Laterality of Ethmoid Roof in a Korean Population

Background and Objectives: The olfactory fossa is an important anatomical structure to prevent surgical complications such as skull base injury and meningitis. The purpose of this study is to determine if there is a difference in lateral lamella length (LLL) between the left and right sides, a topic that has been studied rarely in Korea. Subjects and Method: We analyzed 592 left and right sides of 296 PNS CTs. We measured LLL as the distance between the fovea ethmoidalis and the horizontal cribriform plate in the olfactory fossa of the coronal surface where the crista galli was observed. Results: The average LLL on the left side was significantly longer than that on the right. Age and LLL showed a negative correlation. Multiple regression analysis revealed younger age and left side as independent variables for predicting increasing LLL. Conclusion: There was a significant difference between the two sides of LLL on sinus CT in Koreans. Before sinus surgery, the asymmetry of the ethmoid roof must be assessed, even by skilled doctors. If the height of the ethmoid roof is asymmetric, extra care is required during sinus surgery.