A cross-sectional study of the olfactory fossa in Delta State, Nigeria

Abstract

Introduction: Evaluation of the olfactory fossa (OF) before endoscopic sinus surgery is important in minimizing inadvertent penetration into the anterior cranial fossa. This study assessed the depth of the OF using computed tomography (CT) images of adult Nigerians. Materials and Methods: Cranial CT images were obtained from the database of the radiological unit of a referral center in Delta State, Nigeria, after ethical clearance. The images belonged to 137 female and 199 male adults aged ≥20 years. The depth of OF was measured as the perpendicular distance between the cribriform plate (CP) inferiorly to the superior end of the lateral lamella of the CP on coronal sections. The fossae were classified as Keros Type I (0.1–0.39 cm), Type II (0.4–0.79 cm), and Type III (>0.8 cm). Data collected were analyzed using the Statistical Package for the Social Sciences version 23. Side and gender comparisons of the depth were evaluated using the Student's t-test, while the variations in the OF types were assessed using the Chi-square test. These comparisons were regarded significant when P < 0.05. Results: The mean OF depth was larger in males (0.543 ± 0.183 cm) than in females (0.527 ± 0.169 cm) (P = 0.018). The prevalence of symmetrical (64.9%) and asymmetrical (35.1%) OF showed significant sex differences (P < 0.05). Type II OF was the most common (77.2%), followed by Type I (15.8%) and Type III (7%). Conclusion: The presence of the deep (Type III) and asymmetric OF in the patients studied emphasizes the importance of their preoperative radiological identification to minimize complications.