Osteoma in medial pterygoid muscle: an unusual case.

Soft tissues osteoma is an execeedingly rare tumour. It is a benign often asymptomatic neoplasm. The exact etiology and pathogenesis of osteomas are unclear. This paper report a case of peripheral osteoma located in the middle part of the medial pterygoid muscle of the right infratemporal region in a 60-year-old woman. Clinical examination did not reveal any extraoral swelling, facial asymmetry or difficulty in mouth opening, and the regional lymph nodes were non-palpable. Panoramic radiograph show a round well-circumscribed free/independent radiopaque mass located in the middle part of the right infratemporal region. Intraoperatively, the mass was surrounded by muscle fibers with no attachment to bone. Microscopic examination revealed mature bone without special characteristics. The precise location of an osteoma in the muscle is usually in close proximity to regions of muscle attachment it is possible that muscle traction may play a role in its development.