Biologic basis for modification of the sagittal ramus split operation.

Ten adult rhesus monkeys were used as experimental models to investigate revascularization and bone healing associated with sagittal splitting of the mandibular rami by two different techniques. Microangiographic and histologic studies showed intraosseous ischemia in the margins of the osteotomized segments and areas where the pterygomasseteric sling had been detached. When the mucoperiosteum and pterygomasseteric sling were minimally detached from the proximal segment, intraosseous ischemia and necrosis were significantly reduced. The results support the use of a clinical technique of sagittally splitting the mandibular ramus, which maximizes attachment of the pterygomasseteric sling and mucoperiosteum.