Functional characteristics of patients with anterior open bite before and after surgical correction.

The purposes of this investigation were to compare functional performance between controls and a sample of patients with skeletal anterior open bite prior to surgical correction and to examine how the patients' oral motor function adapted after treatment. Five female patients with skeletal open bite malocclusion were treated with Le Fort I osteotomy and compared to sex-, size-, and age-matched controls. Measurements of skeletal morphology, mandibular range of motion, occlusal force, and muscle efficiency were taken on all subjects over time. Prior to surgery, all patients had lower occlusal forces than did controls at all bite positions. After surgery, occlusal forces at several occlusal positions increased significantly from the presurgical recordings but remained below the level of controls. The mechanical advantages of the muscles of mastication were not significantly different between controls and patients either before or after surgery. The results of this study suggest that correction of skeletal open bite malocclusion may improve occlusal force, but a larger sample is needed to confirm this finding.