Sphenoid Sinus Pneumatization and Its Association with Internal Carotid Artery Protrusion and Dehiscence: A CBCT...

To evaluate sphenoid sinus (SS) pneumatization patterns and their lateral extensions and to investigate their association with internal carotid artery (ICA) protrusion and radiographic dehiscence using cone-beam computed tomography (CBCT) in a Turkish population.

CBCT images of 154 patients (64 males, 41.6%; 90 females, 58.4%; mean age, 34.93 ± 15.80 years) were retrospectively evaluated. SS pneumatization was classified as conchal, presellar, sellar, or postsellar, and lateral extensions into the anterior clinoid process (ACP), pterygoid process (PP), and greater wing of the sphenoid (GWS) were recorded. ICA protrusion and radiographic dehiscence were considered positive if present on either side.

The postsellar type was the most common (70.8%), followed by the sellar (26.0%) and presellar (3.2%) types. ICA protrusion was identified in 136 patients (88.3%; 95% CI, 82.3-92.5), and radiographic dehiscence in 116 (75.3%; 95% CI, 68.0-81.5). The prevalence of protrusion in the presellar, sellar, and postsellar groups was 20.0%, 72.5%, and 97.2%, respectively, the corresponding prevalence of radiographic dehiscence was 0%, 62.5%, and 83.5% (p<0.001 for both). SS pneumatization extent was independently associated with ICA protrusion (adjusted OR [aOR]=5.56; 95% CI, 2.17-17.85; p<0.001) and radiographic dehiscence (aOR=2.49; 95% CI, 1.21-5.34; p=0.013). ACP pneumatization was independently associated with radiographic dehiscence (aOR=3.67; 95% CI, 1.36-11.34; p=0.009).

Greater sagittal pneumatization of the SS was associated with ICA protrusion and radiographic dehiscence, while ACP pneumatization was associated with dehiscence risk. Recognizing these anatomical relationships may support more informed preoperative risk stratification for patients undergoing endoscopic skull-base surgery.