Table 2. Meta-analysis of associations between MTHFR C677T, A1298C polymorphisms and OSCC risk using the additive, dominant, recessive model.

SNP	Comparison	OR with 95%CI	Heterogeneity			Publication Bias
			χ2	Q test	I2	Begg	Egger
C677T
Overall	T vs C	1.35 (1.04–2.24)	41.4	<0.01	73.4%	0.83	0.34
	TT vs CT	1.14 (0.82–1.58)	10.6	0.48	0.00%	0.63	0.94
	TT vs CC	1.79 (1.28–2.50)	16.5	0.123	33.5%	0.73	0.98
	CT vs CC	1.45 (1.02–2.08)	40.2	<0.01	72.1%	0.78	0.93
	TT vs CT+CC	1.40 (0.73–2.48)	37.1	<0.01	17.3%	0.58	0.53
	CT+TT vs CC	1.43 (1.02–1.99)	37.3	<0.01	70.5%	0.83	0.44
Asian	T vs C	1.59 (0.91–2.78)	21.6	<0.01	81.0%	0.62	0.52
	TT vs CT	1.55 (0.87–2.78)	0.91	0.92	0.00%	1.00	0.83
	TT vs CC	2.65 (1.51–4.64)	0.75	0.95	0.00%	0.62	0.42
	CT vs CC	1.52 (0.76–3.03)	21.4	<0.01	81.5%	0.62	0.54
	TT vs CT+CC	2.44 (1.42–4.21)	1.07	0.90	0.00%	0.62	0.81
	CT+TT vs CC	1.23 (0.63–2.43)	22.8	<0.01	82.1%	0.14	0.14
European	T vs C	1.33 (1.02–1.75)	8.76	0.07	54.5%	0.22	0.07
	TT vs CT	1.06(0.69–1.64)	5.60	0.23	29.3%	0.46	0.32
	TT vs CC	1.72 (0.85–3.50)	9.06	0.06	55.8%	0.80	0.82
	CT vs CC	1.64 (0.97–2.78)	26.2	<0.01	84.8%	0.08	0.10
	TT vs CT+CC	1.12 (0.38–3.85)	4.67	0.458	0.00%	1.00	0.53
	CT+TT vs CC	1.82 (0.99–3.33)	10.6	0.03	26.1%	0.80	0.98
A1298C
Overall	C vs A	0.91 (0.71–1.17)	6.08	0.05	67.1%	0.60	0.57
	CC vs AA	0.68 (0.30–1.54)	0.22	0.90	0.00%	0.60	0.94
	CC vs AC	0.64 (0.35–1.19)	0.73	0.70	0.00%	0.12	0.15
	AC vs CC	1.06 (0.74–1.51)	6.91	0.03	71.0%	0.60	0.79
	CC vs AC+AA	0.66 (0.27–1.58)	0.05	0.97	0.00%	0.60	0.67
	CC+AC vs AA	1.22 (0.65–2.26)	4.70	<0.10	81.7%	0.12	0.78