Minimally invasive transoral surgical approach to the medial compartment of the masticator space for venous malformation and benign tumor removal

Background: This article describes a new surgical technique to approach a venous malformation and benign tumors located in the medial compartment of the masticator space. Methods: A 50-year-old woman reported painless swelling of the buccal mucosa above the medial surface of the right ramus. A CT scan and MRI imaging suggested a neuroma-like lesion. A radiological examination could not determine the nature of the lesion, and therefore, a convincing diagnosis could not be achieved. Considering the focal bone erosion at the mandibular notch, the uncertain diagnosis, and especially the impossibility of excluding other benign lesions of the masticator space, the patient underwent a surgical removal of the lesion. Results: The hypothesized neuroma turned out to be a venous malformation that was confirmed clinically and histologically. When the diagnosis is uncertain, only a histological examination can determine the true nature of the lesion. The presently described technique considered mouth opening issues: when the mandibular ramus rotates and moves forward, the coronoid process is anatomically close to the tuber maxillae. Therefore, there is not enough space to approach the medial compartment of the masticator space unless the coronoid process is temporarily removed. An L-shaped osteotomy of the coronoid process is minimally invasive, safe, and comfortable. Coronoidotomy offers a wide field of vision and allows easy transoral access to the masticator space. Conclusions: Combined mandibular coronoidotomy, with or without endoscopic magnification, is a suitable approach to treat a well-defined lesion in the medial compartment of the masticator space with the involvement of the mandibular ramus; intralesional injection of n-butyl-2-cyanoacrylate in a venous malformation completes the surgical procedure in a predictable and safe way.