Anatomy, Head and Neck, Maxillary Artery

Structure and Function

The maxillary artery constitutes a terminal branch of the ECA, which originates from the common carotid artery at the C4 vertebral level, where the common carotid bifurcates into its external and internal divisions. The ECA provides arterial supply to superficial structures of the face and scalp. The branches of this blood vessel include the superior thyroid, ascending pharyngeal, lingual, facial, occipital, and posterior auricular arteries, with the maxillary and superficial temporal arteries serving as the terminal divisions.

The maxillary artery gives rise to multiple branches that supply structures of the face and cranium. The artery is classically divided into 3 segments based on its anatomical relationship with the lateral pterygoid muscle. The 1st part is the mandibular portion, which lies posterior to the lateral pterygoid and descends toward the mandible, emitting branches to the meninges and lower teeth. The 2nd segment, the pterygoid part, courses laterally, or less commonly medially, to the lateral pterygoid, supplying the muscles of mastication. The 3rd portion, the pterygopalatine segment, is situated within the pterygopalatine fossa and gives rise to terminal branches that provide arterial supply to the nasal cavity, palate, and maxillary teeth.[3][4] (see Images. Plan of the Maxillary Artery Branches; Maxillary Artery Branches in Lateral Facial View.)

The maxillary artery originates within the parotid gland and courses anteriorly between the neck of the mandible and the sphenomandibular ligament to reach the infratemporal fossa. The blood vessel subsequently traverses the pterygomaxillary fissure to enter the pterygopalatine fossa, a small, inverted pyramid-shaped cavity located deep within the facial skeleton, bounded anteriorly by the maxilla, medially by the palatine bone, and posteriorly by the pterygoid process of the sphenoid.[5]

The deep auricular artery, a branch of the mandibular part of the maxillary artery, enters the external acoustic meatus through the squamotympanic fissure, while the anterior tympanic artery passes through the same fissure to supply the tympanic membrane. The middle meningeal artery (MMA) ascends between the tensor veli palatini and the lateral pterygoid to enter the foramen spinosum, providing vascular supply to the dura mater of the middle cranial fossa. This branch divides into an anterior segment, which crosses the pterion toward the vertex, and a posterior section, which ascends posteriorly within the middle cranial fossa.

The accessory meningeal artery enters the cranial cavity via the foramen ovale. The inferior alveolar artery gives rise to the mylohyoid artery before entering the mandible, supplying the mylohyoid muscle, and then enters the mandibular foramen to supply the lower teeth and mandible. This branch terminates as the mental artery at the mental foramen, providing arterial supply to the skin, muscles of the chin, and surrounding gingivae.[6]

The pterygoid part of the maxillary artery gives rise to the deep temporal arteries—anterior, middle, and posterior—which ascend between the temporalis muscle and the pericranium, providing its primary vascular supply. The buccal artery courses anteriorly along the buccinator muscle, supplying both the muscle and the mucosa of the cheek. The masseteric artery passes laterally through the mandibular notch to vascularize the masseter muscle, while small pterygoid branches supply the medial and lateral pterygoid muscles.

The pterygopalatine part of the maxillary artery gives rise to several branches that supply the pharynx, palate, nasal cavity, and maxillary teeth. The pharyngeal artery descends medially, providing vascular supply to the roof of the pharynx, the soft palate, and the pharyngotympanic (Eustachian) tube. The descending (greater) palatine artery courses through the greater palatine canal to reach the hard palate, giving rise to lesser palatine branches that supply the soft palate. The artery of the pterygoid canal, also referred to as the "Vidian artery," passes posteriorly through the pterygoid canal alongside the Vidian nerve, supplying the upper pharynx, auditory tube, and structures within the pterygoid canal.

The sphenopalatine artery enters the nasal cavity through the sphenopalatine foramen and gives rise to the posterior lateral nasal arteries and posterior septal branches. The posterior superior alveolar artery provides arterial supply to the maxillary molars, premolars, and adjacent gingiva, while the infraorbital artery passes through the inferior orbital fissure into the infraorbital canal, giving rise to the anterior superior alveolar artery for the upper incisors and canines.[7]

Embryology

The maxillary artery arises from the remnant of the 1st aortic arch. Regression of the 1st and 2nd aortic arches occurs during embryogenesis, leaving the maxillary artery among the limited number of permanent derivatives.

Blood Supply and Lymphatics

Mandibular Branches

The deep auricular and anterior tympanic arteries provide arterial supply to the external acoustic meatus and the deep surface of the tympanic membrane, respectively. The MMA, a principal branch of the maxillary artery, supplies the dura mater, cranial bones, and structures of the middle cranial fossa, remaining adherent to the periosteal layer of the dura.[8] The accessory meningeal artery contributes to the vascularization of the dura mater, trigeminal ganglion, and adjacent muscles of the infratemporal region, including the medial and lateral pterygoid, tensor veli palatini, and, occasionally, the tensor tympani muscles.[9] The inferior alveolar artery supplies the lower teeth, lower lip, and chin through its terminal mental branch, while the mylohyoid artery provides arterial supply to the mylohyoid muscle.

Pterygoid Branches

The deep temporal arteries provide vascular supply to the temporalis muscle, which also receives contributions from the superficial temporal artery, a branch of the ECA. The buccal artery supplies the buccinator muscle, while the masseteric artery provides arterial supply to the masseter muscle. Small pterygoid branches supply the medial and lateral pterygoid muscles, ensuring comprehensive vascularization of the muscles of mastication.

Pterygopalatine Branches

The pharyngeal artery provides arterial supply to the posterior roof of the nasal cavity, the sphenoid sinus, and the auditory (Eustachian) tube. The greater palatine artery supplies the hard palate, while its lesser palatine branches vascularize the soft palate. The sphenopalatine artery terminates as the posterior lateral nasal and posterior septal branches, with the posterior septal branches forming anastomoses with the greater palatine artery. The posterior superior alveolar artery supplies the maxillary molars, premolars, and adjacent gingiva, whereas the infraorbital artery provides vascular supply to the lower eyelid, upper lip, cheek, and anterior maxillary teeth.

Venous Drainage

Venous return from regions supplied by the maxillary artery occurs primarily via the pterygoid venous plexus, situated between the medial and lateral pterygoid muscles and between the lateral pterygoid and temporalis muscles. This plexus facilitates drainage from the infratemporal and pterygopalatine fossae and establishes communication with the cavernous sinus through small emissary veins traversing the foramen ovale, foramen lacerum, and sphenoidal emissary foramina.

Muscles

The infratemporal and pterygopalatine fossae contain several muscles, many of which receive vascular supply from branches of the maxillary artery. Among these muscles, the lateral and medial pterygoids are of particular significance due to their anatomical relationships, as they are critical for understanding the divisions of the artery.

The lateral pterygoid muscle comprises upper and lower heads, with the upper head originating from the roof of the infratemporal fossa and the lower head arising from the lateral surface of the lateral pterygoid plate. Both heads insert into the capsule of the temporomandibular joint, and their nearly horizontal fibers facilitate jaw protrusion and lateral movements. The medial pterygoid muscle consists of deep and superficial heads, with the deep head arising from the medial surface of the lateral pterygoid plate and the superficial head originating from the maxillary tuberosity. Both heads insert on the medial surface of the mandible near its angle, functioning to elevate the jaw and assist in side-to-side movements.[10]

Physiologic Variants

Variations in the course of the maxillary artery are frequent. The artery runs lateral to the lateral pterygoid muscle in about 2/3 of cases and medially in the remainder. Additional variations include the presence of common trunks between the deep auricular and anterior tympanic arteries, or between the MMA and accessory meningeal arteries. Evidence suggests that a medially coursing artery is more likely to exhibit separate meningeal branches, while a laterally coursing artery often originates from a common meningeal trunk. Rarely, the artery may course laterally on one side and medially on the contralateral side.

Surgical Considerations

Posterior epistaxis is frequently difficult to control, and anterior nasal packing is typically insufficient. Endovascular embolization of the sphenopalatine and anterior ethmoidal arteries may be required in refractory cases.[11] In recent years, extracranial-to-intracranial (EC-IC) bypass procedures utilizing the maxillary artery have been developed for the treatment of skull base tumors and complex cerebral aneurysms. Traditional approaches involve a zygomatic osteotomy to access the vessel. However, newer techniques achieve exposure through the deep temporal vessels after reflection of the temporalis muscle, eliminating the need for osteotomy.[12][13][14]

Bleeding originating from the deeper branches of the nasal cavity, referred to as "posterior epistaxis," is typically more severe and less responsive to conservative management than bleeding from the anterior nasal region. Standard nasal packing, which applies pressure within the nasal passage to promote clot formation, often fails to control hemorrhage when the source is located in the posterior vasculature. Endovascular embolization may be undertaken in such cases. A fine catheter is advanced through the arterial system to the target vessels, most commonly the sphenopalatine and anterior ethmoidal arteries, where embolic materials, such as coils or microparticles, are deployed to obstruct blood flow and achieve hemostasis.

The maxillary artery provides an essential vascular route for advanced cranial and skull base procedures. An EC-IC bypass may be performed in selected cases of cerebral aneurysm or skull base tumor.[15] This procedure involves creating a surgical connection between an artery located outside the skull and one within the cranial cavity, establishing an alternative channel for cerebral blood flow when normal circulation is compromised.

Historically, exposure of the maxillary artery for EC-IC bypass required a zygomatic osteotomy, involving temporary removal of part of the zygomatic bone to access the vessel. Less invasive approaches have been developed more recently. The artery may be approached by reflecting the temporalis muscle to identify the deep temporal branches, providing direct access to the maxillary artery. This technique eliminates the need for bone removal, shortens operative time, and reduces tissue trauma while maintaining sufficient visualization of the artery for microvascular reconstruction.

The pterygoid venous plexus is clinically significant due to its communication with the cavernous sinus via valveless emissary veins. This connection allows the potential spread of odontogenic or facial infections into the intracranial space, which may result in cavernous sinus thrombosis.

Injury to the MMA constitutes a classic cause of epidural hematoma following trauma to the temporal bone at the pterion. The artery lies within the periosteal layer of the dura, and hemorrhage occurs under high pressure, separating the dura from the skull and producing a biconvex (lens-shaped) hematoma on computed tomography. Patients may present with an initial loss of consciousness, followed by a lucid interval and subsequent neurological deterioration. This condition represents a neurosurgical emergency requiring immediate evacuation, most commonly via craniotomy or, when indicated, burr hole decompression.[16]

Clinical Significance

The maxillary artery is of considerable clinical importance due to its complex anatomy and involvement in multiple pathologic and surgical conditions. The sphenopalatine artery, a terminal branch, constitutes a major source of posterior epistaxis, which is often resistant to anterior nasal packing and may require endovascular embolization for definitive management. In neurosurgical and skull base procedures, the maxillary artery can serve as a donor vessel for EC-IC bypass, reestablishing cerebral perfusion when native intracranial vessels are compromised. Contemporary techniques that utilize the deep temporal branches have reduced operative morbidity by avoiding zygomatic osteotomy.

The pterygoid venous plexus provides a potential route for the spread of odontogenic or facial infections to the cavernous sinus, while trauma to the MMA remains a recognized cause of epidural hematoma following temporal bone injury. Comprehensive knowledge of these vascular relationships is essential for minimizing complications in maxillofacial, otolaryngologic, and neurosurgical interventions.