Two typical cases of pseudoankylosis of the jaw : same treatment, different outcome

Pseudoankylosis of the temporomandibular joint is a rare, extra-articular form of ankylosis of the jaw. It is characterised by limited mandibular movement caused by an extrinsic condition of the joint leading to fusion between the coronoid process and temporal, zygomatic or maxillary bone. Pseudoankylosis is less frequent than the intracapsular form. Extracapsular ankylosis can be congenital or acquired; approximately 70% of cases are associated with trauma. A CT scan is usually requested to achieve a diagnosis. CT can detect bony fusion, thus differentiating pseudoankylosis from true ankylosis. Once symptomatic bone ankylosis is diagnosed, surgery with postoperative physiotherapy is the recommended treatment. The ankylotic bone is removed together with the coronoid process and the mouth is forced open under general anaesthesia. Two cases of post-traumatic pseudoankylosis of the jaw treated with bilateral coronoidectomy and postoperative physiotherapy are described.