Bilateral Omohyoid Variant

Background: This case report describes and documents a bilateral anatomical omohyoid variant that was discovered during a routine cadaveric dissection. The omohyoid is one of the infrahyoid muscles consisting of a superior and inferior muscle belly, with an intermediate tendon connecting the two at an angle. While the omohyoid muscles play an important role in depressing the hyoid bone during phonation and swallowing, they also serve as an important surgical landmark for level III and IV lymph node metastasis. Therefore, it is important for clinicians to be aware of the variations that could occur with the omohyoid muscles and their subsequent potential side effects. Case Information: Careful dissection of the omohyoid muscles of a 92-year-old female cadaver revealed alterations from the normal anatomy. The left omohyoid muscle exhibited two inferior muscle bellies, with one having a midclavicular attachment and the other attaching to the superior border of the scapula. The right omohyoid displayed three different inferior muscle bellies, with one attaching to the midshaft of the clavicle, another attaching to the lateral aspect of the clavicle, and the last attaching to the superior border of the scapula. Conclusions: Aberrant omohyoid musculature has been described on numerous occasions and warrants significant consideration during a variety of procedures. Variations of the omohyoid muscle can have a range of clinical manifestations including torticollis, dysphagia, dyspnea, and they also serve as important surgical landmarks. Therefore, knowledge of omohyoid variants could lead to better management of patients with omohyoid disorders.