Posterior superior alveolar nerve

The posterior superior alveolar nerve (PSAN) is a branch of the maxillary nerve, which is itself a branch of the trigeminal nerve (cranial nerve V). This nerve plays a crucial role in dental sensation, particularly in the upper jaw.

Anatomy

The posterior superior alveolar nerve arises from the maxillary nerve in the pterygopalatine fossa. It descends on the posterior surface of the maxilla, entering the maxillary sinus through small foramina. The nerve then divides into several branches that supply the mucous membrane of the maxillary sinus and the roots of the maxillary molars.

Function

The primary function of the posterior superior alveolar nerve is to provide sensory innervation to the maxillary molars, specifically the second and third molars, and sometimes the first molar. It also supplies the adjacent gingiva and the mucous membrane of the maxillary sinus.

Clinical Significance

The posterior superior alveolar nerve is of particular interest in dentistry and oral surgery. Anesthesia of this nerve is often required for dental procedures involving the maxillary molars. This is typically achieved through a posterior superior alveolar nerve block, which is a common technique used to ensure pain-free dental procedures in the upper jaw.

Damage or injury to the posterior superior alveolar nerve can result in altered sensation or numbness in the areas it supplies. Such injuries can occur during dental extractions or other surgical procedures involving the maxilla.

Also see

• Maxillary nerve
• Trigeminal nerve
• Inferior alveolar nerve
• Dental anesthesia

References

• Gray's Anatomy (1918). Public domain text.