Association between Estrogen Receptor- Gene XbaI and PvuII Polymorphisms and Periodontitis Susceptibility: A Meta-Analysis

Table 1

Characteristics of the studies included in the present meta-analysis.

Authors and year	Race	Disease type	DNA extraction method	Control source	Age (years)	Sample size	Females (%)	for HWE	Power (%)	Quality score
XbaI (rs9340799)
Zhang et al., 2004 [19]	Han	AgP	Peripheral blood	PB	29.0 ± 6.3/29.1 ± 6.2	90/91	58.9/52.8	<0.01	26.97	7
Zhang et al., 2004 [19]	Han	CP	Peripheral blood	PB	38.0 ± 10.4/29.1 ± 6.2	34/91	44.1/52.8	<0.01	20.00	7
Wu et al., 2007 [23]	Han	CP	Buccal mucosa	HB	49/35	55/60	56.4/50.0	0.04	18.76	8
Wang et al., 2008 [24]	Han	CP	Peripheral blood	HB	41.7 ± 7.4/40.8 ± 6.0	106/80	59.4/60.0	0.01	27.59	7
Wu et al., 2009 [26]	Han	AgP	Buccal mucosa	HB	31/35	48/60	72.9/50.0	0.04	17.89	7
Zhang et al., 2010 [39]	Han	CP	Buccal mucosa	HB	20~65	109/99	52.3/51.5	0.01	30.28	7
Qiu et al., 2013 [27]	Han	CP	Buccal mucosa	HB	46.4/37.2	60/81	65/51.9	0.91	22.01	7
Ma et al., 2013 [28]	Han	CP	Peripheral blood	HB	33~72	135/139	58.5/58.3	0.85	38.14	9
Ma et al., 2013 [28]	Hui	CP	Peripheral blood	HB	35~73	120/126	54.0/53.2	0.45	34.85	9
PvuII (rs2234693)
Zhang et al., 2004 [19]	Han	AgP	Peripheral blood	PB	29.0 ± 6.3/29.1 ± 6.2	90/91	58.9/52.8	0.26	26.97	8
Zhang et al., 2004 [19]	Han	CP	Peripheral blood	PB	38.0 ± 10.4/29.1 ± 6.2	34/91	44.1/52.8	0.26	20.00	8
Wu et al., 2007 [23]	Han	CP	Buccal mucosa	HB	49/35	55/60	56.4/50.0	0.70	18.76	9
Wu et al., 2009 [26]	Han	AgP	Buccal mucosa	HB	31/35	48/60	72.9/50.0	0.70	17.89	8
Zhang et al., 2010 [39]	Han	CP	Buccal mucosa	HB	20~65	109/99	52.3/51.5	<0.01	30.28	7
Qiu et al., 2013 [27]	Han	CP	Buccal mucosa	HB	46.4/37.2	60/81	65/51.9	0.64	22.01	7
Ma et al., 2013 [28]	Han	CP	Peripheral blood	HB	33~72	135/139	58.5/58.3	0.52	38.14	9
Ma et al., 2013 [28]	Hui	CP	Peripheral blood	HB	35~73	120/126	54.0/53.2	0.23	34.85	9

CP: chronic periodontitis, AgP: aggressive periodontitis, HWE: Hardy-Weinberg equilibrium, PB: population-based, and HB: hospital-based.
Cases/controls.
Assuming an odds ratio of 1.5 (small effect size) at level of significance.