Radiological Analysis of the Ethmoid Roof in the Malaysian Population

Objective: To ascertain the prevalence of the lateral lamella of the cribriform plate height according to Keros classification in the Malaysian population, and to find if there is any difference between the major ethnic groups in Malaysia (Malay, Chinese, Indian).

Methods: Retrospective analysis of 150 CT scan studies of the paranasal sinuses.

Results: The mean height of the lateral lamella of the cribriform plate (LLCP) in 300 sides was 2.64mm. Keros type I was seen in 240 sides (80%), while, Keros type II was seen in 60 sides (20%). There was no significant difference in the distribution of Keros classification among the major ethnic groups of Malaysia (Malay, Chinese, Indian). Keros type I was seen in 103 sides in males and 137 sides in females. Significant difference was observed in type II between the male and female (47 sides in males and 13 sides in female; p-value <0.001). When comparing the difference in the height of the LLCP in the same individual, asymmetry was observed in 139 patients. The LLCP height was higher on the left side in 71 patients and higher on the right in 68.

Conclusion: The understanding of the anatomy of the ethmoid roof with its possible variation is crucial to give the surgeon the optimal information about the possible risk that one can face during the surgery.