In an extensive body of case-control studies and meta-analyses, the functional SNPs in MMP8 have been shown to associate with the risk and progression of diseases such as colorectal and breast cancers [22,23,24], atherosclerosis [16], hypertension [19], bronchial asthma [26], osteoarthritis [27], and several oral pathological conditions such as periodontitis [5,17,18,28,29,30,31], gingivitis, caries, peri-implantitis and early implant failure [2,32]. This evidence concerns the gene MMP8 and periodontitis.