Hyoid bone

The hyoid bone (lingual bone or tongue-bone) (/ˈhaɪɔɪd/) is a horseshoe-shaped bone situated in the anterior midline of the neck between the chin and the thyroid cartilage. At rest, it lies between the base of the mandible and the third cervical vertebra.

Unlike other bones, the hyoid is only distantly articulated to other bones by muscles or ligaments. It is the only bone in the human body that is not connected to any other bones. The hyoid is anchored by muscles from the anterior, posterior and inferior directions, and aids in tongue movement and swallowing. The hyoid bone provides attachment to the muscles of the floor of the mouth and the tongue above, the larynx below, and the epiglottis and pharynx behind.^{[citation needed]}

Its name is derived from Greek hyoeides 'shaped like the letter upsilon (υ)'.

The hyoid bone is classed as an irregular bone and consists of a central part called the body, and two pairs of horns, the greater and lesser horns.

The body of the hyoid bone is the central part of the hyoid bone.^{[clarification needed]}

The greater and lesser horns (Latin: cornua) are two sections of bone that project from each side of the hyoid.

The greater horns project backward from the outer borders of the body; they are flattened from above downward and taper to their end, which is a bony tubercle connecting to the lateral thyrohyoid ligament. The upper surface of the greater horns are rough and close to its lateral border, and facilitates muscular attachment. The largest of muscles that attach to the upper surface of the greater horns are the hyoglossus and the middle pharyngeal constrictor, which extend along the whole length of the horns; the digastric muscle and stylohyoid muscle have small insertions in front of these near the junction of the body with the horns. To the medial border, the thyrohyoid membrane is attached, while the anterior half of the lateral border gives insertion to the thyrohyoid muscle.^{[citation needed]}

The lesser horns are two small, conical eminences, attached by their bases to the angles of junction between the body and greater horns of the hyoid bone. They are connected to the body of the bone by fibrous tissue, and occasionally to the greater horns by distinct diarthrodial joints, which usually persist throughout life, but occasionally become ankylosed. The lesser horns are situated in the line of the transverse ridge on the body and appear to be continuations of it. The apex of each horn gives attachment to the stylohyoid ligament; the chondroglossus rises from the medial side of the base.^{[citation needed]}