These were in line with a report by Okamoto et al. (20), in which it was shown that during orthodontic treatment with periodontitis, PGE2 is increased and that PGE2 can inhibit RANKL release from fibroblasts by blocking the Ras/Raf/ERK signaling pathway, which is not only activated by orthodontic force but can also promote OPG release, in turn inhibiting the differentiation and maturation of osteoclasts. This evidence concerns the gene TNFSF11 and periodontitis.