[Gnathographic study of mandibular borderline movements and chewing patterns before and after surgical dysgnathia correction in retrognathism and prognathism].

Chewing patterns and longitudinal border movements of 16 patients with severe dysgnathia were examined preoperatively and up to 12 months postoperatively by means of sirognathographic records of surgical-orthodontic treatment results. Patients with a skeletal class-III malocclusion showed an increased range of movement compared to the preoperative situation, after a surgical mandibular setback performed by wire osteosynthesis, followed by an intermaxillary immobilisation of 6 weeks. Patients with a skeletal class-II malocclusion showed a considerably limited range of movement during the first postoperative registration after a surgical mandibular advancement. The preoperative situation had not been fully achieved even after 12 months. The postoperative sirognathographic records present distinct differences in functional adaptation between surgical mandibular advancement and mandibular setback.