Lateral temporomandibular ligament

At a glance

English

Lateral temporomandibular ligament

Latin (TA2)

Ligamentum temporomandibulare laterale

System

Ligament

Region

Head

Side

Paired, left and right

About the lateral temporomandibular ligament

The lateral ligament is the main reinforcement of the temporomandibular joint, the hinge-and-glide joint between the mandible and the temporal bone just in front of the ear. It is not a free-standing cord but a thickening of the outer part of the joint capsule. Above, it is fixed to the articular tubercle at the root of the zygomatic arch, a bump whose surface is usually roughened where the ligament attaches. Below, it fixes to the outer face and back edge of the mandibular neck.

The ligament is wider at the top than at the bottom, and its fibres slope downwards and backwards. It is usually described in two short, narrow parts, one lying in front of the other: an outer oblique band and an inner, more horizontal band that runs back to the lateral pole of the condyle and the articular disc. Superficially, only the parotid gland and skin lie over it.

As the mouth opens, the condyle first rotates in its socket. The oblique fibres soon tighten and stop simple rotation, so that further opening forces the condyle and disc to slide forwards onto the articular tubercle. The horizontal fibres keep the condyle from being pushed backwards towards the ear canal. The ligament also braces the joint against an upward blow to the chin, which could otherwise drive the condyle into the thin roof of the glenoid fossa and the floor of the middle cranial fossa.

The joint is a common site of pain and clicking. Laxity or strain of the lateral ligament contributes to disorders in which the disc slips out of place, and a forceful blow can still fracture the condylar neck, the weakest part of the mandible, rather than letting the condyle enter the skull.

Attachments and function

Attaches from

The articular tubercle on the root of the zygomatic process of the temporal bone.

Attaches to

The outer surface and back edge of the mandibular neck, with inner fibres reaching the lateral pole of the condyle.

Function

Limits backward and downward displacement of the condyle and converts jaw opening from rotation into forward gliding.

Nerve supply

The auriculotemporal nerve, with twigs from the masseteric nerve.

Blood supply

Articular branches of the superficial temporal artery.