Post-operative relapse following sagittal split osteotomy

Abstract

In a series of 16 cases treated for mandibular prognathism by the Obwegeser-Dal Pont osteotomy, the changes at operation and during the first post-operative year have been analysed using new techniques. The statistically significant changes were all horizontal. 50 per cent of the material showed evidence of relapse.Futher analysis of the cases showing relapse using the Adams blink comparator and the intra-osseous wire as an implant, revealed that condylar growth and altered mandibular posture were important factors producing relapse. The condylar growth factor can be minimised by delaying operation until towards the end of the growth period and the tendency for the patient to protrude the mandible might be lessened by detaching the medial pterygoid muscle and the spheno-mandibular ligament.