Abstract: Objective　 To establish animal model of TMJ ankylosis secondary to complex trauma and to provide the experimental carrier for the further research on its mechanism . Methods Five sheep were used in this study. Four were included in the operation group, while one was left as control. In the operation, bilateral TMJ osteotomies were performed on the four sheep to induce sagittal fractures of the mandibular condyle, the glenoid fossa was damaged and the lateral one-fourth segment of the disc was removed. At the end of the 12th week postoperatively, spiral CT scanning, gross observation and histological observation were used to evaluate the changes of the TMJ. Results Bilateral TMJ of the four sheep occurred bone ankylosis. CT scanning detected calcified callus formation in the joint space. Articular surfaces were roughened after the formation of new bone, which protruded into the joint space. Histological observation showed that joint space was filled with abundant new cartilaginous matrix, cartilage cells, and a small amount of fibrous tissue. Conclusions This study successfully establishes the animal model of s TMJ ankylosis resulting from complex trauma, which conforms to the clinical damage modes and disease process, and provides a stable and practical animal model for the further study of traumatic TMJ.

Key words: temporomandibular joint, ankylosis, complex trauma, animal model