The posterior superior alveolar artery is a branch of the maxillary artery, specifically arising from its third part within the pterygopalatine fossa. It supplies blood to the molar and premolar teeth of the upper jaw, the adjacent gingiva, and parts of the maxillary sinus.
Location
The posterior superior alveolar artery emerges from the maxillary artery in the pterygopalatine fossa and travels through the pterygomaxillary fissure. It descends along the posterior surface of the maxilla and enters the posterior superior alveolar foramina to supply the maxillary molars and premolars. The artery forms anastomoses with the anterior superior alveolar artery within the bone, creating a vascular network for the upper teeth and surrounding structures.
Origin
The posterior superior alveolar artery arises from the third part of the maxillary artery, which is the terminal segment of the maxillary artery located within the pterygopalatine fossa. The maxillary artery is a major branch of the external carotid artery, and the posterior superior alveolar artery is one of its important branches that specifically supplies the posterior aspects of the upper jaw.
Course and Pathway
Pterygopalatine Fossa
The posterior superior alveolar artery originates in the pterygopalatine fossa, a small space located between the maxilla, sphenoid, and palatine bones. This fossa houses several other branches of the maxillary artery and serves as a key location where the artery begins its course toward the upper jaw.
Pterygomaxillary Fissure
After originating in the pterygopalatine fossa, the posterior superior alveolar artery passes through the pterygomaxillary fissure. This fissure is a vertical gap between the lateral pterygoid plate of the sphenoid bone and the posterior surface of the maxilla. It serves as the passage through which the artery exits the pterygopalatine fossa and begins its descent toward the posterior aspect of the maxilla.
Posterior Surface of the Maxilla
Once the posterior superior alveolar artery exits the pterygomaxillary fissure, it travels along the posterior surface of the maxilla. Here, the artery gives off branches that enter the posterior superior alveolar foramina to supply blood to the upper posterior teeth and related structures.
Posterior Superior Alveolar Foramina
The artery enters the posterior superior alveolar foramina, a series of small openings located on the posterior surface of the maxilla. These foramina serve as entry points for the artery to penetrate the maxilla and reach the posterior superior alveolar canal, which houses the artery and its branches as they travel through the bone.
Branching
Dental and Alveolar Branches
The posterior superior alveolar artery gives rise to small dental and alveolar branches that supply the maxillary molars and premolars. These branches provide blood to the pulp, periodontium, and surrounding bone of the posterior maxillary teeth.
Maxillary Sinus Branches
As the artery travels along the maxilla, it also sends small branches to the maxillary sinus. These branches supply the mucosal lining of the sinus, contributing to the overall blood supply of this important cavity.
Anastomosis with the Anterior Superior Alveolar Artery
One of the important features of the posterior superior alveolar artery is its anastomosis with the anterior superior alveolar artery, a branch of the infraorbital artery. This anastomosis occurs within the maxilla and helps form a continuous vascular network that supplies the maxillary teeth and related structures.
Distribution
The posterior superior alveolar artery primarily supplies the following structures:
- Maxillary Molars and Premolars: Through its dental and alveolar branches, the artery supplies blood to the posterior teeth in the upper jaw.
- Maxillary Sinus: The artery sends small branches to the maxillary sinus, providing blood to the mucosa lining this air-filled cavity.
- Gingiva: The artery also supplies the gingiva (gums) surrounding the posterior teeth in the upper jaw.
Relations
The posterior superior alveolar artery runs alongside the posterior superior alveolar nerve, a branch of the maxillary nerve (CN V2). Both the artery and the nerve pass through the posterior superior alveolar foramina and travel together along the posterior surface of the maxilla, supplying the teeth, gums, and surrounding structures. The close relationship between the artery and the nerve is clinically important, as they are often encountered together during dental or surgical procedures in the upper jaw.
Variations
While the general course of the posterior superior alveolar artery is relatively consistent, some variations in its size and branching pattern may occur. For example, the number of posterior superior alveolar foramina can vary between individuals, which can affect the number and size of arterial branches that penetrate the maxilla. Additionally, the extent of the anastomosis with the anterior superior alveolar artery may vary slightly, influencing the overall vascularization of the maxillary teeth and sinus.
Function
The posterior superior alveolar artery plays an essential role in supplying blood to various structures in the upper jaw, particularly the posterior teeth and the maxillary sinus. Its function is vital in ensuring proper nourishment and health of these regions. Below is a detailed explanation of the artery’s functions.
Blood Supply to Maxillary Molars and Premolars
One of the primary functions of the posterior superior alveolar artery is to supply blood to the maxillary molars and premolars. Through its dental and alveolar branches, the artery ensures that these teeth receive the necessary oxygen and nutrients to maintain their vitality.
- Dental Pulp: The artery supplies the dental pulp of the posterior teeth, the soft tissue inside the tooth that contains nerves and blood vessels. The dental pulp relies on this blood supply to stay healthy, ensuring that the tooth remains alive and functional.
- Periodontal Ligaments: The periodontal ligaments, which anchor the teeth to the surrounding bone, are also supplied by the posterior superior alveolar artery. These ligaments need a steady supply of blood to maintain their health and function, supporting tooth stability and resilience.
- Alveolar Bone: The artery supplies the alveolar bone surrounding the posterior teeth, helping to maintain the density and strength of the bone. Adequate blood flow to this region is important for preventing bone resorption, which could lead to tooth instability or loss.
Blood Supply to the Maxillary Sinus
The posterior superior alveolar artery also plays a crucial role in supplying blood to the maxillary sinus, an air-filled cavity located above the maxillary teeth.
- Maxillary Sinus Mucosa: The artery provides blood to the mucosal lining of the maxillary sinus. This mucosa is responsible for producing mucus, which helps protect the respiratory tract and maintain sinus health. Adequate blood supply ensures the proper function of the mucosa and prevents issues like sinus infections or inflammation.
- Sinus Healing: In the case of sinus infections, surgeries, or trauma, the blood flow provided by the posterior superior alveolar artery helps support healing and tissue repair in the sinus region.
Support for Gingival Blood Supply
The posterior superior alveolar artery also provides blood to the gingiva (gums) surrounding the posterior teeth.
- Gingival Health: Healthy gums are crucial for dental health, and the artery’s blood supply to the gingiva ensures the tissues remain well-nourished and resistant to infections. Proper gingival blood flow helps prevent conditions such as gingivitis and periodontitis, which can lead to tooth loss if left untreated.
- Wound Healing: After dental procedures or injuries, such as tooth extractions or periodontal surgeries, the artery supports healing in the gingival tissues by providing the necessary oxygen and nutrients for tissue repair.
Role in Healing and Tissue Repair
The posterior superior alveolar artery plays a critical role in healing and tissue repair after dental procedures or trauma to the posterior maxillary region.
- Post-surgical Healing: After procedures like tooth extractions, dental implants, or sinus surgeries, the artery supplies blood to the affected tissues, ensuring proper healing. Its role in providing oxygen and nutrients is essential for the formation of new tissue and preventing complications, such as delayed healing or infection.
- Tissue Regeneration: In case of bone damage or gum injuries, the posterior superior alveolar artery delivers a rich blood supply that supports the regeneration of bone and soft tissues in the upper jaw.
Contribution to Collateral Circulation
The posterior superior alveolar artery forms an anastomosis with the anterior superior alveolar artery, creating a continuous vascular network that supports blood flow to the upper jaw.
- Collateral Blood Flow: This anastomosis ensures that if one arterial supply is compromised, blood flow can continue through alternative routes, preventing tissue damage or ischemia (reduced blood flow). This collateral circulation is particularly important during facial trauma or surgical interventions, as it provides a backup system to maintain blood supply to the teeth, sinus, and surrounding tissues.
- Vascular Network for Upper Jaw: Through its anastomosis, the artery helps form a robust vascular network that supplies the maxillary bone, teeth, and soft tissues. This network is crucial for maintaining the overall health and function of the upper jaw.
Support for Sensory Function
Although the posterior superior alveolar artery primarily serves a vascular role, it also indirectly supports the posterior superior alveolar nerve, which is responsible for sensory innervation to the posterior teeth, gums, and surrounding structures. The artery ensures that the nerve receives sufficient blood flow to maintain its function and health.
Nerve Function: The artery’s blood supply helps support the health of the posterior superior alveolar nerve, enabling proper sensation in the posterior teeth and gums. This blood flow ensures that the nerve remains healthy and functional, reducing the risk of nerve damage or sensory impairment.
Clinical Significance
The posterior superior alveolar artery is of significant clinical importance, particularly in dental and maxillofacial procedures. During surgeries involving the upper jaw, such as tooth extractions, dental implants, or sinus lift procedures, injury to this artery can result in excessive bleeding or hematoma formation. Understanding the location of this artery is crucial in minimizing the risk of vascular damage during such procedures.
The artery also plays a critical role in sinus surgeries and treatments for sinus infections due to its supply to the mucosa of the maxillary sinus. Damage to this artery can affect healing and tissue regeneration in the sinus and upper jaw region. Additionally, the artery’s anastomosis with the anterior superior alveolar artery ensures collateral blood supply, making it an important structure for maintaining the vascular integrity of the upper jaw.
