[Management of traumatic temporomandibular joint ankylosis: a perspective]

Traumatic injury to the temporomandibular joint (TMJ) was the most common cause of TMJ ankylosis (85%), while sagittal fracture of the mandibular condyle was identified as the high risk fracture pattern. TMJ disc displacement is one of the prerequisite factors of TMJ ankylosis. The severe damage and close contacts of both the articular surface of glenoid fossa and condyle were also crucial pathogenic factors in the development of TMJ ankylosis. The mechanism and development of TMJ ankylosis may be similar to hypertrophic non-union, and the persistence of radiolucent zone within the ankylotic callus governs the clinical and pathological process of TMJ ankylosis. In type Ⅰ traumatic TMJ ankylosis, repositioning of the displaced disk is required, while the preservation of pseudo-joint is essential in the management of the type Ⅱ traumatic TMJ ankylosis. Nevertheless, the rate of TMJ reankylosis still remains high. Higher rate of TMJ reankylosis was observed in paediatric population, bilateral involvement of TMJ ankylosis, and in cases with reconstruction of mandibular condyle with coronoid process.