A rare variation of omohyoid and its embryological correlations- A case report

The omohyoid muscle is important in radical neck dissection, as it is a landmark for this operation. Because it divides the anterior and posterior cervical triangles into smaller triangles and its particular relationship to the large cervical vessels, the presence of an anatomical variation of the omohyoid muscle is important. Either belly may be absent or double; and the inferior belly may be attached directly to the clavicle and the superior is sometimes fused with sternohyoid. Variations in the omohyoid muscle might be linked to differences in embryological development, which could influence the muscle’s final form and function. Anderson (Anderson, 1881) theorized that the superior belly of the omohyoid muscle is a true infrahyoid muscle, whereas the inferior belly most likely shares a common embryology with the subclavius muscle. As omohyoid mucle is used to achieve the reconstruction of the laryngeal muscles and bowed vocal folds, the knowledge of the possible anomalies of the omohyoid muscle is important. In the present study, we have found a case with two inferior bellies & aberrant course of superior belly of omohyoid on right side of 40 years female cadaver embalmed with formalin during routine dissection at Department of Anatomy AIIMS Gorakhpur. Omohyoid muscle is closely related to large vessels of neck & brachial plexus, so variations in this muscle are clinically important.