Study of the location of sphenoid ostium in adults based on computed tomography images
Abstract
Background: The sphenoid sinus is closely surrounded by many important vascular and neurological. The natural ostium is the safest place to enter the sphenoid sinus without injuring adjacent structures. A better understanding of the position and distance of the sphenoid ostium (SO) with respect to the other anatomic landmark is essential for the safety and effectiveness of laparoscopic surgery.
Objective: The purpose of this study was to investigate the relationship between the SO and surrounding landmark structures. Besides, we examine the effect of the Onodi cell and pneumatization of the sphenoidal sinus on the position of the SO.
Methods: Cross-sectional study of 162 sinus CT scan data obtained from the PACS system at University Medical Center Ho Chi Minh City. The image is reconstructed and measured by the Multiplanar reconstruction (MPR) software of the PACS Carestream.
Results: The mean distance between the SO and the lateral wall was 9.1 ± 1.8 mm. The mean distance from the SO to the median line was 4.1 ± 1.8 mm. The mean distance between the SO and the roof sphenoid sinus was 7.9 ± 2.9 mm. The average distance from the sphenoid ostium to superior border of posterior choana was 12.9 ± 3.5 mm. The mean distance from the sphenoid ostium to the anterior nasal spine was 65.2 ± 4.5 mm and to the posterior wall of the sphenoid sinus was 12.8 ± 2.7 mm. The angle between the SO - the anterior nasal spine and the floor of the nose is 33.5 ± 3.5 degrees. The distance from the SO to the roof sphenoid sinus was found to increase in cases where Onodi cells are present. For lateral pneumatization, the distance from the SO to the lateral wall in type II to be less in type III. The sphenoid sinus pneumatization on the sagittal plane did not affect the distance from SO to the posterior choana and the roof sphenoid sinus.
Conclusions: The study determined the distances between the SO and some surrounding anatomical landmarks, and also investigated the influence of the Onodi cell and pneumatization on the position of the sphenoid sinus by CT scan images. The measurements described in this study may be very valuable in avoiding serious complications while performing surgery.
