The anatomical variability of the sphenoid sinus in CBCT - a retrospective study.

The aim of this retrospective study was to assess and illustrate the anatomical variability of the sphenoid sinus (SPS) on cone-beam computed tomography (CBCT) scans. A total of 50 SPS were assessed. CBCT images were oriented in the sagittal plane to evaluate the type of pneumatization (conchal, presellar, sellar and postsellar). Size measurements (width, length and height) of the SPS as well as the septation pattern and the presence or absence of pathologies were examined in all three planes. The postsellar type (28 cases, 56%) was the most common pattern of pneumatization. Conchal, presellar, or sellar pneumatization were significantly less frequent. There was only one case (2%) with a conchal and two cases (4%) with a presellar type. Multiple septa were found in 75% of patients with postsellar pneumatization, but only in 45.5% of patients featuring conchal, presellar or sellar type. In the postsellar category, all measured dimensions were significantly higher compared to the other types of pneumatization. Pathologies in the SPS were found in 7 patients (14%). It was concluded that the anatomical structure of the SPS is highly variable. Knowledge about its radiological appearance in CBCT will help in identification of pathologies and surrounding anatomical structures.