A STUDY ON CHANGE OF THE SOFT TISSUE FACIAL PROFILE AFTER ORTHOGNATHIC SORCERY IN PATIENTS WITH THE MANDIBULAR PROGNATHISM

ABSTRACT

tissue facial profile after mandibular set back surgery during time intervals. For this study 33 patient, 8 males and 25 females, were selected and their lateral cephalograms were taken and analyzed periodically. Hard and soft tissue changes during postoperative time intervals, correlation between surgical skeletal changes and postoperative soft tissue changes, and prediction for long-time soft tissue changes were established through varying statistical methods. The results were as follow 1. There were meaningful changes of anteroposterior skeletal position at 6 months and 2 years after mandibular set back by mandibular ramus osteotomy. Two years postoperatively. there was 30%, 32%, 29% relapse on B point, pogonion, menton each. 3. The movements of the mandibular landmarks in correlation to anteroposterior position of the lower lip and soft tissue of the chin showed to be effective on a long-term basis. 4. Using surgical changes of pogonion, prediction of changes in soft and hard tissue pogonion was useful and the coefficient of determination was 0.046 each and their reliability decreased 2 years postoperatively. 5. The upper lip position after the mandibular set back surgery was somewhat anterior 2 year postoperatively, but that has no statistical meanings.