Stylomandibular ligament

At a glance

English

Stylomandibular ligament

Latin (TA2)

Ligamentum stylomandibulare

System

Ligament

Region

Head

Side

Paired, left and right

About the stylomandibular ligament

The stylomandibular ligament is a thickened band of deep cervical fascia rather than a true joint ligament. It forms where the investing layer of the fascia, having enclosed the parotid gland, condenses into a firm strip at the back of the jaw. The band runs from close to the tip of the temporal styloid process down to the angle of the mandible and the adjoining posterior border of the ramus.

At its lower end it passes between two chewing muscles, the masseter on the outside of the ramus and the medial pterygoid on the inside. Some fibres of styloglossus take origin from its deep surface. The band also separates the parotid gland, which lies above and behind it, from the submandibular gland in front and below, so it is a useful boundary in surgery of this region.

Anatomy texts usually group it with the jaw-joint ligaments, but it lies far from the joint and is only an accessory support. Together with the sphenomandibular ligament it sets outer limits to jaw movement, tightening when the mandible is pushed forwards and at the extreme of wide opening.

Its practical value lies in surgery. In operations on the parotid gland and in maxillofacial procedures that divide or reposition the ramus, the ligament is identified and, where possible, preserved, because it helps to keep the mandible stable afterwards. It is also a guide to the position of the facial nerve and the external carotid artery, which run nearby in the parotid region.

Attachments and function

Attaches from

Close to the tip of the temporal styloid process.

Attaches to

The angle of the mandible and the adjoining posterior border of the ramus.

Function

Limits forward protrusion and extreme opening of the mandible and separates the parotid from the submandibular gland.