Septic arthritis of the temporomandibular joint （SATMJ） is a rare disease, with the main symptoms of pain, swelling, redness, and TMJ malocclusion. In most cases the causative factor is unknown. The present report describes a case caused by bacterial infection revealed by blood culture test results in which the originally infected organ could be identified. The patient was a female in her 60s with the chief complaint of trismus.
At the first visit, tenderness of the right temporomandibular joint and diffuse swelling, as well as trismus were noted. Anterior deviation of the right mandibular condyle was seen in X-ray images and enlargement of the right masticatory muscle was indicated by CT imaging. Streptococcus constellatus was detected in a blood culture test. Following administration of meropenem （MEPM）, the symptoms were improved. This result suggests that bacterial infection associated with chronic periodontitis of the maxillary right second molar may have led to hematogenous infection of the temporomandibular joint in this case.
