CT Assessment of the Presence of Septation Between the Frontal Sinus and Supraorbital Ethmoid Cells: A Retrospective Study

Abstract

Abstract Background Supraorbital ethmoidal cells (SOEC) are air-filled ethmoidal cells found in the orbital plate of the frontal bone. It is located close to the frontal recess and sinus and is usually separated by a thin bony septum from the frontal sinus. Unaddressed SOEC can lead to failed or complicated endoscopic sinus procedures, residual fungal elements, or mucocele. Moreover, improper localization during the procedure may contribute to an increased risk of orbital and skull base injuries. Objectives To determine the presence of septation between the frontal and the supraorbital ethmoid cell based on radiological imaging and to study the degree of SOEC pneumatization. Methods A retrospective study that included 244 computed tomography images of the paranasal sinuses was conducted from November 2022 to April 2023 at King Abdullah bin Abdulaziz University Hospital (KAAUH). Results This study included 244 participants. Most participants (55.7%) were female, with the largest age group falling between 18 and 28 (34.8%). Most cases (60.7%) had bilateral Supra-Orbital Ethmoidal Cells. The pneumatization of SOEC was classified into three types based on its lateral extension on computed tomography images. Majority of patients were found to have type 1 pneumatization, followed by type 2 then type 3. Most cases showed septation between the frontal and SOEC on both the right (74.1%) and left (59.3%) sides. According to this study, there is no association between many factors such as gender, age, chronic rhinosinusitis, pneumatization of the sinuses, and the occurrence of septation between the frontal and SOEC. Conclusion Surgeons should have heightened awareness regarding the complexity of the anatomical variation of the frontal sinus and SOEC. A new classification is proposed regarding the degree of pneumatization of SOEC that has value in understanding the anatomy and planning the surgical approach.