RESUMEN
BACKGROUND: The evaluation of orthodontic treatment outcomes using an objective method is important in order to maintain high treatment quality and final healthcare of patients. It allows professionals and university students to raise the level of the therapy. The aim of this study was to assess the orthodontic treatment outcomes in an Italian postgraduate School of Orthodontics using Peer Assessment Rating (PAR) Index. METHODS: A sample of 50 patients treated in a postgraduate program was randomly selected. PAR index was used to assess pre-treatment and post-treatment study casts by two different examiners. The influence of different variables such as gender, treatment method, and need for extraction was statistically analyzed. RESULTS: The average numerical reduction of PAR between the beginning and the end of the treatment was 18.74 (CI 95% 16.53-20.95), while the percentage reduction was 94.8% (CI 95% 91.91-97.68). All cases improved: 8% of patients resulted in the improved category, while 92% of them were in the greatly improved group. CONCLUSIONS: According to PAR index, the results showed that patients received a high-standard therapy. None of the factors studied influenced significantly the treatment outcomes.