METHODS: A cross-sectional study of 252 AEA identified by computed tomography (CT) of the paranasal sinuses. The multiplanar CT images were acquired from SOMATOM® Definition AS+ and reconstructed to axial, coronal and sagittal view at 1 mm slice thickness.
RESULTS: 42.5% of AEA was within skull base (grade I), 20.2% at skull base (grade II) and 37.3% coursed freely below skull base (grade III). The prevalence of supraorbital ethmoid cell (SOEC) and suprabullar cell (SBC) was 29.8% and 48.0%. The position of AEA at skull base has significant association with SOEC (p skull base was 1.93 ± 2.03 mm, orbital floor 21.91 ± 2.47 mm and nasal floor 49.01 ± 3.53 mm.
CONCLUSIONS: The position of AEA at skull base depends on the presence of SOEC and length of lateral lamella, but not with SBC. When compared to European population, the mean distance between AEA and nasal floor is shorter in Asians.