The omohyoid muscle is an essential surgical landmark in cervical dissection since it separates cervical areas and is closely related to the neurovascular bundle of the neck and brachial plexus. We present the omohyoid muscle variation, poorly described in the literature, and concisely review other already known anatomical variations. We present the case of a 30-year-old woman with an oral squamous cell carcinoma staged as cT3N0M0. She was submitted to a subtotal glossectomy via pull-through approach and bilateral neck dissection. The defect was reconstructed using an anterolateral thigh free flap. During the neck dissection, we noticed a unilateral anatomical variation of the omohyoid muscle that passed deep to the internal jugular vein, maintaining the remaining path and insertions as traditionally described. A knowledge of the variations of the omohyoid muscle is important to the head and neck surgeon, considering its relationship with various noble structures of the neck, serving as a reference in various surgical procedures. We report this case of a variation deeper to the internal jugular vein to alert to a potential hazard during neck dissection and to contribute to the literature about omohyoid variations.
Cite this article as: Caneira T, Subtil J, Nabuco C, Porfírio Costa T, Saraiva J. An unusual variation of the omohyoid muscle with surgical implications and review of the literature. Essent Dent. 2023;2(3):141-145.