Cephalometric diagram used for cephalogram measurements. The centroid (Cr) point was a constructed point 15 mm from the incisal edge along the long axis of the maxillary incisor. 1 = U1 angle to X: angulation of maxillary central incisor to X-axis; 2 = U1cr to X (linear distance of maxillary incisor centroid to x axis); 3 = U1 tip to U6D (linear distance of maxillary incisor tip to maxillary first molar distal aspect, perpendicular to x axis); 4 = U6 to X: angle of a line perpendicular to maxillary first molar mesial surface to x axis); 5 = U1 tip to X (linear distance between maxillary incisor tip to x axis perpendicularly); 6 = U6 apex to X (distance of maxillary first molar mesialbuccal root apex to x axis); 7 = U1 apex to X (distance of maxillary incisor apex to x axis); 8 = U1 apex to Y (distance of maxillary incisor apex to y axis); 9 = U1 tip to Y (distance of maxillary incisor edge to y axis). X indicates horizontal reference line passing from the ANS to the PNS; Y, vertical reference line perpendicular to the x axis passing through sella turcica. U1, maxillary central incisor; U1cr, centroid point of maxillary central incisor; U6, maxillary first molar; U6D, distal aspect of maxillary first molar.