Interestingly, when using ratios, the diagnostic potential increased with MMP-8/TIMP-1 (AUC of 0.986, p value = 0.0001) and MMP-9/TIMP-1 (AUC of 1.000, p value = 0.0001) between periodontal health and periodontitis. The gene discussed is MMP9; the disease is periodontitis.