Influence of edentulousness on gonial angle, ramus and condylar height

It has been shown that the shape of the mandible correlates with occlusal condition and the function of the masticatory muscles. Edentulous subjects have a wider gonial angle than dentate subjects, and a gender difference has also been shown. However, some studies have reported differing results. Less is known about the effect of dental status and gender on the ramus and condylar height. The aim of this study was to evaluate the association of tooth loss on the shape of mandible (i.e., gonial angle, ramus height and condylar height) in subjects aged 60 years and older. A total of 1036 subjects (667 dentate, 389 edentulous; 554 women and 482 men) were included in the study. Interviews and clinical and panoramic radiographic examinations were carried out. The gonial angle of the mandible and the mandibular and condylar height were measured using panoramic radiographs. In edentulous subjects, the gonial angle was significantly larger, while the ramus and condylar height was significantly smaller on both sides compared with dentate subjects. Women had a significantly larger gonial angle and smaller ramus and condylar height on both sides compared with men. In conclusion, the morphology of the mandible changes as a consequence of tooth loss, which can be expressed as a widening of the gonial angle and shortening of the ramus and condylar height. These findings highlight the importance of rehabilitation of the masticatory system to maintain good functioning of the masticatory muscles for as long as possible.