The submandibular triangle (or submaxillary or digastric triangle) corresponds to the region of the neck immediately beneath the body of the mandible.

Boundaries and coverings

It is bounded:

• above, by the lower border of the body of the mandible, and a line drawn from its angle to the mastoid process
  Mastoid process
  The mastoid process is a conical prominence projecting from the undersurface of the mastoid portion of the temporal bone. It is located just behind the external acoustic meatus, and lateral to the styloid process...
  
  ;
• below, by the posterior belly of the Digastricus; in front, by the anterior belly of the Digastricus.

It is covered by the integument, superficial fascia

Superficial fascia

Superficial fascia is found in the subcutis in most regions of the body, blending with the reticular layer of the dermis. It is present on the face, over the upper portion of the sternocleidomastoid, at the nape of the neck, and overlying the sternum. It is mainly loose areolar connective tissue...

, Platysma, and deep fascia, ramifying in which are branches of the facial nerve

Facial nerve

The facial nerve is the seventh of twelve paired cranial nerves. It emerges from the brainstem between the pons and the medulla, and controls the muscles of facial expression, and functions in the conveyance of taste sensations from the anterior two-thirds of the tongue and oral cavity...

 and ascending filaments of the cutaneous cervical nerve.

Its floor is formed by the Mylohyoideus.

Divisions

It is divided into an anterior and a posterior part by the stylomandibular ligament

Stylomandibular ligament

The stylomandibular ligament is a specialized band of the cervical fascia, which extends from near the apex of the styloid process of the temporal bone to the angle and posterior border of the angle of the mandible, between the Masseter and Pterygoideus internus.This ligament separates the parotid...

.

Anterior part

The anterior part contains the submandibular gland, superficial to which is the anterior facial vein

Anterior facial vein

The anterior facial vein commences at the side of the root of the nose and is a direct continuation of the angular vein where it also receives a small nasal branch. It lies behind the facial artery and follows a less tortuous course...

, while imbedded in the gland is the external maxillary artery and its glandular branches.

Beneath the gland, on the surface of the Mylohyoideus, are the submental artery

Submental artery

The submental artery is a branch of the facial artery that runs on the underside of the chin.-Course:The submental artery is the largest of the cervical branches of the facial artery, given off just as that vessel leaves the submandibular gland: it runs forward upon the mylohyoid, just below the...

 and the mylohyoid artery and nerve.

Posterior part

The posterior part of this triangle contains the external carotid artery, ascending deeply in the substance of the parotid gland

Parotid gland

The paired parotid glands are the largest of the salivary glands. They are each found wrapped around the mandibular ramus, and secrete saliva through Stensen's ducts into the oral cavity, to facilitate mastication and swallowing and to begin the digestion of starches.-Location:The parotid glands...

This vessel lies here in front of, and superficial to, the internal carotid, being crossed by the facial nerve

Facial nerve

The facial nerve is the seventh of twelve paired cranial nerves. It emerges from the brainstem between the pons and the medulla, and controls the muscles of facial expression, and functions in the conveyance of taste sensations from the anterior two-thirds of the tongue and oral cavity...

, and gives off in its course the posterior auricular

Posterior auricular

Posterior auricular can refer to:* Posterior auricular artery* Posterior auricular muscle* Posterior auricular vein...

, superficial temporal, and internal maxillary branches: more deeply are the internal carotid, the internal jugular vein

Internal jugular vein

The two internal jugular veins collect the blood from the brain, the superficial parts of the face, and the neck.-Path:On both sides and at the base of the brain, the inferior petrosal sinus and the sigmoid sinus join to form the internal jugular vein...

, and the vagus nerve

Vagus nerve

The vagus nerve , also called pneumogastric nerve or cranial nerve X, is the tenth of twelve paired cranial nerves...

, separated from the external carotid by the Styloglossus

Styloglossus

The Styloglossus, the shortest and smallest of the three styloid muscles, arises from the anterior and lateral surfaces of the styloid process, near its apex, and from the stylomandibular ligament....

 and Stylopharyngeus, and the hypoglossal nerve

Hypoglossal nerve

The hypoglossal nerve is the twelfth cranial nerve , leading to the tongue. The nerve arises from the hypoglossal nucleus and emerges from the medulla oblongata in the preolivary sulcus separating the olive and the pyramid. It then passes through the hypoglossal canal...

Summary of contents

There summarizes the important structures found in the submandibular triangle:

• 1. The external and internal carotid artery
• 2. The internal jugular vein
• 3. The deep cervical lymph nodes
• 4. The 10 th cranial nerve ( Vagus Nerve )
• 5. The submandibular gland
• 6. The submandibular lymph nodes
• 7. The Facial artery and vein
• 8. The 12 th cranial nerve ( Hypoglossal Nerve )

External links

• Overview at bcm.edu
• Overview at howard.edu