[Condylar positioning during mandibular orthognatic surgery].

Sagittal split osteotomy of the mandible is the most frequently used method in orthognatic surgery. Osteosynthesis was performed with wires in the 1970s. The instability of fixation allowed condyle movements and there was no problem of condylar positioning. The drawback of this technique was that it required a strict intermaxillary fixation for 6 weeks. Osteosynthesis evolved in the 1980s to a rigid and semi-rigid fixation, with no longer any need for an intermaxillary fixation. But accurately determining the condyle position in the fossa is essential when using a rigid fixation, because no spontaneous adaptation is possible. Moreover, an improper condyle positioning is known to increase short term skeletal relapse, inadequate corrections, and a high incidence of temporomandibular joint dysfunctions. Many solutions have been proposed to solve the problem of condylar positioning: manual positioning technique at osteosynthesis, and mechanical or computer assisted devices to control condylar positioning. The repositionable and adjustable miniplates have also been designed to improve condyle positioning, with the possibility of peroperative adjustment.