Stylohyoid ligament

At a glance

English

Stylohyoid ligament

Latin (TA2)

Ligamentum stylohyoideum

System

Ligament

Region

Head

Side

Paired, left and right

About the stylohyoid ligament

The stylohyoid ligament is a slender cord that slings the hyoid bone from the base of the skull. It begins at the tip of the styloid process, the thin spike of the temporal bone that points downwards and forwards below the ear, and it ends on the lesser horn of the hyoid, the small knob where the body of the hyoid meets its greater horn.

Its course takes it down and forwards along the side wall of the pharynx. The ligament gives attachment to some of the uppermost fibres of the middle pharyngeal constrictor and lies close to the stylohyoid and styloglossus muscles, which come from the same process. With the styloid process and the lesser horn, it forms a chain that is a remnant of the cartilage of the second pharyngeal arch.

That embryonic origin explains a frequent finding: a small piece of cartilage is often present in the middle of the ligament, and parts of the ligament may turn to bone. In many mammals this middle segment is a separate bone, the epihyal, so the hyoid hangs from the skull by a jointed bony chain rather than a ligament.

When the styloid process is unusually long or the ligament is ossified, the condition is called Eagle syndrome. The rigid bar can press on nearby structures, causing pain in the throat or ear, a feeling of something stuck on swallowing, and pain when turning the head. Pressure on the internal carotid artery or the sympathetic fibres around it can give a vascular form of the condition. Treatment, when needed, is shortening of the styloid process.

Attachments and function

Attaches from

The apex of the temporal styloid process.

Attaches to

The lesser horn of the hyoid bone.

Function

Suspends the hyoid bone from the skull base and gives attachment to fibres of the middle pharyngeal constrictor.