Determinants of sphenoid sinus ostium localization: implications for safer endoscopic sinus surgery

This study aimed to evaluate multiple anatomical and morphological factors influencing the localization of the sphenoid sinus ostium (SSO) to improve surgical safety in endoscopic sinus surgery. Computed tomography (CT) images of 302 subjects were examined. The vertical and horizontal positions of the SSO were assessed using standardized reference lines on sagittal and axial sections. Pneumatization patterns were classified on sagittal and coronal planes. Rostrum pneumatization and the presence of Onodi cells were also evaluated. Morphometric measurements and potential influencing factors were analyzed using logistic and linear regression models. The SSO was most frequently located in the superior (72.8%) and medial (55.6%) thirds. The female gender increased the likelihood of medial ostium localization by 2.715-fold. Compared to the sellar type, conchal pneumatization increased the probability of medial positioning by 9.82-fold, while the postsellar type reduced it (OR: 0.208). The postrotundum type was strongly associated with superior and medial localizations (OR: 3.289 and OR: 2.978, respectively). A wider sphenoid rostrum reduced the probability of medial localization, whereas rostrum pneumatization promoted superior displacement of the SSO. Onodi cells and increased sinus height shifted the SSO inferiorly by 1.929 and 0.341 units, respectively. The localization of the SSO was found to be significantly influenced by gender, sphenoid sinus pneumatization patterns, rostrum morphology, and the presence of Onodi cells. Careful preoperative evaluation of CT images for these factors may provide valuable insights for surgeons and help minimize the risk of serious complications during endoscopic sinus surgery.