Dynamic measurement of orthodontic force using a tooth movement simulation system based on a wax model

2020 ◽  
pp. 1-11
Author(s):  
Jianlei Wu ◽  
Yunfeng Liu ◽  
Dongcai Wang ◽  
Senda Huang ◽  
Jianxing Zhang ◽  
...  

BACKGROUND: Orthodontic force is often statically measured in general, and only the initial force derived from appliances can be assessed. OBJECTIVE: We aimed to investigate a technological method for measuring dynamic force using tooth movement simulation. METHODS: Tooth movement was simulated in a softened wax model. A canine tooth was selected for evaluation and divided into the crown and root. A force transducer was plugged in and fixed between the two parts for measuring force. Forces on this tooth were derived by ordinary nickel-titanium (Ni-Ti) wire, hyperelastic Ni-Ti wire, low-hysteresis (LH) Ti-Ni wire and self-made glass fibre-reinforced shape memory polyurethane (GFRSMPU) wire. These forces were measured after the tooth movement. RESULTS: The canine tooth moved to the desired location, and only a 0.2 mm deviation remained. The changing trends and magnitudes of forces produced by the wires were consistent with the data reported by other studies. The tooth had a higher moving velocity with ordinary Ni-Ti wires in comparison to the other wires. Force attenuation for the GFRSMPU wire was the lowest (40.17%) at the end of the test, indicating that it provided light but continuous force. CONCLUSIONS: Mimicked tooth movements and dynamic force measurements were successfully determined in tooth movement simulation. These findings could help with estimating treatment effects and optimising the treatment plan.

2021 ◽  
pp. 002203452110199
Author(s):  
Y. Xie ◽  
Q. Tang ◽  
S. Yu ◽  
W. Zheng ◽  
G. Chen ◽  
...  

Orthodontic tooth movement (OTM) depends on periodontal ligament cells (PDLCs) sensing biomechanical stimuli and subsequently releasing signals to initiate alveolar bone remodeling. However, the mechanisms by which PDLCs sense biomechanical stimuli and affect osteoclastic activities are still unclear. This study demonstrates that the core circadian protein aryl hydrocarbon receptor nuclear translocator–like protein 1 (BMAL1) in PDLCs is highly involved in sensing and delivering biomechanical signals. Orthodontic force upregulates BMAL1 expression in periodontal tissues and cultured PDLCs in manners dependent on ERK (extracellular signal–regulated kinase) and AP1 (activator protein 1). Increased BMAL1 expression can enhance secretion of CCL2 (C-C motif chemokine 2) and RANKL (receptor activator of nuclear factor–κB ligand) in PDLCs, which subsequently promotes the recruitment of monocytes that differentiate into osteoclasts. The mechanistic delineation clarifies that AP1 induced by orthodontic force can directly interact with the BMAL1 promoter and activate gene transcription in PDLCs. Localized administration of the ERK phosphorylation inhibitor U0126 or the BMAL1 inhibitor GSK4112 suppressed ERK/AP1/BMAL1 signaling. These treatments dramatically reduced osteoclastic activity in the compression side of a rat orthodontic model, and the OTM rate was almost nonexistent. In summary, our results suggest that force-induced expression of BMAL1 in PDLCs is closely involved in controlling osteoclastic activities during OTM and plays a vital role in alveolar bone remodeling. It could be a useful therapeutic target for accelerating the OTM rate and controlling pathologic bone-remodeling activities.


1996 ◽  
Vol 23 (3) ◽  
pp. 241-248 ◽  
Author(s):  
Dan Lundgren ◽  
Py Owman-Moll ◽  
Jüri Kurol ◽  
Birgit Mårtensson

This study was designed to test the accuracy of measurement methods for assessment of force and tooth movement in orthodontic procedures. Daily in vivo measurements of the force produced by activated archwires showed that the initial force declined substantially (by 20 per cent of mean value) within 3 days. Both the ‘trueness’ (validity) and precision of the force measurements, obtained with a strain gauge, were found to be high (SD values were 1·0 cN and 0·4 cN, respectively). Horizontal tooth movements were measured with three different instruments: a slide calliper, a co-ordinate measuring machine, and laser measuring equipment based on holograms. There was a good level of agreement between these methods. This was also confirmed by calibration data. The precision of the methods was (SD values) 0·06, 0·07, and 0·13 mm, respectively. The benefits of the use of the co-ordinate measuring machine are obvious, since it can measure tooth movements in relation to reference planes in all directions.


2016 ◽  
Vol 19 (2) ◽  
pp. 83-92 ◽  
Author(s):  
K. Arita ◽  
H. Hotokezaka ◽  
M. Hashimoto ◽  
T. Nakano-Tajima ◽  
T. Kurohama ◽  
...  

2019 ◽  
Vol 8 (7) ◽  
pp. 2373
Author(s):  
PoonamK Jayaprakash ◽  
Rajeshwar Singh ◽  
Ankit Yadav ◽  
Meeta Dawar ◽  
Harpreet Grewal ◽  
...  

2021 ◽  
pp. 53-59
Author(s):  
Ajit Vikram Parihar ◽  
Shishupal Meena

Background: The purpose of this systematic review was to examine the available evidence of root resorption during orthodontic treatment with different force systems using nite element analysis. Methods: The following electronic databases were searched for literature till June 2021 : Pro-Quest Dissertation Abstracts and Thesis database, Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Google Scholar, Embase, US National Library of Medicine, and National Research Register. Root resorption studied under orthodontic forces, which simulated under various technique of nite element method (3D FEM) models were included in the study. The selected studies were assessed for the risk of bias using the Cochrane Collaboration risk of bias tool. The “trafc plot” and “weighted plot” risk of bias distribution were designed using the ROBVIS tool. The authors extracted and analyzed the data. Results: Fourteen studies fullled the inclusion criteria. The risks of biases were high for all studies.Data on quantity and direction of force applied, different type of root morphology and its various surface inuence on root resorption were extracted. The outcomes of the included studies were heterogeneous. Conclusion: Based on the current available literature, for reducing root resorption the excessive force may accelerate root resorption when it exceeds the typical human capillary blood pressure. Root resorption occurs more when extrusion/intrusion and tipping occur than when teeth actually move. A tooth with little or no orthodontic force load hardly shows any root resorption compared to one that has orthodontic force.


2018 ◽  
Vol 88 (6) ◽  
pp. 733-739 ◽  
Author(s):  
Nurhat Ozkalayci ◽  
Ersan Ilsay Karadeniz ◽  
Selma Elekdag-Turk ◽  
Tamer Turk ◽  
Lam L. Cheng ◽  
...  

ABSTRACT Objectives: To compare the extent of root resorption and the amount of tooth movement between continuous orthodontic force and intermittent orthodontic force that was activated in a similar way to a 4-week orthodontic adjustment period. Materials and Methods: Twenty-five patients who required the extraction of upper first premolars were recruited in this study. A buccally directed continuous force of 150 g was applied to the upper first premolar on one side for 15 weeks. A buccally directed intermittent force (28 days on, 7 days off) of the same magnitude was applied to the contralateral first premolar. The teeth were extracted at the end of the experimental period and processed for volumetric evaluations of resorption craters. The degree of tooth movement and rotation were measured on the study models. Results: Continuous force application displayed significantly higher root resorption volume than the intermittent force application (P < .05), particularly on the buccal and lingual surfaces (P < .05) and the middle third of the root (P < .01). There was more tipping and rotational movement in the continuous force group. Conclusions: In a 4-week orthodontic adjustment period, intermittent force significantly reduced the amount of root resorption compared with continuous force. Although there was less degree of tooth movement with intermittent force, unwanted rotational movement was avoided. This is crucial in patients who are predisposed to orthodontically induced inflammatory root resorption, and the use of this intermittent regimen should be considered.


Author(s):  
Jingang Jiang ◽  
Houjun Chen ◽  
Zhiyuan Huang ◽  
Xuefeng Ma ◽  
Yongde Zhang ◽  
...  

Malocclusion has been seriously endangering human oral function. The most effective and mature therapy is orthodontic treatment. But the relationship between the shape of the T-loop and the orthodontic force is unclear, and the precise mathematical model has not been established. In this article, the dynamic orthodontic force prediction model of the T-loop was established by analyzing the treatment process of the T-loop. The model was based on the dynamic resistance model of waxy dental jaw, the theory of beam deformation, and the deformation characteristics of the T-loop. In the experimental process, 11 kinds of orthodontic archwires were used as experimental samples, including 2 kinds of common archwire materials, 7 kinds of cross-sectional sizes, and 10 kinds of clearance distances. The T-loop was put into the extraction space and immersed in 75°C constant temperature water for 2 min. And the experimental data were measured and collected by the dynamic force measuring device. The experimental results show that the cross-sectional size and the clearance distance are positively correlated with the orthodontic force. The influence of the clearance distance on the orthodontic force is greater than that of the cross-section size. The deviation rates between the experimental values of orthodontic force and the theoretical values are between 1.10% and 9.09%, which verifies the accuracy of the dynamic orthodontic force prediction model. The model can predict the orthodontic force, improve the treatment effect, shorten the treatment cycle, and provide reference and guidance for orthodontists to carry out orthodontic treatment safely and effectively.


Author(s):  
Kaoru Igarashi ◽  
Kotaro Miyoshi ◽  
Hisashi Shinoda ◽  
Shuichi Saeki ◽  
Hideo Mitani

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