The masseter: an enigmatic muscle

Purpose: To try and explain the frequency of pathologic processes involving the masseter muscle. Materials and Methods : Anatomical and histological e valuation of the masseter muscle and its partial continuity with the medial pterygoid muscle. Retrospective evaluation of 21 cases of pathology of the masseter muscle imaged by CT and/or MRI. Results: Two main groups of pathology are identified : benign masseter hype rtrophy and hemodynamically inactive vascular malformations. Other etiologi es are quite varied. Some are secondary to processes involving the nearby m andible and parotid gland. Others, including tumors, involved the masseter muscle in a non specific fashion. CT and especially MRI were quite valuable with accurate diagnosis in 17/21 cases, two of which with the help of clin ical data. Conclusion: The main question regarding the preferential involvement of the masseter muscle over nearby muscles remains unanswered.