Anatomy of the posterior superior alveolar nerve: - Origin: Arises from the maxillary nerve within the pterygopalatine fossa. - Course: Exits the pterygopalatine fossa through the pterygomaxillary fissure, passes within or upon the posterior wall of the maxilla, descends on the tuberosity of the maxilla, and gives off twigs to the gums and neighboring parts of the mucous membrane of the cheek. - Distribution: Provides sensory innervation to the upper/maxillary molar teeth, associated gingiva of the vestibule, and the maxillary sinus. - Teeth innervated: Innervates the second and third maxillary/upper molar teeth, and two of the three roots of the maxillary/upper first molar tooth.

Clinical significance of the posterior superior alveolar nerve: - Anaesthesia: A posterior superior alveolar nerve block can anesthetize the mesiobuccal root of the maxillary/upper first molar tooth approximately 72% of the time.

Related nerves: - Alveolar nerve (Dental nerve) - Superior alveolar nerve (Superior dental nerve) - Anterior superior alveolar nerve (Anterior superior dental nerve) - Middle superior alveolar nerve (Middle superior dental nerve) - Inferior alveolar nerve (Inferior dental nerve)