Biological basis for vertical ramus osteotomies--a study of bone healing and revascularization in adult rhesus monkeys.

Fifteen adult rhesus monkeys were used as experimental models to investigate revascularization and bone healing associated with pedicled and nonpedicled vertical ramus osteotomies and to elucidate the problem of vascular ischemia of the proximal segment and healing of the osteotomized bone. Microangiographic and histologic studies of vertical ramus osteotomies in which the proximal segment was not pedicled to soft tissue showed intraosseous necrosis, vascular ischemia, and delayed healing. Similar studies of pedicled vertical ramus osteotomies showed early osseous union, minimal osteonecrosis, and minimal vascular ischemia. The results indicate that continuous circulation to the proximal segment is necessary to retain osseous viability and to support the clinical practice of pedicling the proximal condylar segment to the articular capsule and lateral pterygoid muscle.