Abstract
Myositis ossificans (MO), as its name implies, is ossification and bone formation within a muscle. 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. When it affects the muscles of mastication, it causes severe trismus. This rare disorder and its limited treatment options can potentially have debilitating effects to the patient's normal oral functioning and health. A computed tomographic scan and panoramic radiographs are essential diagnostic aids for evaluating conditions such as MO. Myositis ossificans can be one of the causes of extra-articular temporomandibular joint ankylosis. Surgical excision of the ossification is the main treatment modality. This is a case report of a patient who developed MO of the muscles of mastication.