Comparison of the gonial angle measurements on Lateral Cephalogram and both hemispheres of Orthopantomogram

Abstract

Introduction: Gonial angle is one of the most important values ascertained in lateral cephalogram (lat ceph) tracing. According to the literature, gonial angle can be measured from orthopantomogram (OPG). The objective of this study was to test the reliability of left and right hemispheres of OPG in measuring the gonial angle and to compare these values with lateral ceph measurements.

Material and Methods: A hospital based survey was conducted based on patients visiting Orthodontic Department, Peshawar Dental Hospital, Peshawar, from 1^st January 2012 to 31^st March 2015. The radiographs (OPG and lateral ceph) were advised and gonial angle traced to check their accuracy.

Results: The sample comprised of 80 patients with class I malocclusion. Mean value of gonial angle measured from lateral ceph was 125.4 + 6.34, from left OPG was 123.8 + 6.17 and from right OPG was 123.2 + 6.38.

Conclusions: The gonial angle measured from both sides (left and right) of OPG is equally reliable but significantly different than gonial angle measured from lateral ceph.