A woman in her 50s developed severe trismus several months after treatment of a dental abscess. Approximately 10 years after onset of symptoms, she was seen by an oral surgeon who attempted mandibular release via a cervical incision. According to the patient, the surgeon was “unable to reach” the affected area, and the operation was unsuccessful. There was no other significant medical or surgical history. On physical examination, severe trismus was present with maximal interdental distance of 1 mm. The patient was brought to the operating room for excision. A maxillofacial computed tomographic (CT) examination was performed (Figure).