Maxillary Artery: Anatomy and Branches

• The maxillary artery, along with the superficial temporal artery, is a terminal division of the external carotid artery.

Course of the Maxillary Artery

• It enters the infratemporal fossa by winding around deep to the mandible's neck, passing forward between the neck and the sphenomandibular ligament.
• The auriculotemporal nerve lies above it, and the maxillary veins below it
• It usually runs deep to the lower head of the lateral pterygoid muscle, but variations are common, and it may pass below (or rarely, above) the muscle.
• It passes into the pterygomaxillary fissure and then into the pterygopalatine fossa.

Divisions and Branches

• Conventionally described in three parts: before, on, and beyond the lateral pterygoid muscle.
• Each part gives off five branches.
• Branches from the first and third parts enter foramina in bones.
• Branches from the second part supply soft tissues.

First Part Branches (Bony)

• All five branches from the first part enter foramina in bones
• Include the inferior alveolar, middle meningeal, accessory meningeal arteries, and two branches to the ear.
• The inferior alveolar and middle meningeal arteries are the most important.

Inferior Alveolar Artery

• The inferior alveolar artery passes downwards and forwards (vein behind it) towards the inferior alveolar nerve
• It meets the inferior alveolar nerve at the mandibular foramen, in which all three lie.
• It passes forwards in the mandible, supplying the pulps of the mandibular teeth (dental branches) and the body of the mandible.
• The mental branch emerges from the mental foramen and supplies the nearby lip and skin.
• In the edentulous mandible of old age, where alveolar bone has become resorbed, the artery atrophies.

Middle Meningeal Artery

• Passes vertically upwards to the foramen spinosum.
• It is embraced by the two roots of the auriculotemporal nerve.
• Supplies bone of the skull.
• A branch from the sympathetic plexus on the artery enters the otic ganglion.

Accessory Meningeal Artery

• The accessory meningeal artery passes upwards through the foramen ovale
• It supplies the dura mater of the floor of the middle fossa and of the trigeminal (Meckel's) cave.
• Main source of blood supply to the trigeminal ganglion.

Ear Branches

• The deep auricular artery is the more superficial of the two, supplying the external acoustic meatus.
• The anterior tympanic artery passes through the petrotympanic fissure to the middle ear, joining the circular anastomosis around the tympanic membrane.

Second Part Branches

• Supplies the pterygoid muscles and deep temporal branches to temporalis.
• Branches accompany the lingual and buccal nerves.
• Supplies the soft parts

Third Part Branches

• Located in the pterygopalatine fossa, it gives off five branches which accompany nerves including branches of the pterygopalatine ganglion.
• Leaves the fossa through the sphenopalatine foramen, becoming the sphenopalatine artery, the main artery of the nasal cavity.

Posterior Superior Alveolar Artery

• Gives branches that accompany the corresponding nerves through foramina in the posterior wall of the maxilla.

Greater Palatine Artery

• Enters the foramen of the same name to reach the hard palate.

Pharyngeal Artery

• Enters the palatovaginal canal

Artery of the Pterygoid Canal

• Runs into its own canal.

Infraorbital Artery

• Passes forwards through the inferior orbital fissure, along the floor of the orbit and infraorbital canal.
• It emerges with the infraorbital nerve on the face.

Pterygoid Plexus

• A pterygoid plexus runs around and within the lateral pterygoid muscle
• Often not demonstrable in dissected cadavers, sometimes appearing on the lateral muscle surface.
• Drains into a pair of large, short maxillary veins deep to the mandible's neck, which join the superficial temporal vein to form the retromandibular vein.
• Receives drainage from the inferior ophthalmic veins (via the inferior orbital fissure) and the deep facial vein.
• Acts as a 'peripheral heart', aiding venous return by the pumping action of the lateral pterygoid muscle.
• Pumps blood from incompressible parts (face bones, orbit) back into the maxillary veins each time the mouth is actively opened.

Sphenomandibular Ligament

• A flat band of tough fibrous tissue extending from the spine of the sphenoid to the lingula and inferior margin of the mandibular foramen.
• It is the perichondrium of Meckel's cartilage.
• The auriculotemporal nerve and the maxillary artery and vein pass between it and the neck of the mandible.
• The inferior alveolar vessels and nerve converge to the mandibular foramen between it and the ramus of the mandible.
• Pierced by the mylohyoid nerve, which lies in the groove on the mandible at the margin of attachment of the medial pterygoid muscle.
• The mylohyoid artery, a small branch of the inferior alveolar artery, accompanies the nerve to anastomose with the submental branch of the facial artery.
• The small vein accompanying the mylohyoid artery is responsible for making the mylohyoid groove on the mandible.

The maxillary artery, a terminal branch of the external carotid artery, traverses the infratemporal fossa. It's divided into three parts, each with five branches supplying bony structures and soft tissues. Variations in its path relative to the lateral pterygoid muscle are common.