Table 7 Comparison between chronological age and estimated age by EGY I (upper & lower jaws) in group I (n = 1000) at different class intervals

Mean ± SD

Mean ± SD

Mean ± SD

149

6.43 ± 0.22

6.71 ± 0.56

0.28 ± 0.57

6.132^*

 < 0.001^*

145

7.45 ± 0.24

7.87 ± 0.77

0.41 ± 0.76

6.524^*

 < 0.001^*

219

8.47 ± 0.26

8.81 ± 0.79

0.34 ± 0.75

6.631^*

 < 0.001^*

106

9.60 ± 0.33

9.71 ± 0.84

0.11 ± 0.88

1.305

0.195

258

10.48 ± 0.26

10.12 ± 0.64

-0.36 ± 0.68

8.518^*

 < 0.001^*

87

11.45 ± 0.26

10.85 ± 0.72

-0.60 ± 0.63

8.877^*

 < 0.001^*

36

12.42 ± 0.25

11.27 ± 0.42

-1.15 ± 0.52

13.420^*

 < 0.001^*