Temporomandibular ankylosis in the cat: a review of seven cases.

Ankylosis of the temporomandibular joint (TMJ) in the cat is an unusual complication of traumatic lesions involving articular (true ankylosis) or periarticular structures (false ankylosis). Seven cats with true ankylosis of the TMJ (four cases unilateral and three cases bilateral), of which previous trauma had been documented in five cases, were referred to the authors' clinic between September 1991 and October 1996. Radiographic assessment was performed in all cases, using dorsoventral and oblique projections. Five subjects underwent arthroplastic excision of the TMJ and, in the remaining two cases, stretching of the jaws was performed under general anaesthesia. The surgical outcome was satisfactory in all but one case, where partially decreased joint mobility was observed (follow-up time one to five years), but in the two cases where non-surgical treatment was carried out, recurrence of TMJ ankylosis was observed (follow-up time two to five months). In the authors' experience, surgery represents the treatment of choice for TMJ ankylosis in cats. Additional mandibular symphysiotomy can confirm the radiological findings in unilateral cases.