Effects of a doubled orthodontic force magnitude on tooth movement and root resorptions. An inter-individual study in adolescents

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.

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Effect of orthodontic force magnitude on cytokine networks in gingival crevicular fluid: a longitudinal randomized split-mouth study

European Journal of Orthodontics ◽

10.1093/ejo/cjy068 ◽

2018 ◽

Vol 41 (2) ◽

pp. 214-222 ◽

Cited By ~ 2

Author(s):

Beral Afacan ◽

Veli Özgen Öztürk ◽

Mine Geçgelen Cesur ◽

Timur Köse ◽

Nagihan Bostanci

Keyword(s):

Gingival Crevicular Fluid ◽

Orthodontic Force ◽

Force Magnitude ◽

Cytokine Networks ◽

Crevicular Fluid

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Effects of diabetes on tooth movement and root resorption after orthodontic force application in rats

Orthodontics and Craniofacial Research ◽

10.1111/ocr.12117 ◽

2016 ◽

Vol 19 (2) ◽

pp. 83-92 ◽

Cited By ~ 13

Author(s):

K. Arita ◽

H. Hotokezaka ◽

M. Hashimoto ◽

T. Nakano-Tajima ◽

T. Kurohama ◽

...

Keyword(s):

Tooth Movement ◽

Root Resorption ◽

Orthodontic Force ◽

Force Application

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Evaluation of levels of Interleukin-1b, intensity of pain and tooth movement during canine retraction using different magnitudes of continuous orthodontic force

Journal of Family Medicine and Primary Care ◽

10.4103/jfmpc.jfmpc_357_19 ◽

2019 ◽

Vol 8 (7) ◽

pp. 2373

Author(s):

PoonamK Jayaprakash ◽

Rajeshwar Singh ◽

Ankit Yadav ◽

Meeta Dawar ◽

Harpreet Grewal ◽

...

Keyword(s):

Tooth Movement ◽

Orthodontic Force ◽

Canine Retraction

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FINITE ELEMENT ANALYSIS OF ROOT RESORPTION ASSOCIATED WITH TOOTH MOVEMENT: A SYSTEMATIC REVIEW”

10.36106/ijsr/6801719 ◽

2021 ◽

pp. 53-59

Author(s):

Ajit Vikram Parihar ◽

Shishupal Meena

Keyword(s):

Systematic Review ◽

Tooth Movement ◽

Root Resorption ◽

Cochrane Collaboration ◽

Risk Of Bias ◽

Cochrane Central Register ◽

3D Fem ◽

Element Analysis ◽

Orthodontic Force ◽

Nite Element

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.

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Effect of continuous versus intermittent orthodontic forces on root resorption: A microcomputed tomography study

The Angle Orthodontist ◽

10.2319/012518-68.1 ◽

2018 ◽

Vol 88 (6) ◽

pp. 733-739 ◽

Cited By ~ 4

Author(s):

Nurhat Ozkalayci ◽

Ersan Ilsay Karadeniz ◽

Selma Elekdag-Turk ◽

Tamer Turk ◽

Lam L. Cheng ◽

...

Keyword(s):

Tooth Movement ◽

Root Resorption ◽

Experimental Period ◽

Microcomputed Tomography ◽

Orthodontic Force ◽

Rotational Movement ◽

Force Application ◽

Orthodontic Forces ◽

Intermittent Regimen

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.

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