Variations of the height of the ethmoid roof among Egyptian adult population: MDCT study

Fovea ethmoidalis and lateral lamella of the cribriform plate of ethmoid bone (LLCP) are the most vulnerable parts of the skull base for iatrogenic complication during functional endoscopic sinus surgery. Keros classified the depth of the olfactory fossa into 3 types. According to Keros, the greater the height of LLCP, the higher the risk of its iatrogenic injury. The aim of this study was to evaluate variations of the height of ethmoid roof among Egyptian adults using MDCT. Patients and methods: This study was conducted on 100 Egyptian adult patients referred for MDCT evaluation of PNS. Patients with any pathology involving the ethmoid roof were excluded from the study. MDCT machines were used for evaluation of all patients. Results: The mean age of our patients was 38.34±12.79years. The right lateral lamella height ranges from 0.50 to 10.0mm, while the left lateral lamella height ranges from 0.80 to 9.40mm. Keros type I was seen in 56.5%, type II in 40.5% and type III in 3%. Conclusion: The majority of studied Egyptian adult population showed Keros type I (56.5%) followed by type II (40.5%). Keros type III is seen in only 3% of studied adult Egyptian population.