Table 2. Comparison of chronological age (CA) and Demirjian dental age (DA) by gender and age group.

Gender	Age group (years)	N	CA	DA	DA-CA	p value*	p value#
			Mean ± SD (years)
GIRLS	5	24	5.46 ± 0.33	5.53 ± 0.58	+ 0.07 ± 0.43	0.543	0.846
	6	39	6.57 ± 0.32	7.11 ± 0.58	+ 0.54 ± 0.38	< 0.001	< 0.001
	7	46	7.52 ± 0.26	7.65 ± 0.67	+ 0.13 ± 0.47	0.097	0.167
	8	50	8.51 ± 0.31	8.30 ± 0.73	- 0.21 ± 0.44	0.049	0.048
	9	55	9.48 ± 0.30	9.84 ± 0.77	+ 0.36 ± 0.43	0.001	0.001
	10	55	10.55 ± 0.32	10.72 ± 0.85	+ 0.17 ± 0.52	0.173	0.101
	11	40	11.44 ± 0.32	11.58 ± 0.84	+ 0.14 ± 0.54	0.352	0.357
	12	55	12.49 ± 0.32	12.75 ± 0.87	+ 0.26 ± 0.53	0.048	0.049
	13	57	13.46 ± 0.30	13.52 ± 0.83	+ 0.06 ± 0.50	0.607	0.502
	14	59	14.48 ± 0.28	14.11 ± 0.62	- 0.37 ± 0.39	< 0.001	< 0.001
	15	21	15.48 ± 0.27	15.73 ± 0.51	+ 0.25 ± 0.26	0.024	0.023
	Total	501	10.68 ± 2.87	10.79 ± 2.86	+ 0.11 ± 0.81	0.003	0.002
BOYS	5	23	5.56 ± 0.29	5.43 ± 0.98	- 0.13 ± 0.42	0.551	0.503
	6	40	6.52 ± 0.31	7.05 ± 0.78	+ 0.53 ± 0.44	< 0.001	< 0.001
	7	58	7.48 ± 0.29	7.72 ± 0.67	+ 0.24 ± 0.46	0.015	0.004
	8	58	8.47 ± 0.29	8.89 ± 0.61	+ 0.42 ± 0.97	< 0.001	< 0.001
	9	78	9.46 ± 0.28	9.61 ± 0.82	+ 0.15 ± 0.45	0.111	0.069
	10	100	10.45 ± 0.29	10.76 ± 0.84	+ 0.31 ± 0.47	< 0.001	< 0.000
	11	82	11.51 ± 0.30	11.66 ± 0.70	+ 0.15 ± 0.37	0.035	< 0.001
	12	91	12.44 ± 0.30	12.42 ± 0.74	- 0.02 ± 0.45	0.705	0.541
	13	82	13.41 ± 0.31	13.56 ± 0.78	+ 0.15 ± 0.36	0.088	0.106
	14	58	14.47 ± 0.31	15.06 ± 0.58	+ 0.59 ± 0.46	< 0.001	< 0.001
	15	29	15.24 ± 0.25	15.80 ± 0.40	+ 0.56 ± 0.35	< 0.001	< 0.001
	Total	699	10.81 ± 2.60	11.05 ± 2.71	+ 0.24 ± 0.80	< 0.001	< 0.001
Total sample		1200	10.75 ± 2.72	10.94 ± 2.78	+ 0.19 ± 0.80	< 0.001	< 0.001

*Paired t test, ^#Wilcoxon Signed Rank test: p ≤ 0.05 = significant