Sphenoid sinus pneumatization: the good, the bad, and the beautiful

To study different types of extension of sphenoid sinus pneumatization detected by CT and examine their correlation with other anatomical variants.

Sphenoid sinus pneumatization was characterized (780 hemi-sinuses) on CT scans. Its incidence and correlations with related anatomical variants were evaluated. Dimensions of surgical window were measured in the lateral type, where pneumatization extends beyond a line connecting Vidian (pteregoid) canal (VC) and foramen rotundum (FR).

The lateral recess of the sphenoid sinus was pneumatized in 27.3% of patients with a mean width of 7.59 mm. The distance separating the FR and the VC correlated strongly with the depth of the lateral recess. There was significant positive correlation between pneumatization of lateral recess and Vidian nerve prominence to other pneumatization patterns (lesser sphenoid, frontal, and Maxillary sinuses) (p < 0.0001). Lateral recess pneumatization in coronal cuts was also significantly correlated with anterior-posterior sphenoid pneumatization in sagittal cuts (p < 0.0001).

Pre-operative assessment of sphenoid sinus pneumatization is essential in the endoscopic approach to skull base structures to facilitate surgical access and avoid injury of the nearby structures. Our study showed significant correlation among anatomical variants and different measurements which allows the surgeon to predict abnormal anatomy with high accuracy.