ORTHODONTIC PROCESS SAFETY EVALUATION BASED ON PERIODONTAL LIGAMENT CAPILLARY PRESSURE AND OGDEN MODEL

2018 ◽  
Vol 18 (08) ◽  
pp. 1840033 ◽  
Author(s):  
JINGANG JIANG ◽  
ZHIYUAN HUANG ◽  
XUEFENG MA ◽  
YONGDE ZHANG ◽  
YINGSHUAI HAN ◽  
...  
Keyword(s):  
Finite Element ◽  
Capillary Pressure ◽  
Periodontal Ligament ◽  
Alveolar Bone ◽  
Safety Evaluation ◽  
Finite Element Software ◽  
Solid Models ◽  
Biomechanical Simulation ◽  
Force Range ◽  
Orthodontic Forces

Taking the lower maxillary incisors as an example and the orthodontic forces along the near–far middle direction, the orthodontic forces along the crown–root direction and the orthodontic moment around the tongue–cheek direction as loading condition, the biomechanical simulation of the tooth is carried out by the method of finite element simulation in this paper. The CT images of the skull are segmented and denoised by Mimics. The solid models of teeth, periodontal ligament (PDL), alveolar bone and brackets are established by Gomagic and Solidworks. The material characteristics of the PDL are defined by the two-order Ogden hyperelastic model. Taking the PDL capillary pressure as a criterion for orthodontic safety, combined with the stress response of PDL, the safe orthodontic force range of mandibular central incisors is obtained by ANSYS finite element software.

scholarly journals Finite Element Analysis of Mandibular Anterior Teeth with Healthy, but Reduced Periodontium

2021 ◽  
Vol 11 (9) ◽  
pp. 3824
Author(s):  
Ioana-Andreea Sioustis ◽  
Mihai Axinte ◽  
Marius Prelipceanu ◽  
Alexandra Martu ◽  
Diana-Cristala Kappenberg-Nitescu ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Periodontal Ligament ◽  
Tooth Movement ◽  
Orthodontic Tooth Movement ◽  
Real Data ◽  
Element Analysis ◽  
Anterior Teeth ◽  
Applied Forces ◽  
Orthodontic Forces

Finite element analysis studies have been of interest in the field of orthodontics and this is due to the ability to study the stress in the bone, periodontal ligament (PDL), teeth and the displacement in the bone by using this method. Our study aimed to present a method that determines the effect of applying orthodontic forces in bodily direction on a healthy and reduced periodontium and to demonstrate the utility of finite element analysis. Using the cone-beam computed tomography (CBCT) of a patient with a healthy and reduced periodontium, we modeled the geometric construction of the contour of the elements necessary for the study. Afterwards, we applied a force of 1 N and a force of 0.8 N in order to achieve bodily movement and to analyze the stress in the bone, in the periodontal ligament and the absolute displacement. The analysis of the applied forces showed that a minimal ligament thickness is correlated with the highest value of the maximum stress in the PDL and a decreased displacement. This confirms the results obtained in previous clinical practice, confirming the validity of the simulation. During orthodontic tooth movement, the morphology of the teeth and of the periodontium should be taken into account. The effect of orthodontic forces on a particular anatomy could be studied using FEA, a method that provides real data. This is necessary for proper treatment planning and its particularization depends on the patient’s particular situation.

scholarly journals Force Transfer and Stress Distribution in an Implant-Supported Overdenture Retained with a Hader Bar Attachment: A Finite Element Analysis

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Preeti Satheesh Kumar ◽  
Kumar K. S. Satheesh ◽  
Jins John ◽  
Geetha Patil ◽  
Ruchi Patel
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Stress Distribution ◽  
Maximum Stress ◽  
Alveolar Bone ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Finite Element Software ◽  
Force Transfer ◽  
Edentulous Mandible

Background and Objectives. A key factor for the long-term function of a dental implant is the manner in which stresses are transferred to the surrounding bone. The effect of adding a stiffener to the tissue side of the Hader bar helps to reduce the transmission of the stresses to the alveolar bone. But the ideal thickness of the stiffener to be attached to the bar is a subject of much debate. This study aims to analyze the force transfer and stress distribution of an implant-supported overdenture with a Hader bar attachment. The stiffener of the bar attachments was varied and the stress distribution to the bone around the implant was studied. Methods. A CT scan of edentulous mandible was used and three models with 1, 2, and 3 mm thick stiffeners were created and subjected to loads of emulating the masticatory forces. These different models were analyzed by the Finite Element Software (Ansys, Version 8.0) using von Mises stress analysis. Results. The results showed that the maximum stress concentration was seen in the neck of the implant for models A and B. In model C the maximum stress concentration was in the bar attachment making it the model with the best stress distribution, as far as implant failures are concerned. Conclusion. The implant with Hader bar attachment with a 3 mm stiffener is the best in terms of stress distribution, where the stress is concentrated at the bar and stiffener regions.

scholarly journals Biological Events in Periodontal Ligament and Alveolar Bone Associated with Application of Orthodontic Forces

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
L. Feller ◽  
R. A. G. Khammissa ◽  
I. Schechter ◽  
G. Thomadakis ◽  
J. Fourie ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Periodontal Ligament ◽  
Alveolar Bone ◽  
Tooth Movement ◽  
Bone Remodelling ◽  
Orthodontic Tooth Movement ◽  
Review Article ◽  
Tissue Changes ◽  
Induced Stresses ◽  
Orthodontic Forces

Orthodontic force-induced stresses cause dynamic alterations within the extracellular matrix and within the cytoskeleton of cells in the periodontal ligament and alveolar bone, mediating bone remodelling, ultimately enabling orthodontic tooth movement. In the periodontal ligament and alveolar bone, the mechanically induced tensile strains upregulate the expression of osteogenic genes resulting in bone formation, while mechanically induced compressive strains mediate predominantly catabolic tissue changes and bone resorption. In this review article we summarize some of the currently known biological events occurring in the periodontal ligament and in the alveolar bone in response to application of orthodontic forces and how these facilitate tooth movement.

scholarly journals Effects of Variable Composite Attachment Shapes in Controlling Upper Molar Distalization with Aligners: A Nonlinear Finite Element Study

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Cengiz Ayidağa ◽  
Beste Kamiloğlu
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Periodontal Ligament ◽  
Alveolar Bone ◽  
Molar Distalization ◽  
The Third ◽  
Maxillary Molar ◽  
Von Mises ◽  
Displacement Patterns ◽  
Upper Molar

The objective of the present study is to describe the stress and displacement patterns created by clear aligners and composite attachments bonded with the acid-etch technique on the labial surface of the maxillary first upper molar during its distalization. Maxillary molar distalization is a clinical orthodontics procedure used to move the first maxillary molar distally. The procedure is useful in patients with some Class II malocclusion allowing the first molar to move into a Class I relationship and the correction of associated malocclusion features. Three finite element models were designed to simulate the alveolar bone, molar tooth, periodontal ligament, aligner, and composite attachments. The first model had no composite attachment, the second model had a vertical rectangular attachment, and the third model had a newly designed attachment. A loading method was developed that mimicked the aligner’s molar distal movement. PDL was set as a viscoelastic material with a nonlinear mechanical response. von Mises and maximum principal stresses and tooth displacement patterns were analyzed using dedicated software. All the configurations showed some form of clockwise rotation in addition to the distal movement. The crown portion of the tooth showed maximum displacement in all three models; however, in the absence of attachment, the root apex moved in the opposite direction which was compatible with uncontrolled tipping movement. Simulations with attachments exhibited the best performance regarding the movement patterns. The third group, with the newly designed attachment, exhibited the best performance concerning stress distribution (principal stress and von Mises stresses) and higher stresses in the periodontal ligament and tooth. Incorporating a vertical rectangular attachment in a clear aligner resulted in the reduction of mesiodistal tipping tendency during molar distalization. The third model was the most efficient considering both displacement pattern and stress distribution. The level of stress generated by the third model needs to be further investigated in future studies.

Study on Seismic Safety Evaluation of RCC Gravity Dam Based on Strength

2014 ◽  
Vol 501-504 ◽  
pp. 1493-1497
Author(s):  
Shu He Wang ◽  
Ji Yuan ◽  
Rui Guo Ma ◽  
Ju Bing Zhang
Keyword(s):  
Finite Element ◽  
Response Spectrum ◽  
Three Dimensional ◽  
Safety Evaluation ◽  
Time History ◽  
Element Model ◽  
Gravity Dam ◽  
Seismic Safety ◽  
Finite Element Software ◽  
Three Dimensional Finite Element

According to No.3 dam section of Dahuaqiao gravity dam, a three-dimensional finite element model is built by finite element software ANSYS. Mechanics of materials method, response spectrum method and time history analysis method are employed to analyze the strength of the dam section. Results show that the stress of dam toe, dam heel and downstream fold slope are relatively high and stress concentration emerges in those positions. The phenomenon indicates that these areas are vulnerable under the earthquake and precautions must be taken. But under the designed earthquake, the maximum stress of the dam section is below the allowable stress, representing the dam is in a safe state and the strength requirement is satisfied.

scholarly journals Analysis of Stress in the Periodontal Ligament and Alveolar Bone of the Maxillary First Molars during Intrusion with Microscrew Implants: A 3D Finite Element Study

2014 ◽  
Vol 5 (1) ◽  
pp. 11-16 ◽  
Author(s):  
AS Pavithra ◽  
GS Prashanth ◽  
SE Shekar
Keyword(s):  
Finite Element ◽  
Periodontal Ligament ◽  
Maximum Stress ◽  
Alveolar Bone ◽  
Root Surface ◽  
3D Finite Element ◽  
Finite Element Study ◽  
Palatal Implant ◽  
Transpalatal Arch ◽  
Element Study

ABSTRACT Objectives The objective of this study was to graphically display the pattern and magnitude of stress distribution along the periodontal ligament and the alveolar bone of upper first molars on application of intrusive forces using microscrew implants. Materials and methods A computer simulation of threedimensional model of maxillary first molars and second molars bilaterally with their periodontal ligament and alveolar bone, with microscrew implants, force element and a transpalatal arch were constructed on the basis of average anatomic morphology. Finite element analysis was done to evaluate the amount of stress and its distribution during orthodontic intrusive force. Results Overall maximum stress in this study was seen in the alveolar bone in the implant insertion area of 7.155 N/mm2. Maximum stress in the periodontal ligament was seen in middle third distocervical palatal root surface of the first molar (0.008993 N/mm2). Maximum stress in the enamel was seen in the distal aspect of the cementoenamel junction (0.423 N/mm2). Maximum stress in the dentin was observed in apical one-third of the mesiobuccal root surface of first molar (0.1785 N/mm2). Conclusion In this study with the use of palatal implant and transpalatal arch, we found that there was no tipping observed during intrusion. This study demonstrates that significant true intrusion of maxillary molars could be obtained in a wellcontrolled manner by using fixed appliances with microscrew implant as bony anchorage. How to cite this article Pavithra AS, Prashanth GS, Mathew S, Shekar SE. Analysis of Stress in the Periodontal Ligament and Alveolar Bone of the Maxillary First Molars during Intrusion with Microscrew Implants: A 3D Finite Element Study. World J Dent 2014;5(1):11-16.

scholarly journals Inclusion of periodontal ligament fibres in mandibular finite element models leads to an increase in alveolar bone strains

PLoS ONE ◽  
2017 ◽  
Vol 12 (11) ◽  
pp. e0188707 ◽  
Author(s):  
Steven W. McCormack ◽  
Ulrich Witzel ◽  
Peter J. Watson ◽  
Michael J. Fagan ◽  
Flora Gröning
Keyword(s):  
Finite Element ◽  
Periodontal Ligament ◽  
Alveolar Bone ◽  
Finite Element Models ◽  
Bone Strains

scholarly journals Cyclic Stretch Enhances Osteogenic Differentiation of Human Periodontal Ligament Cells via YAP Activation

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Yang Yang ◽  
Bei-Ke Wang ◽  
Mao-Lin Chang ◽  
Zi-Qiu Wan ◽  
Guang-Li Han
Keyword(s):  
Osteogenic Differentiation ◽  
Periodontal Ligament ◽  
Alveolar Bone ◽  
Tooth Movement ◽  
Nuclear Translocation ◽  
Cyclic Stress ◽  
Cyclic Stretch ◽  
Periodontal Ligament Cells ◽  
Human Periodontal Ligament Cells ◽  
Orthodontic Forces

Periodontal remodeling and alveolar bone resorption and formation play essential roles during orthodontic tooth movement (OTM). In the process, human periodontal ligament cells (HPDLCs) sense and respond to orthodontic forces, contributing to the alveolar bone formation. However, the underlying mechanism in this process is not fully elucidated. In the present study, cyclic stress stimulus was applied on HPDLCs to mimic the orthodontic forces during OTM. Our results demonstrated that cyclic stretch promoted the osteogenic differentiation of HPDLCs. Moreover, our data suggested that yes-associated protein (YAP), the Hippo pathway effector, which also involved in mechanical signaling transduction, was activated as we found that the nuclear translocation of YAP was significantly increased in the cyclic stress treated HPDLCs. The mRNA expression of CTGF and CYR61, the target genes of YAP, was also remarkably increased. Furthermore, knockdown of YAP suppressed the cyclic stretch induced osteogenesis in HPDLCs, while overexpression of YAP in HPDLCs enhanced osteogenesis. We also noticed that YAP activities could be suppressed by the ROCK and nonmuscle myosin II inhibitors, Y-27632 and Blebbistatin. The inhibitors also significantly inhibited the cyclic stretch induced osteogenesis in HPDLCs. Finally, in the murine OTM model, our results revealed that YAP was upregulated and nuclearly translocated in the PDLCs at the tension side. In summary, our present study demonstrated that cytoskeleton remodeling induced activation of YAP signaling pathway was crucial for the cyclic stretch-induced osteogenesis of HPDLCs, which might play important roles during OTM.

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