scholarly journals Comparison of one versus two maxillary molars distalization with iPanda: a finite element analysis

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Kamontip Sujaritwanid ◽  
Boonsiva Suzuki ◽  
Eduardo Yugo Suzuki
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Alveolar Bone ◽  
Vertical Direction ◽  
Minimal Amount ◽  
Element Analysis ◽  
Molar Distalization ◽  
Second Molar ◽  
Maxillary Molars ◽  
Displacement Patterns

Abstract Background The purpose of this study was to compare the stress distribution and displacement patterns of the one versus two maxillary molars distalization with iPanda and to evaluate the biomechanical effect of distalization on the iPanda using the finite element method. Methods The finite element models of a maxillary arch with complete dentition, periodontal ligament, palatal and alveolar bone, and an iPanda connected to a pair of midpalatal miniscrews were created. Two models were created to simulate maxillary molar distalization. In the first model, the iPanda was connected to the second molar to simulate a single molar distalization. In the second model, the iPanda was connected to the first molar to simulate “en-masse” first and second molar distalization. A varying force from 50 to 200 g was applied. The stress distribution and displacement patterns were analyzed. Results For one molar, the stress was concentrated at the furcation and along the distal surface in all roots with a large amount of distalization and distobuccal crown tipping. For two molars, the stress in the first molar was 10 times higher than in the second molar with a great tendency for buccal tipping and a minimal amount of distalization. Moreover, the stress concentration on the distal miniscrew was six times higher than in the mesial miniscrew with an extrusive and intrusive vector, respectively. Conclusions Individual molar distalization provides the most effective stress distribution and displacement patterns with reduced force levels. In contrast, the en-masse distalization of two molars results in increased force levels with undesirable effects in the transverse and vertical direction.

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.

scholarly journals Characteristics and Dynamics of Full Arch Distalization Using Transpalatal Arches with Midpalatal and Interradicular Miniscrews as Temporary Anchorage Devices: A Preliminary Finite Element Analysis

2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Mashallah Khanehmasjedi ◽  
Sepideh Bagheri ◽  
Vahid Rakhshan ◽  
Mojtaba Hasani
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Orthodontic Appliances ◽  
Element Analysis ◽  
Midpalatal Suture ◽  
Second Molar ◽  
Bodily Movement ◽  
Anterior Teeth ◽  
The Right

Introduction. Miniscrews have proved quite effective in fixed orthodontic treatment. They can be placed in areas like palatal interradicular zones or midpalatal suture. Despite the value of these methods and their ever-increasing use, their characteristics are not assessed before when implanted in palatal interradicular areas or in the midpalatal suture. We aimed to assess, for the first time, the dynamics of full arch distalization using such miniscrews. Methods. A 3D model of maxilla with all permanent dentition was created from a CT scan volume. Tissues were segmented and differentiated. Afterward, miniscrews and appliances were designed, and the whole model was registered within a finite element analysis software by assigning proper mechanical properties to tissues and orthodontic appliances. The full arches were distalized using transpalatal arches with miniscrews as anchorage devices (in two different models). The extents of stresses and patterns of movements of various elements (teeth, miniscrews, appliances, tissues) were estimated. Results and Conclusions. Comparing the two models, it is obvious that in both models, the stress distribution is the highest in the TPA arms and the head of the miniscrew where the spring is connected. In comparison with the displacement in the X-axis, the “mesial in” rotation is seen in the first molar of both models. But there is one exception and that is the “mesial out” rotation of the right second molar. In all measurements, the amount of movement in Model 2 (with palatal interradicular miniscrews) is more than that in Model 1 (with midpalatal miniscrew). In the Y-axis, more tipping is seen in Model 2, especially the anterior teeth (detorque) and the first molar, but in Model 1, bodily movement of the first molar is more evident. Along the Z-axis, the mesial intrusion of the first molar and the distal extrusion of this tooth can be seen in both models. Again, the displacement values are higher in the second model (with interradicular miniscrews). In comparison with micromotion and stress distribution of miniscrews, in Model 1, maximum stress and micromotion is observed at the head of the miniscrew where it is attached to the spring. Of course, this amount of micromotion increases over time. The same is true for Model 2, but with a lower micromotion. As for the amount of stress, the stress distribution in both miniscrews of both models is almost uniform and rather severe.

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 Three-Dimensional Finite Element Analysis to Evaluate Stress Distribution in Tooth and Implant-Supported Fixed Partial Denture–An In Vitro Study

2020 ◽  
Vol 8 (03) ◽  
pp. 084-091
Author(s):  
Himani Jain ◽  
Tarun Kalra ◽  
Manjit Kumar ◽  
Ajay Bansal ◽  
Deepti Jain
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Alveolar Bone ◽  
Three Dimensional ◽  
In Vitro Study ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Three Dimensional Finite Element

Abstract Introduction This study was undertaken to assess the influence of different superstructure materials, when subjected to occlusal loading, on the pattern of stress distribution in tooth-supported, implant-supported, and tooth implant-supported fixed partial prostheses, using the finite element analysis with a comparative viewpoint. Materials and Methods The geometric models of implant and mandibular bone were generated. Three models were created in accordance with the need of the study. The first model was given a tooth-supported fixed partial prosthesis. The second model was given tooth implant-supported fixed partial prosthesis, and the third model was given implant-supported fixed partial prosthesis. Forces of 100 N and 50 N were applied axially and buccolingually, respectively. Results The present study compared the stresses arising in the natural tooth, implant, and the whole prostheses under simulated axial and buccolingual loading of three types of fixed partial dentures, namely, tooth-supported, tooth implant-supported, and implant-supported fixed partial dental prostheses using three different types of materials. Conclusion The pattern of stress distribution did not appear to be significantly affected by the type of prosthesis materials in all models. The maximum stress concentrations were found in the alveolar bone around the neck of the teeth and implants.

scholarly journals Upper Second Molar Distalization with Clear Aligners: A Finite Element Study

2020 ◽  
Vol 10 (21) ◽  
pp. 7739
Author(s):  
Gabriele Rossini ◽  
Matteo Schiaffino ◽  
Simone Parrini ◽  
Ambra Sedran ◽  
Andrea Deregibus ◽  
...  
Keyword(s):  
Finite Element ◽  
Periodontal Ligament ◽  
Element Analysis ◽  
Molar Distalization ◽  
Force System ◽  
Second Molar ◽  
Maxillary Molar ◽  
Clinical Environments ◽  
Upper Molar ◽  
Element Study

Among orthodontists and scientists, in the last years, upper molar distalization has been a debated topic in the orthodontic aligner field. However, despite that few clinical studies have been published, no insights on aligners’ biomechanics regarding this movement are available. The aim of this study was to assess, through finite element analysis, the force system resulting in the upper arch during second maxillary molar distalization with clear aligners and variable attachments settings. The average tooth distalization was found to be 0.029, with buccal flaring of the upper incisors in all attachment configurations. The mesial deformation of the aligner was registered to be 0.2 mm on average. Different pressure areas on the interface between aligners and upper molars were registered, with the mesial attachment surface to be directly involved when present. Periodontal ligament pressure was reported to range between 67 g/cm2 and 132 g/cm2. Configurations with rectangular attachments from second molar-to-canine and from first molar-to-canine present, in an in silico environment, almost equal efficiency in distalizing the upper second molar. However, attachments from the second molar to the canine are suggested to be adopted in clinical environments due to greater feasibility in everyday practice.

Effects of Lingualized and Linear Occlusion Schemes on the Stress Distribution of an Implant Retained Overdenture Using Finite Element Analysis

2015 ◽  
Author(s):  
Md Abu Hasan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Alveolar Bone ◽  
High Stress ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Molar Teeth ◽  
The Right ◽  
Mandibular Overdenture

This study compares the effects of lingualized and linear occlusion schemes on the stress distribution of an implant retained mandibular overdenture (IRO) using finite element analysis (FEA). A high fidelity solid model of mandibular overdenture incorporating cusps and fossae of occlusal surface with two anterior implants in the canine regions and residual ridge support in the posterior region of the alveolar bone was modeled in SolidWorks and imported to ANSYS for stress analysis. The load was applied vertically to the central grooves and buccal cusp tips of the premolars and molar teeth for the lingualized and linear occlusion respectively. The loading magnitudes were 200 N on the premolars and 200 N on the molar teeth with multiple contact locations. The results show that the linear occlusion scheme generated higher stress in the implants and the prosthetic bar than the lingualized occlusion. The locations of high stress concentrations were the neck of the implants and the implant-prosthetic bar intersection for both the occlusion schemes. However, in the cortical bone lingualized occlusion loading scheme generated higher stress (max principal stress) than the linear one suggesting possibility of greater bone loss. The results of this study could be used to comprehend the stress distribution in the denture teeth, base, bone-implant interface and surrounding bone for the two occlusion concepts and may be of help to the clinicians in choosing the right scheme for the edentulous patients.

3D Finite Element Stress Analysis of an Implant Supported Overdenture Under Bruxism and Lingualized Loading Conditions

2015 ◽  
Author(s):  
Md Abu Hasan ◽  
Panos S. Shiakolas
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Stress Analysis ◽  
Loading Condition ◽  
Alveolar Bone ◽  
Von Mises Stress ◽  
Loading Conditions ◽  
Long Term Effects ◽  
Element Analysis ◽  
Implant Complications

Bruxism is a nonfunctional motor activity that is characterized by grinding and clenching of the teeth. It has been postulated that bruxism causes excessive occlusal load on the dental implant and its superstructures leading to biological and biomechanical complications. While many researchers suggest that grinding/clenching causes early implant complications and accelerated bone loss, others indicate that the long term effects are still unclear. The goal of this study is to analyze the effect of bruxism loading condition on the stress distribution of an implant supported overdenture (ISO) using finite element analysis (FEA) and compare the results with one of the most functionally efficient occlusion schemes in the clinical dentistry — lingualized occlusion. A high fidelity solid model of a mandibular denture encompassing lingual and buccal cusps, mesial and distal fossae supported by four implants and a connecting titanium prosthetic bar, resting on alveolar bone were modeled in SolidWorks 2013 following proper clinical guidelines and imported to ANSYS 15.0 for stress analysis. The results of the study demonstrate that the stress distribution in the implant prostheses and surrounding bone is significantly affected due to bruxism as compared to the lingualized loading. While the location of the maximum stress concentration was the same (neck of the posterior implants) for both loading conditions, there was an increase of approximately 115% von-Mises stress for bruxism loading condition as compared to the lingualized occlusion. The maximum principal stress in the cortical bone surpassed the ultimate tensile strength limit of the jaw bone implying possibility of bone resorption in the peri-implant area.

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