Analysis of Olfactory Fossa Anatomy using Cone Beam Computed Tomography

Abstract

Introduction: Olfactory fossa is an important structure in the anterior skull base. It is made of Lateral Lamella of Cribriform Plate (LLCP) and fovea ethmoidalis which are very delicate parts that can get damaged during surgical procedures causing numerous serious complications. To avoid such complications, the knowledge of anatomical variations of these parts is mandatory. As there are very few studies which have used Cone Beam Computed Tomography (CBCT) for evaluation of olfactory fossa, the authors have assessed the olfactory fossa with the help of Kero’s and Gera’s classification for lateral lamella of cribriform plate. Aim: To evaluate the anatomy of olfactory fossa using CBCT. Materials and Methods: A retrospective observational study was conducted in the Department of Oral Medicine and Radiology, from 1st January 2019 to September 2021. The CBCT scans of 107 adults were analysed to evaluate the height of LLCP according to Kero’s classification and the angle between the LLCP and the true horizontal plane according to Gera’s classification. Comparison of height of lateral lamella (mm) and Gera angle (degree) among right and left sides were done using Student’s Independent t-test. The comparison of Gera angle with Kero’s type was analysed by one way Analysis of Variance (ANOVA) test. Chi-square test was performed to assess categorical data on the right and left sides. Results: A total of 107 CBCT scans consisting of 59 males (55.14%) and 48 females (44.86%) were included in the study. The mean age of the study population was 31.60±11.17 years. Kero’s type II (69.6%) and Gera’s class II (92.1%) LLCP were found to be most commonly seen. The Gera angle on right side (60.26±9.84) was greater than on left side (56.38±10.16) which was statistically significant (p-value=0.005). On right side, Kero’s type II was more common in males (71.2%) and on left side, Kero’s type II was more common in females (77.1%). Conclusion: Kero’s type II Olfactory fossa (OF) was found as most common type, with no significant difference between gender and /or side. Similarly, class II Gera angle was most common and the values were higher on right side.

Keywords

• ethmoid roof
• fovea ethmoidalis
• gera angle
• kero type
• lateral lamella of cribriform plate