A Case of Septic Arthritis of the TMJ without Malocclusion

Objective: The purpose of this study was to report a rare case of septic arthritis of the temporomandibular joint (TMJ) associated with osteomyelitis in which malocclusion was not observed. Methods: A 33-year-old man presented to our dental hospital with the chief complaint of pain and swelling in the right mandible, including increasing difficulty opening his mouth, which had persisted for 3 years. Panoramic radiographs and X-ray computed tomography (CT) images clearly showed a prominent deformity with bone destruction of the right mandible, including the right condyle. Magnetic resonance imaging (MRI) showed inflammatory findings in the mandible, such as MR signal alteration, mandibular and condylar deformation, and bone destructions without mass lesions. The inflammatory changes in soft tissues at the TMJ were more prominent than those in the mandible. Results: We made a diagnosis of septic arthritis of the TMJ. Malocclusion resulting from condylar deformity and anterior displacement of the condyle, a typical finding in seprtic arthritis of the TMJ, was not found on three-dimensional (3D) CT images or following oral examination. Oral cephem antibiotics was administrated. However, the patient has not since returned to our dental hospital. Conclusion: As the present patient was not cooperative in receiving medical treatment, we propose that non-cooperation with treatment should be considered a predisposing factor for the development of septic arthritis of the TMJ, and we must be aware of the presence of septic arthritis of the TMJ without malocclusion.