INTERNAL MAXILLARY ARTERY: ANATOMY, CLINICAL CONSIDERATIONS - ANATOMY AND PHYSIOLOGY - 2024

The internal maxillary artery is one of the two terminal branches of the external carotid artery. This, in turn, is one of the terminal branches of the common carotid artery. Known simply as the maxillary artery, it arises at the level of the neck of the mandibular bone and runs horizontally and slightly upward.

The maxillary artery provides many branches of supply to the deep planes of the muscles of the face. For the simplification of its anatomical and surgical study, the artery is divided into three parts that are determined by their relationship with the lateral pterygoid muscle.

From Henry Vandyke Carter - Henry Gray (1918) Anatomy of the Human Body (See "Book" section below) Bartleby.com: Gray's Anatomy, Plate 510, Public Domain, https://commons.wikimedia.org/w/index. php?

Head trauma can injure it, causing bleeding between the meningeal laminae. This condition is known as an epidural hematoma and when not treated in time it can lead to serious complications and even death.

Anatomy

The external carotid artery is one of the most important blood vessels involved in supplying the structures of the face and skull.

It has an ascending course from its beginning at the level of the fourth cervical vertebra. On its way it gives six collateral branches that are responsible for the blood supply of the structures of the neck and face.

Some of its most important branches are the superior thyroid artery and the facial artery.

By BruceBlaus. When using this image in external sources it can be cited as: Blausen.com staff (2014). "Medical gallery of Blausen Medical 2014". WikiJournal of Medicine 1 (2). DOI: 10.15347 / wjm / 2014.010. ISSN 2002-4436. - Own work, CC BY 3.0, The external carotid completes its journey at the level of the temporomandibular joint and it is there where it divides, giving its two terminal branches, the superficial temporal artery and the internal maxillary artery.

Internal maxillary artery

It was previously known as the internal maxillary artery to differentiate it from the external maxillary artery. Later, the «external maxilla» became the facial artery, so it is no longer pertinent to make that differentiation.

The terms "maxillary artery" and "internal maxillary artery" are currently in common and indifferent use. It can also be found in some medical literature under the name "internal mandibular artery."

The internal maxilla is one of the terminal branches of the external carotid artery. It follows an almost horizontal path and is responsible for giving multiple collateral branches that are important in the irrigation of the structures of the mouth and face.

By User: Mikael Häggström, Public Domain, From the beginning of its journey in the temporo-mandibular joint, the maxillary artery enters the infratemporal fossa of the skull, an area is formed by the sphenoid, maxillary, temporal and mandibular bones.

Then it continues its journey towards the pterygopalatine fossa, where it is related to the lateral pterygoid muscle, following a path parallel to it.

Collateral branch segments

Since this artery provides a considerable amount of collateral branches, its course is divided into three segments to simplify its anatomical study.

By Henry Vandyke Carter - Henry Gray (1918) Anatomy of the Human Body (See «Book» section below) Bartleby.com: Gray's Anatomy, Plate 511, Public Domain, https://commons.wikimedia.org/w/index. php? curid = 540888

This division is made according to the relationship of the artery to the lateral pterygoid muscle. Thus, the following segments are found:

- Segment 1: also known as bone segment. It is located in the neck of the jaw. In this small path the artery gives five branches that are responsible for nourishing internal structures of the skull.

- Segment 2: called the muscle segment because in this part it runs parallel to the lateral pterygoid muscle. This section gives four vascular branches to buccal structures and is also the main supply of the lateral pterygoid muscle.

- Segment 3: called the pterygopalatin segment or, it is the portion that is located anterior to the lateral pterygoid muscle and gives eight vascular branches that are responsible for supplying the palate, the chewing muscles and the infraorbital region.

Importance

The maxillary artery is responsible for supplying neighboring structures of the face and skull, through its multiple collateral vessels.

These branches nourish such important structures as the parotid gland, chewing muscles, oral structures, cranial nerves, and even the meninges.

In addition, it is the terminal branch of the external carotid artery and through it there is a communication network with the internal carotid artery through arches that join both vascular pathways.

By Double-M from Athens, GA, USA - Maxillary Artery, CC BY 2.0, Several of the collateral branches of the maxillary artery are responsible for supplying the sense organs, including the nasal mucosa and the orbital region that gives small branches to the eyes.

It also provides multiple collateral branches that travel within the skull and supply some nerves at the base of the skull.

These branches create anastomotic arches with branches from the internal carotid artery. That is, both arteries are communicated through the union of their collateral branches, which form a complex vascular network at the base of the skull.

By Circle_of_Willis_pt.svg: Rhcastilhosderivative work: Ninovolador (talk) - Circle_of_Willis_pt.svg, Public Domain, Thanks to these vascular junctions, the circulation is in constant flow even if one of the two arteries is injured.

The network formed by the carotid arteries through their branches, especially with the collaterals of the internal maxilla, ensure blood perfusion of the intracranial structures.

Clinical considerations

Despite the advantages of communication between the circulation of the external and internal carotid arteries, this also causes infections in areas near the maxillary artery to evolve rapidly, causing serious complications.

An example of this is bacterial tooth infections, which when deep enough can allow bacteria to enter the bloodstream.

Through the arterial anastomotic network, through the collateral branches of the maxillary artery, bacteria quickly ascend to the brain structures causing important problems, such as meningitis, which can lead to delicate health situations such as coma and even death..

By Mikael Häggström - See above. All used images are in public domain., Public Domain, Another clinical condition that occurs due to injury to the internal maxillary artery is epidural hematoma. In this case, the affected one is one of the first collateral branches, called the middle meningeal artery. This branch is located above the fibrous layer that covers the brain, the dura mater.

By BruceBlaus - Own work, CC BY-SA 4.0, When a person suffers a trauma to the skull, specifically at the level of the temporal bone, the middle meningeal artery can be injured and bleed, causing a hematoma that rapidly increases the pressure within the skull.

An epidural hematoma can cause death in about 15 to 20% of patients who present with this condition.

References

1. Tanoue, S; Kiyosue, H; Mori, H; Hori, Y; Okahara, M; Sagara, Y. (2013). Maxillary Artery: Functional and Imaging Anatomy for Safe and Effective Transcatheter Treatment. Radiographics: a review publication of the Radiological Society of North America. Taken from: pubs.rsna.org
2. Uysal, I; Büyükmumcu, M; Dogan, N; Seker, M; Ziylan, T. (2011). Clinical Significance of Maxillary Artery and its Branches: A Cadaver Study and Review of the Literature. International Journal of Morphology. Taken from: scielo.conicyt.cl
3. Gofur, EM; Al Khalili, Y. (2019). Anatomy, Head and Neck, Internal Maxillary Arteries. Treasure Island (FL): StatPearls Publishing. Taken from: ncbi.nlm.nih.gov
4. Sethi D, Gofur EM, Waheed A. Anatomy, Head and Neck, Carotid Arteries. Treasure Island (FL): StatPearls Publishing. Taken from: ncbi.nlm.nih.gov
5. Iglesias, P; Moreno, M; Gallo, A. (2007). Relationship between the internal maxillary artery and the branches of the mandibular nerve. Anatomical variants. Los Andes Dental Journal. Taken from: erevistas.saber.ula.ve