Myositis Ossificans Traumatica (MOT) is a rare condition that affects soft tissues after a trauma and hardly affects the mastication muscles. The occurrence in the temporal muscle is uncommon, and trismus is the most prevalent symptom. The diagnosis of the pathology is sufficiently obtained through the collection of clinical history, physical and imaging exams. Differential diagnosis is important mainly to rule out more aggressive diseases, such as osteosarcoma. Treatment becomes more invasive as the ossification matures, and resection of structures adjacent to the tumor, such as coronoidectomy, is well indicated for promoting good results on the mouth opening amplitude. However, to maintain this amplitude, aggressive myofunctional therapy is required. Nevertheless, the literature has no well-defined protocol for this physiotherapy. Therefore, this article reports a rare case of MOT in the temporal muscle that was treated conservatively, with bilateral coronoidectomy and mouth opening physiotherapy, and obtained a satisfactory result. Consequently, it also presents a suggestion of a postoperative physiotherapy protocol.