Figure 6: Various ratios: (d) Ratio 4 = Maxillary intercanine width (1)/ Visible dentition width (2); E. Ratio 5 = Interpremolar distance (1)/ Smile width (2); (f) Ratio 6 (Smile line ratio) = Length of perpendicular for the arc of upper incisors (1)/Length of perpendicular for the arc of lower lip (2); (g) Ratio 7 (Smile symmetry ratio) = Distance from RCh to C Low + Distance from RCh to C Lab (1 + 2)/Distance from LCh to C Low + Distance from LCh to C Lab (3 + 4)