[Functionally stable osteosynthesis and simulography in sagittal osteotomy of the ascending ramus. A comparative clinical study].

Sagittal mandibular osteotomy is a well-founded means to correct various dysgnathias. The method is enhanced by the possibilities of fixation which osteosynthesis has offered to the treatment of bone fractures. The success of using osteosynthesis in osteotomy depends partly of preoperative planning combined with simulography which allows for orthograde adaptation of the proximal fragments and the proper localization of the traction screws. 75 sagittal osteotomies were checked. They had all been operated the same way, but the fixation was varied: without fixation, fixation by wiring, fixation by Kirschner wire, fixation by bilateral traction screws, 1 each, 2 each, 3 each. The evaluation was made by using many criteria. It was found that without functionally stable osteosynthesis, inspite of 2-3 months immobilization a recurrence occurred in most cases and that postoperative treatment by activator or by head-chin appliance was necessary. With 3 screws on each side and preoperative planning with simulography no recurrence was found in 30 cases. Also, the hospitalization could be shortened and with it the working incapacity. These patients could be left without intermaxillary fixation and late postoperative treatment.