IL1B and periodontal disorder: In total analysis, non-significant correlation was observed between IL-1β rs1143627 polymorphism and periodontal disease susceptibility under all 5 genetic models [T vs. C: odds ratio (OR) = 0.92, 95% confidence interval (CI) = 0.81-1.12, I2= 0% (Figure 2); TT vs. CC: OR = 1.22, 95% CI = 0.80-1.87, I2= 13.32%; CT vs. CC: OR = 0.92, 95% CI = 0.69-1.23, I2= 0%; CT+TT vs. CC: OR = 0.66, 95% CI = 0.44-1.01, I2= 57.8%; TT vs. CT + CC: OR = 1.19, 95% CI = 0.81-1.74, I2= 38.91%].