Download or read book A Bone Density Based Finite Element Study of the Efficacy of Maxillary Protraction Protocols with and Without Mini implants written by Howard Chu and published by . This book was released on 2015 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt: Objectives: The purpose of this study was to develop a geometrically accurate and adaptable finite element head model for orthodontic and orthopedic simulations. This finite element head model will use a grayscale conversion and image-based meshing method to apply anatomically accurate bone densities of the human skull and craniofacial sutures. The model can then be used to simulate different clinical maxillary protraction protocols using a conventional facemask appliance and a mico-implant assisted rapid palatal expander (MARPE). Our goal was to improve upon the existing finite element model and to analyze how a bone and suture density based human skull model can improve the analysis of the skeletal effects of these two clinical treatment protocols. Methods: A 3-dimensional cranial mesh model with associated circummaxillary sutures was developed from CT images and Simpleware modeling software. Using a novel image-based meshing approach rather than the conventional computer-aided design (CAD) approach, the different regions of interests such as bone and sutures are separated into different masks. These masked are defined based on the image grayscale within the region of interest. Mesh generation was completed using a multi-part Extended Volumetric Marching Cubes (EVOMAC) approach where voxels are converted directly into finite elements. The material properties of the craniofacial bone and sutures were extracted from the underlying grayscale intensity Hounsfield (HU) of the CT image. Utilizing ANSYS simulation software, two different maxillary protraction protocols including conventional facemask therapy and micro-implant assisted rapid palatal expander (MARPE) were simulated. The stress distribution and displacement of these two different protraction protocols were analyzed. Superimpositions and video animations were generated to visualize the skeletal effects and to compare the results from the newly generated image-based finite element mesh model with the previous CAD-based mesh model generated from the Mimics software. Results: Both the newly designed image-based finite element mesh model and the previous CAD-based mesh model produced similar results in regards to direction of maxillary protraction: Conventional facemask results in counter-clockwise rotation of the maxillary complex. In contrast, facemask with the use of micro-implant assisted rapid palatal expander (MARPE) produces translation of the maxilla in a downward and forward direction. However, the newly designed image-based finite element mesh model produced less magnitudes of movement and less mesh deformation. Conclusion: The newly generated image-based finite element mesh model produced more clinically accurate results compared to the previous CAD-based mesh model. While the direction of the maxillary movement for the two different protocols is the same for both models, the geometrically accurate bone and suture density based model produced less mesh deformation and more accurately represents actual clinical outcomes. Further maxillary protraction protocols can be tested with this newly developed finite element mesh model.

Download or read book The Efficacy of Maxillary Protraction Protocols with and Without Micro implants written by Kimberley Wu and published by . This book was released on 2012 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: Objectives: The purpose of this study was to use Finite Element Method (FEM) to simulate various clinical protocols for maxillary protraction with micro-implants, which can provide skeletal changes without the use of surgery. We aim to analyze how location and direction force alters the skeletal effect. Analysis of the skeletal effects can be used to improve clinical protocols for treating class III patients. Methods: A 3-dimensional cranial mesh model with associated maxillary sutures was developed from CT images and Mimics modeling software. Utilizing ANSYS simulation software, protraction forces were applied at different locations and directions to simulate conventional facemask therapy; seven different maxillary protraction protocols utilizing micro-implants. Stress distribution and displacement were analyzed. Video animations and superimpositions were created to illustrate the skeletal effect from varying location and direction of force application. Results: Conventional facemask and facemask from anterior micro-implants at 15° below and 30° above the occlusal plane result in counter-clockwise rotation of the maxillary complex. In contrast, maxillary protraction at 45° below the occlusal plane with anterior or posterior micro-implants displayed clockwise rotation of the maxilla. At 30° below the occlusal plane, Facemask with palatal or anterior micro-implants translated the maxilla downward and forward, while protraction from posterior micro-implants closely resembled pure anterior protraction of the maxilla. Facemask without micro-implants resulted in higher internal stresses, suggesting force dissipation to bone rather than to the sutures. Conclusion: Location of micro-implant placement and direction of pull altered the skeletal response, changing the upward or downward displacement of the maxillary complex, maxillary incisor upward or downward movement, and amount of protraction. Brachyfacial class III patients with a deep bite would benefit from counter-clockwise rotation of the maxilla, resulting in bite opening. Dolicofacial patients with open bite tendency require protraction that minimizes maxillary downward movement. As a result, class III growth modification treatment with micro-implants can be customized for each patient to maximize clinical effectiveness.

Download or read book Finite Element Analysis of Bone Remodeling Implementation of a Remodeling Algorithm in Matlab and Ansys written by Martin Groß and published by GRIN Verlag. This book was released on 2008-08 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt: Master's Thesis from the year 2006 in the subject Medicine - Biomedical Engineering, grade: 1.0, Technical University of Munich (LS Statik), course: Master of Science of Computational Mechanics, 94 entries in the bibliography, language: English, abstract: The process of adaptive bone remodeling can be described mathematically and simulated in a computer model, integrated with the finite element method. The main focus of this thesis is the implementation of a bone remodeling algorithm in MATLAB and ANSYS on the basis of FEM. The strain energy density is used as mechanical stimulus. The cortical and trabecular bone are described as continuous materials with variable density. This thesis can be divided into four main parts. The first part is due to the material properties of cortical and trabecular bone. The second part is about the remodeling theory and gives an historical review of the developed numerical approaches up to now. The implementation of the remodeling algorithm in ANSYS and MATLAB as well as its validation is topic of part three. In last main part, the algorithm is applied to a 2D FE-model of a human proximal femur.

Download or read book A Finite Element Study of Stresses in Bone Near Transcortical Implants written by Xin Zhang and published by . This book was released on 1998 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Orthodontics E Book written by Lee W. Graber and published by Elsevier Health Sciences. This book was released on 2022-08-26 with total page 1348 pages. Available in PDF, EPUB and Kindle. Book excerpt: **Selected for Doody's Core Titles® 2024 in Dentistry** Comprehensive, cutting-edge content addresses contemporary orthodontic practice! Orthodontics: Current Principles and Techniques, 7th Edition provides an evidence-based approach to orthodontic diagnosis, treatment planning, and clinical techniques, including esthetics, genetics, temporary anchorage devices, aligners, technology-assisted biomechanics, and much more. New to this edition are seven chapters, covering topics like AI, maxillary expansion in adults, Class II correctors, and autotransplantation. Newly authored chapters on orthognathic surgery and the craniofacial team, the periodontal-orthodontic interface, interdisciplinary treatment, and accelerated tooth movement, among others, address current perspectives. The 7th edition comes with access to an enhanced eBook version, which includes videos and additional visuals to show concepts difficult to explain with words alone. Readers can also find additional, online-only chapters and a fully searchable version of the text. Respected editors Lee Graber, Katherine Vig, and Greg Huang are joined by new editor Pádhraig Fleming, along with expert contributors from around the world. This text provides the most current and comprehensive collection of orthodontic knowledge, making it the go-to book for orthodontic residents and practitioners! - Comprehensive coverage provides a one-stop resource for the field of orthodontics, including foundational theory and the latest on the materials and techniques used in today's practice. - Experienced, renowned editors lead a team of expert, international contributors to provide the most authoritative clinical practice and supporting science from the best and brightest in the industry. - More than 3,400 images include a mixture of radiographs, full-color clinical photos, and anatomic or schematic line drawings, showing examples of treatment, techniques, and outcomes. - Detailed, illustrated case studies show the decision-making process, highlighting the consequences of various treatment techniques over time. - Extensive references make it easy to look up the latest in orthodontic research and evidence-based information, and all references also appear online. - Enhanced ebook, included with every print purchase, features a fully searchable version of the text and bonus online-only chapters, instructional videos, and more. - NEW! Seven chapters cover topics such as AI, maxillary expansion in adults, Class II correctors, and autotransplantation. Newly authored chapters on aligners, orthognathic surgery, the periodontal-orthodontic interface, interdisciplinary and computer-assisted treatment, temporary anchorage devices, and accelerated tooth movement, among others, address current perspectives. - UPDATED! Relevant literature and evidence-based practices are featured throughout the text. - NEW! Additional photos and illustrations visually reinforce key concepts and procedures.

Download or read book Finite Element Analysis of Stress Induced Fractures in Bone Around Dental Implants written by George A. Papavasiliou and published by . This book was released on 1992 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Comparison of Two Protocols for Maxillary Protraction written by Nicole M. Deshon and published by . This book was released on 2014 with total page 77 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Finite Element Study of a Shape Memory Alloy Bone Implant written by Ahmadreza Eshghinejad and published by . This book was released on 2012 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shape memory alloys have been used in several biomedical devices in recent years. Their special thermo-mechanical behavior in recovering a certain shape upon heating and being able to tolerate large deformations without undergoing the plastic transformations make them a good choice for different applications. Biocompatibility of nitinol as a widely used shape memory alloy material is the other main property for biomedical devices. Osteoporosis is a common bone disease especially in elderly people. Bone degradation as the result of osteoporosis causes loosing of screws implanted in the bone during or after surgery. A new nitinol-based device which is designed to mitigate this adverse effect has been studied. This thesis analyzes the functionality of this novel nitinol-based expandable-retractable pedicle screw. The unique feature of this screw is that it is removable as needed. The functionality of the screw is verified by experiment and compared to the results of the numerical simulation in Abaqus. This simulation tool is the combination of the numerical implementation of shape memory alloy constitutive thermo-mechanical modeling into the Abaqus UMAT Fortran subroutine and the Abaqus finite element solver. The verification of this tool in several experiments has been carried out to establish validity of the numerical approach. The effect of the designed pedicle screw in mitigating the loosing effect has also been studied. Pullout test is a common way of evaluating a bone implant. The pullout force of a normal screw out of a normal bone was simulated with finite element in Abaqus. Consequently, performance of the new design in improving pull-out strength in osteoporosis bones has been studied. This thesis presents the design of the novel pedicle screw and paves the way of evaluating various medical devices with enhanced functionality.

Download or read book Finite Element Analysis of Different Placement and Materials of Mini implant Orthodontic written by Siti Noreen Mustapa and published by . This book was released on 2013 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Finite Element Study of Intervertebral Cages and Spinal Bone Remodelding written by Young Kim and published by . This book was released on 1996 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Finite Element Analysis of Orthopaedic Plates and Screws to Reduce the Effects of Stress Shielding written by Kristina Haase and published by . This book was released on 2009 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of a 3D Finite Element Model for the Biomechanical Study of Maxillary Expansion Treatments Using Bone anchors written by Yi Fang and published by . This book was released on 2006 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Finite Element Study of Dominant Stimulus in Regulating Femur Bone Remodeling written by Yichen Zhang and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Based on the Wolff's law, mechanical stimuli affect bone strength and therefore affect its bone mineral density (BMD) distribution. There are a number of mechanical stimuli, for example, von-Mises stress, tensile stress, compressive stress, and strain energy density (SED). It is not clear which is the dominant stimulus. The objective of this study was to determine the dominant stimulus that regulates femur BMD by iterative finite element simulations of Wolff's law. Four finite element models of the same femur initially had the same uniform BMD and were affected by the same loading. In the iterative simulations, BMD in each model was 'remodeled' by one of the four stimuli. The results showed BMD distribution in the finite element model regulated by SED was closest to QCT measured BMD, followed by von-Mises stress, then tensile and compressive stress. It is thus concluded that SED was the dominant stimulus in regulating femur BMD.

Download or read book A Finite Element Analysis of Maxillary Centers of Resistance written by Edward A Cronauer and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Comparison of Two Rapid Maxillary Expansion Appliances Using Three dimensional Finite Element Analysis written by Scott W. Ralph and published by . This book was released on 1998 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Use of Angulated Implants in the Maxillary Tuberosty Region A 3 Dimensional Finite Element Analysis Study written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The prosthetic rehabilitation of edentulous maxillary arches is a challenging procedure. When an implant retained prosthesis is considered, more satisfactory results can be obtained but the anatomy and the bone quality of the maxilla limits the usege of dental implants in in edentulous maxilla and necessiates advanced surgical procedures. The use of tuber implants are becoming increasingly in comprehensive restorative procedures. There are limited numbers of studies on tuber implants, many of which have examined either the success and/or survival rate of implants or discussed the surgical difficulties of them. None of them have evaluated the biomechanical factors related to implant tilting. this study is designed to examine in-vitro the magnitude and character of the loads acting on the tilted implants in the tuberosity region. An anatomical 3-D finite element model of an atrophied maxilla was constructed. The implants were placed with different angles. Horizontal and vertical loads were applied. According to the results of this study, the tuberosty area can be used for implant placement. The results of this numerical study coincided with the results of clinical studies.

Download or read book Finite Element Analysis on Dental Implant Supported Prostheses Without Passive Fit written by Chatchai Kunavisarut and published by . This book was released on 2000 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: