Table 3. Pooled effect estimates (dental age vs. chronological age) for ages 4–18 and sex using the Willems method.

Age group	Male					Female
	Number of studies	n	I2 (%)	Effect estimate (95% CI)	SD	Number of studies	n	I2 (%)	Effect estimate (95% CI)	SD
4	2	18	0	-0.05 [-0.39, 0.30]	0.91	2	20	0	0.02 [-0.35, 0.40]	0.80
5	4	140	0	0.31 [0.12, 0.50]	1.40	4	134	65	0.45 [0.28, 0.62]	1.22
6	6	348	73	0.54 [0.42, 0.65]	1.33	6	326	83	0.17 [0.07, 0.26]	1.07
7	8	510	91	0.55[0.47, 0.63]	1.12	8	558	70	0.18 [0.09, 0.27]	1.32
8	9	654	89	0.24 [0.15, 0.33]	1.43	9	738	55	0.16 [0.08, 0.25]	1.43
9	9	764	0	0.23 [0.15, 0.30]	1.29	9	694	28	0.07 [-0.03, 0.17]	1.64
10	9	788	53	0.36 [0.26, 0.46]	1.74	9	696	55	0.09 [-0.02, 0.19]	1.72
11	10	976	78	0.30 [0.21, 0.38]	1.65	10	924	70	0.19 [0.09, 0.29]	1.89
12	10	916	97	0.76 [0.67, 0.85]	1.69	10	1048	36	0.13 [0.03, 0.22]	1.91
13	10	874	97	0.58 [0.50, 0.65]	1.38	10	874	99	0.36 [0.27, 0.45]	1.65
14	9	574	85	0.20 [0.08, 0.33]	1.86	9	764	91	-0.06 [-0.19, 0.06]	2.15
15	8	438	91	0.00 [-0.10, 0.11]	1.36	8	494	79	-0.21 [-0.33, -0.09]	1.66
16	2	98	NA	-1.63 [-2.01, -1.25]	2.34	3	196	0	-0.94 [-1.13, -0.74]	1.70
17	1	76	NA	-2.15 [-2.46, -1.84]	1.68	1	148	NA	-1.64 [-1.77, -1.51]	0.98
18	1	36	NA	-2.72 [-3.10, -2.34]	1.42	1	176	NA	-2.66 [-2.78, -2.54]	0.99

Significant values in bold.