Study on the changes of occlusal plane angle in mandible prognathism after orthognathic surgery

ABSTRACT

11degree). Three groups were compared with the change of anatomical landmarks and occlusal plane angle alteration of lateral cephalometric radiography at each period of preoperative to immediate postoperative stage, preoperative to postoperative stage and immediate postoperative to postoperative 6month stage. As a result of this study, The clinical correlation between preoperative occlusal plane angle and severity of mandibular prognathism wasn't found. there is no statistical correlation between postoperative occlusal plane angle and severity of mandibular prognathism, but postoperative occlusal plane angle was increased in group of lower occlusal plane angle preoperatively, and postoperative occlusal plane angle was decreased in group of higher occlusal plane angle preoperatively. And, there is no clinical correlation between the relapse of B point to vertical plane and degree of preoperative occlusal plane angle. Therefore, from the results obtained in this study, we should suggest that mandible was rotated to clockwise direction on mandibular prognathism patient with the low occlusal plane angle postoperatively, and mandible was rotated to anti-clockwise direction on mandibular prognathism patient with the high occlusal plane angle postoperatively.