Orthodontic treatment--improvement and standards using the peer assessment rating index.

This article is aimed at assessing the orthodontic treatment outcome in an accredited graduate orthodontic clinic in the United States, using the original Peer Assessment Rating (PAR) Index. A sample of 100 pre- and posttreatment study models was randomly selected from the clinic model storage. One investigator assessed all the components of the PAR Index. Descriptive statistics and Scheffe test were used to analyze the data. The mean weighted PAR point reduction was 22.11, and mean percentage reduction was 86.20. "Greatly improved" conditions were seen in 50% of patients while 47% accounted for the "improved category." Only 3% belonged to the "worse or no different" group. Statistically significant differences were observed between the three improvement groups for weighted pre- and posttreatment PAR scores, reduction, and percentage reduction. The results indicated an excellent improvement of the patients, with patients being treated to a high standard and a great proportion of patients with a clear need for treatment.