Computed Tomographic Findings of Temporomandibular Joint Disorders in Dogs and Cats

Temporomandibular joint (TMJ) is created by the connection between the mandibular condylar process and the mandibular fossa of the temporal bone in all mammalian species. This is a synovial joint and has a fibrocartilage disc. The joint disorders affect mastication, movements of TMJ, and mandibular functions. TMJ imaging can be evaluated by radiography; however, CT imaging is preferred, since the images have no superimposition and present more details of different structures and therefore show a more accurate evaluation of TMJ.

This study aimed to provide accurate statistics on TMJ disorders and to evaluate their prevalence based on CT-scan findings in dogs and cats.

In this study, 265 cases of cats and dogs (102 cats and 163 dogs) were evaluated. A total of 59 cases (38 cats and 21 dogs) had temporomandibular joint disorders. In this study, information on sex, breed, and age regarding TMJ disorders were described in detail.

In the evaluated CT images, osteoarthritis, fracture, dislocation (luxation and subluxation), ankylosis, osteochondrosis, dysplasia, and osteomyelitis were observed.

This study indicated that although the total number of dogs was larger than that of cats, the incidence of temporomandibular joint disorders was higher in cats than in dogs. The most common disorders in cats and dogs were fractures, followed by dislocations (luxation and subluxation), and then osteoarthritis exhibited the highest frequency. In the next rank of frequency in cats, ankylosis and then osteomyelitis were observed. Additionally, osteochondrosis and dysplasia and then ankylosis were observed in dogs in the next ranks.