The hyoid boneDr. Muhammad MustafaLectrure Anatomy NCS University System (DHS) , PeshawarDPT, KMU (IPMR), Peshawarfacebook.com/ Muhammad Mutafa

• It is a u shaped bone• Situated in the anterior midline of the neck between the chin and the

thyroid caartilage.• At rest it lies at the level of the 3rd cervical vertebra behind and the base of

the mandible in front.• It is kept in suspended postion by muscles and ligaments• It provides attachment to the floor of the mouth and to the tongue above,

to the larynx below and the epiglottis and the phraynx behind• It consists of central part called the body, and two pairs of cornua,greater

and lesser.

The body

• It has anterior and posterior surfaces ,and upper and lower borders.• The anterior surface is convex and is directed

forwards and upwards.it is often divided by a median ridge into two halves.• The posterior surface in concave and is directed

backwards and downwards.• Each lateral end is continous posteriorly with the

greater horn or cornua.• Till middle life this connection between the body

and greater cornua is fibrous.

The greater cornua

• These are flatenned from above downwards.each cornua tapers posteriorly ,but ends in a tubercle. • it has two surfaces Upper and lower • Two borders medial and lateral and a tubercle.

The lesser cornua

• These are small conical pieces of bone which project upwards from the junction of the body and greater cornua.• The lesser cornua are connected to the body of

fibrous tissue .• Occasionally they are connected to the greater

cornua by synovial joints which usually persist throughout life but may get ankylosed

attachments• Suprahyoid and infrahyoid muscles• Hypoglossus• Thyrohyoid membrane

• Anterior surface provides insertion to the geniohyoid and mylohyoid muscles • Gives origin to a part of the hypoglossus which extends to greater cornua

• The upper border of body provides insertion to the lower fibres of the genioglossi and attachment to the thyrohyoid membrane

• The lower border of the body provides attachment to the pretracheal fascia .in front of the fascia ,the sternohyoid is inserted medially and the omohyoid laterally

• Below the omohyoid there is the linear attachment of the thyrohyoid,extedning back to the lower border of the greater cornua.

• The medial border of the greater cornua provides attachment to they thyrohyoid membrane ,stylohyoid muscle and diagetric pulley

• The lateral border of the greater cornua provides insertion to the thyrohyoid muscle anteriorly.the investing fascia is attached throughout length.

Clinical anatomy

• In a suspected case of murder ,fracture of the hyoid bone strongly indicates throtting and strangulation .