Tropical Journal of Pharmaceutical Research

Original Research Article | OPEN ACCESS

Anti-resorptive effects of cementocytes during orthodontic tooth movement

Yufei Xie^1-3, Ning Zhao^1-3 , Gang Shen^1-3

¹Department of Orthodontics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine; ¹Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology; ³National Clinical Research Center of Stomatology, Shanghai, China.

For correspondence:- Ning Zhao Email: zhaon1995@126.com

Accepted: 25 October 2018 Published: 30 November 2018

Citation: Xie Y, Zhao N, Shen G. Anti-resorptive effects of cementocytes during orthodontic tooth movement. Trop J Pharm Res 2018; 17(11):2291-2298 doi: 10.4314/tjpr.v17i11.26

© 2018 The authors.
This is an Open Access article that uses a funding model which does not charge readers or their institutions for access and distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0) and the Budapest Open Access Initiative (http://www.budapestopenaccessinitiative.org/read), which permit unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited..

Abstract

Purpose: To investigate the mechanism involved in the anti-resorptive effect of cementocytes during orthodontic tooth movement in mice and human specimens.

Methods: The morphology, molecular structure and biological expression of cellular cementum in mice and human samples were examined using hematoxylin and eosin staining, immuno-histochemical staining, scanning electron microscopy, and Raman spectroscopy. The expressions of osteoprotegerin (OPG), receptor activator of nuclear κB ligand (RANKL) and sclerostin (SOST) encoding genes in cementocytes and alveolar bone osteocytes were evaluated by quantitative real-time polymerase chain reaction (qRT-PCR).

Results: Results demonstrated that cementocyte lacunae were larger and more irregular in shape than the regular ellipsoid osteocyte lacunae. The ratio of phosphate to amino acid was significantly lower in cellular cementum than that in alveolar bone and dentin. In mice, OPG/RANKL ratio was significantly higher in cementocytes (4.8 ± 0.37) than in alveolar bone osteocytes (0.17 ± 0.42) in natural state. In humans, OPG/RANKL ratio was 1.41 ± 0.07 in cementocytes and 0.71 ± 0.04 in alveolar bone osteocytes under natural conditions, and 37.69 ± 0.15 in cementocytes and 1.95 ± 0.83 in alveolar bone osteocytes applying fluid flow shear stress. Moreover, SOST was extremely low expressed under force application in cementocytes.

Conclusion: Under fluid flow sheer stress, cementocytes stimulate the differentiation of osteoblasts and inhibit the activation of osteoclasts, showing greater potential for bone protection than alveolar bone osteocytes. Cementocytes might play an important role in preventing root resorption in the process of orthodontic tooth movement.

Keywords: Cementocytes, Bone protection, Microfluidic chip, Orthodontic tooth movement