Septic arthritis of the temporo-mandibular joint--a problematic diagnosis.

A rare case of chronic septic arthritis of the temporo-mandibular joint is described, which presented as a pre-auricular swelling several weeks after a blow to the chin. Although the history indicated an inflammatory process precipitated by trauma, the clinical findings suggested a neoplastic aetiology. The treatment and problems in making an early diagnosis in this condition are discussed.