New biomaterials and methods for craniofacial bone defect: chondroid bone grafts in maxillary alveolar clefts

The purpose of this study was to evaluate autogenous osteogenic marrow with in chondroid bone grafts in simulated alveolar defects of mice in order to determine the ability of the graft material to effectively close the cleft from an osseous standpoint and to observe the effect of the grafting proced ure. Critical-sized defects were made in the premaxillary bones of male mic e using a surgical trephine and a low-speed dental engine as a model of the maxillary alveolar cleft for testing bone-inductive agents. Premaxillary t rephine defects were not repaired by fibrous tissue or bone formation 30 da ys after operation. This nonhealing bony wound of the premaxilla in mice ma y be useful as a model for studying the effect of bone-inductive agents on the healing of alveolar clefts. Distraction osteogenesis is a recently adva nced principle of bone lengthening in which a long bone separated by osteot omy is subjected to slow progressive distraction using an external fixation device. The osteotomy site was surrounded by an external callus consisting of hyaline cartilage. The callus contained a lot of chondroid bone. The tr ansplant bone within chondroid bone was characterized by bone formation and remodeling 30 days after transplantation. Throughout the experiment, our f indings demonstrated, for the first time, that the transplant bone that con tains chondroid bone may be used clinically in relation to craniofacial bon e defects to improve the treatment of bone grafts.