The Hyoid Is Unique in the Body
The hyoid bone is unique in the body because it is the only bone with no articulations: it forms no joints with any other bones. The hyoid is located in the throat area just below the chin and above the Adam's apple at the level of the third cervical vertebra.
Hyoid Anatomy
The hyoid is a horseshoe-shaped bone with a body and two sets of projections, the greater and lesser cornu. These horn-like structures are where muscles attach to the hyoid. The hyoid is about the same size as the projection of the larynx (the Adam's apple) and is located just above this landmark of the throat. The hyoid can be located by pressing the throat just behind the chin--it is the first hard ring below the jaw in the throat.
Hyoid Attachments and Functions
The hyoid is held in position by the thyroid ligaments, which attach it to the cartilage below. It is also held in place by attachments to several muscles. Above the hyoid, it attaches to the hyoglossus, digastric, glenohyoid, stylohyoid, mylohyoid and pharyngeal constrictor muscles. Below the hyoid it attaches to the omohyoid, sternohyoid and thyrohyoid muscles, as well as the thyroid ligaments.
The hyoid anchors these muscles and assists in complex motions of swallowing and vocalization.
References
- "Gray's Anatomy: The Anatomical Basis of Clinical Practice," Susan Standring (Editor), 2008
