Interleukin-20 Acts as a Promotor of Osteoclastogenesis and Orthodontic Tooth Movement

Figure 6

(a) OTM + IL-20 group: during the application of orthodontic force, an IL-20 solution with a concentration of 40 mg/kg body weight was injected at 2-day intervals. Seven days after the application of orthodontic force, micro-CT showed larger gaps between first and second molars. (b) Micro-CT measurement revealed that the gap between the first and second molars was significantly greater in the OTM + IL-20 group than in the OTM group. Bars represent the of three independent experiments (). vs. OTM group; ns: not significant. (c) Control group: no orthodontic force was applied, and 0.9% saline alone was injected at 2-day intervals. Micro-CT showed no obvious gap between first and second molars. (d and f) HE staining showed significant changes in first molar periodontal ligament thickness. (e) OTM group: during the application of orthodontic force, 0.9% saline was injected at 2-day intervals. Seven days after the application of orthodontic force, micro-CT showed obvious gaps between first and second molars. (g) Double-labelled immunofluorescence staining showed that, in the context of orthodontic force, the expression levels of TRAP and YAP increased in the first molar periodontal ligament; both showed high expression in the region near IL-20 expression. (h) There was no significant change in the periodontal ligament in the control group. (i) HE staining was used to measure the periodontal ligament on the compressed and traction sides of the first molar in the control and OTM groups. The periodontal ligament thickness in the OTM group was significantly thinner on the compressed side than on the traction side. Bars represent the of three independent experiments (). vs. OTM group; N.S.: not significant.

(a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)

(i)