Maxillary artery

The maxillary artery is one of the two terminal branches of the external carotid artery, the other being the superficial temporal artery. It is a major artery that supplies deep facial structures, including the nasal cavity, palate, maxilla, mandible, and portions of the dura mater in the skull.

Location

The maxillary artery originates from the external carotid artery near the neck of the mandible, in the region of the parotid gland. It travels through the infratemporal fossa, passing deep to the mandibular condyle, and then continues through the pterygopalatine fossa. The artery is divided into three parts based on its location: the mandibular, pterygoid, and pterygopalatine parts. Along its course, the maxillary artery gives off numerous branches that supply various structures in the face, jaw, and cranial cavity.

Origin

The maxillary artery is one of the two terminal branches of the external carotid artery. It originates behind the neck of the mandible, in the region of the parotid gland. The maxillary artery arises just below the temporomandibular joint (TMJ) and travels medially into the deeper structures of the face. It plays a crucial role in supplying blood to various regions of the face, jaw, and cranial cavity.

Course and Division

The maxillary artery is anatomically divided into three parts based on its course:

First (Mandibular) Part

The first part of the maxillary artery is located in the infratemporal fossa, a space beneath the base of the skull and deep to the zygomatic arch. It begins behind the neck of the mandible and runs forward, deep to the ramus of the mandible. This part of the artery travels between the mandibular condyle and the sphenomandibular ligament. The first part gives rise to several important branches:

• Deep auricular artery: Supplies the external acoustic meatus and part of the tympanic membrane.
• Anterior tympanic artery: Supplies the tympanic membrane and middle ear cavity.
• Inferior alveolar artery: Enters the mandibular foramen to supply the lower teeth and emerges as the mental artery.
• Middle meningeal artery: Passes through the foramen spinosum to supply the dura mater and bones of the cranial vault.
• Accessory meningeal artery: Supplies the meninges and enters the cranial cavity through the foramen ovale.

Second (Pterygoid) Part

The second part of the maxillary artery lies within the infratemporal fossa, running superficial or deep to the lateral pterygoid muscle, depending on anatomical variations. This part primarily supplies the muscles of mastication and surrounding structures. The branches of the second part include:

• Masseteric artery: Supplies the masseter muscle.
• Deep temporal arteries (anterior and posterior): Supply the temporalis muscle.
• Pterygoid arteries: Supply the lateral and medial pterygoid muscles.
• Buccal artery: Supplies the buccinator muscle and the mucosa of the cheek.

Third (Pterygopalatine) Part

The third part of the maxillary artery lies within the pterygopalatine fossa, a small space located behind the maxilla and between the pterygoid processes of the sphenoid bone. This part of the artery is located more medially and deeper than the first two parts, and it supplies the nasal cavity, palate, and upper face. The branches of the third part include:

• Posterior superior alveolar artery: Supplies the maxillary molar and premolar teeth and the maxillary sinus.
• Infraorbital artery: Passes through the infraorbital foramen to supply the lower eyelid, cheek, and upper lip.
• Greater palatine artery: Supplies the hard palate and the palatal mucosa.
• Pharyngeal artery: Supplies the nasopharynx.
• Artery of the pterygoid canal: Supplies the pterygoid canal and the structures within it.
• Sphenopalatine artery: The terminal branch of the maxillary artery, which supplies the nasal cavity and contributes to the vascularization of the septum and lateral nasal wall.

Branches

The maxillary artery has multiple branches, divided according to its three parts. Each part gives off specific branches that supply blood to a variety of structures in the face, jaw, and cranial regions.

Branches of the First (Mandibular) Part

• Deep auricular artery: Supplies the external acoustic meatus and the outer part of the tympanic membrane.
• Anterior tympanic artery: Supplies the tympanic membrane and middle ear cavity.
• Inferior alveolar artery: Supplies the mandibular teeth and chin via the mental artery.
• Middle meningeal artery: Supplies the dura mater and bones of the cranial vault.
• Accessory meningeal artery: Supplies the meninges and enters the skull through the foramen ovale.

Branches of the Second (Pterygoid) Part

• Masseteric artery: Supplies the masseter muscle.
• Anterior and posterior deep temporal arteries: Supply the temporalis muscle.
• Pterygoid arteries: Supply the medial and lateral pterygoid muscles.
• Buccal artery: Supplies the buccinator muscle and the cheek.

Branches of the Third (Pterygopalatine) Part

• Posterior superior alveolar artery: Supplies the maxillary molars, premolars, and maxillary sinus.
• Infraorbital artery: Passes through the infraorbital foramen and supplies the upper lip, lower eyelid, and cheek.
• Greater palatine artery: Supplies the hard palate and palatal mucosa.
• Pharyngeal artery: Supplies the nasopharynx.
• Artery of the pterygoid canal: Supplies the pterygoid canal and its structures.
• Sphenopalatine artery: The terminal branch, which supplies the nasal cavity and contributes to the vascularization of the septum and lateral nasal wall.

Relations with Surrounding Structures

The maxillary artery is in close proximity to several key structures throughout its course:

• Mandibular nerve (V3): The artery passes near the mandibular nerve and its branches in the infratemporal fossa.
• Pterygoid muscles: The second part of the artery is closely related to the lateral pterygoid muscle, which it may pass either superficial or deep to.
• Pterygopalatine ganglion: The third part of the artery is closely related to the pterygopalatine ganglion, which lies in the pterygopalatine fossa and is involved in innervating the nasal and palatine mucosa.
• Infraorbital nerve: The infraorbital artery, a branch of the maxillary artery, runs with the infraorbital nerve through the infraorbital canal to emerge at the infraorbital foramen, supplying the lower eyelid, cheek, and upper lip.

Variations

The anatomy of the maxillary artery can vary in terms of the number, size, and course of its branches. In some individuals, branches may arise from slightly different locations along the artery. Additionally, the relationship between the maxillary artery and the lateral pterygoid muscle can differ, with the artery passing either superficial or deep to the muscle. Variations in the anatomy of the maxillary artery are important to consider during surgical procedures involving the infratemporal fossa or pterygopalatine fossa.

Function

The maxillary artery is one of the principal arteries that supplies blood to the deep structures of the face, oral cavity, nasal cavity, cranial cavity, and the muscles of mastication. Its many branches ensure that various tissues, including bones, muscles, teeth, and sensory organs, receive adequate oxygen and nutrients to function properly. Below is a detailed description of its key functions.

Blood Supply to the Muscles of Mastication

The maxillary artery supplies the muscles involved in chewing and jaw movement through its branches from the second (pterygoid) part.

• Masseteric artery: This branch supplies the masseter muscle, which is essential for elevating the mandible and enabling chewing.
• Deep temporal arteries (anterior and posterior): These arteries supply the temporalis muscle, which plays a crucial role in elevating and retracting the mandible.
• Pterygoid arteries: These supply the medial and lateral pterygoid muscles, which are important for the lateral movements of the jaw (side-to-side grinding motion during chewing).

By providing blood to these muscles, the maxillary artery ensures the proper function of the mandible in actions such as chewing, speaking, and swallowing.

Blood Supply to the Mandible and Lower Teeth

The inferior alveolar artery, a branch of the maxillary artery, supplies the mandibular teeth, as well as the mandible itself.

• Dental branches: These supply the roots and pulp of the mandibular teeth, keeping the teeth healthy and functional.
• Mandibular bone: The artery also nourishes the mandible, ensuring the bone remains strong and capable of supporting the teeth.

After passing through the mandibular canal, the mental artery, a terminal branch of the inferior alveolar artery, exits through the mental foramen to supply the chin and lower lip.

Blood Supply to the Maxillary Sinus and Upper Teeth

The posterior superior alveolar artery, a branch of the third (pterygopalatine) part of the maxillary artery, supplies the maxillary sinus and upper molar and premolar teeth.

• Dental branches: These supply the upper teeth, particularly the molars and premolars, providing essential oxygen and nutrients to the dental pulp and surrounding alveolar bone.
• Maxillary sinus: The artery also supplies the mucosa of the maxillary sinus, playing a role in sinus health and function.

Blood Supply to the Nasal Cavity

The maxillary artery, particularly through its terminal branch, the sphenopalatine artery, supplies the nasal cavity and contributes to the vascular network of the nasal septum and lateral walls.

• Sphenopalatine artery: This branch enters the nasal cavity and supplies the septal mucosa and lateral nasal wall. It is one of the major arteries responsible for providing blood to the nasal mucosa, helping to warm and humidify the air we breathe.
• Pharyngeal artery: This branch contributes to the blood supply of the nasopharynx.

The rich blood supply to the nasal mucosa is essential for maintaining proper function, particularly in filtering and humidifying the air entering the lungs.

Blood Supply to the Palate

The greater palatine artery, a branch of the third (pterygopalatine) part of the maxillary artery, supplies the hard palate and parts of the soft palate.

• Palatal mucosa: The artery supplies the mucosa of the hard palate, ensuring that the tissues in the roof of the mouth remain healthy and functional, particularly in speaking and swallowing.
• Anastomosis with the lesser palatine artery: This connection helps supply the soft palate.

This blood supply ensures the health of the palatal tissues, which are essential for articulation, swallowing, and forming a barrier between the nasal and oral cavities during these functions.

Blood Supply to the Cranial Cavity

The middle meningeal artery, a branch of the first (mandibular) part of the maxillary artery, is a major supplier of blood to the dura mater and cranial bones.

• Dura mater: The middle meningeal artery supplies the outer protective covering of the brain, ensuring that it remains healthy and capable of protecting the brain from injury.
• Cranial vault bones: The artery also nourishes the bones of the cranial vault, helping maintain their strength and function in protecting the brain.

The artery passes through the foramen spinosum into the cranial cavity, supplying the meninges and contributing to the vascular network that supports the dura mater and other intracranial structures.

Blood Supply to the Orbit and Facial Structures

The infraorbital artery, another branch of the third part of the maxillary artery, supplies the orbit, the lower eyelid, the cheek, and the upper lip.

• Infraorbital region: The infraorbital artery travels through the infraorbital foramen and provides blood to the cheek, lower eyelid, and upper lip.
• Orbital structures: This artery contributes to the blood supply of structures around the orbit, supporting the function and health of the lower parts of the eye and face.

This vascularization is important for the integrity and function of facial tissues, as well as supporting facial expressions and movements.

Blood Supply to the Ear

The deep auricular artery and anterior tympanic artery, both branches of the maxillary artery, contribute to the blood supply of the external ear and middle ear structures.

• Deep auricular artery: This artery supplies the external acoustic meatus and the outer surface of the tympanic membrane.
• Anterior tympanic artery: This branch supplies the tympanic membrane and parts of the middle ear cavity.

These arteries play essential roles in maintaining the health of the ear canal and tympanic membrane, which are critical for sound conduction and hearing.

Role in Collateral Circulation

The maxillary artery forms important anastomoses with other arteries in the face and cranial regions, contributing to collateral circulation and ensuring that blood supply remains intact even if one pathway is compromised.

• Anastomosis with facial and superficial temporal arteries: These connections provide alternate blood flow routes to maintain the vascular supply of the face and deep facial structures.
• Anastomosis with ophthalmic artery branches: Connections between the infraorbital artery and branches of the ophthalmic artery ensure the blood supply to the orbit and surrounding facial tissues remains consistent.

Clinical Significance

The maxillary artery is clinically significant due to its extensive role in supplying blood to the deep facial structures, oral cavity, nasal cavity, cranial cavity, and muscles of mastication. Injuries or diseases affecting the artery can lead to complications such as bleeding, ischemia, or infarction of the areas it supplies.

In cases of facial trauma, particularly to the mandible or maxilla, the maxillary artery or its branches can be damaged, leading to severe bleeding. It is also a critical vessel in maxillofacial surgeries, such as reconstructive procedures, dental surgeries, and surgeries involving the sinuses, palate, or middle ear.

The artery’s branches, such as the middle meningeal artery, are also vital in conditions like epidural hematomas, where damage to the artery can cause life-threatening blood accumulation between the dura mater and skull. Understanding its course is essential for avoiding complications during head and neck surgeries.