Radiologic evaluation of the anterior and posterior ethmoidal foramen and optic canal by paranasal sinus computed tomography scan among adult Filipinos

Objective@#To measure the average distances from anterior lacrimal crest (ALC) to anterior ethmoidal foramen (AEF), anterior ethmoidal foramen to posterior ethmoidal foramen (PEF) and posterior ethmoidal foramen to optic canal (OC) using plain paranasal sinus (PNS) computed tomography (CT) scans of adults in a tertiary private hospital in the Philippines. @*Methods@#Design: Retrospective review of plain PNS CT scans. Setting: Tertiary Private Teaching Hospital. Participants: One hundred four (104) plain PNS CT scans from January 2018 to December 2020 were considered for inclusion. @*Results@#Of the 104 PNS CT scans, 35 were excluded - seven for age less than eighteen, six for undistinguishable PEF and twenty-two for chronic rhinosinusitis. The remaining 69 PNS CT scans demonstrated identifiable structures, with overall average distances from ALC to AEF of 23.71 ± 2.43 mm, AEF to PEF of 10.87 ± 2.39 mm and PEF to OC of 7.39 ± 2.28 mm. @*Conclusion@#Our study suggests average distances for localization of vital structures such as the anterior ethmoidal artery, posterior ethmoidal artery and optic nerve among Filipinos. Because of considerable variation between and within sexes, individual measurements should still be obtained for each patient in performing endonasal, skull base and orbital surgery.

APPLIED ANATOMY OF THE ETHMOIDAL ARTERIES / 第二军医大学学报

An anatomical study was made in 40 dried skulls (80 orbits) and 20 cadavers with the ethmoidal arteries. In the dried skulls, a large number of the ethmoidal foramen lie to the frontoethmoidal suture line or above it.The distance from dacryon point to the anterior ethmoidal foramen is about 16 mm and to the posterior ethmoidal foramen, about 30 mm.The distance from the posterior ethmoidal foramen to the orbital opening of the optic canal is 5-8 mm in 78%.In this cadaver study, the anterior ethmoidal arteries are shorter in length and larger in diameter, and they run close to the orbital wall.The posterior ethmoidal arteries arc longer and thinner than the anterior ethmoidal arteries, and they are closely related to the superior oblique muscles.Sometime they give off some branches to the extra-ocular muscles