TNFRSF11B and periodontitis: After periodontitis treatment, the total OPG levels increased (82.66 pg/mL) when compared with those detected at the periodontitis examination (47.49 pg/mL, p = 0.005) and remained increased during the entire orthodontic treatment: 1 week (88.60 pg/mL, p = 0.001), 1 month (91.32 pg/mL, p < 0.001), 3 months (93.35 pg/mL, p < 0.001), 6 months (104.02 pg/mL, p = 0.004), 12 months (98.29 pg/mL, p = 0.008), 18 months (95.91 pg/mL, p = 0.002), and 24 months (94.81 pg/mL, p = 0.008) (Figure 2a).