Table3. Root mean square errors from the regression model with only permanent teeth, only third molar and the combined tooth development information as predictor(s) and age as response.

	Female			Male
Age category	RMSE PT	RMSE TM	RMSE PT+TM	RMSE PT	RMSE TM	RMSE PT+TM
<8 years	0.80 (0.67;0.94)	1.97 (1.65;2.30)	0.76 (0.63;0.88)	0.77 (0.64;0.89)	2.31 (1.91;2.68)	0.75 (0.63;0.88)
8-10 years	1.03 (0.81;1.25)	0.81 (0.64;0.98)	0.91 (0.72;1.10)	1.01 (0.80;1.22)	0.58 (0.46;0.70)	0.94 (0.75;1.14)
10-12 years	1.43 (1.11;1.75)	1.83 (1.41;2.24)	1.45 (1.13;1.78)	1.18 (0.93;1.44)	1.80 (1.41;2.20)	1.19 (0.93;1.45)
12-14 years	0.79 (0.60;0.97)	2.62 (2.00;3.24)	0.890 (0.69;1.11)	0.92 (0.71;1.13)	2.82 (2.18;3.47)	0.90 (0.70;1.11)
14-16 years	1.26 (0.98;1.54)	2.89 (2.24;3.54)	1.27 (0.98;1.56)	0.98 (0.75;1.21)	2.71 (2.06;3.36)	1.03 (0.78;1.28)
8-16 year	1.06 (0.96;1.16)	2.09 (1.90;2.29)	1.05 (0.95;1.14)	0.96 (0.87;1.05)	2.16 (1.96;2.36)	0.95 (0.86;1.04)