Mandibular antegonial and ramus notch depths and condylar bone change.

The present study sought to clarify the relationship between antegonial and ramus notch depths and condylar bone change, and analyse the effects of such change on craniofacial structure. The study sample was of 28 pre-orthodontic patients with signs and symptoms of temporomandibular joint (TMJ) disorders, who underwent helical computed tomography to diagnose their TMJ pathology. Craniofacial structures were compared between 14 subjects with bilateral condylar bone change (BBC group: two male and 12 female) and 14 subjects with no bone change (NBC group: two male and 12 female). Sella-nasion-point B (SNB) and point A-nasion-point B (ANB) angles were significantly smaller in BBC than in NBC, with ramus height and mandibular body lengths significantly shorter in BBC than in NBC. The BBC lower facial height and SN-Go-Ar angle, as well as antegonial and ramus notch depths, were significantly greater than in NBC, and the mandible was significantly more retruded in BBC than in NBC. These results showed that condylar bone change might be related not only to mandibular size (e.g. retrusion) but also to mandibular outline (including antegonial and ramus notch depth).