Posterior superior alveolar nerve

Last revised by Raymond Chieng on 26 Jan 2023

The posterior superior alveolar nerve, also known as the posterior superior dental nerve, is a branch of the maxillary division of the trigeminal nerve arising just before the infra-orbital nerve. It is the first of the superior alveolar nerves and contributes to the superior dental plexus.

Gross anatomy

It arises from the maxillary division of the trigeminal nerve in the pterygopalatine fossa just before it enters the inferior orbital fissure 4, and descends into the pterygomaxillary fissure. From here it or several individual branches enter the maxilla via small alveolar canals. Terminal dental branches enter the apical foramina at the dental roots.

The nerves supply the maxillary sinus, posterior maxillary oral mucosa and the maxillary molar teeth apart from the mesiobuccal root of the first maxillary molar tooth, which is supplied by the middle superior alveolar nerve.

Variant anatomy

When the middle superior alveolar nerve is absent, the posterior superior alveolar nerve will supply all the molars and premolars.

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