Biological effects of orthodontic tooth movement into the grafted alveolar cleft

Publication date: Available online 24 August 2017
Source:Journal of Oral and Maxillofacial Surgery
Author(s): Jian Sun, Xiaoyue Zhang, Renmei Li, Zhengxi Chen, Yuanliang Huang, Zhenqi Chen
ObjectiveFunctional stimulus as orthodontic tooth movement into the grafted bone can lead to better ABG outcomes. The aim of this study was to analyze the biological effects of orthodontic tooth movement in the grafted alveolar cleft area using histological staining, fluorescence staining, and Real-time PCR.MethodThe animal model of orthodontic tooth movement into the grafted alveolar cleft area was established in 8-week-old SD rats. Animals were divided into the experimental group and the control group. Four checkpoints were observed as follows: before orthodontic stimuli, day 1 after orthodontic stimuli, day 3 after orthodontic stimuli, and day 5 after orthodontic stimuli. The cleft bone formation conditions, including the collagen fibers and the activities of the osteoclasts and osteoblasts were evaluated by histological staining respectively. The expression of TRAP / RANKL / RUNX2 were detected by Real-time PCR in both groups.ResultHE staining showed that the remodeling process of iliac autografts was completed when the orthodontic stress was applied whilst the bone tissues first revealed osteoclastogenesis and then osteogenesis. On the basis of TRAP staining, the osteoclasts increased to the maximal amount on Day 3 before it decreased afterwards. Evidence from the tetracycline fluorescence staining indicated that no obvious changes in the osteoblast activity were detected at the early stage, however, it gradually increased, especially in the region close to the root surface. According to Real-time PCR, the expression of TRAP increased in both the early and middle stages, RANKL increased at the early stage while RUNX2 increased at the late stage. Moreover, the results revealed significant differences between the experimental and control groups.ConclusionOrthodontic tooth movement into the alveolar cleft bone graft area promoted bone remodeling of embedded bone, thus induced bone resorption and subsequent deposition.



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