Search

The zygomatic nerve (ZN), which originates from the maxillary nerve at the pterygopalatine fossa, enters the orbit through the inferior orbital fissure. Within the lateral region of the orbit, the ZN divides into the zygomaticofacial (ZF) and zygomaticotemporal (ZT) nerves. The ZF and ZT nerves then pass on to the face and temporal region through the zygomaticoorbital foramen and enter their own bony canals within the zygomatic bone. However, multiple zygomaticofacial and zygomaticotemporal canals (ZFCs and ZTCs, respectively) can be observed, and their detailed intrabony courses are unknown. The aim of this study was clarify the three-dimensional intrabony courses and running patterns of the ZFCs and ZTCs, both to obtain a detailed anatomical description and for clinical purposes. Fourteen sides of the zygomatic bones were scanned as two-dimensional images using a micro-computed tomography (CT), with 32-μm slice thickness. Intrabony structures of each canals were three-dimensionally reconstructed and analyzed using Mimics computer software (Version 10.01; Materialise, Leuven, Belgium). We found that some ZTC was originated from ZFC. In 71.4% of the specimens, the ZTC(s) divided from the intrabony canal along the course of the ZFC(s). In other cases, 28.6% of ZTCs were opened through each corresponding ZT foramen. Zygomaticofacial canal originates from zygomaticoorbital foramen, divided into some of ZTCs, and is finally opened as ZF foramen. This new anatomical description of the intrabony structures of the ZFC(s) and ZTC(s) within the zygomatic bone by micro-CT technology provided helpful information to surgeons performing clinical procedures such as Le Fort osteotomy and reconstructive surgeries in the midface region.

Purpose: To present three cases of chronic infraorbital nerve hyperesthesia relieved by surgical decompression of the infraorbital nerve., Methods: Retrospective chart review., Results: We identified three cases of chronic hyperesthesia of the infraorbital nerve. Two cases were related to previous blunt orbital trauma, whereas the third was associated with a long-standing anophthalmic socket with numerous previous surgeries. In each case, patients had dramatic relief of infraorbital nerve hyperesthesia and pain after surgical decompression of the infraorbital nerve., Conclusions: Surgical decompression of the infraorbital nerve can provide significant symptomatic improvement in patients with chronic infraorbital nerve hyperesthesia secondary to nerve compression.

Objective: Elevation of the lateral orbital rim and zygomatic arch during an orbitozygomatic craniotomy requires a bone cut across the zygoma, which commonly extends into the lateral edge of the inferior orbital fissure. The zygomaticofacial foramen has been identified as a superficial landmark for the cut that extends into the inferior orbital fissure. This study examined the usefulness of the zygomaticofacial foramen during orbitozygomatic craniotomy., Methods: One-hundred two dry hemicrania were used in this study. The zygomaticofacial foramen was considered to be related to the inferior orbital fissure when it was located on the zygoma in the area between lines extending in the medial-to-lateral direction along the long axis of the fissure and crossing the anterior and posterior ends of the lateral edge of the fissure., Results: The zygomaticofacial foramen varied from being absent to representing as many as four small openings. A single foramen was observed in one-half of the specimens. Of the 115 zygomaticofacial foramina, 93 were related to the inferior orbital fissure. Among the 51 specimens with a single foramen, 49 foramina met the criteria for being related to the inferior orbital fissure; in those cases, there would have been no difference in the amount of bone resected using the inferior orbital fissure or the zygomaticofacial foramen as the landmark for the zygomatic cut., Conclusion: The zygomaticofacial foramen was a reliable landmark for locating the inferior orbital fissure and making the cut across the zygoma in only 50% of the specimens.

Although inferior alveolar and lingual nerve injuries appear to occur more often, there are undoubtedly cases of ION injury that require evaluation and possible surgical intervention by the oral and maxillofacial surgeon. Patients with ION injuries will require a neurosensory examination for the determination of the level of sensory impairment, or the localization of pain of peripheral origin (centrally mediated pain will not benefit from peripheral nerve surgery). The surgical management of ION injury might be as relatively simple as decompression of the nerve by reduction of a zygomatic complex fracture, or may require extensive mobilization of the nerve and surrounding soft tissue and bone to allow for primary anastomosis or a nerve autograft. In specific instances, improvement in ION sensory function or alleviation of pain within the distribution of the ION can be expected.

Glycerol was injected into the infraorbital canal of 12 rats to determine neurolytic effects on the peripheral trigeminal nerve. Saline and 90% ethanol were injected in control animals. One week after the injection, histopathological changes were noted in both glycerol and alcohol groups. In the former group, axonolysis and demyelination were restricted to the outer zone of the nerve bundles. Centrally located axons remained undamaged. A total destruction of all axons was found in the alcohol group. Four weeks after the injection in the glycerol group, small sized axons with thin myelin replaced damaged axons at the periphery of the bundle. No signs of regeneration were noted in the alcohol group. A possible mode of action of glycerol injected at the peripheral trigeminal nerve in relieving trigeminal neuralgia is described.