Three-headed duplicated omohyoid muscle in a human cadaver.

The omohyoid is a digastric muscle that crosses the neck from the superior border of the scapula to the body of the hyoid bone. Variations in the omohyoid muscle are common, but a double omohyoid is considered rare and may have important clinical implications. The anatomical dissection of the neck of a middle-aged male cadaver revealed an abnormal three-headed duplicated omohyoid muscle. Behind the clavicle, the intermediate head bifurcated and fused with the medial and lateral heads, forming a small plexus that gave rise to two separate bellies, one lateral, and one medial. The bellies ascended in a superomedial direction before inserting into the hyoid bone next to each other. The intermediate tendon was rudimentary in the lateral belly and absent in the medial one. The anatomical variation described here has not been previously reported and may have clinical significance.