Morphological variations of the middle and superior turbinates, olfactory fossa and nasal septum in different sphenoid sinus pneumatization patterns.

Abstract

Purpose: Detailed assessment of the extrasinusal pneumatization of the superior and middle turbinate (SCB, MCB), olfactory fossa (OFP), and nasal septum (NSP) in coronal and sagittal sphenoid sinus (SS) pneumatization types provides a precise understanding of the surgical corridors used for skull base surgery. We aimed to analyze the relationships among these variations using computed tomography (CT) images.

Methods: CT images of 153 patients were retrospectively analyzed for all types of sinonasal pneumatizations and volumes of SCB and sphenoid sinus, together with the prevalence of mucosal thickening of the sphenoid sinus (MTSS).

Results: The prevalences of cellular, extensive, and complete SCB were 28.6%, 21.1%, and 23.5% in prepterygoid; 38.1%, 42.1%, and 35.3% in prerotundum; and 33.3%, 36.8%, and 41.2% in postrotundum CSSP types, respectively. The frequencies of lamellar, bulbous, and extensive MCB were 29%, 14.3%, and 33.3% in pterygoid, 38.7%, 57.1%, and 25.9% in prerotundum, 32.3%, 8%, and 40.8% in postrotundum CSSP types, respectively. SCB and MCB were observed unilaterally at 24.8% and 30% and bilaterally at 12.8% and 32.7%, respectively. OFP, NSP, and MTSS were detected at 24.2%, 31.4%, and 27.5%, respectively. Increased age was significantly associated with a lower probability of pneumatization in SS and MCB.

Conclusions: The data obtained showed that the degree of SS pneumatization significantly affected the frequencies of the SCB, MCB, OFP, NSP, and MTSS. Also, the SCB volume is significantly related to the CSSP types. Preoperative CT evaluation is crucial for surgeons to be aware of these variations and to avoid iatrogenic injury.