General Course of the Vessel
Courseing anteriorly and laterally, the maxillary artery navigates through narrow anatomical spaces. Initially, it passes between the mandibular ramus and the sphenomandibular ligament (lig. sphenomandibulare). Next, its trunk runs through the intermuscular space between the lateral pterygoid (m. pterygoideus lateralis) and temporalis (m. temporalis) muscles. The vessel completes its course deep within the facial skeleton, reaching the pterygopalatine fossa (fossa pterygopalatina), where it gives off its terminal branches.
For clarity, the entire trunk of the artery is typically divided into three parts based on surrounding anatomical landmarks.
I. Mandibular Part (pars mandibularis)
This initial segment of the vessel lies in close proximity to the neck of the mandible. It gives rise to vessels supplying the ear, temporomandibular joint, and mandible:
- Deep auricular artery (a. auricularis profunda) — travels to the temporomandibular joint (supplying its capsule), and also supplies the tympanic membrane and walls of the external acoustic meatus.
- Anterior tympanic artery (a. tympanica anterior) — enters the tympanic cavity through the petrotympanic fissure (fissura petrotympanica), supplying its mucous membrane.
- Inferior alveolar artery (a. alveolaris inferior) — a major vessel that descends with the corresponding nerve into the mandibular canal (canalis mandibulae). Within the canal, it gives off dental branches (rr. dentales), alveolar branches, and peridental branches to the gingiva (rr. peridentales). Before entering the canal, it gives off the mylohyoid branch (r. mylohyoideus). The terminal part exits through the mental foramen as the mental branch (r. mentalis), which supplies the lower lip and chin, forming anastomoses with the submental (a. submentalis) and inferior labial (a. labialis inferior) arteries.
II. Pterygoid Part (pars pterygoidea)
The second part lies within the muscular mass between the temporalis and lateral pterygoid muscles. Its primary role is supplying the muscles of mastication and the meninges.
- Middle meningeal artery (a. meningea media) — a crucial vessel entering the cranial cavity via the foramen spinosum. Inside the cranium, the artery divides into frontal (r. frontalis) and parietal (r. parietalis) branches running along the external surface of the dura mater. It also gives off branches to the tympanic cavity (a. tympanica superior), the orbital region (r. orbitalis), the canal of the greater petrosal nerve (r. petrosus), and anastomoses with the lacrimal artery. A separate branch (a. pterygomeningea) goes to the auditory tube and pterygoid muscles.
- Deep temporal arteries (aa. temporales profundae anterior et posterior) — ascend into the temporal fossa, located between the bone and the temporalis muscle, supplying the latter.
- Masseteric artery (a. masseterica) — passes through the mandibular notch to reach the masseter muscle.
- Buccal artery (a. buccalis) — runs onto the buccinator muscle, supplying the muscle itself as well as the oral mucosa and maxillary gingiva. It forms an anastomosis with the facial artery.
- Pterygoid branches (rr. pterygoidei) — run to the medial and lateral pterygoid muscles.
- Posterior superior alveolar artery (a. alveolaris superior posterior) — runs toward the maxillary tuberosity (tuber maxillae). It gives off dental and periodontal branches supplying the upper molar teeth.
III. Pterygopalatine Part (pars pterygopalatina)
The third and terminal part is hidden inside the pterygopalatine fossa. From here, vessels diverge toward the face, nasal cavity, and palate.
- Infraorbital artery (a. infraorbitalis) — enters the orbit via the inferior orbital fissure, runs in the infraorbital sulcus, and emerges onto the facial surface through the infraorbital canal. It gives off the anterior superior alveolar arteries (aa. alveolares superiores anteriores), which supply the upper anterior teeth. On the face, it anastomoses with branches of the facial artery.
- Descending palatine artery (a. palatina descendens) — descends into the greater palatine canal. It divides into the lesser palatine arteries (supplying the soft palate and tonsils) and the greater palatine artery (runs along the hard palate, anastomosing with the posterior septal and superior labial arteries).
- Sphenopalatine artery (a. sphenopalatina) — enters the nasal cavity through the sphenopalatine foramen. It gives off posterior lateral nasal branches to the conchae and walls, as well as the posterior septal branch (r. septalis posterior). It forms connections with branches of the ophthalmic artery and, via the incisive canal, with the greater palatine artery.
- Artery of the pterygoid canal (a. canalis pterygoidei) — may arise independently or from the descending palatine artery. It sends a pharyngeal branch (r. pharyngeus) to the walls of the pharynx.