Effect of auricular cartilage graft in the surgical treatment of temporomandibular joint ankylosis: An animal study using sheep.

PURPOSE: The purpose of this study was to test the functional and histologic fate of an auricular cartilage graft used in reconstruction of an ankylosed sheep temporomandibular joint (TMJ). MATERIALS AND METHODS: Five sheep were used in this study. TMJ ankylosis was induced in the right joints and the left joints were used as controls. The ankylosed TMJ was released by gap arthroplasty with an interposed auricular cartilage graft at 3 months. The sheep were sacrificed at 3 months after the arthroplasty. The maximal mouth opening was measured pre- and postoperatively. The joints were evaluated radiologically and histologically. RESULTS: Maximal mouth opening was maintained after placement of an auricular graft into the gap arthroplasty. Radiographically the surfaces of the temporal bone and ramus stumps were irregular, but radiolucent gaps were formed between them. Histologically, the auricular cartilage graft was alive and well attached to the mandibular ramus stump. In all operated joints, there was joint space between the grafted cartilage and temporal bone, with the space filled with fibrous connective tissue, which was oriented parallel to the temporal surface. CONCLUSION: Auricular cartilage graft with gap arthroplasty is useful in preventing reankylosis after TMJ gap arthroplasty for ankylosis.