The aim of this study is to determine skeletal asymmetry in clinically symmetrical faces with an Angle Class I occlusion. Material of this study is consisted of twenty females with normal vertical growth, Angle Class I occlusion and skeletal Class I relationship. The non-growing subjects’ mean age was 14 years 4 months. Posteroanterior cephalograms were obtained and reference points and lines were determined. A vertical line (Vr) was drawn from crista galli to the line connecting larerosuperior orbit points and horizontal distances to this line from Lo, Zg, Mx, Go, Ma were measured for right and left sides respectively. Paired t-tests were performed to compare the measurements between right and left sides. Statistically significant differences were found between right and left sides for the horizontal measurements from the points Lo, Zg, Mx, and Go to the Vr (p<0,01). The horizontal distance of Nc to the Vr showed a statistically significant differences between right and left sides (p<0,05). The horizontal distance of point Ma to the Vr was similar for right and left sides. As a result, by using postero-anterior analysis statistically significant skeletal asymmetries between right and left sides were found in clinically simmetrical faces.

Keywords: Asymmetry, PA analysis, symmetry