Compressive stress in periodontal ligament under orthodontic movements during periodontal breakdown

2021 ◽  
Vol 159 (3) ◽  
pp. e291-e299
Author(s):  
Radu Andrei Moga ◽  
Stefan Marius Buru ◽  
Cosmin Gruia Chiorean ◽  
Raluca Cosgarea
Keyword(s):  
Compressive Stress ◽  
Periodontal Ligament ◽  
Periodontal Breakdown

scholarly journals An Analysis of the Stress Induced in the Periodontal Ligament during Extrusion and Rotation Movements: A Finite Element Method Linear Study Part I

2015 ◽  
Vol 16 (9) ◽  
pp. 740-743 ◽  
Author(s):  
HP Raghuveer ◽  
M Hemanth ◽  
MS Rani ◽  
Chathura Hegde ◽  
B Vedavathi ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Compressive Stress ◽  
Periodontal Ligament ◽  
Tooth Movement ◽  
Root Resorption ◽  
Orthodontic Tooth Movement ◽  
3D Fem ◽  
Force System ◽  
Element Method

ABSTRACT Background Orthodontic tooth movement occurs due to various biomechanical changes in the periodontium. Forces within the optimal range yield maximum tooth movement with minimum deleterious effects. Among various types of tooth movements, extrusion and rotational movements are seen to be associated with the least amount of root resorption and have not been studied in detail. Therefore in this study, the stress patterns in the periodontal ligament (PDL) were evaluated with extrusion and rotational movements using the finite element method FEM. Materials and methods A three-dimensional (3D) FEM model of the maxillary incisors was generated using SOLIDWORKS modeling software. Stresses in the PDL were evaluated with extrusive and rotational movements by a 3D FEM using ANSYS software with linear material properties. Results It was observed that with the application of extrusive load, the tensile stresses were seen at the apex, whereas the compressive stress was distributed at the cervical margin. With the application of rotational movements, maximum compressive stress was distributed at the apex and cervical third, whereas the tensile stress was distributed on cervical third of the PDL on the lingual surface. Conclusion For extrusive movements, stress values over the periodontal ligament was within the range of optimal stress value as proposed by Lee, with a given force system by Profitt as optimum forces for orthodontic tooth movement using linear properties. During rotation there are stresses concentrated at the apex, hence due to the concentration of the compressive forces at the apex a clinician must avoid placing heavy stresses during tooth movement. How to cite this article Hemanth M, Raghuveer HP, Rani MS, Hegde C, Kabbur KJ, Vedavathi B, Chaithra D. An Analysis of the Stress Induced in the Periodontal Ligament during Extrusion and Rotation Movements: A Finite Element Method Linear Study Part I. J Contemp Dent Pract 2015;16(9):740-743.

scholarly journals Intermittent Compressive Stress Enhanced Insulin-Like Growth Factor-1 Expression in Human Periodontal Ligament Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Jittima Pumklin ◽  
Jeeranan Manokawinchoke ◽  
Kanokporn Bhalang ◽  
Prasit Pavasant
Keyword(s):  
Mechanical Stress ◽  
Compressive Stress ◽  
Periodontal Ligament ◽  
Molecular Mechanisms ◽  
Treated Group ◽  
Periodontal Ligament Cells ◽  
Human Periodontal Ligament Cells ◽  
Chemical Inhibitors

Mechanical force was shown to promote IGF-1 expression in periodontal ligament both in vitro and in vivo. Though the mechanism of this effect has not yet been proved, here we investigated the molecular mechanism of intermittent mechanical stress on IGF-1 expression. In addition, the role of hypoxia on the intermittent compressive stress on IGF-1 expression was also examined. In this study, human periodontal ligament cells (HPDLs) were stimulated with intermittent mechanical stress for 24 hours. IGF-1 expression was examined by real-time polymerase chain reaction. Chemical inhibitors were used to determine molecular mechanisms of these effects. For hypoxic mimic condition, the CoCl2 supplementation was employed. The results showed that intermittent mechanical stress dramatically increased IGF-1 expression at 24 h. The pretreatment with TGF-β receptor I or TGF-β1 antibody could inhibit the intermittent mechanical stress-induced IGF-1 expression. Moreover, the upregulation of TGF-β1 proteins was detected in intermittent mechanical stress treated group. Correspondingly, the IGF-1 expression was upregulated upon being treated with recombinant human TGF-β1. Further, the hypoxic mimic condition attenuated the intermittent mechanical stress and rhTGF-β1-induced IGF-1 expression. In summary, this study suggests intermittent mechanical stress-induced IGF-1 expression in HPDLs through TGF-β1 and this phenomenon could be inhibited in hypoxic mimic condition.

scholarly journals Cell survival and gene expression under compressive stress in a three-dimensional in vitro human periodontal ligament-like tissue model

2014 ◽  
Vol 68 (2) ◽  
pp. 249-260 ◽  
Author(s):  
Wen Liao ◽  
Masahiro Okada ◽  
Kaoru Inami ◽  
Yoshiya Hashimoto ◽  
Naoyuki Matsumoto
Keyword(s):  
Gene Expression ◽  
Cell Survival ◽  
Compressive Stress ◽  
Periodontal Ligament ◽  
Three Dimensional ◽  
Tissue Model

scholarly journals The long non-coding RNA landscape of periodontal ligament stem cells subjected to compressive force

2018 ◽  
Vol 41 (4) ◽  
pp. 333-342 ◽  
Author(s):  
Yiping Huang ◽  
Yingying Zhang ◽  
Xiaobei Li ◽  
Hao Liu ◽  
Qiaolin Yang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Compressive Stress ◽  
Periodontal Ligament ◽  
Kegg Pathway ◽  
Compressive Force ◽  
Differentially Expressed ◽  
Periodontal Ligament Stem Cells ◽  
Expression Levels ◽  
Qrt Pcr ◽  
Pathway Analyses

Summary Objective The role of long non-coding ribonucleic acids (lncRNAs) during orthodontic tooth movement remains unclear. We explored the lncRNA landscape of periodontal ligament stem cells (PDLSCs) subjected to compressive force. Materials and methods PDLSCs were subjected to static compressive stress (2 g/cm2) for 12 hours. Total RNA was then extracted and sequenced to measure changes in lncRNA and messenger RNA (mRNA) expression levels. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to validate the expression levels of certain lncRNAs. Differential expression analysis as well as Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were also performed. Results In total, 90 lncRNAs and 519 mRNAs were differentially expressed in PDLSCs under compressive stress. Of the lncRNAs, 72 were upregulated and 18 downregulated. The levels of eight lncRNAs of interest (FER1L4, HIF1A-AS2, MIAT, NEAT1, ADAMTS9-AS2, LUCAT1, MIR31HG, and DHFRP1) were measured via qRT-PCR, and the results were found to be consistent with those of RNA sequencing. GO and KEGG pathway analyses showed that a wide range of biological functions were expressed during compressive loading; most differentially expressed genes were involved in extracellular matrix organization, collagen fibril organization, and the cellular response to hypoxia. Conclusions The lncRNA expression profile was significantly altered in PDLSCs subjected to compressive stress. These findings expand our understanding of molecular regulation in the mechanoresponse of PDLSCs.

The relaxation of compressive biaxial strains in SOS via microtwins

1989 ◽  
Vol 47 ◽  
pp. 608-609
Author(s):  
M. E. Twigg ◽  
E. D. Richmond ◽  
J. G. Pellegrino
Keyword(s):  
Thin Film ◽  
Chemical Vapor Deposition ◽  
Molecular Beam Epitaxy ◽  
Compressive Stress ◽  
Vapor Deposition ◽  
Partial Dislocation ◽  
Molecular Beam ◽  
Volume Fraction ◽  
Chemical Vapor ◽  
Silicon Thin Film

For heteroepitaxial systems, such as silicon on sapphire (SOS), microtwins occur in significant numbers and are thought to contribute to strain relief in the silicon thin film. The size of this contribution can be assessed from TEM measurements, of the differential volume fraction of microtwins, dV/dν (the derivative of the microtwin volume V with respect to the film volume ν), for SOS grown by both chemical vapor deposition (CVD) and molecular beam epitaxy (MBE).In a (001) silicon thin film subjected to compressive stress along the [100] axis , this stress can be relieved by four twinning systems: a/6[211]/( lll), a/6(21l]/(l1l), a/6[21l] /( l1l), and a/6(2ll)/(1ll).3 For the a/6[211]/(1ll) system, the glide of a single a/6[2ll] twinning partial dislocation draws the two halves of the crystal, separated by the microtwin, closer together by a/3.

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