An experimental rabbit model for studying the healing of onlay bone grafts

An experimental rabbit model for studying the incorporation of onlay bone grafts is described. Bone grafts from radius served as the graft and were positioned beneath the mandibular basis. Six rabbits were used in the study and healing periods of 6 weeks and 6 months were used. Each animal was operated twice and in this way the grafts could be followed for six weeks on one side and for 6 months on the contralateral side of the mandible. Healing of the bone graft with bony union to the mandibular base with cortical bone in contact with cortical bone was encouraging. Remodelling of the graft was observed after 6 weeks but was even more pronounced after 6 months. After 6 weeks osteoclastic/osteoblastic activity was primarily observed in the graft-recipient contact area and in the intracortical compartment of the grafted bone. The resorption was most pronounced in the borderlines of the graft. It is concluded that the described experimental model can serve as a useful method for the study of onlay bone graft healing and interaction between implants and bone transplants.