To assess the outcome of orthodontic treatment, 224 cases treated in a postgraduate clinic were evaluated. Pre-treatment (T1), post-treatment (T2) and 5-year follow-up (T3) study casts were assessed by the Peer Assessment Rating (PAR) Index. The influence of various factors upon treatment and long-term outcome was analysed. According to the PAR Index, orthodontic treatment reduced the malocclusions on average by 76.7 per cent, and at follow-up the reduction was 63.8 per cent. Follow-up stability was good for 76.3 per cent of the cases. Some cases (4.0 per cent) even improved, while moderate to severe post-treatment relapse occurred in 19.7 per cent of the cases. Orthodontic treatment changed Angle Class I, II and III malocclusions to near ideal occlusion (PAR scores 4.4-6.8). No long-term interaction between the groups was discovered. Sex and extraction/non-extraction treatments did not significantly affect the results. The initial PAR score accounted for 77.8 per cent of the variation in treatment PAR score change (T1-T2), and for 61.8 per cent of the variation of long-term PAR score change (T1-T3). Age at treatment start accounted significantly for the variability of treatment changes (P < 0.001). The PAR score at the end of treatment had some explanatory importance (R2 = 0.099) for the long-term (T1-T3) result. However, PAR score changes in the follow-up period were difficult to predict.

The purpose of the present study was to determine the validity of prevalence of filled surfaces at 9 years of age as a screening criterion for prediction of future caries incidence. Retrospective data were available for 114 children who had participated in an incremental dental care program from 7 to 16 years of age. There was a significant positive correlation between prevalence of filled surfaces (FS) at age 9 and increment of surfaces filled during the subsequent 7 years. Thus only 13% of the variation in increment of surfaces filled was explained by the variation in prevalence of FS. Subjects who had eight or more filled surfaces at 9 years of age were classed as the Expected H-group (22 subjects), while the Real H-group consisted of the 22 subjects who experienced the highest increment of surfaces filled between the ages of 9 and 16. Sensitivity and diagnostic power were both 45%, specificity 87%. While sensitivity decreased with increasing FS score at age 9, specificity and diagnostic power increased. A detailed analysis of the increment of surfaces filled each year from age 11 to 16 revealed that a considerable number of subjects not included in the H-groups also received many fillings.