Computed Tomographic Analysis: The Effects of Frontal Recess Morphology and the Presence of Anatomical Variations on Frontal Sinus Pneumatization.

The aim of this study is to describe the morphology of frontal recess area with its anatomical variations and to reveal if frontal recess morphology and the anatomical variations related to that region have effects on the pneumatization of the frontal sinuses. The frontal sinus and recess morphometry of 136 sides of 68 dry skulls were evaluated on multislice high-resolution computed tomography. The relationships between frontal sinus and frontal recess measurements were analyzed by correlation and linear regression analysis. The variables between the groups of anatomical variations were analyzed by Mann-Whitney U test and χ test or Fisher exact test. A positive relationship between the sagittal length of spina nasalis interna and morphometric measurements of frontal sinus was revealed (P <0.05). Agger nasi cells were present in 64.2% of sides, supraorbital ethmoid cells (SOECs) in 19.6%, type 3 frontal cells (FCs) in 18.9%, suprabullar cells in 24.3%, and frontal bulla was noted in 5.4%. Intersinus septal cells were observed in 16.2% of the skulls. There were statistically different increases in the measurements of frontal sinus morphometry in the presences of SOECs and type 3 FCs (P <0.05). The diameter of frontal sinus ostium was decreased in the presences of AN, SOEC, type 3 FC, and supraorbital ethmoid cell statistically (P = 0.049, P = 0.029, P = 0.043, P <0.001 respectively). In conclusion, frontal sinus pneumatization was affected by the spina nasalis interna and the presence of anatomical variations related to frontal recess or ostium region instead of the morphology of that area.