Evaluation of different skeletal classes on basis of angles of convexity

Abstract

The goal of this study was to determine whether it was possible to identify the underlying skeletal Class using a lateral (profile) photograph, as well as which reference points of the angle of convexity are most useful for doing so. Retrospective evaluation of 60 Orthodontic patients baseline profile photos and lateral cephalograms was performed. Based on the Wits values determined by radiographic analysis, the subjects were assigned to skeletal Classes. The Class I subjects were 20 patients (05 males, 15 females) with an average age of 13.3 ±1.42 years, the Class II subjects 20 patients (9 males, 11 females) with an average age of 13.85 ± 1.27 years, and the Class III subjects 20 patients (10 males, 10 females) with an average age of 13.60 ± 1.23 years. A'OrB '(=POrA '-POrA'), A'N'B ', and the angle of convexity with its variants (N'SnPog ', N'A'Pog', TrSnPog', TrA'Pog, Gl'SnPog', and Gl'A'Pog ') were measured. Highly Significant differences between Class II and Class III subjects were seen for all angles (P 0.001). Nearly all angles showed highly significant differences between Classes I and III (P 0.001), and A'N'B' showed significant differences (P 0.05). Only some angles showed significant (P > 0.05) differences between Class I and Class II. It was simpler to distinguish between skeletal Classes I and III than between Classes I and II. The lack of distinction between Division I and Division II subclasses within the Class II subjects could be one of the causes.