Antegonial notching and the pattern of vertical facial growth

Abstract

Introduction: This study had two aims. The first was to evaluate the correlation between antegonial notch depth on panoramic and cephalometric radiographs. The second was to compare development of the antegonial notch with vertical growth in various patient groups. Methods: Longitudinal cephalograms were collected for 43 open bite (OB), 61 Pierre Robin sequence (PRS), 13 idiopathic condylar resorption (ICR), and 104 matched controls, along with 55 pairs of panoramic and cephalometric radiographs. Notch depth, mandibular plane angle and vertical facial dimensions were measured during a period of 5.2-9.5 years. Results: Antegonial notch depth measured from panoramic radiographs was well correlated with cephalometric measurements. However, the regression equation cannot be validated due to inherent magnification and distortion on both image methods. At T1, notch depth was greater in patient groups than in controls. With the exception of the ICR group, notch depth did not change significantly during growth. Notch depth also could not be used to predict vertical growth patterns. The ICR group was unique in having greater notch depth than OB at T1, in showing poor growth (sometimes decrease) of posterior facial height, and in having increased mandibular plane angles over time. In controls, antegonial notch depth was positively correlated with vertical dimensions and mandibular plane angle. Conclusions: Panoramic radiographs cannot be substituted for cephalograms for estimating antegonial notch depth. Except in ICR, notch depth is established early and maintained throughout the growth period, and therefore is not a good predictor of future vertical facial growth.