Mandibular function and dysfunction in patients with mandibular prognathism.

There are indications that in patients with mandibular prognathism there is a great risk of mandibular dysfunction symptoms. The present study was undertaken to verify this and to investigate whether surgical correction of the sagittal discrepancy would improve the functional abilities. The material comprised a group of 28 untreated patients with mandibular protrusion and another group of 44 patients who were operated on 10 years ago. The functional status and subjective symptoms were recorded according to the principles introduced by Helkimo. The results indicate a great reduction of the subjective symptoms in the treated group, and even the objective evaluation shows a reduction of the dysfunctional symptoms in the treated persons, particularly in relation to the movement capacity of the mandible. The number of occluding teeth was significantly greater in the treated persons, and the number of occlusal interferences was smaller. Thus, it seems that a repositioning of the mandible to a correct sagittal position will improve function. A normal anatomic foundation may therefore be an important factor in securing normal mandibular function.