Experimental studies on vascular cahnges and bone regeneration after subperiosteal hemimandibulectomy

When jaw resection is necessitated by mandibular tumors, deformities and dys- or hypofunction of the jaw are unavoidable. To secure recovery from impairment, prostheses of the jaw bone, for instance, artificial substances or autologous bone, are usually utilized. When an artificial substance is used, however, it is difficult to obtain satisfactory results due to poor tissue affinity and compatibility. When an autologous transplantation is performed, healthy tissue other than the lesion it self is inevitably damaged in addtion to bone fragments being required from the patients. Recent reports have shown that bone regeneration occurs without bone transplantation if the periosteum is left behind at the time of jaw resection. Thus, attention has been paid to bone regeneration by the periosteum, especially among young patients. To my knowledge, there have been no reports concerning vascular and bone regeneration after subperiosteal hemimandibulectomy. Subperiosteal hemimandibulectomy, including removal of the mandibular head, was performed in rabbits. Dry-cast models were prepared by resin injection into the carotid artery, and transparent specimens were prepared by chloropercha injection into the carotid artery. Regeneration of blood vessels and bone were observed macro- and microscopically. During the initial stage, blood supply to the site of the bone defect was made mainly from periosteal blood vessels. The periosteal blood vessels, related to bone regeneration, gradually developed and anastomosed with the blood vessels extending from the bonr marrow, resulting in a fine vascular network. The external carotid, facial, and transverse facial arteries extended to the site of the bone defect approximately thirty days after the operation. The periosteal, bone marrow and extramaxillary blood vessels probably play an important role in bone regeneration.