Table 1.

Definitions of the Cone Beam Computed Tomography measurements used in the study

Cbct measurements
MBW	The maxillary first molar basal width dimension was measured as distance between the lateral limits of the right and left sides of the maxilla along the nasal floor reference plane.
MAW	The maxillary first molar alveolar width dimension was measured as the distance between the right and left tip of the maxillary first molar alveolar process on the coronal slice.
PMBW	The maxillary first premolar basal width dimension was measured as the distance between the lateral limits of the right and left sides of the maxilla along the nasal floor reference plane.
PMAW	The maxillary first premolar alveolar width dimension was measured as the distance between the right and left tip of the maxillary first molar alveolar process on the coronal slice.
PD	Palatal depth was measured on the axial view by locating the coronal plane on the sites of the upper first molars in both the left and right sides and ensuring that it will be passed through the left of the tooth. Then a line was drawn between the cemento-enamel junctions (C.E.J) of the two first molars. From the mid-point of this line, another perpendicular line was drawn up to the palate
AL	Maxillary arch length (AL) was measured on an axial plane as the distance from incisal foramina to the line that connects the distal ends of right and left first molars