抄録
Postoperative changes of various hard tissue landmarks, U1, L1, point B, Pog, over jet and over bite, were assessed for 17 cases of prognathism that had been surgically corrected by Obwegeser-Dal Pont technique, by means of a series of lateral cephalograms at four times: preoperatively, immediate-postoperatively, 3 months postoperatively and more than 6 months postoperatively.
During intermaxillary fixation U1 might move upwards and anteriorly in some cases. More than 6 months postoperatively each of U1, L1, point B and Pog tended to move upwards, or upwards and anteriorly. In the period of immediate-postoperative time to 3 months postoperatively, movement of each landmark varied significantly. It was probably caused by postoperative orthodontic treatment. Neither over jet nor over bite changed postoperatively. It suggested that postoperative orthodontic treatment could help the stability of anterior occlusal relationship.
Anterior movement of Pog was larger than that of L1 presumably because of lingual inclination or (and) displacement of lower anterior teeth.
No correlation was found between horizantal or vertical extent of displacement by surgery, and amount of postoperative change of Pog. However, cases of larger amount of vertical extent of displacement showed large variety of postoperative vertical changes of Pog, suggesting poor stability of these cases.
It was also discussed that postsurgical dento-facial changes could be affected by intermaxillary xation, postoperative orthodontic treatment, mobile tendency of teeth and occlusal interdigitation.
