Infraorbital nerve

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Major nerves of the head and neck.

The infraorbital nerve originates from one of the major branches of the maxillary nerve (CN V₂). The inferior orbital fissure is the point at which the maxillary nerve (CN V₂), becomes the infraorbital nerve.

From the inferior orbital fissure, the infraorbital nerve runs anteriorly along the floor of the orbit in the infraorbital groove. The infraorbital nerve penetrates the maxillary bone through the infraorbital canal at the anterior aspect of the orbit. This canal ends at the infraorbital foramen where the infraorbital nerve exits onto the the face. This exit point can be found below the orbit and lateral to the nasal cavity.

As the infraorbital nerve travels along its course, it gives off branches. Both the middle and anterior superior alveolar nerves originate within the orbit. The palpebral branches travel upward beneath the orbicularis oculi muscle to innervate the lower eyelid. The nasal branches of the infraorbital nerve project to the skin on the outer part of the nose. Lastly, the superior labial branches descend beneath the levator labii superioris muscle.

The infraorbital nerve has both sensory and parasympathetic fibers. The sensory fibers originate from cell bodies situated in the trigeminal ganglion. On the other hand, the parasympathetic fibers arise from the pterygopalatine ganglion.

The sensory fibers convey general sense information from the lower eyelid and conjunctiva, maxillary sinus, maxillary incisors, canines, and premolar teeth, the nasal cavity, the skin of the cheek and upper lip, and the oral mucosa of the upper lip.

The parasympathetic fibers innervate the labial glands of the upper lip and mucosa.