The effectiveness of Class II, division 1 treatment.

The aim of this retrospective study was to evaluate the effectiveness of orthodontic treatment in terms of two outcome variables, namely, the percentage change in a valid and reliable occlusal index, the Peer Assessment Rating (PAR) score, and the duration of treatment. Data were collected from the records of 250 patients with Class II, Division 1 malocclusions who were treated in the Orthodontic Department of the University of Pittsburgh between 1977 and 1989. The relationships between the outcome and the treatment variables were analyzed with multiple regression techniques. Those variables significantly associated with the duration of treatment (p < 0.01) were (1) the pretreatment PAR score, (2) the number of treatment stages, (3) the percentage of appointments attended, (4) the number of appliance repairs, and (5) whether the patient was treated with or without extractions. The only variable that influenced the percentage change in PAR was the pretreatment PAR score (p < 0.01).