The Cleidohyoid: A Variant of Omohyoid Muscle?

Abstract

Abstract:Variations in the infrahyoid muscle were identified as early as 19 th century. During regular dissection of cadaver in anatomy department in Kota an unilateral anomalous infrahyoid muscle was noted on right side with the absence of omohyoid muscle on same side. It was a flat, strap muscle 12 cm long and 2 cm wide. On one end it was attached to antero-lateral aspect of body of hyoid bone and on the other end to the clavicle. Its nerve supply was noted to be from the ansa cervicalis. Apart from this other infrahyoid muscles were normal. This muscle is best described as a cleidohyoid rather than the omohyoid. Hence in our case cleidohyoid appears to be variation of omohyoid muscle whereas some other workers have reported cleidohyoid as a variation of sternohyoid muscle. Surgeons and radiologists should be aware of such variations as it might interfere with the invasive techniques and knowledge of such variations should be kept in mind while interpreting MRI images of cervical region.

Sternocleidohyoid muscle: an unreported variant of cleidohyoid muscle

“…Either one or both its bellies may be absent [ 24 ]. Apart from the three known infrahyoid muscles, a fourth muscle originating from clavicle and getting inserted to the hyoid bone has been reported [ 25 ].…”