This work demonstrated that ligature-induced periodontitis induced neuroinflammation via the activation of STAT3, as the levels of inflammatory factors were increased as well as the activated state of microglia and astrocytes were found in the hippocampus and cortex, while these changes could be alleviated by pSTAT3 inhibitor CTS (Figs. 6 and 7). This evidence concerns the gene STAT3 and periodontitis.