[A preliminary report of histological study on TMJ reconstruction with autogenous costochondral graft]

To study histologically the biological behaviour of the grafts and the reactions in the receipt area after reconstruction of temporomandibular joint (TMJ), we have reconstructed experimentally removed TMJs on purebred juvenile pigs by transplanting autogenous costo-chondral grafts. The findings of continuously survey of histologic changes in the receipt areas and the grafts showed that autogenous grafts healed well with the surrounding soft tissues, and induced the mesenchymal-like cells from the receipt region, rather than the periosteal cells which might be left, to differentiate and ossify both within and at the surface of them, and they themselves were gradually replaced by the new-formed bone; and that active osteogenesis could also be seen within the thick tissues far from the graft, which could not be the result of graft's induction. It may be concluded that the new bone, both from the induction of the graft which acts as a framework and somehow from the outside tissues, reconstructs the new condyle and determines the postsurgical growth of the mandible.