Computed Tomography Analysis of the Anterosuperior Portion of the Bulla Lamella in Chinese Subjects and Its Surgical Significance in Endoscopic Frontal Sinusotomy

The Effects of Suprabullar Pneumatization on the Orientation of Its Surrounding Anatomical Structures Relevant to the Frontal Drainage Pathway

Objective: The aim of this study was to evaluate the effects of suprabullar pneumatization on the orientation of the frontal sinus outflow structures and its association with the volume of anterior ethmoid sinus. Methods: A retrospective chart review of computed tomography of paranasal sinuses (CTPNS) images was conducted. A total of 370 sides of the CTPNS of 185 patients were analyzed. Results: The course of anterior ethmoidal artery (AEA) along the skull base (p = 0.04) and position of AEA at the second lamella (p = 0.04) was significantly associated with the type of suprabullar pneumatization. The AEA is expected to be lower at the skull base and at a longer distance from the second lamella with the increase in grading of the suprabullar pneumatization. The distance of AEA to the second lamella (p < 0.001) and third lamella (p = 0.04) was significantly different depending on the type of suprabullar pneumatization, which indicates AEA is expected to be at a longer distance from the second lamella and third lamella in higher grade suprabullar pneumatization. The type of suprabullar pneumatization has a significant but weak association with the anterior ethmoid sinus volume (p = 0.04). Conclusions: There is a significant effect of the type of suprabullar pneumatization on the orientation of the surrounding anatomical structures at the frontal recess. The type of suprabullar pneumatization is influenced by the anterior ethmoid sinus volume, which suggests it has a possible role in the frontal drainage pathway.