Cephalometrically analysis of the convexity angle

Abstract

The convexity angle of facial bone structures ( N-A: A-Pg) expresses the sagittal protrusion of the maxillary part of the face compared to facial profile (the convex or concave face).The convexity angle is defined as the angle colligated by the lines N-A and A-Pg. The aims of the present study were: to analyse the convexity angle in participants with natural teeth skeletal class I, to cephalometrically evaluate the reconstructing angle of hard facial profile structures of edentulous patients skeletal class I, to compare examined variables between individuals with natural teeth and edentulous patients. The control group consisted of 30 lateral cephalometric radiographs of participants with natural teeth skeletal class I. The experimental group consisted of 30 lateral cephalometric radiographs of edentulous patients, with models of complete dentures after clinical methods of determining the vertical and horizontal intermaxillary relation. Analysis of the convexity angle was done in cephalometric radiographs by Downs metod. The results showed the facial bone structure convexity angle span a range between -13? and 10? (X= 0.45?) in subjects with natural teeth. In edentulous patients the values of facial bone structure convexity angles span a range between -5? and 10? (X=1.7?). The results of t-test proved that there were no statistically significant differences in examined variables between persons with natural teeth and edentulous patients (p>0.05). The conclusion is that clinical methods of determining the sagittal protrusion of the maxillary part of the face against the facial profile of edentulous patients used in the designing procedures of complete dentures were reliable enough in reconstruction of examined angles of hard facial profile structures.