E, Superior view of the floor of both orbits. The roof of the maxillary sinus forms the orbital floors. The infraorbital and zygomatic branches of the maxillary nerve enter the orbit by passing through the inferior orbital fissure. The zygomatic nerve courses along the lateral wall of the orbit to give rise to the zygomaticofacial and zygomaticotemporal nerves, which innervate the skin over the malar eminence and temporal region, respectively. The infraorbital nerve and artery course along the floor of the orbit to reach the cheek. F, Enlarged view of the right orbit showing the course along the orbital walls taken by the zygomaticofacial, zygomaticotemporal, and infraorbital nerves. The zygomaticofacial nerves pierce the lateral orbital rim to reach the malar eminence and the zygomaticotemporal branches pass upward to reach the temple. G, Anterior view of both orbits in another specimen. A portion of the floor of both orbits has been removed to expose the maxillary sinus while preserving the infraorbital and zygomatic nerves. The rectus muscles arise in the orbital apex from the annular tendon, which surrounds the optic canal and adjacent part of the superior orbital fissure. The ethmoidal sinuses are located on the medial side of the orbit. H, Enlarged view. Some of the posterior wall of the maxillary sinus has been removed to expose the pterygopalatine fossa and the origin of the infraorbital and zygomatic nerves from the maxillary nerve. The structures in the pterygopalatine fossa are the maxillary nerve and its terminal branches, the pterygopalatine ganglion, and the terminal branches of the maxillary artery. The maxillary nerve gives rise to communicating rami to the pterygopalatine ganglion. (Images courtesy of AL Rhoton, Jr.)