The Morphometric Analysis of the Ethmoid Roof for Endoscopic Sinus Surgery With Multidetector Computed Tomography

Most potential major complications in endoscopic sinus surgery are related to the ethmoid bone. To prevent complications, it is necessary to define the concept of a "dangerous ethmoid." The coronal multidetector computed tomography (MDCT) scans of a total of 271 patients, including 101 patients under 18 years old and 170 patients over 18 years old, were examined. For each patient, the depth of the olfactory fossa (DOF), the width of the olfactory fossa (WOF), the angle between the lateral lamella and the cribriform plate (LLCPA), the length of the lateral lamella (LLL), the distance between the nasal floor and the ethmoid roof (NFERL), and the width of the olfactory cleft (WOC) were recorded. The Keros and Gera types were determined. NFERL was found to be significantly higher in males across all age groups. WOC was significantly higher in males only under 18 years old. Only LLCPA was found to be significantly higher on the right side in both sexes. It was determined that NFERL increased with age, while WOC increased with age until 18. Keros type III and Gera type C, which are called dangerous types, were detected in 28 and 24 cases in total, respectively. The data obtained from significant anatomical landmarks in pediatric and adult cases provide useful information about the region in preoperative planning. The analysis results of the prevalence of Keros and Gera classifications allow the identification of high-risk anatomical conditions within the ethmoid.