Fig. 2From: The effect of rapid maxillary expansion on the upper airway’s aerodynamic characteristicsThe measurement of AN ratio on CBCT images. a A, perpendicular distance from the maximal convexity of the adenoid identifying by scrolling through the sagittal slice that showed maximal convexity of the adenoid (where the intersecting axial view also showed maximal convexity) to the anterior margin of the basiocciput. b N, distance between the posterosuperior point of the hard palate and the anteroinferior point of the spheno-occipital synchondrosis on the mid-sagittal planeBack to article page