Objective: To describe CT findings in dogs and cats with temporomandibular joint (TMJ) disorders.
Design: Retrospective case series.
Animals: 41 dogs and 17 cats.
Procedures: Medical records and CT images of the skull were reviewed for dogs and cats that were examined at a dentistry and oral surgery specialty practice between 2006 and 2011.
Results: Of 142 dogs and 42 cats evaluated, 41 dogs and 17 cats had CT findings consistent with a TMJ disorder. In dogs, the most common TMJ disorder was osteoarthritis; however, in most cases, there were other TMJ disorders present in addition to osteoarthritis. Osteoarthritis was more frequently identified at the medial aspect rather than the lateral aspect of the TMJ, whereas the frequency of osteoarthritic involvement of the dorsal and ventral compartments did not differ significantly. In cats, fractures were the most common TMJ disorder, followed by osteoarthritis. Clinical signs were observed in all dogs and cats with TMJ fractures, dysplasia, ankylosis, luxation, and tumors; however, only 4 of 15 dogs and 2 of 4 cats with osteoarthritis alone had clinical signs.
Conclusions and clinical relevance: Results indicated that TMJ disorders were frequently present in combination. Osteoarthritis was the most common TMJ disorder in dogs and the second most common TMJ disorder in cats. Computed tomography should be considered as a tool for the diagnosis of TMJ disorders in dogs and cats with suspected orofacial disorders and signs of pain. (J Am Vet Med Assoc 2013;242:69-75).