The greater palatine nerve passes forward on the roof of the oral cavity to innervate mucosa and glands of the hard palate and the adjacent gingiva, almost as far forward as the incisor teeth.
In the palatine canal, the greater palatine nerve gives origin to posterior inferior nasal nerves, which pass medially through small foramina in the perpendicular plate of the palatine bone and contribute to the innervation of the lateral nasal wall.
After passing through the lesser palatine foramen, the lesser palatine nerve passes posteriorly to supply the soft palate.
Nasal nerves. The nasal nerves (Fig. 8.156), approximately seven in number, pass medially through the sphenopalatine foramen to enter the nasal cavity. Most pass anteriorly to supply the lateral wall of the nasal cavity, while others pass across the roof to supply the medial wall.
One of the nerves passing across the roof to supply the medial wall of the nasal cavity (the nasopalatine nerve) is the largest of the nasal nerves and passes anteriorly down the nasal septum, through the incisive canal and fossa in the hard palate to enter the roof of the oral cavity and supply mucosa, gingiva, and glands adjacent to the incisor teeth.
Pharyngeal nerve. The pharyngeal nerve (Fig. 8.156) passes posteriorly from the pterygopalatine ganglion, and leaves the fossa through the palatovaginal canal, which it then exits to supply the mucosa and glands of the nasopharynx.
Zygomatic nerve. The zygomatic nerve (Fig. 8.156) originates directly from the maxillary nerve [V2] in the pterygopalatine fossa, which it leaves to enter the orbit through the inferior orbital fissure. It passes forward on the lateral orbital wall and divides into zygomaticotemporal and zygomaticofacial branches:
The zygomaticotemporal branch continues forward at the base of the lateral orbital wall, passes through a small bony canal in the zygomatic bone to enter the temporal fossa through a small foramen in the lateral orbital margin on the posterior surface of the frontal process of the zygomatic bone, and passes superficially to supply skin over the temple.
The zygomaticofacial branch also passes forward at the base of the lateral orbital wall and leaves through a small bony canal, in the orbital margin, which opens via multiple small foramina on the anterolateral surface of the zygomatic bone, and its branches supply the adjacent skin.
Posterior superior alveolar nerve. The posterior superior alveolar nerve (Fig. 8.156) originates from the maxillary nerve [V2] in the pterygopalatine fossa and passes laterally out of the fossa through the pterygomaxillary fissure to enter the infratemporal fossa. It continues laterally and inferiorly to enter the posterior surface of the maxilla through a small alveolar foramen approximately midway between the last molar tooth and the inferior orbital fissure. It then passes inferiorly just deep to the mucosa of the maxillary sinus to join the superior dental plexus.
The posterior superior alveolar nerve supplies the molar teeth and adjacent buccal gingivae, and contributes to the supply of the maxillary sinus.
Infra-orbital nerve. The infra-orbital nerve (Fig. 8.156) is the anterior continuation of the maxillary nerve [V2] that leaves the pterygopalatine fossa through the inferior orbital fissure. It lies first in the infra-orbital groove in the floor of the orbit and then continues forward in the infra-orbital canal.
While in the infra-orbital groove and canal, the infra-orbital nerve gives origin to middle and anterior superior alveolar nerves, respectively, which ultimately join the superior alveolar plexus to supply the upper teeth:
The middle superior alveolar nerve also supplies the maxillary sinus.