The maxillary artery is one of the two terminal divisions of the external carotid artery. The second terminal branch is the superficial temporal artery. Therefore the maxillary artery can be defined as one of the continuations of the external carotid artery, and distributes the blood flow to the upper (maxilla) and lower (mandible) jaw bones, deep facial areas, cerebral dura mater and the nasal cavity. Hence it is considered a blood vessel which supports both hard and soft tissues in the maxillofacial region.
The main trunk of the maxillary artery is divided into three parts, which are named according to related structures along the artery’s course (path of travel). These three parts are the:
- Mandibular part (1st part) – named as such because it winds around deep to the neck of the mandible,
- Pterygoid part (2nd part) – it has this name because it travels between the two heads of the lateral pterygoid muscle,
- Pterygopalatine part (3rd part) – this part derived its name from the pterygopalatine fossa, into which it enters.
Conventionally, these three parts are described as the part before-, part on-, and part beyond the lateral pterygoid muscle. This is also useful since out of the 15 branches of the maxillary artery, the 5 branches from the second part (part on the lateral pterygoid muscle) are regarded as branches to soft tissues and they DO NOT course through foramina in bones. However, the remaining 10 branches, from the first and third parts, go through foramina in bones.
The maxillary artery continues as one of the terminal divisions of the external carotid artery at the level of the neck of the mandible and passes forwards between the neck of the mandible and the sphenomandibular ligament. It continues its path by running deeply to the lower head and passes forward between the two heads of the lateral pterygoid muscle to break into its terminal branches at the pterygopalatine fossa.
Branches & Distribution
The main trunk of the maxillary artery extends into the following fifteen branches, which can be remembered using the mnemonic:
“DAMn I AM Piss Drunk But Stupid Drunk I Prefer, Must Phone Alcoholics Anonymous”
Based on that mnemonic, the order of the branches and their distributions is the following:
From the Mandibular Part
D – deep auricular artery - this branch runs upwards to enter the ear and courses superficially to the tympanic membrane, passing between the cartilage and bone to supply blood to the external acoustic meatus of the ear.
A – anterior tympanic artery - this is the second branch that courses near the tympanic membrane. It passes deep to the membrane, through the petrotympanic fissure to the middle ear to join the circular anastomosis around the tympanic membrane.
M – middle meningeal artery - this one passes straight upwards through the foramen spinosum to join the two roots of the auriculotemporal nerve. It supplies bones of the skull (calvaria) and the dura mater.
I – inferior alveolar artery - runs downwards and forwards towards the inferior alveolar nerve, to meet the nerve at the mandibular foramen. The artery runs further anteriorly in the mandible, supplying the pulps of the mandibular teeth (with its dental branches) and the body of the mandible. Its other branch, the mental branch, emerges from the mental foramen and supplies the nearby lip and skin.
A – accessory meningeal artery - this branch is the chief source of blood supply to the trigeminal ganglion. It passes upwards through the foramen ovale to supply the dura mater of the floor of the middle fossa and of the trigeminal cave (Meckel’s cave).
From the Pterygoid Part
All the branches from the pterygoid part supply only soft tissues.
M – masseteric artery - accompanies the lingual nerve. It is small, and passes laterally through the mandibular notch to the deep surface of the masseter muscle, which it supplies.
P – pterygoid artery - this artery varies in its number according to authors. However, it supplies the lateral pterygoid muscle and medial pterygoid muscle.
D – deep temporal artery - this branch bifurcates into two - anterior and posterior. They course between the temporalis and the pericranium respectively, supplying the muscles, and anastomose with the middle temporal artery. The anterior division communicates with the lacrimal artery by means of small branches which perforate the zygomatic bone and great wing of the sphenoid.
B – buccal or buccinator artery - runs obliquely forward, between the pterygoideus internus and the insertion of the temporalis muscle, to the outer surface of the buccinator muscles, to which it supplies. It anastomoses with branches of the facial artery and with the infraorbital artery. From the infraorbital area, the buccal artery descends bilaterally in the superficial face along the lateral margin of the nose, then running anti-parallel to the facial artery across the lateral oral region.
From the Pterygopalatine Part
S – sphenopalatine artery - supplies the nasal cavity; it is also called nasopalatine artery. It passes through the sphenopalatine foramen into the cavity of the nose, at the back part of the superior meatus. Here it gives off its posterior lateral nasal branches. Crossing the inferior surface of the sphenoid, the sphenopalatine artery ends on the nasal septum as the posterior septal branches.
D – descending palatine artery - this divides to form the greater and lesser palatine arteries to supply the hard palate and soft palate respectively. It descends through the greater palatine canal with the greater and lesser palatine branches of the pterygopalatine ganglion. It emerges from the greater palatine foramen, runs forward in a groove on the medial side of the alveolar border of the hard palate to the incisive canal; the terminal branch of the artery passes upward through this canal to anastomose with the sphenopalatine artery.
I – infraorbital artery - passes forwards through the inferior orbital fissure, along the floor of the orbit and infraorbital canal to emerge with the infraorbital nerve on the face.
P – posterior superior alveolar artery - supplies the maxillary teeth. Gives branches that accompany the corresponding nerves through foramina in the posterior wall of the maxilla.
M - middle superior alveolar artery (branch of the infraorbital artery).
P – pharyngeal artery - supplies structures such as the pharynx and roof of the nose.
A - anterior superior alveolar artery (branch of the infraorbital artery).
A – artery of the pterygoid canal - runs into the pterygoid canal. It passes backwards along the pterygoid canal with the corresponding nerve. It supplies the upper part of the pharynx, and sends a small division into the tympanic cavity to anastomose with the tympanic arteries.
This is also called epidural haematoma, and it is the accumulation of blood in the epidural space due to injury, for example from a road traffic accident or sports injury, involving the middle meningeal artery. Treatment may require decompression of the haematoma, usually by craniotomy to ease-out the pressure cause by the clothed blood on the brain.