Body of hyoid bone

The body of hyoid bone or central part is of a quadrilateral form.


 * Its anterior surface is convex and directed forward and upward.
 * It is crossed in its upper half by a well-marked transverse ridge with a slight downward convexity, and in many cases a vertical median ridge divides it into two lateral halves.
 * The portion of the vertical ridge above the transverse line is present in a majority of specimens, but the lower portion is evident only in rare cases.
 * The anterior surface gives insertion to the geniohyoid muscle in the greater part of its extent both above and below the transverse ridge; a portion of the origin of the hyoglossus notches the lateral margin of the geniohyoid attachment.
 * Below the transverse ridge the mylohyoid, sternohyoid, and omohyoid are inserted.


 * The posterior surface is smooth, concave, directed backward and downward, and separated from the epiglottis by the hyothyroid membrane and a quantity of loose areolar tissue; a bursa intervenes between it and the hyothyroid membrane.


 * The superior border is rounded, and gives attachment to the hyothyroid membrane and some aponeurotic fibers of the genioglossus.


 * The inferior border affords insertion medially to the sternohyoid and laterally to the omohyoid and occasionally a portion of the thyrohyoid. It also gives attachment to the Levator glandulae thyreoideae, when this muscle is present.


 * In early life the lateral borders are connected to the greater cornua by synchondroses; after middle life usually by bony union.