The Hyoid Bone

The hyoid bone is a small U-shaped bone located in the upper neck at the level of the inferior mandible, with its tips pointing posteriorly. It does not directly articulate with any other bone in the body. The hyoid acts as the attachment site for the tongue, the larynx, and the pharynx. It is held in position by a series of small muscles attached from above or below. These muscles help to move the hyoid up/down or forward/back in coordination with movements of the tongue, larynx, and pharynx during swallowing and speaking.

The hyoid bone consists of a central body and laterally extends to form two pairs of cornua, or horns, known as greater and lesser cornua. The backward projecting greater horns attach stylohyoid and thyrohyoid muscles and ligaments. The smaller eminences, the lesser horns, project superiorly and are attached to the body by fibrous tissue.

The ossification of the hyoid occurs towards the end of fetal development. Ossification begins in the greater cornua and ends with the body shortly after birth. The connecting fibrous material between the greater cornua and the body ossifies towards middle age.

The hyoid is involved in most functions performed by the orofacial complex. For example, the region ranging from the oropharynx above and the tracheal rings below the hyoid bone helps to maintain airway patency. The hyoid also has a vital role in phonation as it connects to the larynx. In addition, it also aids in respiratory and digestive functions, such as tongue movement, mastication, swallowing, and preventing regurgitation.

This text is partially adapted from Openstax, Anatomy and Physiology 2e, 7.2 The Skull