Do Onodi Cells Influence the Onset of Sphenoiditis? A Multicentric Cross-Sectional Study

Background: Sphenoiditis poses diagnostic and treatment challenges due to its complex anatomy and potential for serious complications. Anatomic variations, such as Onodi cells, could play a role in the onset and spreading of inflammation. The diagnosis and treatment of sphenoiditis can be more difficult if Onodi cells are present, especially due to their proximity to delicate vital tissues. Objectives: The purpose of this study was to look at the frequency, features, and relationship between Onodi cells and sphenoiditis. Methods: This multicentric study comprised 550 people who received sinonasal CT imaging. The Thimmaiah classification was used to assess the presence and features of Onodi cells, and radiographic results were used to diagnose sphenoiditis. We conducted univariate and multivariate logistic regression to evaluate the relationships between sphenoiditis and Onodi cells. Results: The prevalence of Onodi cells was 32.40%, with a higher prevalence on the right side (18.40%) compared to the left side (8.40%). The multivariable analysis revealed a significant correlation between right-side Type II Onodi cells and a higher incidence of sphenoiditis (OR = 6.81, 95% CI: 1.14–38.97, p = 0.029). In the univariable analysis (OR = 3.00, 95% CI: 1.15–6.96, p = 0.015), but not in the multivariable analysis, the presence of Type I Onodi cells on the left side was significantly associated with sphenoiditis. Conclusions: There may be a link between a higher incidence of sphenoiditis and the presence of Type II Onodi cells on the right side. In order to validate these findings and clarify the underlying processes of this connection, more prospective research is required.