Coefficient of regression to predict skeletal patterns for nongrowing subjects using gonial angle on orthopantomogram

Introduction: The gonial angle plays to be one of the significant indicators for the diagnosis of growth pattern of orthodontic patients. It is a known fact that lateral cephalograms are commonly used for the measurement of gonial angle, but panoramic radiographs (PRs) can display both the gonial angles simultaneously and as accurately as lateral cephalograms. The aim of this study is to develop an equation for the prediction of the skeletal pattern of nongrowing participants from gonial angle values on PR.Materials and Methods: PRs and lateral cephalograms of 75 orthodontic patients were selected. The gonial angle was measured on PR and Sella Nasion-mandibular plane (SN-MP) angle was measured on lateral cephalograms. The values obtained were analyzed using paired Pearson's correlation test and regression analysis was done.Results: The relationship between the gonial angle measurements obtained from each radiograph was represented as, “SN-MP angle (Skeletal pattern) = −44.297 + 0.6318 × Gonial angle (PR) in the linear function.”Conclusion: Hence, PR could be used to determine the gonial angle as accurately as a lateral cephalogram and a useful tool for examining the skeletal pattern of patients.