A review of the ethmoidal foramina and their clinical application

The ethmoidal foramina (EF), located on the medial orbital wall along the frontoethmoidal sutures, are criticalanatomical landmarks for surgeries involving the medial orbital wall. This review aimed to review the surgical anatomy ofthe EF, including their embryology and radiology. Although the frontoethmoidal sutures mostly have two foramina passingthrough them, there are reports of single foramen or multiple, up to six foramina. These foramina provide a passage forthe ethmoidal arteries and nerves, branches of ophthalmic arteries and nerves. The surgical guideline “24-12-6” is basedon the approximate distance between the anterior lacrimal crest, the anterior and posterior ethmoidal arteries, and theoptic canal, commonly used to navigate this area. However, some studies from various populations defined different ratios. Embryologically, the EF were formed by the union of intramembranous ossified frontal bones and endochondral ossifiedethmoid bones. EF and neurovascular structures can be identified in computed tomography even in the 3 mm sectionalintervals. A comprehensive anatomical understanding of EF will help clinicians improve surgical guidelines and ultimatelyreduce the risk of complications.