Inhibitory effect of exogenous IL-4 on orthodontic relapse in rats

Objective Interleukin-4 is proven to regulate bone metabolism. This study aimed to assess the effect of exogenous interleukin-4 on orthodontic relapse. Materials and methods Bilateral maxillary first molars of 25 male Sprague Dawley rats were moved mesially for 3 weeks using orthodontic appliances an activating force of 50 g. After tooth movement, exogenous interleukin-4 was injected into the buccal and palatine sides of the right maxillary first molars (experimental group), and phosphate-buffered saline was injected at the same sites on the left side (negative control group). At the end of the study, the relapse distance between the mesial fissure of the first molar and the distal fissure of the second molar was measured. Three different histological stains were used to visualize the changes in the periodontium. Results After interleukin-4 injection, the relapse distance significantly reduced. Time-dependent effects played a more important role than the dose-dependent effects, and there was no correlation between these factors. Tissue staining showed that interleukin-4 reduced osteoclastogenesis and promoted osteoblastogenesis. Conclusion Exogenous interleukin-4 reduced the relapse of orthodontically treated teeth by promoting osteoblastogenesis and inhibiting osteoclastogenesis. Our findings can potentially benefit specialists in the future by improving their patients' treatment outcomes.

Automated summary

Exogenous interleukin-4 was found to reduce orthodontic relapse by promoting osteoblastogenesis and inhibiting osteoclastogenesis. Time-dependent effects were more significant than dose-dependent effects, with no correlation between the two. The study's findings could potentially benefit specialists by improving treatment outcomes for their patients.