Blood Vessels of the Infratemporal Region

• Arises from the external carotid artery at the posterior border of the ramus of the mandible.

• Divides into three parts:

1. Mandibular part

• Runs anteriorly between the neck of the mandible and the sphenomandibular ligament.

• Gives rise to the following branches:

• Deep auricular artery
• Supplies the external acoustic meatus.
• Anterior tympanic artery
• Supplies the tympanic cavity and tympanic membrane.
• Middle meningeal artery
• Is embraced by two roots of the auriculotemporal nerve and enters the middle cranial fossa through the foramen spinosum.
• Runs between the dura mater and the periosteum.
• May be damaged, resulting in epidural hematoma.
• Accessory meningeal artery
  
  • Passes through the foramen ovale.

• Inferior alveolar artery
• Follows the inferior alveolar nerve between the sphenomandibular ligament and the ramus of the mandible.
• Enters the mandibular canal through the mandibular foramen and supplies the tissues of the chin and lower teeth.

2. Pterygoid part

• Runs anteriorly deep to the temporalis and lies superficial (or deep) to the lateral pterygoid muscle.
• Has branches that include the anterior and posterior deep temporal, pterygoid, masseteric, and buccal arteries, which supply chiefly the muscles of mastication.

3. Pterygopalatine part

• Runs between the two heads of the lateral pterygoid muscle and then through the pterygomaxillary fissure into the pterygopalatine fossa.

• Has branches that include the following arteries:

• Posterior superior alveolar arteries
• Run downward on the posterior surface of the maxilla and supply the molar and premolar teeth and the maxillary sinus.
• Infraorbital artery
  
  • Runs upward and forward to enter the orbit through the inferior orbital fissure.
  • Traverses the infraorbital groove and canal and emerges on the face through the infraorbital foramen.
  • Divides into branches to supply the lower eyelid, lacrimal sac, upper lip, and cheek.
  • Gives rise to anterior and middle superior alveolar branches to the upper canine and incisor teeth and the maxillary sinus.

• Descending palatine artery
• Descends in the pterygopalatine fossa and the palatine canal.
• Supplies the soft and hard palates.
• Gives rise to the greater and lesser palatine arteries , which pass through the greater and lesser palatine foramina, respectively. The lesser palatine artery supplies the soft palate. The greater palatine artery supplies the hard palate and sends a branch to anastomose with the terminal (nasopalatine) branch of the sphenopalatine artery in the incisive canal or on the nasal septum.
• Artery of the pterygoid canal
  
  • Passes through the pterygoid canal and supplies the upper part of the pharynx, auditory tube, and tympanic cavity.

• Pharyngeal artery
• Supplies the roof of the nose and pharynx, sphenoid sinus, and auditory tube.
• Sphenopalatine artery
  
  • Is the terminal branch of the maxillary artery.
  • Enters the nasal cavity through the sphenopalatine foramen in company with the nasopalatine branch of the maxillary nerve.
  • Is the principal artery to the nasal cavity, supplying the conchae, meatus, and paranasal sinuses.
  • May be damaged, resulting in epistaxis (nosebleed).

• Lies on the lateral surface of the medial pterygoid muscle, receives veins corresponding to the branches of the maxillary artery, and drains into the maxillary vein.
• Communicates with the cavernous sinus by emissary veins (that pass through the foramen ovale), the inferior ophthalmic vein by a vein (that runs through the infraorbital fissure), and the facial vein by the deep facial vein.

• Is formed by the superficial temporal vein and the maxillary vein.
• Divides into an anterior branch, which joins the facial vein to form the common facial vein, and a posterior branch, which joins the posterior auricular vein to form the external jugular vein.