FGD5 and periodontitis: The ROC curve for diagnosis of chronic periodontitis revealed that the area under the lncRNA FGD5-AS1 curve was 0.835 and the best specificity and sensitivity were 88.51% and 72.22%, respectively, when the cut-off point was 0.805; the area under the miR-130a curve was 0.851 and the best specificity and sensitivity were 80.46% and 77.78%, respectively, when the cut-off point was 1.227; and the area under the joint detection curve was 0.929 and the best specificity and sensitivity were 80.46% and 90.28%, respectively, when the cut-off point was 0.321 (Figure 1, Table 3).