Functional endoscopic sinus surgery (FESS) is a frequently used treatment method, and it is important to know the anatomy of the paranasal sinuses, olfactory fossa and adjacent anatomical structures during surgery. Paranasal sinus computed tomography (CT) is a frequently used imaging method in the evaluation of the paranasal sinuses, nasal cavity and nasopharynx. Our study aims to determine Keros types and their incidence by retrospectively evaluating the depth of the olfactory fossa in our population according to the Keros classification on paranasal sinus CT images.Methods: In this study, the images of the patients who were directed by the otorhinolaryngology clinic and who underwent non-contrast paranasal sinus CT examination in the Radiology clinic between December 2018 and June 2019 were evaluated retrospectively. As a result, 522 patients between the ages of 18 and 87 were included in our study.
Results:The average depth of the total 1044 olfactory fossa (OF) examined was 4.89 mm with a standard deviation (SD) calculated of ±2.79. Statistically, a significant difference was found between males and females in mean OF depth (p<0.001). According to Keros classification, 322 sides (30.85%) had type 1, 697 sides (66.75%), type 2 and 25 sides (2.4%) had type 3 in 1044 olfactory fossa. To our knowledge, this study has the largest case series for the olfactory fossa in our country, and the data were obtained in a tertiary health center.
Conclusion:The routine use of Keros classification for the left and right side in paranasal sinus CT reporting will help minimize surgical complications by providing valuable contributions to the surgical branches related to the anatomy of this region.