Does local injection of reveromycin A inhibit tooth movement without causing systemic side effects?

Effects of coenzyme Q10 on orthodontic tooth movement and alveolar bone remodeling in rats

OBJECTIVES

To evaluate the effects of coenzyme Q10 (CoQ10) on alveolar bone remodeling and orthodontic tooth movement (OTM).

MATERIALS AND METHODS

An orthodontic appliance was placed in 42 female Sprague‒Dawley rats were divided into two groups: the orthodontic force (OF) group (n = 21) and the OF + CoQ10 (CoQ10) treatment group (n = 21). Each group was divided into 3 subgroups, and the rats were sacrificed on days 3, 7 and 14. The rats in CoQ10 and OF groups were administered 100 mg/kg b.w./day CoQ10 (in 1 mL/b.w. soybean oil) and 1 mL b.w./day soybean oil, respectively, by orogastric gavage. The OTM was measured at the end of the experiment. The osteoclast, osteoblast and capillary numbers; vascular endothelial growth factor (VEGF), receptor activator nuclear kappa B ligand (RANKL) and osteoprotegrin (OPG) levels in tissue; and total antioxidant status (TAS) and total oxidant status (TOS) in blood were determined.

RESULTS

Compared with the OF group, the CoQ10 treatment group exhibited decreased orthodontic tooth movement and osteoclast and capillary numbers. Indeed, the levels of VEGF and RANKL decreased, while the levels of OPG increased except on day 7. Additionally, the CoQ10 treatment group exhibited lower TOS and higher TAS on days 7 and 14 (p < 0.05). Histological findings showed that the morphology of osteoblasts changed in the CoQ10 group; however, there was no significant difference in the number of osteoblasts between the groups (p > 0.05).

CONCLUSION

Due to its effect on oxidative stress and inflammation, CoQ10 regulates bone remodeling by inhibiting osteoclast differentiation, promoting osteoblast differentiation and reducing the amount of OTM.

CLINICAL RELEVANCE

Considering that OTM may be slowed with the use of CoQ10, topics such as orthodontic treatment duration, orthodontic force activation and appointment frequency should be considered in treatment planning. It is predicted that the use of CoQ10 will support the effectiveness of treatment in clinical applications such as preventing relapse in orthodontic treatment by regulating bone modulation and anchorage methods that suppress/optimize unwanted tooth movement.

Periodontal ligament and alveolar bone remodeling during long orthodontic tooth movement analyzed by a novel user-independent 3D-methodology

The structural process of bone and periodontal ligament (PDL) remodeling during long-term orthodontic tooth movement (OTM) has not been satisfactorily described yet. Although the mechanism of bone changes in the directly affected alveolar bone has been deeply investigated, detailed knowledge about specific mechanism of PDL remodeling and its interaction with alveolar bone during OTM is missing. This work aims to provide an accurate and user-independent analysis of the alveolar bone and PDL remodeling following a prolonged OTM treatment in mice. Orthodontic forces were applied using a Ni-Ti coil-spring in a split-mouth mice model. After 5 weeks both sides of maxillae were scanned by high-resolution micro-CT. Following a precise tooth movement estimation, an extensive 3D analysis of the alveolar bone adjacent to the first molar were performed to estimate the morphological and compositional parameters. Additionally, changes of PDL were characterized by using a novel 3D model approach. Bone loss and thinning, higher connectivity as well as lower bone mineral density were found in both studied regions. Also, a non-uniformly widened PDL with increased thickness was observed. The extended and novel methodology in this study provides a comprehensive insight about the alveolar bone and PDL remodeling process after a long-duration OTM.

Dynamics and observations of long-term orthodontic tooth movement and subsequent relapse in C57BL/6 mice

The risk of relapse associated with orthodontic treatment is a major problem. Despite extensive research and discussion regarding the risk of orthodontic relapse, the underlying mechanisms remain to be elucidated. This study aimed to evaluate relapse following orthodontic treatment in mice (C57BL/6) tested via the coil spring method based on tooth movement at 21 days and mechanical retention at 7 days after completion of the procedure. During the experiment, relapse was observed and evaluated over 7 days. At the end of orthodontic tooth movement, the average distance was 259.6 (± 10.9) µm, and tooth movement was observed in all mice. No significant differences in distance were observed at the end of the experimental treatment period or after 7 days of mechanical retention. The distance at the start of observation was 258.6 (± 10.4) µm, whereas that at the end was 155.4 (± 12.4) µm, indicating that the distance had decreased significantly. Relative to the total relapse distance over the 7-day period, 45.7 (± 4.3)% of the relapse was observed on Day 0-1. The mouse model established in the current study provides an effective and reproducible method for the optimal evaluation of relapse. Our findings clarified that most of the relapse occurs within 7 days during the initial observation stage.

[68Ga]Ga-Pentixafor and Sodium [18F]Fluoride PET Can Non-Invasively Identify and Monitor the Dynamics of Orthodontic Tooth Movement in Mouse Model

The cellular and molecular mechanisms of orthodontic tooth movement (OTM) are not yet fully understood, partly due to the lack of dynamical datasets within the same subject. Inflammation and calcification are two main processes during OTM. Given the high sensitivity and specificity of [⁶⁸Ga]Ga-Pentixafor and Sodium [¹⁸F]Fluoride (Na[¹⁸F]F) for inflammation and calcification, respectively, the aim of this study is to assess their ability to identify and monitor the dynamics of OTM in an established mouse model. To monitor the processes during OTM in real time, animals were scanned using a small animal PET/CT during week 1, 3, and 5 post-implantation, with [⁶⁸Ga]Ga-Pentixafor and Na[¹⁸F]F. Both tracers showed an increased uptake in the region of interest compared to the control. For [⁶⁸Ga]Ga-Pentixafor, an increased uptake was observed within the 5-week trial, suggesting the continuous presence of inflammatory markers. Na[¹⁸F]F showed an increased uptake during the trial, indicating an intensification of bone remodelling. Interim and end-of-experiment histological assessments visualised increased amounts of chemokine receptor CXCR4 and TRAP-positive cells in the periodontal ligament on the compression side. This approach establishes the first in vivo model for periodontal remodelling during OTM, which efficiently detects and monitors the intricate dynamics of periodontal ligament.