Concha Bullosa and Ethmoid Structures Pneumatization: The Effect of Altitude and Other Variables.

The effect of altitude on the paranasal sinus pneumatization is not well understood. This study aims to evaluate the effect of altitude on the surface area and type of the concha bullosa (CB) as well as the number of aerated ethmoid structures, and to study the correlation between CB, age, gender, and Lund-Mackay score (LMS).Sixty-five randomly collected paranasal sinus computed tomography scans of adult patients with sinonasal symptoms who had CB were reviewed for the type and surface area of CB, ethmoid structures pnumatization including crista galli, nasal septum, superior turbinate, and uncinate process, as well as the LMS. The mean age of patients was 35 ± 9.64 years, with 29 females (41.7%) and 36 males (58.3%). The average LMS, altitude, and number of aerated ethmoid structures were 6 ± 4, 580 ± 325 m, and 4 ± 1.4, respectively.The average CB surface area in females was 163 mm compared to 109 mm in men; this difference was statistically significant. Furthermore, females had significantly higher prevalence of bulbous and extensive CB. There was no significant correlation between altitude and the presence of ethmoid structures pneumatization.We concluded that altitude is not an important factor in ethmoid structures aeration. Our results indicate that female patients have larger CB and number of pneumatized ethmoid structures than males. We found a significant correlation between the surface area of CB and the number of aerated ethmoid structures, which indicates possible common etiology.