Comparative evaluation of buccolingual inclination of molars in low-angle cases and high-angle cases using manual technique- A pilot study

Abstract

The general feature of occlusal curvature, when viewed from the front, consists of a buccal inclination of the maxillary molars and a lingual inclination of the mandibular molars. The fourth key of Andrew’s six keys of occlusion is related to the curve of Wilson, describing the posterior inclination of the crowns of the lower posterior teeth as a concave curve, setting the molars with a lingual torque. Facial skeletal characteristics of subjects with a vertical growth pattern include increased total face height, especially the lower anterior face height, high mandibular plane angle, clockwise mandibular rotation, short mandibular ramus, and high gonial angle. Opposite aspects are present in subjects with a horizontal growth pattern. This study aimed to measure the buccolingual inclination of maxillary first molars in low-angle and high-angle cases using a manual technique. 20 subjects with permanent dentition were divided into 2 groups. Group I comprises 10 subjects with a low-angle case (proportionally short lower anterior facial height) and group II with a high-angle case (proportionally long lower anterior facial height). The buccolingual inclination of 1st molar was assessed on model casts.The maxillary posterior teeth of subjects with a vertical growth pattern (group II) had a significantly greater buccal inclination compared with those of subjects with a horizontal growth pattern (group I).