CBCT imaging has been recognized as a more sensitive imaging modality for identifying sinus thickening and pathoses in the posterior maxilla compared to panoramic radiography. This could explain why the current study identified a higher prevalence of mucosal thickening compared to earlier studies. However, compared to other similar CBCT studies, the prevalence reported in the current study is still much higher than the previously published articles with a similar study design. Ritter et al. in a retrospective CBCT study reported 38.1% of subjects presented with mucosal thickening. Similarly, Pazera et al. reported a prevalence of 23.7% and Janner et al. reported 37% of cases with membrane thickening. In a recent study, Brüllmann et al. found 74% of evaluated sinuses had sinus findings upon CBCT examination. These differences in prevalence might result from the different inclusion criteria among the studies. Another potential explanation for these differences in the reported prevalence of mucosal thickening may be due to the ambiguous definition used in the early studies. Some studies suggested that 2 mm should be considered the threshold for identifying mucosal thickening, and thus the prevalence of slight mucosal thickening may have been underestimated. To avoid this situation, the current study analyzed the thickness of sinus membranes based on four different categories: no thickening (≤1 mm), minimal (>1 mm but ≤2 mm), moderate (>2 mm but ≤5 mm), and severe thickening (>5 mm). According to this index (Fig. 2), 93.1% of cases examined had maxillary sinus mucosal/tissue thickening and 65.5% had severe thickening.