RESUMO
The aim of this study was to determine which of two occlusal indices were the most appropriate for use in the assessment of orthognathic outcome. The indices used were the Peer Assessment Rating (PAR) Index and the Index of Treatment Complexity, Outcome, and Need (ICON). These indices were validated against the subjective assessments of treatment outcome and treatment improvement obtained from a panel of experienced orthodontic consultants. For the subjective assessment, intraexaminer agreement for ranking treatment outcome, from patient study models (30 models), was good. Interexaminer agreement for ranking treatment outcome, in the same way, was good or moderate. Intraexaminer agreement for ranking treatment improvement (30 start and finish pairs of models) was very good or good. Interexaminer agreement for ranking treatment improvement ranged from good to fair. All the patient study models were scored using PAR and ICON. The level of correlation between PAR and ICON scores of treatment outcome and the subjective ranking of treatment outcome was significant (P < 0.001). The level of correlation between PAR and ICON scores of treatment improvement and the subjective ranking of treatment improvement was also significant (P < 0.001). It is concluded that both PAR and ICON are suitable indices for assessing the clinical outcome of combined orthodontic treatment and orthognathic surgery.