We then performed stratified analysis by ethnicity and found a significant association between the MMP-2 -753C>T polymorphism and periodontitis risk in the Asians under the allele model (T vs. C, OR=0.766, 95% C=0.590–0.996, P=0.046) and the recessive mode (TT vs. TC+CC, OR=0.587, 95% CI=0.320–1.237, P=0.002), but not in Caucasian populations. The gene discussed is MMP2; the disease is periodontitis.