Figure 4: Mean finger ridge density (RD) of 10 fingers for each area for the left and right hands. L_u, ulnar RD of the left hand; L_r, radial RD of the left hand; R_u, ulnar RD in the right hand; R_r, radial RD of the right hand; Mean RD in both sexes is greater in the areas of the left hand, thus showing finer ridges than in the right hand with statistically significant difference only in girls (P = 0.25 in boys; P = 0.026