Posterior superior alveolar nerve

The posterior superior alveolar branches (posterior superior dental branches) arise from the trunk of the maxillary nerve just before it enters the infraorbital groove; they are generally two in number, but sometimes arise by a single trunk.

They descend on the tuberosity of the maxilla and give off several twigs to the gums and neighboring parts of the mucous membrane of the cheek.

They then enter the posterior alveolar canals on the infratemporal surface of the maxilla, and, passing from behind forward in the substance of the bone, communicate with the middle superior alveolar nerve, and give off branches to the lining membrane of the maxillary sinus and gingival and dental branches to each molar tooth from a superior dental plexus; these branches enter the foramina at the apices of the roots of the teeth.