The effect of corticotomy on the compensatory remodeling of alveolar bone during orthodontic treatment.

BACKGROUND

This study aimed to explore whether compensatory remodeling of the alveolar bone surface occurred during the buccal palatal movement of orthodontic teeth. We preliminarily explored whether corticotomy could activate or accelerate osteogenesis in the alveolar bone surface by measuring the expression of TGF-β1 (transforming growth factor-β1), which can facilitate the proliferation and differentiation of osteoblasts and regulate the maturity and formation of bone.

METHODS

Sixty 10-week-old male Wistar rats were selected. In the orthodontic group, 20 rats were implanted with a constriction device between the maxillary first molars under general anesthesia. In the corticotomy group, 20 rats were implanted with a constriction device, and a palatal incision was made to penetrate the cortical bone. In the control group, 20 rats underwent no experimental operation except general anesthesia. After 1, 3, 5 and 7 days, the maxillary first molars and the surrounding alveolar bone were harvested, and coronal sections containing the apical mesial buccal root were prepared and observed using tetracycline fluorescence, HE staining and immunohistochemical staining for TGF-β1. Image-Pro Plus software was used to assess the immunohistochemical results, and SPSS 22.0 statistical software was used to analyze variance and perform the LSD test.

RESULTS

The tetracycline fluorescence results showed that in the periosteum near the apical region, an obvious fluorescence signal was observed in the orthodontic group and the corticotomy group compared with the control group. In the orthodontic group and corticotomy group, HE staining showed that the morphology was similar to cube-shaped. The immunohistochemical results showed that TGF-β1 was significantly increased in the periosteum near the apical region in the orthodontic group and corticotomy group, and there were significant differences among the three groups. In addition, the expression of TGF-β1 in the periosteum in the orthodontic group and the corticotomy group gradually increased over time, reaching a peak on day 5 and slightly decreasing on day 7.

CONCLUSION

Osteogenesis occurred on the alveolar bone surface during the buccal palatal movement of orthodontic teeth, and corticotomy had a positive effect, and TGF-β1 was involved in this process.