The Retromolar Trigone: Anatomy, Cancer Treatment Modalities, Reconstruction, and a Classification System

Retromolar trigone (RMT) tumors are rare and aggressive malignancies, spreading rapidly into surrounding structures. In reviewing the literature, there is lack of information and quality evidence pertaining to their management and high heterogeneity in treatment modalities.

A systematic Medline search was performed to gather all reports of articles related to retromolar trigone in tle last 10 years (2005-2015). Papers were excluded if they were related to oral cavity cancer but not specific for the RMT.

Results were divided into 5 sections: anatomy and lymphatic drainage; etiology and diagnosis; cancer treatment modalities; reconstructive options; proposal of a classifications system. A clinical patient exemplification was also included. Various treatment modalities have been tried in the past including surgery, radiotherapy, and combination therapy using chemoradiation. All these modalities have intrinsic risks. There is also controversy regarding the extent of surgery. Reconstructive options differ with the size of the defects. The ability of the propeller lingual flap to rotate any angle up to 180 degrees allows it to reconstruct small-to-medium sized defects. If bulkier reconstructions are needed to separate oral and nasal cavities, a free flap (radial forearm, anterolateral thigh, medial sural) should be planned.

In view of the rarity of the tumor and heterogeneity of treatment, there is limited information available pertaining to retromolar trigone tumors. A better understanding of RMT amatomy, cancer treatment modalities, and reconstructive options can improve the surgeon decision capacity and clinical results, when dealing with such uncommon and challenging tumors.