EVALUATION OF TREATMENT AND POSTTREATMENT CHANGES BY THE PAR INDEX

To assess the outcome of orthodontic treatment, 224 cases treated in a postgraduate clinic were evaluated. Pre-treatment (T-1), post-treatme nt (T-2) and 5-year follow-up (T-3) study casts were assessed by the P eer Assessment Rating (PAR) index. The influence of various factors up on treatment and long-term outcome was analysed. According to the PAR Index, orthodontic treatment reduced the malocclusions on average by 7 6.7 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 Gases (4.0 per cent) even improved, while moderate to severe post-treatment rela pse occurred in 19.7 per cent of the cases. Orthodontic treatment chan ged Angle Class I, II and III malocclusions to near ideal occlusion (P AR scores 4.4-6.8). No long-term interaction between the groups was di scovered. Sex and extraction/non-extraction treatments did not signifi cantly affect the results. The initial PAR score accounted for 77.8 pe r cent of the variation in treatment PAR score change (T-1-T-2), and f or 61.8 per cent of the variation of long-term PAR score change (T-1-T -3). Age at treatment start accounted significantly for the variabilit y of treatment changes (P < 0.001). The PAR score at the end of treatm ent had some explanatory importance (R-2 = 0.099) for the long-term (T -1-T-3) result. However, PAR score changes in the follow-up period wer e difficult to predict.