Table 2: Mean difference (±standard deviation) between dental age based on the Demirjian method and chronological age as determined by the different methods in boys.

Age group ( ) French-Canadian (SD) Belgian (SD) Kuwaiti (SD) Saudi (SD)

4-5 (7)0.75 (0.18)−1.26 (0.53)0.03 (0.17)NA
5-6 (12)0.82 (0.78)0.11 (1.67)0.04 (0.79)NA
6-7 (26)1.04 (0.35)1.57 (0.96)0.51 (0.70) NA
7-8 (28)0.66 (0.42)2.11 (1.01)0.60 (0.69)1.68 (0.00)
8-9 (26)0.69 (0.98)2.81 (1.33)0.85 (0.92)1.22 (0.77)
9-10 (30)0.97 (0.84)3.23 (0.82)0.83 (0.57)0.95 (0.68)
10-11 (30)1.21 (0.56)3.05 (0.48)0.60 (0.48)0.80 (0.43)
11-12 (16)0.17 (1.05)2.14 (0.65)−0.39 (0.62)−0.19 (0.67)
12-13 (30)0.69 (1.18)1.91 (0.53)−0.20 (1.15)−0.19 (0.88)
13-14 (12)−0.12 (0.69)1.20 (0.86)−1.51 (0.63) −1.22 (0.41)

Total (217)0.76 (0.85)2.12 (1.36)0.30 (0.96)0.40 (1.00)