As Table 1 shows, the pooled ORs for the association between alleles and genotypes of IL−1A (−889) polymorphism and the risk of dental PID were 1.19 (95% CI: 0.92, 1.55; p = 0.19; I2 = 0%) for allelic, 1.18 (95% CI: 0.62, 2.55; p = 0.61; I2 = 0%) for homozygous, 1.45 (95% CI: 0.97, 2.16; p = 0.07; I2 = 0%) for heterozygous, 1.43 (95% CI: 0.98, 2.10; p = 0.07; I2 = 0%) for recessive, and 1.02 (95% CI: 0.64, 1.63; p = 0.94; I2 = 0%) for dominant models. The gene discussed is IL1A; the disease is pelvic inflammatory disease.