Three-dimensional Courses of Zygomaticofacial and Zygomaticotemporal Canals Using Micro-computed Tomography in Korean

Abstract

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.

Anatomical Description of Zygomatic Foramina in African American Skulls

“…The average number of foramina was 1.98 ± 0.93 in this African American population. While higher than previous studies, this is similar to results found in a recent micro-CT study of Koreans where an average of 2.2 foramina per zygomatic bone was reported 17 . While previous studies suggest no significant difference in the average number of zygomaticofacial foramina between right and left hemicrania, we found that the right side contained significantly more (2.13 ± 0.98) zygomatic foramina than the left side (1.68 ± 0.79) 12 .…”

“…Methods of examining the zygoma include digital photographs and image analysis software, direct examination of the dry skull, and micro-CT 6, 9, 12 . Kim et al used micro-CT to assess number and the path of the foramen through the zygoma 17 . They compared their results to a previous study of Korean skulls examined in a similar manner to Mangal et al 9, 18 .…”

Development of the method of conducting anesthesia of zygomaticofacial nerve in people with different face shape and its clinical evaluation

“…The results of craniometric research of topographic anatomical peculiarities of zygomaticofacial foramina location on the facial surface of zygomatic bone turned out to be similar to the data of other authors regarding the variability of quantity and orderliness of zygomaticofacial foramina location [15][16][17][18][19][20]. There is great variability regarding the site of nerve division outside/inside the zygomatic bone and the number of foramina/canals, where nerves enter and leave the zygomatic bone [18].…”

Anatomical Study of the Zygomaticotemporal Branch Inside the Orbit

“…Previous anatomical studies of the ZTF have revealed morphological features of the foramina on the lateral surface of the zygomatic bone [ 7 - 8 ]. Kim et al investigated the ZTF using micro-computed tomography (micro-CT) and found that the bony canal often bifurcates inside the zygomatic bone [ 9 ]. However, the bony canals identified in dry skulls or on CT could include not only the nerves but also vessels.…”