Public Dental Health
Dental health status and treatment needs of students at a disadvantaged secondary school, Victoria, Australia - 1975 A. JDepartment
of Conservative Dentistry, University oj Melbourne, Victoria, Australia Spencer, A. J.; Dental health status and treattnent needs of students at a disadvantaged secondary school, Victoria, Australia - 1975. Corntnunity Dent. Oral Epidetniol. 1978: 6217-221. Abstract - The dental health status and treatmerit needs of 302 secondary school students (182 boys, 120 girls; age range 11-16 years) were surveyed. Restorative, exodontic, periodontic, prosthetic, and orthodontic treatment needs were assessed at the time of examination. The dental health status was poor and the amount of treattnent needed was high. Treatment needs increased with age and were donrinated by restorative work. The average student required 19.8 relative value units of work, taking 234 hours and costing A$ 93.00. Keywords: dental health survey. A. J. Spencer, Departnrent of Conservative Dentistry, University of Melbourne, 711 Elizabeth Street, Melbourne, Victoria, 3000, Australia (Accepted for publication 27 May 1978)
In the past, few Australian studies have placed emphasis on the collection of information on treatment needs (2,8, 11, 14). The rapid expansion of the Victorian public dental health services has made it desirable that effective methods of collecting information on treatment needs be established, Xhis survey was designed to assess both the dental health status and treatment needs of students at a secondary school in Melbourne, Victoria. The 837 students attending the school lived within a Victorian Government Housing Commission Estate, providing housing to large families with low income. The majority of parents were either tradesmen, process 'Workers, labourers or unskilled workers and few had schooling past the required minimum age of 15 years. At the time of the study the water supply of Melbourne was not fluoridated.
MATERIAL AND METHODS A randotn sample of 302 students (males 182, females 120; age range 11-16 years) participated in inspection-type examinations. The examinations were carried out by graduate students of the University of Melbourne. All examiners participated in criteria discussions and calibration exercises prior to the survey.
DENTAL HEALTH STATUS Dental caries experience status was assessed by the DMFT Index based on a diagonal half-mouth examitialion. Alternate sides of the tnouth were examined in successive patients. The 'WHO recommendations (21) for the recording of caries experience were followed with the exception that three caries diagnostic severity levels (Decay Types 1, 2 and 3) were delineated, adapted from those of MOLI^ER & Pour.sr:N (15). Oral hygiene and periodontal status were assessed according to the system designed for public health purposes by DAVit'.s, HoROwrTZ & WADA (7). Prosthetic status was categorized by the presence and type of removable pros-
218
SPENCER
thetic appliance worn at the time of exatrrination. Orthodontic status was assessed by means of occlusal traits similar to the systetn used by the Danish Child Dental Health Service (12), and subjectively applying the criteria of BjORK, KREBS & SoLow (3). TREATMENT NEEDS Restorative, endodontic and exodontic treatment needs were recorded for the teeth in the diagonal half-mouth examination usitig criteria based on those recommended by DAvrr:s, HOROWITZ & WADA (6). The criteria for recording the need for a filling was the invasion of dentine by caries (Decay Type 2). Periodontal treatment needs were based on the Periodontal Treatment Needs System described by JOHANSEN, GJERMO & BEi.LtNr (13) with treatment categories applied to the whole mouth only and the critical depth of pockets indicating surgery increased to 6 mm instead of 5 mm. Prosthetic treatment needs were assessed after examination of existing appliances, edentulous areas or teeth indicated for extraction in the whole mouth. Eixed prosthetic appliances were not included as possible prosthetic treatment. Orthodontic treatment was considered inappropriate for students with many untreated carious lesions, missing teeth, poor oral hygiene or poor periodontal health and poor long-term prognosis. Treatment needs were then subjectively assessed, applying the Malocclusion Severity Score described by Scrvtt^R, MENtiZES & PARKr'.R (17). A scale of relative value units (RVU) representing work units, based on the Canadian Dental Association's Relative Value Method of Fee Determination (4), and a time scale were constructed for the treatment categories. The cost scale was taken directly from the Australian Repatriation Commission's Fee List (18), and all three estimates calculated for individual or combined treatment categories. Orthodontic needs requiring specialist treatment were excluded from these estimates. The students were divided into three age groups (11-12 years, 13-14 years and 15-16 years). One-way analysis of variance and t-tests were used to test for significant group differences where appropriate. A significance level of P < 0.05 was set.
RESULTS DENTAL HEALTH STATUS Caries experience was high as 98.3 % of the sample had evidence of caries experienee. Of the total sample only 11.2 % had no untreated caries. No sex differenees were observed. The average number of decayed teeth was 6.5. The average number of teeth missing because of caries was 0.6, and another 0.7 teeth were missing for other reasons. The average number of filled teeth was 3.2. These combined to give a DMFT of 10.3. The DMFT increased significantly between eaeh age group. The average
Table 1. The frequency with which categories of treatment needs were required and the percentage of the total work units which they represent • Treatment item Examination, diagnosis and treatment planning Restorative 1 - surface filling 2 - surface filling 3 - surface filling Multisurface filling Other
Frequency
% of total RVU
100.00
70.6 64.7 26.7
26.7
14.4 21.5 9.2
5.6
1.9
5.0
1.7
48.7
Endodontics
3.0
Exodontics: due to caries prosthetic reasons
9.6 LO
1.9 LO
2.9
Oral hygiene and periodontic O.H.L only O.H.L plus scaling
44.2 55.8
2.2 4.0
6.2
0.3 0.7
0.3 Ll LO
Prosthetic F/F/P P/P P/-/P Orthodontic Extraction of shortterm appliance Appliance (orthodontic specialist advice) Advanced treattnent Severe condition
0.7 0.3 1.3
:
2.6
1
0.2 LO
3.6 •••••1
4.6
1.8
6.0
7.5 * *
17.9 LO
9.3
* Not included in the calculation of work units
ratio of D/DMFT was 0.65 and of F/DMFT was.
0.28.
I
Oral hygiene was generally poor. No student was S free of oral debris and this was visible without probing in 23.8 % of students and on probing in a further 76.2 %. Galeulus was observed in 55.8 % • of students. Gingival inflammation was present in nearly all segments and was observed without | bleeding in 65.0 % of students and with bleeding in ' 32.7 % of students. Only 2.3 % had no gingival inflammation. 62.0 % of students had pocket depths under 3 mm and 38.0 % had some pockets between 3 mm and 6 mm deep. The average seg- i
Dental status and Ireatment needs
mental severity ratikitig scores were: oral debris 1,1, calculus 0,1, gingival itiflamtnation 1.0, and pocketing 0.2. These showed tio significant age or sex ^ trends. Prosthetic appliances, upper acrylic partial dentures only, were worn by 1.3 % of students. Orthodontic atiomalies were common. The most frequent: ly observed traits were rotated teeth (67,3 % ) , tipping (35,3 % ) , crowding of the incisal segment of the maxilla (29,4%) atid tnandible (30,0%), •spacing of the right (40,3%) and left posterior segments of the tnandible (38,9%), and tnidlirte displacement (39,9 % ) , Orthodontie appliances, in all cases removable, were observed in 1,0 % of I students. TREATMENT NEEDS The categories of treatment and the frequeney with which they were required, arc listed in Table 1, Restorative, endodontie and/or exodontie treatJment was required by 88,8 % of studetits. No sex * differences were observed. All categories of restorative treatment showed a trend to inerease with increasing age. An average of 6,1 fillitigs was required per student. This was made up of 2.9 otiesurface, 2.3 two-surface, 0.8 three-surface and 0.1 multisurfaee ( > 3 surface) fillings. Oral hygiene education and instruetion (OHI) ; alone or with aeeompanying sealing of the teeth i was the periodontal treatment required. There was I a trend towards sealing of the teeth to be required in proportionally more students in the older age groups. All prostheses required were first appliances, either full or aerylie partial dentures. The types of appliances required are listed in Table 1. Orthodontic treatment was needed by 29.5 % of the total sample. The varying complexity of treatment is listed in Table 1. UNITS OF TREATMENT, TIME AND COST ESTIMATES Tbe pereentage of the total RVU represented by individual treatment items, is given iti Table 1. Estimates of the average RVU, treatment time and cost by age are represented in Fig. 1. All eategories of treatment needs increase with age exeept orthodontic treatment needs, examination, diagnosis and treatment planning. Overall estimates also inereased with age. The inereases iti all three estimates from
219
RFSTORATIVE [NDnoONTIC EXOtXlNTIC EXAMINATION DIAGNOSIS TREATMENT PLANNING
11,1? 13,14 15,16
11,12 13,14 15,16
AGE GROUPS
AGE GROUPS
11.12 13,14 15,16 AGE GROUPS
Eig. 1. Estimates of the average number of work units (RVU), treatment time and eost by age.
the youngest to middle age group were signifieant. The average student required 19,8 RVU, taking 2 4 hours and eosting A$ 93.00.
DISCUSSION The dental health status was similar to reports from other states of Australia (1, 8, 11, 14, 16). The study populatioti was one experieneing a high prevalenee of dental earies, but a low restorative treatment eomponent. The average ratio of teeth involved in aetive lesions to teeth restored was 2.0:1. The figures for the teeth missing beeause of earies and missing for other reasons demonstrated that a eonsiderable atnount of the treatment reeeived by the studetits was of an exodontie nature. The large number of tnissing teeth may have infhieneed the oeelusal traits observed. Assessing both treatment needs and oral health status at the time of examination provides valuable data for the planning of dental health eare delivery serviees. It overeomes the inadequaeies of esti-
220 SPENCER
mating treatmetit needs based on caries experienee data (5), In this .study estimates were made only on the existing dental treatment needs and no eomment ean be made on estimates of maintenance. Although the yearly increment of new carious lesion.s requiring filling and the number of failed fillings is not known, the increase in the baeklog of treatment needs by age is shown in Fig, 1, The inability of most publie health systems to cope with the enormous backlog of treatment needs has led to the development of incremental eare programs. These are generally implemented at the earliest practicable age and often extend only up to the end of primary school education. The timing of the itnplementation of sueh incremental eare programs (10) and their duration (20) has been questioned. Issues that need to be examined include: the importance of the permanent dentition; the inereased need for fillings from the post-primary period until the age of 24 years; the value of the prevention of early loss of primary teeth compared with the prevention of loss of permanent teeth in preventing malocelusion; and the educational and behavioural effectiveness of incremental care programs implemented at an early age and of limited duration. The percentage of the RVU represented by individual treatment items determines the type of serviee required. The type of serviee had emphasis on accurate examination, diagnosis and treatment planning, and prevention both of caries and periodontal disease. Filling carious teeth dominated the estimates of work units. Prosthe.ses played a lesser role. The estimation of orthodontie treatment ineluded only those le.ss complex proeedures which a general practitioner would undertake and hence was under-represented. A further 18,9 % of the students were thought to require orthodontic specialist treatment. The provision of access to sueh treatment and the availability of a diagnostie referral system for general practitioners is required. The proportion oi treatment that could be earried out by auxiliary personnel is important, both from cost and manpower considerations (9). Sehool Dental Therapists eould undertake a great proportion of the work, and the recently proposed Lieensed Dental Nurse and Dental Hygienist (19) could also be effectively utilized.
Acknowledgemenls - I would like to acknowledge the work of those graduate students of tre Department of Conservative Dentistry who participated in the field work of the survey.
REFERENCES 1. BAKN.ARD, P. D . : Dental .survey of .state school children in New South Wales. N, H, & M. R. C. Special Report Series No. 8. Canberra 1956. 2. BARNAKD, P . D , & BovLES, J. R.: Dental service for Australian university students, Au.st. Univ. 1976: 1465-68. 3. BjoKK, A., KRI;I!S, A. A, & Soi.ow, B.: A method for epidemiological registration of malocelusion, Acta Odontoi. Scand. 1964: 22: 2 7 ^ 1 . 4. CLAPPISON, R . A., PRIVSSEY, W . W . & FKKEMAN, R . C :
Relative value method of fee determination. Can. Dent. Assoe. J. 1965: 31: 763-778. 5. D.wiES, C. N.: Cost and benefit of fluoride in the prevention of dental earies. World Health Organization. Geneva 1974, Annex 2, pp. 77-81. 6. DAVIES, G . N . , HOROWITZ, H , S, & WADA, W . : The as-
sessment of dental earies for public health purposes. Community Dent. Or(d Epidemiol. 1973: 1: 68-73, 7. DAVIES, G . N . , HOROWITZ, H . S, & WADA, W , : The as-
sessment of periodontal disease for public health purposes. / . Periodontal Res. 1974: 9: 62-70, 8. DAVIES, G , N , , KRUGER, B . J., & HOMAN, B . T . : Dental
survey of children in country districts of Queensland, '• Aust. Dent. / . 1969: 14: 153-161. 9. DUNNING, J. M.: Development and eontrol of dental auxiliaries in New Zealand and Australia. / . Am. Dent. Assoe. 1972: 85; 618-626. 10. DUNNING, J. M,: Dental care for everyone. Problems ' and proposals. Harvard University Press, Cambridge, Mass. 1976, pp. 65-69, 11. FANNING, E . A., GOTJAMANOS, T . & VOWI.ES, N . J,,-
Dental health and treatment requirements of South Australian secondary school children, Med. J. Aust 1969: 2: 899-901, 12. HEI.M, S,: Reeording system for the Danish dental health services. Community Dent. Oral Epidemiot 1973: /.• 3-8, 13. JoHANSEN, J, R., GJERMO, P. & BELLINI, H . T , : A sys-
tem to clarify the need for periodontal treatment. Aeta Odontot. Scand. 1973: 31: 297-306. 14. MEDCAI.F, G . W . : Report on caries experience and treatment needs in Western Australian children aged J 6-14 years. Prefluoridation dental assessment sur\-ey, ' November 1967. Aust, Dent. J. 1970: 15: 50-54. '• 15. MoLLER, I. J. & PouLSEN, S.: A standardized system j for diagnosing, recording and analysing dental caries ' data. Scand. j . Dent. Res. 1973: 8 / ; 1-11. : 16. RoDER, D. M.: The dental health and habits of South j Australian children from different soeio-economic environments, Aust. Dent. J. 1971: 16: 34-40, 17. SciviER, G. A., MENEZES, D , M , & P.ARKER, C . D . : A
pilot study to assess the validity of the orthodontic
Dental status and treatment needs 221 treatment priority index in English schoolchildren. Community Dent. Oral Epidetniol. 1974: 2: 246-252. '18. Australian Dental Association: News Bulletin 1975: No. 5 7 : p. 45. ]9. D e n t a l Board of Victoria: Advisory cotnntittee upon t h e duties of dental nurse. The auxiliary and dental practice: report of advisory comtnittee. Melbourne 1976.
20. New Zealand Departrnent of Health: Dental health status oj the New Zealattd population in late adolescence and young adulthood. Special report series No. 29. Cotnpiled Beck, D. J. Govennnent Printer, Welliugton 1968, pp. 82-84. 21. World Health Organization: Oral health surveys. Basic methods. WHO, Geneva 1971.
Dental health status and treatment needs of students at a disadvantaged secondary school, Victoria, Australia - 1975 A. JDepartment
of Conservative Dentistry, University oj Melbourne, Victoria, Australia Spencer, A. J.; Dental health status and treattnent needs of students at a disadvantaged secondary school, Victoria, Australia - 1975. Corntnunity Dent. Oral Epidetniol. 1978: 6217-221. Abstract - The dental health status and treatmerit needs of 302 secondary school students (182 boys, 120 girls; age range 11-16 years) were surveyed. Restorative, exodontic, periodontic, prosthetic, and orthodontic treatment needs were assessed at the time of examination. The dental health status was poor and the amount of treattnent needed was high. Treatment needs increased with age and were donrinated by restorative work. The average student required 19.8 relative value units of work, taking 234 hours and costing A$ 93.00. Keywords: dental health survey. A. J. Spencer, Departnrent of Conservative Dentistry, University of Melbourne, 711 Elizabeth Street, Melbourne, Victoria, 3000, Australia (Accepted for publication 27 May 1978)
In the past, few Australian studies have placed emphasis on the collection of information on treatment needs (2,8, 11, 14). The rapid expansion of the Victorian public dental health services has made it desirable that effective methods of collecting information on treatment needs be established, Xhis survey was designed to assess both the dental health status and treatment needs of students at a secondary school in Melbourne, Victoria. The 837 students attending the school lived within a Victorian Government Housing Commission Estate, providing housing to large families with low income. The majority of parents were either tradesmen, process 'Workers, labourers or unskilled workers and few had schooling past the required minimum age of 15 years. At the time of the study the water supply of Melbourne was not fluoridated.
MATERIAL AND METHODS A randotn sample of 302 students (males 182, females 120; age range 11-16 years) participated in inspection-type examinations. The examinations were carried out by graduate students of the University of Melbourne. All examiners participated in criteria discussions and calibration exercises prior to the survey.
DENTAL HEALTH STATUS Dental caries experience status was assessed by the DMFT Index based on a diagonal half-mouth examitialion. Alternate sides of the tnouth were examined in successive patients. The 'WHO recommendations (21) for the recording of caries experience were followed with the exception that three caries diagnostic severity levels (Decay Types 1, 2 and 3) were delineated, adapted from those of MOLI^ER & Pour.sr:N (15). Oral hygiene and periodontal status were assessed according to the system designed for public health purposes by DAVit'.s, HoROwrTZ & WADA (7). Prosthetic status was categorized by the presence and type of removable pros-
218
SPENCER
thetic appliance worn at the time of exatrrination. Orthodontic status was assessed by means of occlusal traits similar to the systetn used by the Danish Child Dental Health Service (12), and subjectively applying the criteria of BjORK, KREBS & SoLow (3). TREATMENT NEEDS Restorative, endodontic and exodontic treatment needs were recorded for the teeth in the diagonal half-mouth examination usitig criteria based on those recommended by DAvrr:s, HOROWITZ & WADA (6). The criteria for recording the need for a filling was the invasion of dentine by caries (Decay Type 2). Periodontal treatment needs were based on the Periodontal Treatment Needs System described by JOHANSEN, GJERMO & BEi.LtNr (13) with treatment categories applied to the whole mouth only and the critical depth of pockets indicating surgery increased to 6 mm instead of 5 mm. Prosthetic treatment needs were assessed after examination of existing appliances, edentulous areas or teeth indicated for extraction in the whole mouth. Eixed prosthetic appliances were not included as possible prosthetic treatment. Orthodontic treatment was considered inappropriate for students with many untreated carious lesions, missing teeth, poor oral hygiene or poor periodontal health and poor long-term prognosis. Treatment needs were then subjectively assessed, applying the Malocclusion Severity Score described by Scrvtt^R, MENtiZES & PARKr'.R (17). A scale of relative value units (RVU) representing work units, based on the Canadian Dental Association's Relative Value Method of Fee Determination (4), and a time scale were constructed for the treatment categories. The cost scale was taken directly from the Australian Repatriation Commission's Fee List (18), and all three estimates calculated for individual or combined treatment categories. Orthodontic needs requiring specialist treatment were excluded from these estimates. The students were divided into three age groups (11-12 years, 13-14 years and 15-16 years). One-way analysis of variance and t-tests were used to test for significant group differences where appropriate. A significance level of P < 0.05 was set.
RESULTS DENTAL HEALTH STATUS Caries experience was high as 98.3 % of the sample had evidence of caries experienee. Of the total sample only 11.2 % had no untreated caries. No sex differenees were observed. The average number of decayed teeth was 6.5. The average number of teeth missing because of caries was 0.6, and another 0.7 teeth were missing for other reasons. The average number of filled teeth was 3.2. These combined to give a DMFT of 10.3. The DMFT increased significantly between eaeh age group. The average
Table 1. The frequency with which categories of treatment needs were required and the percentage of the total work units which they represent • Treatment item Examination, diagnosis and treatment planning Restorative 1 - surface filling 2 - surface filling 3 - surface filling Multisurface filling Other
Frequency
% of total RVU
100.00
70.6 64.7 26.7
26.7
14.4 21.5 9.2
5.6
1.9
5.0
1.7
48.7
Endodontics
3.0
Exodontics: due to caries prosthetic reasons
9.6 LO
1.9 LO
2.9
Oral hygiene and periodontic O.H.L only O.H.L plus scaling
44.2 55.8
2.2 4.0
6.2
0.3 0.7
0.3 Ll LO
Prosthetic F/F/P P/P P/-/P Orthodontic Extraction of shortterm appliance Appliance (orthodontic specialist advice) Advanced treattnent Severe condition
0.7 0.3 1.3
:
2.6
1
0.2 LO
3.6 •••••1
4.6
1.8
6.0
7.5 * *
17.9 LO
9.3
* Not included in the calculation of work units
ratio of D/DMFT was 0.65 and of F/DMFT was.
0.28.
I
Oral hygiene was generally poor. No student was S free of oral debris and this was visible without probing in 23.8 % of students and on probing in a further 76.2 %. Galeulus was observed in 55.8 % • of students. Gingival inflammation was present in nearly all segments and was observed without | bleeding in 65.0 % of students and with bleeding in ' 32.7 % of students. Only 2.3 % had no gingival inflammation. 62.0 % of students had pocket depths under 3 mm and 38.0 % had some pockets between 3 mm and 6 mm deep. The average seg- i
Dental status and Ireatment needs
mental severity ratikitig scores were: oral debris 1,1, calculus 0,1, gingival itiflamtnation 1.0, and pocketing 0.2. These showed tio significant age or sex ^ trends. Prosthetic appliances, upper acrylic partial dentures only, were worn by 1.3 % of students. Orthodontic atiomalies were common. The most frequent: ly observed traits were rotated teeth (67,3 % ) , tipping (35,3 % ) , crowding of the incisal segment of the maxilla (29,4%) atid tnandible (30,0%), •spacing of the right (40,3%) and left posterior segments of the tnandible (38,9%), and tnidlirte displacement (39,9 % ) , Orthodontie appliances, in all cases removable, were observed in 1,0 % of I students. TREATMENT NEEDS The categories of treatment and the frequeney with which they were required, arc listed in Table 1, Restorative, endodontie and/or exodontie treatJment was required by 88,8 % of studetits. No sex * differences were observed. All categories of restorative treatment showed a trend to inerease with increasing age. An average of 6,1 fillitigs was required per student. This was made up of 2.9 otiesurface, 2.3 two-surface, 0.8 three-surface and 0.1 multisurfaee ( > 3 surface) fillings. Oral hygiene education and instruetion (OHI) ; alone or with aeeompanying sealing of the teeth i was the periodontal treatment required. There was I a trend towards sealing of the teeth to be required in proportionally more students in the older age groups. All prostheses required were first appliances, either full or aerylie partial dentures. The types of appliances required are listed in Table 1. Orthodontic treatment was needed by 29.5 % of the total sample. The varying complexity of treatment is listed in Table 1. UNITS OF TREATMENT, TIME AND COST ESTIMATES Tbe pereentage of the total RVU represented by individual treatment items, is given iti Table 1. Estimates of the average RVU, treatment time and cost by age are represented in Fig. 1. All eategories of treatment needs increase with age exeept orthodontic treatment needs, examination, diagnosis and treatment planning. Overall estimates also inereased with age. The inereases iti all three estimates from
219
RFSTORATIVE [NDnoONTIC EXOtXlNTIC EXAMINATION DIAGNOSIS TREATMENT PLANNING
11,1? 13,14 15,16
11,12 13,14 15,16
AGE GROUPS
AGE GROUPS
11.12 13,14 15,16 AGE GROUPS
Eig. 1. Estimates of the average number of work units (RVU), treatment time and eost by age.
the youngest to middle age group were signifieant. The average student required 19,8 RVU, taking 2 4 hours and eosting A$ 93.00.
DISCUSSION The dental health status was similar to reports from other states of Australia (1, 8, 11, 14, 16). The study populatioti was one experieneing a high prevalenee of dental earies, but a low restorative treatment eomponent. The average ratio of teeth involved in aetive lesions to teeth restored was 2.0:1. The figures for the teeth missing beeause of earies and missing for other reasons demonstrated that a eonsiderable atnount of the treatment reeeived by the studetits was of an exodontie nature. The large number of tnissing teeth may have infhieneed the oeelusal traits observed. Assessing both treatment needs and oral health status at the time of examination provides valuable data for the planning of dental health eare delivery serviees. It overeomes the inadequaeies of esti-
220 SPENCER
mating treatmetit needs based on caries experienee data (5), In this .study estimates were made only on the existing dental treatment needs and no eomment ean be made on estimates of maintenance. Although the yearly increment of new carious lesion.s requiring filling and the number of failed fillings is not known, the increase in the baeklog of treatment needs by age is shown in Fig, 1, The inability of most publie health systems to cope with the enormous backlog of treatment needs has led to the development of incremental eare programs. These are generally implemented at the earliest practicable age and often extend only up to the end of primary school education. The timing of the itnplementation of sueh incremental eare programs (10) and their duration (20) has been questioned. Issues that need to be examined include: the importance of the permanent dentition; the inereased need for fillings from the post-primary period until the age of 24 years; the value of the prevention of early loss of primary teeth compared with the prevention of loss of permanent teeth in preventing malocelusion; and the educational and behavioural effectiveness of incremental care programs implemented at an early age and of limited duration. The percentage of the RVU represented by individual treatment items determines the type of serviee required. The type of serviee had emphasis on accurate examination, diagnosis and treatment planning, and prevention both of caries and periodontal disease. Filling carious teeth dominated the estimates of work units. Prosthe.ses played a lesser role. The estimation of orthodontie treatment ineluded only those le.ss complex proeedures which a general practitioner would undertake and hence was under-represented. A further 18,9 % of the students were thought to require orthodontic specialist treatment. The provision of access to sueh treatment and the availability of a diagnostie referral system for general practitioners is required. The proportion oi treatment that could be earried out by auxiliary personnel is important, both from cost and manpower considerations (9). Sehool Dental Therapists eould undertake a great proportion of the work, and the recently proposed Lieensed Dental Nurse and Dental Hygienist (19) could also be effectively utilized.
Acknowledgemenls - I would like to acknowledge the work of those graduate students of tre Department of Conservative Dentistry who participated in the field work of the survey.
REFERENCES 1. BAKN.ARD, P. D . : Dental .survey of .state school children in New South Wales. N, H, & M. R. C. Special Report Series No. 8. Canberra 1956. 2. BARNAKD, P . D , & BovLES, J. R.: Dental service for Australian university students, Au.st. Univ. 1976: 1465-68. 3. BjoKK, A., KRI;I!S, A. A, & Soi.ow, B.: A method for epidemiological registration of malocelusion, Acta Odontoi. Scand. 1964: 22: 2 7 ^ 1 . 4. CLAPPISON, R . A., PRIVSSEY, W . W . & FKKEMAN, R . C :
Relative value method of fee determination. Can. Dent. Assoe. J. 1965: 31: 763-778. 5. D.wiES, C. N.: Cost and benefit of fluoride in the prevention of dental earies. World Health Organization. Geneva 1974, Annex 2, pp. 77-81. 6. DAVIES, G . N . , HOROWITZ, H , S, & WADA, W . : The as-
sessment of dental earies for public health purposes. Community Dent. Or(d Epidemiol. 1973: 1: 68-73, 7. DAVIES, G . N . , HOROWITZ, H . S, & WADA, W , : The as-
sessment of periodontal disease for public health purposes. / . Periodontal Res. 1974: 9: 62-70, 8. DAVIES, G , N , , KRUGER, B . J., & HOMAN, B . T . : Dental
survey of children in country districts of Queensland, '• Aust. Dent. / . 1969: 14: 153-161. 9. DUNNING, J. M.: Development and eontrol of dental auxiliaries in New Zealand and Australia. / . Am. Dent. Assoe. 1972: 85; 618-626. 10. DUNNING, J. M,: Dental care for everyone. Problems ' and proposals. Harvard University Press, Cambridge, Mass. 1976, pp. 65-69, 11. FANNING, E . A., GOTJAMANOS, T . & VOWI.ES, N . J,,-
Dental health and treatment requirements of South Australian secondary school children, Med. J. Aust 1969: 2: 899-901, 12. HEI.M, S,: Reeording system for the Danish dental health services. Community Dent. Oral Epidemiot 1973: /.• 3-8, 13. JoHANSEN, J, R., GJERMO, P. & BELLINI, H . T , : A sys-
tem to clarify the need for periodontal treatment. Aeta Odontot. Scand. 1973: 31: 297-306. 14. MEDCAI.F, G . W . : Report on caries experience and treatment needs in Western Australian children aged J 6-14 years. Prefluoridation dental assessment sur\-ey, ' November 1967. Aust, Dent. J. 1970: 15: 50-54. '• 15. MoLLER, I. J. & PouLSEN, S.: A standardized system j for diagnosing, recording and analysing dental caries ' data. Scand. j . Dent. Res. 1973: 8 / ; 1-11. : 16. RoDER, D. M.: The dental health and habits of South j Australian children from different soeio-economic environments, Aust. Dent. J. 1971: 16: 34-40, 17. SciviER, G. A., MENEZES, D , M , & P.ARKER, C . D . : A
pilot study to assess the validity of the orthodontic
Dental status and treatment needs 221 treatment priority index in English schoolchildren. Community Dent. Oral Epidetniol. 1974: 2: 246-252. '18. Australian Dental Association: News Bulletin 1975: No. 5 7 : p. 45. ]9. D e n t a l Board of Victoria: Advisory cotnntittee upon t h e duties of dental nurse. The auxiliary and dental practice: report of advisory comtnittee. Melbourne 1976.
20. New Zealand Departrnent of Health: Dental health status oj the New Zealattd population in late adolescence and young adulthood. Special report series No. 29. Cotnpiled Beck, D. J. Govennnent Printer, Welliugton 1968, pp. 82-84. 21. World Health Organization: Oral health surveys. Basic methods. WHO, Geneva 1971.
