The Anatomy of the Facial Artery

The facial artery—also called the external maxillary artery—is a primary source of oxygenated blood to the muscles and skin of the face. It is one of the eight branches of the external carotid artery,

Each of the paired facial arteries takes a twisted, bent route as it progresses along the nasolabial fold (the “smile lines” running from the corners of the nose to the sides of the mouth) towards the corner of the eye adjacent to the nose, where it terminates. Along the way, it passes through important structures and muscles in the mouth and around the jaw bone.

Anatomy

Structure and Location

Arising from the anterior (front) surface of the external carotid artery, an ascending artery that gives off numerous branches, the facial artery runs upwards along the nasolabial fold. As it does so it takes a twisted, bending pattern that passes through the digastric and stylohyoid muscles, which regulate tongue and jaw mobility, before accessing the submandibular glands, a major source of saliva located on each side of the base of the mouth.

In the latter portion of the facial artery’s course, it bends over the mandible (jaw bone), crossing the rear side of the masseter, a muscle essential for chewing. From there it moves upward and crosses the cheek to reach the junction of the bottom corner of the nose, where it continues its vertical course. The artery terminates at the medial aspect of the eye, which is the part closest to the nose.

Along its course, this artery gives rise to important cervical branches (arising in the neck):

• Ascending Palatine Artery: Passing upwards between the styloglossus and stylopharyngeus—muscle groups that connect to the tongue and the pharynx, respectively—before splitting into two branches. One of these accesses the auditory tube of the ear and the palatine tonsil (a soft tissue mass in the throat), while the other reaches the superior pharyngeal constrictor muscle of the pharynx.
• Tonsillar Branch: Running between the styloglossus and medial pterygoid muscle (located towards the back of the mouth), the tonsillar branch pierces the superior pharyngeal constrictor before getting to the palatine tonsil. At that point, it connects with one of the branches of the ascending palatine artery.
• Submental Artery: Moving alongside the underside of the chin, the submental artery is the largest branch of the facial artery. It splits off at the point where the course passes through the submandibular gland, passing over the mylohyoid muscle just behind the body of the mandible. It eventually splits further into a superficial (surface) and a deep branch.
• Glandular Branches: Three to four branches arise as well, moving towards the submandibular salivary gland as well as surrounding structures.

Further, on its course, the facial artery splits off into several facial branches:

• Inferior Labial Artery: Emerging close to the corner of the mouth before passing upwards and forwards as it passes underneath the triangularis (a facial muscle associated with frowning) and the orbicularis oris muscle (a muscle that surrounds the lips). It then connects with its counterpart from the other side of the head as well as the mental branch.
• Superior Labial Artery: Larger than the inferior labial artery, this artery runs to muscles of the upper lip, the septum, as well as the ala, or wing, of the nose.
• Lateral Nasal Branch: This branch runs along the side of the nose to supply important parts of the nose as well as the area around the eye.
• Angular Artery: The terminal branch of the facial artery, this artery supplies structures in the cheek before ultimately connecting with the ophthalmic artery (associated with vision). It runs upwards, reaching the medial canthus of the eye.

Anatomical Variations

In some cases, doctors have observed variations in the structure and course of the facial artery. The most common of these are:

• Maxillary Artery Origin: Researchers have found the facial artery emerging higher than normal, at the level of the maxillary artery rather than the external carotid artery. One study noted an incidence of this occurring about 3.3% of the time.  
• Linguo-Facial Trunk: Among the more common variations seen is the facial artery arising from the lingual artery, forming what’s called a lingual-facial trunk.
• Failure of Development: Though rarely observed, doctors have noted cases where this artery never develops at all. In these cases, surrounding arteries provide blood to regions usually supplied by the facial artery.
• Underdevelopment of Artery: One or both facial arteries may be underdeveloped at birth. In these cases—estimates of prevalence range from 0 to 9% —blood supply is taken up by other facial arteries.

Function

The facial artery plays a very significant role in providing blood to muscles, tissues, and glands in the face and mouth. Broadly speaking, the functions of this artery can be organized based on the part of its course that branches emerge from. Here’s a quick breakdown:

• Cervical Course: The branches coming from the initial course of the facial arteries ensure that structures in the throat and mouth are supplied with oxygenated blood. This includes the auditory tube, palatine tonsil, superior pharyngeal constrictor muscle, soft palate, submental muscle, submental region skin, lymph nodes, as well as the salivary glands.
• Facial Course: The upper branches of this artery are tasked with supplying blood to frontal structures of the face. This includes the upper and lower lip, labial glands (smaller salivary glands closer to the opening of the mouth), the septum and ala (edge) of the nose, the lacrimal sac (associated with tearing of the eye), as well as the orbicularis oculi muscle, which surrounds the lips.

Clinical Significance     

Branches of the external carotid artery, like the facial artery, are well collateralized and tolerate reduced blood flow in the larger vessels that supply the facial artery—with little or no symptoms.

Symptoms of facial arterial damage can develop if the artery is damaged due to trauma. This can include bleeding, which can lead to swelling and compression of nearby structures.