The superior labial branch is a branch of which nerve?

• A. Infraorbital nerve
• B. Superior alveolar nerve
• C. Inferior alveolar nerve
• D. Mental nerve

Answer: (A)

The upper lip is innervated by the superior labial branches that come off the infraorbital nerve, which is a branch of the maxillary division (V2) of the trigeminal nerve. The infraorbital nerve travels through the infraorbital canal and, as it exits the infraorbital foramen, it gives several facial branches, including those that supply the upper lip and the vestibular mucosa.

In contrast, the superior alveolar nerves are branches of V2 that supply the maxillary teeth and their surrounding gingiva; the inferior alveolar nerve (V3) serves the lower jaw and its teeth, with the mental nerve continuing to the chin and lower lip. So the superior labial branch is best understood as a branch of the infraorbital nerve.