scholarly journals Three-dimensional nonlinear prediction of tooth movement from the force system and root morphology

2020 ◽  
Vol 90 (6) ◽  
pp. 811-822
Author(s):  
Roberto Savignano ◽  
Rodrigo F. Viecilli ◽  
Udochukwu Oyoyo
Keyword(s):  
Tooth Movement ◽  
Three Dimensional ◽  
Cone Beam ◽  
Nonlinear Prediction ◽  
Element Analysis ◽  
Force System ◽  
Force Ratio ◽  
Force Direction ◽  
Force Systems ◽  
The Moment

ABSTRACT Objectives To determine the different impact of moment-to-force ratio (M:F) variation for each tooth and spatial plane and to develop a mathematical model to predict the orthodontic movement for every tooth. Materials and Methods Two full sets of teeth were obtained combining cone-beam computed tomography (CBCT) and optical scans for two patients. Subsequently, a finite element analysis was performed for 510 different force systems for each tooth to evaluate the centers of rotation. Results The center of CROT locations were analyzed, showing that the M:F effect was related to the spatial plane on which the moment was applied, to the force direction, and to the tooth morphology. The tooth dimensions on each plane were mathematically used to derive their influence on the tooth movement. Conclusion This study established the basis for an orthodontist to determine how the teeth move and their axes of resistance, depending on their morphology alone. The movement is controlled by a parameter (k), which depends on tooth dimensions and force system features. The k for a tooth can be calculated using a CBCT and a specific set of covariates.

scholarly journals Effect of apical portion of T-, sloped L-, and reversed L-closing loops on their force systems

2016 ◽  
Vol 87 (1) ◽  
pp. 104-110 ◽  
Author(s):  
Paiboon Techalertpaisarn ◽  
Antheunis Versluis
Keyword(s):  
Three Dimensional ◽  
Vertical Force ◽  
Element Analysis ◽  
Force System ◽  
Apical Portion ◽  
Beam Elements ◽  
Force Ratio ◽  
Force Systems ◽  
Three Dimensional Models ◽  
Apical Loop

ABSTRACT Objective: To investigate the effect of the position of the apical portion of closing loops on the force system at both loop ends. Materials and Methods: T-loops were compared with backward-sloped L-loops (SL) and reversed L-loops (RL). SL-loops were directed toward the anterior side; RL-loops were directed toward the posterior side. Loop response to loop pulling was determined with finite element analysis at six positions of the apical loop portion for 12-mm interbracket distance and 8-mm loop length and height. Three-dimensional models of the closing loops were created using beam elements with the properties of stainless steel. Loop responses (horizontal load/deflection, vertical force, and moment-to-force ratio) at both loop ends were calculated as well as at 100 g and 200 g activation forces. Results: T-, SL-, and RL-loops with the same position of the apical portion showed approximately the same force system at both loop ends. This behavior was found across the investigated range through which the loops were moved (interbracket center to posterior bracket). Conclusions: The center of the apical portion determined the force system of the closing loops regardless of the position of the loop legs. The centers of the apical portion of the T-, SL-, and RL-loops acted like V-bend positions.

The Effects of Mini Implant and Anterior Arch Hook Heights on En Masse Retraction: A Finite Element Analysis

2013 ◽  
Vol 461 ◽  
pp. 993-1001
Author(s):  
Wen Wen Deng ◽  
Fang Wang ◽  
Ferdinand M. Machibya ◽  
Shang Gao ◽  
Xiao Long Wang ◽  
...  
Keyword(s):  
Finite Element ◽  
Cone Beam Ct ◽  
Three Dimensional ◽  
Cone Beam ◽  
Finite Element Models ◽  
Treatment Results ◽  
Element Analysis ◽  
Anterior Teeth ◽  
Orofacial Region ◽  
En Masse Retraction

Introduction: An en-masse retraction with mini implant (MI) anchorage may be associated with unwanted intrusion/extrusion and uncontrolled tipping of anterior teeth. An optimum combination of MIs and hooks heights is required for proper treatment results. Materials and Methods: Maxillary finite element models were constructed from a cone beam CT scan of a patient’s orofacial region. The initial tooth displacement at 200g force with 0.019 × 0.025-in stainless steel working archwires engaged in 0.022 brackets slot was assessed. The three-dimensional displacement was examined at various MI and AAH heights. Results: The lower MI position caused extrusion of the central incisors, but the teeth were intruded at higher (6- and 8-mm) MI heights. While the shorter (2- and 4-mm) hooks extruded the central incisors, the higher (6- and 8-mm) intruded the teeth. The higher MI and hooks reduced the palatal tipping of central incisors. The distobucal cusp of the first molar was intruded, while the mesiobucal cusp was extruded in all models: Nonetheless, the shorter hooks and low MI had small molar tipping effects. Conclusions: The higher MIs caused intrusion and less palatal tipping of the central incisors crowns. The increase in hook height resulted into extrusion and reduction in palatal tipping of the central incisors crowns.

scholarly journals Efficient Design of a Clear Aligner Attachment to Induce Bodily Tooth Movement in Orthodontic Treatment Using Finite Element Analysis

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4926
Author(s):  
Kyungjae Hong ◽  
Wonhyeon Kim ◽  
Emmanuel Eghan-Acquah ◽  
Jongho Lee ◽  
Bukyu Lee ◽  
...  
Keyword(s):  
Finite Element ◽  
Orthodontic Treatment ◽  
Tooth Movement ◽  
Axial Rotation ◽  
Tooth Surface ◽  
Central Incisor ◽  
Efficient Design ◽  
Element Analysis ◽  
Force Systems ◽  
Clear Aligner

Clear aligner technology has become the preferred choice of orthodontic treatment for malocclusions for most adult patients due to their esthetic appeal and comfortability. However, limitations exist for aligner technology, such as corrections involving complex force systems. Composite attachments on the tooth surface are intended to enable active control of tooth movements. However, unintended tooth movements still occur. In this study, we present an effective attachment design of an attachment that can efficiently induce tooth movement by comparing and analyzing the movement and rotation of teeth between a general attachment and an overhanging attachment. The 3D finite element modes were constructed from CBCT data and used to analyze the distal displacement of the central incisor using 0.5- and 0.75-mm-thick aligners without an attachment, and with general and overhanging attachments. The results show that the aligner with the overhanging attachment can effectively reduce crown tipping and prevent axial rotation for an intended distal displacement of the central incisor. In all models, an aligner with or without attachments was not capable of preventing the lingual inclination of the tooth.

Numerical Simulation of Breakwaters for Land Reclamation

2009 ◽  
Author(s):  
Jian-Min Zhang ◽  
Jianhong Zhang ◽  
Gang Wang ◽  
Yang Chen
Keyword(s):  
Land Reclamation ◽  
Southern China ◽  
Soft Soil ◽  
Three Dimensional ◽  
Marine Clay ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Reclamation Project ◽  
The Moment ◽  
Three Dimensional Finite Element

This paper highlights some practical considerations of soil structure interactions in the design of the breakwater for a land reclamation project at Da Ya Bay, Southern China sea, through three-dimensional finite element analysis. A pile-breakwater-foundation system is evaluated during its construction and after construction has been completed. The maximum deflections and moments of the piles take place in the soft marine clay underneath the breakwater. The deformation of the soft soil imposes great impact on the slender pile. Based on the study, it is considered inadequate to solely increase the density and stiffness of the piles, as it will not effectively reduce the deformation of the foundation as well as the moment of the pile. On the contrary, the increased stiffness results in significant increase of the stresses in the pile. Consequently, the deformation of pile should be evaluated in terms of interactions between soil and pile. Improvement of the soft marine clay is also of great importance.

Finite Element Analysis and Its Application in Oral Surgery Research

2010 ◽  
pp. 159-170
Author(s):  
Mercedes Gallas
Keyword(s):  
Finite Element ◽  
Oral Surgery ◽  
Three Dimensional ◽  
Element Analysis ◽  
Biomechanical Behavior ◽  
Force Systems ◽  
Surgery Research ◽  
Miniplate Osteosynthesis ◽  
Virtual Modeling ◽  
Regional Stresses

The Finite Element Method (FEM) is a widely applied mathematical model that permit us to know the biomechanical behavior of the human mandible in various clinical situations under physiological and standardized trauma conditions. The three-dimensional FEM provides to simulate force systems applied and allows analysis of the response of the jawbone to the loads in 3D space. Clinical extrapolations from FEM may not give absolute values but they will provide detailed description of biomechanical pattern and a prediction of regional stresses distribution. This virtual modeling is useful to choose the most efficient localization and design of miniplate osteosynthesis and to test new biomaterials.

The Finite Element Analysis of Stress in the Periodontal Ligament when Subject to Vertical Orthodontic Forces

1994 ◽  
Vol 21 (2) ◽  
pp. 161-167 ◽  
Author(s):  
A. N. Wilson ◽  
J. Middleton ◽  
M. L. Jones ◽  
N. J. McGuinness
Keyword(s):  
Finite Element ◽  
Periodontal Ligament ◽  
Tooth Movement ◽  
Root Resorption ◽  
Three Dimensional ◽  
Element Model ◽  
Vertical Movement ◽  
Optimum Level ◽  
Element Analysis ◽  
Three Dimensional Finite Element

In the past, vertical intrusive movement of teeth has been considered difficult and most routine clinical vertical movement of teeth has been confined to extrusion. It has been suggested that attempts at intrusion may result in an increased incidence of root resorption and also in occasional devitalization. The displacement and resulting stress fields associated with such treatment can be successfully studied using the finite element method. In the case being considered initial movements are known to be small; therefore, the assumption in the study that the material behaves linear-elastically is considered to be reasonable. This study of vertical tooth movement demonstrated that the maximum cervical margin stress in the periodontal ligament was 0·0046 N/mm2, whilst the highest apical stress was 0·00205 N/mm2 when intrusive and extrusive forces of 1 Newton were applied to the buccal surface of the crown of a tooth model. These stresses were evaluated in the light of previous studies and found to be within the suggested clinical optimum level. However, the periodontal stress distribution following orthodontic loading within this three-dimensional finite element model was found to be highly complex.

scholarly journals Differences in the force system delivered by different beta-titanium wires in elaborate designs

2015 ◽  
Vol 20 (6) ◽  
pp. 89-96 ◽  
Author(s):  
Renato Parsekian Martins ◽  
Sergei Godeiro Fernandes Rabelo Caldas ◽  
Alexandre Antonio Ribeiro ◽  
Luís Geraldo Vaz ◽  
Roberto Hideo Shimizu ◽  
...  
Keyword(s):  
Testing Machine ◽  
Objective Evaluation ◽  
Neutral Position ◽  
Force System ◽  
Beta Titanium ◽  
Force Systems ◽  
Initial Activation ◽  
The Moment ◽  
Fluorescence Spectrometer ◽  
Similar Force

Abstract Objective: Evaluation of the force system produced by four brands of b-Ti wires bent into an elaborate design. Methods: A total of 40 T-loop springs (TLS) hand-bent from 0.017 x 0.025-in b-Ti were randomly divided into four groups according to wire brand: TMATM(G1), BETA FLEXYTM (G2), BETA III WIRETM (G3) and BETA CNATM (G4). Forces and moments were recorded by a moment transducer, coupled to a digital extensometer indicator adapted to a testing machine, every 0.5 mm of deactivation from 5 mm of the initial activation. The moment-to-force (MF) ratio, the overlapping of the vertical extensions of the TLSs and the load-deflection (LD) ratio were also calculated. To complement the results, the Young's module (YM) of each wire was determined by the slope of the load-deflection graph of a tensile test. The surface chemical composition was also evaluated by an energy dispersive X-ray fluorescence spectrometer. Results: All groups, except for G2, produced similar force levels initially. G3 produced the highest LD rates and G1 and G4 had similar amounts of overlap of the vertical extensions of the TLSs in "neutral position". G1 and G3 delivered the highest levels of moments, and G2 and G3 produced the highest MF ratios. b-Ti wires from G3 produced the highest YM and all groups showed similar composition, except for G2. Conclusion: The four beta-titanium wires analyzed produced different force systems when used in a more elaborate design due to the fact that each wire responds differently to bends.

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