chronologically into 5-year time intervals according to the date at the start of treatment. This allowed comparison of the variables between different time periods to determine whether there were any changes or trends in the type of patients or malocclusions treated. Error of the method
The error of method was obtained by randomly extracting 5 per cent of the records and doublechecking all the variables recorded on these patients and their transfer onto the computer. This was calculated to be only 0·2 per cent, thus indicating the system used to be highly reliable. Results and Discussions Introduction
The findings from this investigation are presented in the form of tables and figures and the discussion following will relate to these. The intergroup comparisons were made using Chi square with the following probability levels: P~0·05
P~O·OI P~O·OOI
*Probably significant **Significant ***Highly significant
The information obtained may be considered under
40% >. (.1
c
cu
:I 0'
30%
cu .... (.I.
20%
Pre 1970
1970--'75
1975-'80
1980--'85
1985-'88
Time period FIG. I
Frequency distribution of patients at start of treatment.
Adult patients orthodontic treatment
BJO Augusr /991
TABLE
I
Comparison of age and sex distribution with other studies
Tayer and Burek Thilander Breece and Neiberg Muir et al. Present study
Year
Number of patients
Percentage female
Age
1981 1979 1986 1986 1989
33 1186 204 611 676
85 63 76 71 71
Age range 18-58 yrs; Mean 30·5 yrs; Mode 30 yrs Age range 18-77 yrs; Mean 31 yrs 67% in 18-27 yr age group 66% in 18-25 yr age group (I% over 46 yrs) 67% in 18-25 yr age group (3·7% over 42 yrs)
three broad categories and will be discussed in that order.
1. Epidemiological analysis of the type of patients presenting and their referral pattern (a) Sex distribution (b) Age at the start of treatment (c) Source of referral 2. Factors relating to the presenting malocclusions (a) Incisor classification (b) Skeletal pattern 3. Factors relating to the treatment undertaken (a) Fixed or removable appliances (b) Interdisciplinary treatment (c) Orthognathic surgery (d) Previous orthodontic treatment The results of this survey support the views of several authors and various studies (Levitt, 1971; Fine, 1972; Thilander, 1979) that the number of adults undergoing orthodontic treatment is increasing since over half (54·4 per cent) of all the cases
analysed had been started in the 1985, 1988 period (Fig. 1).
1. Epidemiological analysis of the type of patients presenting and their referral pattern (a) Sex distribution (Table 1). The overall percentage of female patients in this study was 71·6 per cent which is comparable with other studies of adult orthodontic patients (Breece and Nieberg, 1986; Muir et al., 1986). This figure is however, lower than in Tayer and Burek's ( 1981) sample, but higher than in Thilander's study (1979). It should, however, be mentioned that Thilander analysed 1186 patients referred to the Orthodontic Department in Gothenburg, of which 63 per cent were females, but only 444 out of these patients actually underwent active orthodontic treatment and she does not state the sex ratio of these patients accepting treatment. The increased ratio of female patients to male patients is well recognized by most orthodontists
70%
>. (,)
c
0
:I 0"
~
{.I.
187
60% 50% 40% 30% 20% 10% 0% Pre '70
1970-'75
'1975-'80
1980-'85
'1985-'88
Time period
0
>30 yrs
B
26-29 yrs
LZJ
22-25 yrs
-
18-21 yrs
FIG. 2 Frequency distribution of age at start of treatment over period of study.
188
R. S. Khan and E. N. Horrocks
and may reflect a difference in perception ofmalocelusion between the sexes as suggested by several authors (Shaw et al., 1985; Stricker, 1970; Baldwin and Barnes, 1965) or it may be due to the fact that dental appearance is rated to be more important by females than males (Breece and Nieberg, 1986). The ratio of female to male patients is greater in adults than in children. Murray (1985) found a female: male ratio of 3: 2 which was lower than the 7: 3 ratio found in this study, thus tending to suggest that this apparent difference of perception ofmalocclusion between the sexes and willingness to undergo orthodontic treatment increases with age. This study also demonstrates that the sex ratio of 7: 3 was consistent throughout the period of study thus showing that although the number of adult patients undergoing orthodontic treatment is increasing with time, the relative proportion of female: male patients is remaining the same. (b) Age at the start of treatment (Table 1, Fig. 2). Overall 41·1 per cent of the patients were found to be in the 18-21-year age group and almost twothirds under 26 years, which is similar to the findings of Breece and Nieberg (1986) and Muir et al. ( 1986), but younger than found in other adult orthodontic patient surveys. By comparing age at the start of treatment in the different time intervals studied it was apparent that there are more patients in the older groups in recent years and this was highly significant (P < 0·00 I). Any direct comparison of age of patient at start of treatment with other studies can, therefore, only be made if the period of study is also comparable. Taking this into account, it appears that the p~tients in this study were slightly older than those m the study by Muir et al. (1986) which I?ay reflect.a difference in the adult patient population treated m hospitals as opposed to specialist practice. Perhaps the adult patients treated in hospitals have more difjicult malocclusions requiring an interdisciplinary approach? (c) Source of referral (Fig. 3). Almost two~ thirds of the subjects in this study were secondary referrals which is similar to other adult surveys (Thilander, 1979; M usich, 1986a, b) but much lower than found in children by Banks et al. (1988) and, therefore, highlights the differences in referral pattern between children and adults. This proportion is also lower than found by Muir et al. (1986) and the disparity may be explaine~ by the fact that Muir et al. analysed adult patients treated in specialist practices whereas the Eastman Dental Hospital is a secondary and tertiary referral centre.
BJO Vol. 18 No. 3
GDP 64.9%
Perio Prosthetics 5.3% 0.7% FIG. 3 Source of referral.
Referral from the Oral Surgery Department comprised only 5·9 per cent of the total referr~ls which was much lower than the 11 per cent found m the study by Thilander (1979). The referrals from specialist orthodontic practitioners were very few and were, therefore, not listed separately, but incorporated in the general dental practitioners category. The percentage of referrals from general dental practitioners was found to decrease in recent years and this trend was statistically highly significant (P < 0·00 1), thus demonstrating that referral from other dental specialists is increasing. This may be attributed to a greater awareness by the other dental specialists of the possibility. of ~rthod~n~ic~ for adults and a general increase m an mterdiSCiphnary approach to the treatment of adult patients.
Class 11 div 1 39%
Class 11 div 2 9.7% FIG. 4 Incisor classification.
Adult patients orthodontic treatment
BJO All!lll·'' 1991
189
2 Comparison of surveys of prevalence of malocclusion based on Angle's classification
TABLE
Class I(%)
Shropshire schoolchildren (Foster and Day, 1974) Patients discharged at EDH in 1982 (Murray, 1985) Swedish Army recruitsaged 18 yrs (lngervall, 1974) Swedish women (Mohlin, 1982) 200 completed cases at EDH (Fletcher, 1958) Adult dentition Mixed dentition Present study
Il(i) (%)
Il(ii) (%)
Ill(%)
44
52
3·3
30·08
57
12-64
83 71·2
12
33 23 29-6
37 54 39
4 2-4
25·3
20 10 9·7
10
13 21·6
2. Factors relating to the presenting malocc/usion
(a) Incisor Classification (Table 2, Fig. 4). The incidence of Class Ill malocclusion in the general population varies from l-12·2 per cent (Jacobson et al., 1974) although most studies reflect an incidence below the 5 per cent level. Results of this survey, therefore showed an increased proportion of Class Ill malocclusions (21·6 per cent) than is found in the general population. This proportion is also considerably greater than in children undergoing orthodontic treatment (Murray, 1985; Fletcher, 1958) or a cross-section of a non-orthodontic adult population (Mohlin, 1982; Ingervall and Hedegard, 1974). This is to be expected, since the severity of the Class Ill malocclusion generally tends to increase with age and treatment of Class Ill malocclusions with Class Ill skeletal bases is deferred until adulthood, when mandibular growth has ceased, especially if it is thought likely that orthognathic surgery may be required.
(b) Skeletal pattern (Fig. 5). The skeletal pattern also revealed a greater proportion of Class Ill patients than found in other surveys (Foster and Day, 1974; Fletcher, 1958). The results of this survey therefore support the findings of Helm et al. (1983) who found that the morphological feature most strongly associated with the desire for treatment was mandibular overjet, a characteristic more pronounced in adulthood. Both Skeletal Class Ill and Class III malocclusions were as expected more common in male than female patients and these differences were statistically highly significant (P.
u
c
60%
Ill
:I 0"
J:
40% 20% 0%
pre'70
1970-'75
E3 No surgery
B
191
1975-'80 1980-'85 Time period·
Single arch surgery
•
1985-'88
Bimaxillary surgery
FIG. 8 Frequency distribution of orthognathic surgery over period of study.
192 R. S. Khan and E. N. Horrocks
The percentage of adult orthodontic treatment involving orthognathic surgery had highly significantly increased from 10·2 per cent before 1970 to 23·6 per cent in the 1985-1988 period (P
ISSN: 0301-228X (Print) (Online) Journal homepage: http://www.tandfonline.com/loi/yjor19
A study of adult orthodontic patients and their treatment R. S. Khan B.D.S., F.D.S.R.C.S., M.Sc., M.Orth. & E. N. Horrocks B.Ch.D, F.D.S.R.C.S., M.Orth. To cite this article: R. S. Khan B.D.S., F.D.S.R.C.S., M.Sc., M.Orth. & E. N. Horrocks B.Ch.D, F.D.S.R.C.S., M.Orth. (1991) A study of adult orthodontic patients and their treatment, British Journal of Orthodontics, 18:3, 183-194, DOI: 10.1179/bjo.18.3.183 To link to this article: http://dx.doi.org/10.1179/bjo.18.3.183
Published online: 21 Jun 2016.
Submit your article to this journal
Article views: 1
View related articles
Citing articles: 18 View citing articles
Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=yjor19 Download by: [Tufts University]
Date: 15 October 2016, At: 18:21
British Journal of Orthodontics/Vol. 18/ !99 I /183-194
A study of adult orthodontic patients and their treatment R. S. KHAN, B.D.S., F.D.S.R.C.S., M.Sc., M.ORTH. E. N. HORROCKS, B,CH.D, F.D.S.R.C.S., M.ORTH.
Eastman Dental Hospital, 256 Grays Inn Road, London WCI Received for publication July 1990
Abstract. This retrospective epidemiological study was undertaken to assess factors related to adult orthodontic treatment and to identify any associated trends. Case records of all patients (676) aged 18 years or over at the start of active orthodontic treatment at the Eastman Dental Hospital, London were examined. Variables associated with patients and their treatment (age, sex, source of referral, malocclusion, type of appliance, and interdisciplinary treatment including orthognathic surgery) were studied and the data analysed statistically. Findings revealed that the number of adult patients undergoing orthodontic treatment has increased significantly, especially since 1985. The age of the patients treated was also found to increase in recent years. The percentage of female patients (72 per cent) Class Ill malocclusions (21·6 per cent) and Class Ill skeletal bases (26·2 per cent) was higher than found in studies on children. Most of the treatments required fixed appliances and over half involved interdisciplinary treatment, with an increase in the percentage of orthognathic surgical cases. Surgery was significantly more common in males (P < 0·0 1) and highly significantly associated with Class Ill malocclusions and skeletal Ill bases (P < 0·001). Twenty-five per cent of adult patients were found to have had a previous course of orthodontic treatment though .these patients were not significantly different from adult patients presenting for the first course of treatment. Index words: Adult Orthodontics, Malocclusion, Treatment, Survey.
Introduction Adult orthodontics is a rapidly growing field and over the past two decades there has been a noticeably increased demand for orthodontic treatment from adults. This may be attributed to improved dental services and a greater dental awareness amongst adult patients. This increase will be reflected in both adjunctive and comprehensive procedures, and is likely to continue in the future as more aesthetically acceptable appliances are developed and less social stigma is attached to adults Wearing visible orthodontic appliances. Despite this recent exponential rise in adults seeking and undergoing orthodontic treatment, an extensive search of the literature shows that most of the published work on the subject is subjective and speculative in nature, and certainly prevalence data for British populations are lacking. This epidemiological study was undertaken to bridge this gap. The adult patients treated in the orthodontic 030I-228X/91/000000+00S02.00
department at the Eastman Dental Hospital would provide a large data base for analysis. The aims of this retrospective investigation were to study: (1) general factors relating to the adult population undergoing orthodontic treatment, their mal occlusion and treatment undertaken; (2) changes in trends in the type of adult patients treated over a period of time; (3) whether the adult patients undergoing orthognathic surgery differed from the remainder (non-surgical group) in any of the factors studied; (4) whether the adult patients who have had previous orthodontic treatment differed from those presenting for their first course of treatment. In the current climate of financial constraints on the health services, any differentiating factors may be useful in planning treatment, and in the allocation of resources for adult treatment. © 1991 British Society for the Study of Orthodontics
184 R. S. Khan and E. N. Horrocks
Review of the Literature Orthodontic treatment for adult patients is by no means a recent idea. The first reference to it was made by Pierre Fauchard, author of the first known scientific book on dentistry, Le Chirurgien Dentiste in 1723, when he observed that the teeth of young people were easier to move than those of older persons (Goldstein, 1953).
BJO Vol. 18 No. 3
(1981) found the mean age at onset of treatment within a private practice had increased from 11 years in 1964 to 13 years in 1978, whereas Thilander (1979) noticed an increase in the number of adult referrals from 1970 to 1978. The fact that these surveys were completed over l 0 years ago highlights the need for more up to date studies.
Previous adult surveys Prevalence
Several authors have commented on the general trend in the increase in adult orthodontics and have attributed this to many reasons (Fine, 1972; Baum, 1975; Chiappone, 1976). With the success of preventative dentistry over the past 20 years, more patients are retaining their teeth into adulthood and more attention is now being given to the orthodontic treatment needs of adults who were not given the opportunity to receive orthodontic treatment when they were young (Muir et al., 1986). The Adult Dental Health Report of England and Wales (Todd et al., 1978) noted that in the hfghly selected adult population that finds its way into orthodontic practice, there appear to be two increasingly evident traits. I. An overall improvement in general dental health. 2. An increased interest in and expectation of orthodontic treatment. In North America, the increased interest in adult orthodontic treatment is as a result of increased public advertizing and dental education, coupled with insurance benefits and an increased general dental awareness among the population (McGonagle, 1981). , The prevalence of adult orthodontic treatment is difficult to ascertain since the term 'adult' is taken to mean different age groups by different authors. Watson (1979) estimated the number of adults treated in American orthodontic practices constituted 10-25 per cent of the average patient load. More recently, Norton (1988) stated that there is a predominance o(adults in retirement communities in North America, such as Florida where adults may comprise between 60 and 70 per cent of the practice, and in urban business centres with a large adult white collar worker population where some practices consist of almost 100 per cent adults. Very few statistics are available for the i1umbers and trend of adult orthodontic treatment in Europe. However, two studies have shown that the age of orthodontic patients is increasing. Cousins et al.
Tayer and Burek (1981) surveyed adults' attitudes towards orthodontic therapy since they noted a relative paucity of articles on the subject. Their overall results concluded that adult patients, properly motivated and educated, were excellent candidates for orthodontic treatment and had a great appreciation of the results achieved. Muir et al. (1986) questioned 45 orthodontists in specialist practice in New Zealand about personal details of the adult patients treated, their malocclusion, and the orthodontists' attitude to treating adult patients. The percentage of adult patients was found to vary between I and 12 per cent with a mean of 6 per cent; the female to male ratio being 71 per cent to 29 per cent. 74 per cent of the patients were referred by their general dental practitioner and 70 per cent of the adults who sought treatment did so for cosmetic reasons; the principle conditions requiring treatment being excessive incisal overjet and dental crowding. Eighty-six per cent of the orthodontists who returned the questionnaire did not discourage adults from receiving treatment and considered that adults were more appreciative of the treatment provided for them than children. Seventy-five per cent of the orthodontists, however, felt that it took longer to treat adults than children and the result was more compromised. A number of more objective studies into the demand for adult orthodontic treatment have been carried out in the Scandinavian countries. Thilander (1979) looked at the main indications for orthodontic treatment in adults. She reported that between 1970 and 1978, 1186 adults aged between 18 and 77 years were referred to the orthodontic department at the Faculty of Odontology in Gothenburg, Sweden, and that the numbers increased annually during this period. As expected she found a greater demand for treatment in women (63 per cent); the reason for wanting treatment expressed by almost all the patients was a desire for improved appearance of the upper front teeth. The mean age was 31 years and 65 per cent of the patients were referred by their general dental practitioners. Mohlin ( 1982) interviewed 272 randomly selected
Adult patients orthodontic treatment 185
BJO August /991
women from Gothenburg aged between 20 and 45 years. Nine per cent of that sample desired orthodontic treatment and again the expectation of a cosmetic improvement seemed to be the main motivating factor. Breece and Nieberg (1986) surveyed by questionnaire 180 adult patients treated in private practice and 24 in hospital. The principle findings were that two-thirds of the patients were in the 18-27-year age group. Seventy-five per cent were referred by their general dental practitioner, 76 per cent were female, and just over half were married. The main reasons for deferring treatment until their present age was financial since 41 per cent could not afford treatment earlier, whereas 19 per cent had never been recommended or were unaware that anything could have been done earlier. Only 7·6 per cent were retreatment cases. The main motivating factor was aesthetic improvement which is in agreement with the findings of several workers (Muir et al., 1986; Thilander, 1979; Shaw et al., 1975). This is in contrast to children undergoing orthodontic treatment where the mother's desire for treatment is more influential (Baldwin and Barnes, 1965). Comparison of orthodontic treatment between adults and children
There are several similarities that exist between adults and children in terms of orthodontic treatment, but the major difference between the two is the presence or absence of growth (Bond, 1972). The other special considerations that have to be taken into account when treating adult patients include motivation, co-operation, limitations of treatment, biological factors, adjunctive treatment, and the periodontal and restorative condition of the teeth. As the main motivating factor for adults seeking treatment is aesthetic, the patient's perception of the dental appearance is of considerable importance in determining treatment demand and patient cooperation (Shaw, 1981 ). Dentists' and orthodontists' perception of malocclusion and the individual's own views on the acceptability of his dental appearance differ considerably with the professionals operating a more critical dental/aesthetic scale than society in general (Shaw et al., 1975; Prahl-Anderson et al., 1979). Adult orthodontics prior to the 1970's was mainly of an adjunctive nature, i.e. tooth movement was carried out to facilitate other dental procedures necessary to control disease and restore function, and the literature contains many case study reports (Andreason, 1972; Seide, 1970; Levitt, 1971 ).
Although comprehensive orthodontic treatment for adults is increasing, a high proportion of adult orthodontic treatment still requires adjunctive treatment. In a survey by Musich (1986a) of 1370 consecutively examined adult patients treated by the same orthodontist in two private practices, over two-thirds had undergone adjunctive treatment. Several authors have stressed that close cooperation with other specialists is essential (M usich, l986a; Carastro and Moshiri, 1987; Williams et al., 1982). Not only should the various specialists be aware of the orthodontic possibilities but the orthodontist himself should be fully aware of the scope and capabilities of the other specialists since, in many cases, adult orthodontics can be avoided altogether or treatment time reduced by solutions incorporating prosthetic (Seide, 1970) or restorative (Fine, 1972) care. Materials and methods
The material for this investigation was taken from all available records of adult patients treated, or currently under treatment, in the Orthodontic Department of the Eastman Dental Hospital, London up to December 1988. The term 'adult' in this context referred to any patient aged 18 years or over at the start of active orthodontic treatment. The material obtained fell into two broad categories: Completed cases
These were obtained from the 'Findex System' which is a retrieval system that records all completed orthodontic cases with full records at least I year out of retention or 1 year post-active treatment if there was no retention period. A total of 305 names of adult patients was obtained from this system and the original orthodontic notes of these patients were traced. However, nine sets of notes were unobtainable, leaving 296 available for study. Current cases
These consisted of cases undergoing active treatment or in retention or which were still within the first year post-retention and therefore not yet officially recorded as complete. These were obtained by requesting each treatment operator to make a list of all patients over the age of 18 years at the start of active treatment, who were at that time under their care. By this method a total of 382 names was obtained, the notes of two of them being unavailable for study. Overall there were 676 sets of notes out of a
186 R. S. Khan and E. N. Horrocks
BJO Vol. 18 No. 3
possible 687 (98·4 per cent) available for examination, which were deemed to be representative of the orthodontic adult population treated at the Eastman Dental Hospital. These comprised 296 completed cases and 380 cases which were still under treatment at the time of study. Information collected for each patient included: (I) date of start of treatment, to the nearest month; (2) sex; (3) age at start of treatment, to the nearest month; (4) source of referral; (5) presenting malocclusion, according to Angles incisor classification, as stated in the notes and verified on the L.S. radiograph; (6) presenting skeletal pattern, as stated in notes and checked radiographically (this was classified according to the Eastman Analysis using the corrected ANB value); (7) type of appliance therapy, in terms of fixed or removable appliances; (8) interdisciplinary treatment involving other departments within the hospital; (9) orthognathic surgery-including site of surgery; (10) previous orthodontic treatment. This information relating to the patients and their malocclusion was coded into well defined categories and computerized. The S.P.S.S. (Statistical Package for Social Sciences) program was used in this study to store, assimilate and analyse the data, on an IBM AT compatible computer.
The information obtained was used to determine the frequency distribution of all the variables studied in the population as a whole, which provided some baseline data of adult orthodontics for comparison with other studies and future research. The same data were then grouped chronologically into 5-year time intervals according to the date at the start of treatment. This allowed comparison of the variables between different time periods to determine whether there were any changes or trends in the type of patients or malocclusions treated. Error of the method
The error of method was obtained by randomly extracting 5 per cent of the records and doublechecking all the variables recorded on these patients and their transfer onto the computer. This was calculated to be only 0·2 per cent, thus indicating the system used to be highly reliable. Results and Discussions Introduction
The findings from this investigation are presented in the form of tables and figures and the discussion following will relate to these. The intergroup comparisons were made using Chi square with the following probability levels: P~0·05
P~O·OI P~O·OOI
*Probably significant **Significant ***Highly significant
The information obtained may be considered under
40% >. (.1
c
cu
:I 0'
30%
cu .... (.I.
20%
Pre 1970
1970--'75
1975-'80
1980--'85
1985-'88
Time period FIG. I
Frequency distribution of patients at start of treatment.
Adult patients orthodontic treatment
BJO Augusr /991
TABLE
I
Comparison of age and sex distribution with other studies
Tayer and Burek Thilander Breece and Neiberg Muir et al. Present study
Year
Number of patients
Percentage female
Age
1981 1979 1986 1986 1989
33 1186 204 611 676
85 63 76 71 71
Age range 18-58 yrs; Mean 30·5 yrs; Mode 30 yrs Age range 18-77 yrs; Mean 31 yrs 67% in 18-27 yr age group 66% in 18-25 yr age group (I% over 46 yrs) 67% in 18-25 yr age group (3·7% over 42 yrs)
three broad categories and will be discussed in that order.
1. Epidemiological analysis of the type of patients presenting and their referral pattern (a) Sex distribution (b) Age at the start of treatment (c) Source of referral 2. Factors relating to the presenting malocclusions (a) Incisor classification (b) Skeletal pattern 3. Factors relating to the treatment undertaken (a) Fixed or removable appliances (b) Interdisciplinary treatment (c) Orthognathic surgery (d) Previous orthodontic treatment The results of this survey support the views of several authors and various studies (Levitt, 1971; Fine, 1972; Thilander, 1979) that the number of adults undergoing orthodontic treatment is increasing since over half (54·4 per cent) of all the cases
analysed had been started in the 1985, 1988 period (Fig. 1).
1. Epidemiological analysis of the type of patients presenting and their referral pattern (a) Sex distribution (Table 1). The overall percentage of female patients in this study was 71·6 per cent which is comparable with other studies of adult orthodontic patients (Breece and Nieberg, 1986; Muir et al., 1986). This figure is however, lower than in Tayer and Burek's ( 1981) sample, but higher than in Thilander's study (1979). It should, however, be mentioned that Thilander analysed 1186 patients referred to the Orthodontic Department in Gothenburg, of which 63 per cent were females, but only 444 out of these patients actually underwent active orthodontic treatment and she does not state the sex ratio of these patients accepting treatment. The increased ratio of female patients to male patients is well recognized by most orthodontists
70%
>. (,)
c
0
:I 0"
~
{.I.
187
60% 50% 40% 30% 20% 10% 0% Pre '70
1970-'75
'1975-'80
1980-'85
'1985-'88
Time period
0
>30 yrs
B
26-29 yrs
LZJ
22-25 yrs
-
18-21 yrs
FIG. 2 Frequency distribution of age at start of treatment over period of study.
188
R. S. Khan and E. N. Horrocks
and may reflect a difference in perception ofmalocelusion between the sexes as suggested by several authors (Shaw et al., 1985; Stricker, 1970; Baldwin and Barnes, 1965) or it may be due to the fact that dental appearance is rated to be more important by females than males (Breece and Nieberg, 1986). The ratio of female to male patients is greater in adults than in children. Murray (1985) found a female: male ratio of 3: 2 which was lower than the 7: 3 ratio found in this study, thus tending to suggest that this apparent difference of perception ofmalocclusion between the sexes and willingness to undergo orthodontic treatment increases with age. This study also demonstrates that the sex ratio of 7: 3 was consistent throughout the period of study thus showing that although the number of adult patients undergoing orthodontic treatment is increasing with time, the relative proportion of female: male patients is remaining the same. (b) Age at the start of treatment (Table 1, Fig. 2). Overall 41·1 per cent of the patients were found to be in the 18-21-year age group and almost twothirds under 26 years, which is similar to the findings of Breece and Nieberg (1986) and Muir et al. ( 1986), but younger than found in other adult orthodontic patient surveys. By comparing age at the start of treatment in the different time intervals studied it was apparent that there are more patients in the older groups in recent years and this was highly significant (P < 0·00 I). Any direct comparison of age of patient at start of treatment with other studies can, therefore, only be made if the period of study is also comparable. Taking this into account, it appears that the p~tients in this study were slightly older than those m the study by Muir et al. (1986) which I?ay reflect.a difference in the adult patient population treated m hospitals as opposed to specialist practice. Perhaps the adult patients treated in hospitals have more difjicult malocclusions requiring an interdisciplinary approach? (c) Source of referral (Fig. 3). Almost two~ thirds of the subjects in this study were secondary referrals which is similar to other adult surveys (Thilander, 1979; M usich, 1986a, b) but much lower than found in children by Banks et al. (1988) and, therefore, highlights the differences in referral pattern between children and adults. This proportion is also lower than found by Muir et al. (1986) and the disparity may be explaine~ by the fact that Muir et al. analysed adult patients treated in specialist practices whereas the Eastman Dental Hospital is a secondary and tertiary referral centre.
BJO Vol. 18 No. 3
GDP 64.9%
Perio Prosthetics 5.3% 0.7% FIG. 3 Source of referral.
Referral from the Oral Surgery Department comprised only 5·9 per cent of the total referr~ls which was much lower than the 11 per cent found m the study by Thilander (1979). The referrals from specialist orthodontic practitioners were very few and were, therefore, not listed separately, but incorporated in the general dental practitioners category. The percentage of referrals from general dental practitioners was found to decrease in recent years and this trend was statistically highly significant (P < 0·00 1), thus demonstrating that referral from other dental specialists is increasing. This may be attributed to a greater awareness by the other dental specialists of the possibility. of ~rthod~n~ic~ for adults and a general increase m an mterdiSCiphnary approach to the treatment of adult patients.
Class 11 div 1 39%
Class 11 div 2 9.7% FIG. 4 Incisor classification.
Adult patients orthodontic treatment
BJO All!lll·'' 1991
189
2 Comparison of surveys of prevalence of malocclusion based on Angle's classification
TABLE
Class I(%)
Shropshire schoolchildren (Foster and Day, 1974) Patients discharged at EDH in 1982 (Murray, 1985) Swedish Army recruitsaged 18 yrs (lngervall, 1974) Swedish women (Mohlin, 1982) 200 completed cases at EDH (Fletcher, 1958) Adult dentition Mixed dentition Present study
Il(i) (%)
Il(ii) (%)
Ill(%)
44
52
3·3
30·08
57
12-64
83 71·2
12
33 23 29-6
37 54 39
4 2-4
25·3
20 10 9·7
10
13 21·6
2. Factors relating to the presenting malocc/usion
(a) Incisor Classification (Table 2, Fig. 4). The incidence of Class Ill malocclusion in the general population varies from l-12·2 per cent (Jacobson et al., 1974) although most studies reflect an incidence below the 5 per cent level. Results of this survey, therefore showed an increased proportion of Class Ill malocclusions (21·6 per cent) than is found in the general population. This proportion is also considerably greater than in children undergoing orthodontic treatment (Murray, 1985; Fletcher, 1958) or a cross-section of a non-orthodontic adult population (Mohlin, 1982; Ingervall and Hedegard, 1974). This is to be expected, since the severity of the Class Ill malocclusion generally tends to increase with age and treatment of Class Ill malocclusions with Class Ill skeletal bases is deferred until adulthood, when mandibular growth has ceased, especially if it is thought likely that orthognathic surgery may be required.
(b) Skeletal pattern (Fig. 5). The skeletal pattern also revealed a greater proportion of Class Ill patients than found in other surveys (Foster and Day, 1974; Fletcher, 1958). The results of this survey therefore support the findings of Helm et al. (1983) who found that the morphological feature most strongly associated with the desire for treatment was mandibular overjet, a characteristic more pronounced in adulthood. Both Skeletal Class Ill and Class III malocclusions were as expected more common in male than female patients and these differences were statistically highly significant (P.
u
c
60%
Ill
:I 0"
J:
40% 20% 0%
pre'70
1970-'75
E3 No surgery
B
191
1975-'80 1980-'85 Time period·
Single arch surgery
•
1985-'88
Bimaxillary surgery
FIG. 8 Frequency distribution of orthognathic surgery over period of study.
192 R. S. Khan and E. N. Horrocks
The percentage of adult orthodontic treatment involving orthognathic surgery had highly significantly increased from 10·2 per cent before 1970 to 23·6 per cent in the 1985-1988 period (P
