Table 1. Characteristics of the studies included in the meta-analysis.

Polymorphism	Reference	Year	Country	Ethnicity	Disease type	Control source	Case			Control			Smoking (%)		Genotyping method	P# value	NOS score
							CC	CT	TT	CC	CT	TT	Case	Control
MMP-9-1562 C/T	de Souza	2005	Brazil	Mixed	CP	HB	42	20	0	24	13	1	0	0	PCR-RFLP	0.62	7
	Holla	2006	Czech	Caucasian	CP	HB	122	43	4	93	37	5	26.0	29.6	PCR	0.59	8
	Keles	2006	Turkish	Caucasian	CP	HB	57	13	0	42	24	4	NA	NA	PCR	0.82	7
	Chen	2007	China	Asian	AgP	PB	62	15	2	101	26	1	NA	NA	PCR-RFLP	0.63	7
	Gurkan	2007	Turkish	Caucasian	AgP	HB	58	53	1	78	72	7	32.6	5.1	PCR	0.06	7
	Gurkan	2008	Turkish	Caucasian	CP	PB	54	32	1	52	52	3	47.1	3.7	PCR	0.02	6
	Loo	2011	China	Asian	CP	PB	143	73	64	43	72	135	NA	NA	PCR-RFLP	<0.01	6
	Isaza-Guzman	2011	Colombia	Mixed	CP	HB	58	11	0	47	6	1	14.6	4.9	PCR-RFLP	0.16	7
	Li	2012	China	Asian	CP	PB	68	26	28	99	156	277	93.4	97.7	PCR-RFLP	<0.01	6
MMP-3-1171 A5/A6							A5/A5	A5/A6	A6/A6	A5/A5	A5/A6	A6/A6
	Itagaki	2004	Japan	Asian	AgP	HB	0	17	20	4	38	100	NA	NA	Taqman	0.87	8
	Itagaki	2004	Japan	Asian	CP	HB	5	58	142	4	38	100	NA	NA	Taqman	0.87	8
	Astolfi	2006	Brazil	Mixed	CP	PB	19	52	19	8	70	25	NA	NA	PCR-RFLP	<0.01	6
	Loo	2011	China	Asian	CP	PB	154	115	11	100	135	15	NA	NA	PCR-RFLP	<0.01	6
	Li	2012	China	Asian	CP	PB	75	44	3	213	283	36	93.4	97.7	PCR-RFLP	<0.01	6
	Letra*	2012	Brazil	Mixed	CP	HB	NA	NA	NA	121	114	64	NA	NA	Taqman	<0.01	6
	Letra*	2012	US	Caucasian	CP	HB	NA	NA	NA	51	91	62	NA	NA	Taqman	0.13	7
MMP-8-799C/T							CC	CT	TT	CC	CT	TT
	Chou	2011	China	Asian	CP	PB	122	191	48	53	40	13	25.5	15.1	PCR-RFLP	0.22	8
	Chou	2011	China	Asian	AgP	PB	34	50	12	53	40	13	25	15.1	PCR-RFLP	0.22	7
	Holla	2012	Czech	Caucasian	CP	HB	88	163	90	84	134	60	30	28	PCR-RFLP	0.63	8
	Emingil	2014	Turkey	Caucasian	AgP	PB	11	57	32	76	66	25	29	3.6	TaqMan	0.10	8
MMP-2-753C/T							CC	CT	TT	CC	CT	TT
	Holla	2005	Czech	Caucasian	CP	PB	107	38	4	93	30	4	NA	NA	PCR-RFLP	0.42	8
	Chen	2007	China	Asian	AgP	PB	63	15	1	98	28	2	NA	NA	PCR-RFLP	1.00	7
	Gurkan	2007	Turkish	Caucasian	AgP	HB	49	39	4	98	54	5	32.6	5.1	PCR	0.06	7
	Gurkan	2008	Turkish	Caucasian	CP	PB	51	32	4	67	37	3	47.1	3.7	PCR	0.43	6

CP = chronic periodontitis, AgP = aggressive periodontitis, NA = not available, HB = hospital-based, PB = population-based.

P^# for Hardy-Weinberg equilibrium, *Only allele number available in controls.