Effect of Corticopuncture (CP), Photobiomodulation (PBM) and the Combined Method on the Rate of Tooth Movement and Root Resorption: A Molecular, Histological and Micro-CT Study in Animals
- Author(s): Torres, Martha Carolina
- Advisor(s): Ting, Kang
- et al.
Introduction: Orthodontic treatment time on average lasts 24 months. The long duration of the treatment is one of the most frequent complaints of patients. Moreover, the risks associated include caries, root resorption, decalcification, periodontal disease, and others. For this reason, there is pressing need to develop new methods to accelerate orthodontic tooth movement. The Corticopuncture (CP), Photobiomodulation (PBM) and the combination of both methods have shown in prior studies significant results of increasing tooth displacement. Based on these data, we hypothesize that CP, PBM and CP+PBM can enhance alveolar bone remodeling, rate of tooth movement and minimize root resorption by stimulating metabolic changes and cellular differentiation. I tested my hypothesis through four aims: (1) to assess the rate of tooth displacement on days 1,3 and 7; (2) to investigate the expression levels on days 1,3 and 7; (3) to analyze the changes on bone remodeling on days 1,3 and 7; and (4) to asses root resorption crater volume after 7 days. Methods: Orthodontic tooth movement was induced in 27 male Wistar rats. CP procedure included 3 perforations. GaAlAs diode laser was performed every other day for 7 days (810 nm, 100 mW, 15 s). Gingival tissue was collected and qPCR to isolate and quantify mRNA levels. The tooth displacements were measured directly from rat’s mouth. Bone responses at the tension and compression sites and root resorption were evaluated from micro-CT images. Hemi-maxillae from all groups were dissected and prepared for histological and immunohistochemistry analysis. Results and conclusions: Our findings suggest that all (1) ATM groups showed increase tooth displacement compared to control after 7 days (30% PBM, 45% CP and 58% CP+PBM); (2) all ATM groups showed less RR volume compared to the control group; (4) PBM showed a more significant role in increasing bone formation and CP showed a more significant role in catabolic activity; (5) CP+PBM illustrated synergic effects; (6) higher expression of VEGF, Prx1 and GLUT1 found in all methods; (7) and that PBM can enhance tooth movement by stimulating the RANK/RANKL/OPG system.