Search

Myositis ossificans is ossification and bone formation within muscle. It is a rare and unusual pathologic entity that has defied most efforts to establish definite etiology, pathogenesis, and satisfactory treatment. Myositis ossificans is mainly of 2 types: myositis ossificans progressiva (MOP) and myositis ossificans traumatica (MOT). Myositis ossificans idiopathic is also reported in the literature. When it affects the muscles of mastication, it causes severe trismus. Computed tomography scans and magnetic resonance imaging can effectively delineate the calcified mass. In this article, we present a case of MOT of the medial, lateral pterygoid, and contralateral temporalis muscles., (Copyright © 2013 Elsevier Inc. All rights reserved.)

In this report, we present a case of myositis ossificans traumatica (MOT) of the medial pterygoid muscle that had developed after mandibular block anesthesia administered for endodontic treatment of the lower right second molar, demonstrating typical features of this condition. MOT should be considered as a differential diagnosis when there is severe limitation of jaw opening and an associated trauma. Panoramic radiographs and axial and coronal computed tomography (CT) scans can effectively delineate the calcified mass. Other imaging studies that may be helpful include magnetic resonance imaging (MRI), bone scans, and ultrasound. As shown in our case, calcified masses were found in the right mandibular angle, which severely limited jaw opening. Some earlier reported cases of MOT were treated by extraoral surgical approaches with complete removal of the evolving muscle. The aim of this case report is to present only the diagnostic imaging aspects of myositis ossificans traumatica.

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.

After reviewing the literature, the authors report a case of myositis ossificans of the right pterygoid and temporalis muscles in a patient undergoing surgery to remove the left medial pterygoid muscle owing to the same pathology. The metachronous localisation in contralateral masticatory muscles compared to the primary site leads the authors to emphasize the post-traumatic and iatrogenic etiology of this rare pathology. In the light of their experience, they underline the importance of a precise diagnosis and surgical exeresis, followed by cautious rehabilitation with the least trauma, if necessary backed by appropriate medical treatment.