Submandibular Triangle

trigonum submandibulare

The submandibular, or digastric, triangle lies under the body of the mandible between the lower border of the jaw and the two bellies of digastric. It is mostly filled by the submandibular gland, with the facial artery and vein and submandibular lymph nodes close by.

Anatomical Data

Boundaries & Contents

Location	Under the body of the mandible.
Boundaries	Lower border of the mandible above Anterior belly of digastric Posterior belly of digastric and stylohyoid Mylohyoid and hyoglossus as the floor
Contents	Submandibular gland Submandibular lymph nodes Facial artery and vein Hypoglossal nerve Nerve to mylohyoid

Biomechanics

Function & Actions

Houses the submandibular gland and the vessels and nerves of the upper neck.

Clinical Relevance

Clinical Notes

Swellings here are usually from the submandibular gland (stones or infection) or lymph nodes draining the face and mouth. Surgery in this triangle must protect the marginal mandibular branch of the facial nerve, which runs just under the platysma near the jaw border, as well as the lingual and hypoglossal nerves deeper down.

Pathology

Common Injuries & Conditions

Submandibular Gland Stone

A stone blocking the submandibular duct, causing painful swelling of the gland in the triangle during meals.

Marginal Mandibular Nerve Injury

Damage to this facial nerve branch during surgery in the triangle, producing weakness of the lower lip.

Explore

More in Neck

Browse all of Neck →