After traversing the outer wall of the cavernous sinus, the superior maxillary division emerges from the middle cranial fossa by means of the foramen rotundum, and enters the spheno-maxillary (pterygo-palatine) fossa. The nerve crosses the fossa, and leaves it via the inferior orbital fissure to run in the infra-orbital groove and canal. Here it becomes the infra-orbital nerve, and appears on the face at the infra-orbital foramen where it divides into its terminal branches.
The branches of the superior maxillary division can be classified according to their origin as (a) cranial; (b) pterygo-palatine; (c) infra-orbital; and (d) facial.
A small recurrent branch to the dura mater.
(1) Spheno-palatine, two twigs to Meckel's (sphenopalatine) ganglion.
(2) Orbital (zygomatic) passes to the orbit through the inferior orbital fissure, and divides into temporal (zygomatico-temporal) and malar (zygomatico-facial). Each of these perforates the malar (zygomatic) bone to supply the skin in its vicinity, and communicates with the corresponding branches of the facial nerve.
(3) Posterior superior dental (alveolar) enter the minute foramina on the zygomatic surface of the maxilla to supply the molar teeth.
Middle and anterior dental (alveolar) nerves arise from the infra-orbital, and tunnelling the anterior wall of the antrum of Highmore (maxillary antrum) innervate the premolar, canine, and incisor teeth.
(1) Palpebral to skin of lower eyelid.
(2) Nasal to skin of side of nose.
(3) Labial to skin of upper lip.
They communicate with the zygomatic branches of the facial, forming the infra-orbital plexus.