Surgical anatomy of natural ostium of the sphenoid sinus

Kim, Hyun Ung; Kim, Kyung Su; Kim, Sung Shik; Chung, In Hyuk; Yoon, Joo Heon

Abstract

BACKGROUND AND OBJECTIVES
It is important for surgeons to identify the location of natural ostium of the sphenoid sinus during sphenoidotomy for sphenoiditis and transsphenoidal approach (TSA). But, it is not easy for a beginner to find it. This study aimed to investigate from a clinical aspect the location of natural ostium of the sphenoid sinus using korean adult cadaveric heads. Material and methods : One hundred sagittally-divided adult cadaveric heads were used. After removing the mucosa of anterior wall meticulously, they were carefully examined and documented serially by photography. The items analyzed were the distance from and the degree of nasal sill and limen nasi to the natural ostium of sphenoid sinus, and the distance from the posteroinferior end of the superior turbinate and the skull base to the natural ostium of the sphenoid sinus. In addition, we tried to investigate whether the natural ostium opens into the medial or lateral to the posterior end of the superior turbinate. RESULT: The natural ostium of the sphenoid sinus was located at 34.3 3.8o and 62.7 9.0 mm away from the nasal sill, and at 35.9 3.8o and 56.5 3.2 mm away from the limen nasi. It was located approximately in the middle of the anterior wall of the sphenoid sinus and medially to the posterior end of the superior turbinate in about 83%.
CONCLUSION
By identifying the posteroinferior end of the superior turbinate, the location of natural ostium of the sphenoid sinus can be identified. We recommend that surgeons should look for the natural ostium in the middle of the anterior wall of the sphenoid sinus and medial to the posterior end of the superior turbinate.