The sphenoid sinus natural ostium is consistently medial to the superior turbinate.

BACKGROUND: This study was performed to determine the location of the natural ostium of the sphenoid sinus relative to the intact superior turbinate.

METHODS: Forty-seven cadaveric specimens were examined. Mucosa over the sphenoethmoidal recess, superior turbinate, and posterior ethmoid was left intact. The position of the sphenoid sinus natural ostium relative to the superior turbinate was identified.

RESULTS: The sphenoid ostium was identified in all specimens. In all specimens, the sphenoid ostium was found to be medial to the intact superior turbinate, notwithstanding lateral deflection of the posterior few millimeters of the superior turbinate in some cases.

CONCLUSION: The superior turbinate is an excellent landmark for the sphenoid sinus natural ostium. Previous observations of the ostium positioned lateral to the superior turbinate may have been caused by stripping of the superior turbinate mucosa before measurements were taken. In the intact specimen, the sphenoid ostium is reliably found medial to the superior turbinate.