Stylohyoid muscle

At a glance

English

Stylohyoid muscle

Latin (TA2)

Musculus stylohyoideus

System

Muscle

Region

Neck

Side

Paired, left and right

About the stylohyoid muscle

Stylohyoid is a thin muscle of the upper neck and one of the suprahyoid group. It lies just in front of and above the posterior belly of digastric, which it follows closely, and the two muscles share their nerve, which comes from the facial nerve. Both develop from the second pharyngeal arch.

It begins on the back and outer face of the temporal bone's styloid process, close to its base. From there it runs down and forward to reach the hyoid bone where the body meets the greater horn, just above the attachment of the superior belly of omohyoid. Near its lower end the muscle usually splits into two slips that wrap around the intermediate tendon of digastric, so that tendon passes through it.

When stylohyoid contracts it pulls the hyoid upward and backward. This lengthens the floor of the mouth and lifts the tongue base, and is part of the start of swallowing, when the hyoid and larynx move up and the bolus is pushed backward. Stylohyoid also steadies the hyoid against the pull of the infrahyoid muscles.

The muscle may be missing or doubled, it may pass deep to the external carotid artery, or it may end on omohyoid or mylohyoid instead of the hyoid. Its blood comes mainly from the lingual artery, with help from the facial and occipital arteries. A long or calcified stylohyoid ligament, which lies close to the muscle, can cause throat pain on swallowing and turning the head, a condition known as Eagle syndrome.

Attachments, action and supply

Origin

Back and outer face of the styloid process near its base.

Insertion

Hyoid bone at the junction of the body and greater horn.

Action

Draws the hyoid up and back, starting swallowing and lengthening the floor of the mouth.

Nerve supply

Facial nerve (CN VII), by its stylohyoid branch.

Blood supply

Lingual artery, with branches of the facial and occipital arteries.