Myositis ossificans (MO) is a disease whose main feature is the formation of heterotopic bone involving muscle or any other soft tissue. Pathogenesis is not all clear, but trauma is universally recognized as a trigger event. Myositis ossificans can be divided into 2 classifications: MO progressiva and MO traumatica. The authors present a case of a 64-year-old man who was diagnosed with MOT of the left medial pterygoid muscle. The patient had a long clinical history of signs and symptoms of temporomandibular articulation related to previous conditions, and no major traumatic events were reported, apparently related to MOT.