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DOGRU SUZANCANSEL, CANSIZ EROL, ARSLAN YUNUSZIYA. A REVIEW OF FINITE ELEMENT APPLICATIONS IN ORAL AND MAXILLOFACIAL BIOMECHANICS. J MECH MED BIOL 2018. [DOI: 10.1142/s0219519418300028] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Finite element method (FEM) is preferred to carry out mechanical analyses for many complex biomechanical structures. For most of the biomechanical models such as oral and maxillofacial structures or patient-specific dental instruments, including nonlinearities, complicated geometries, complex material properties, or loading/boundary conditions, it is not possible to accomplish an analytical solution. The FEM is the most widely used numerical approach for such cases and found a wide range of application fields for investigating the biomechanical characteristics of oral and maxillofacial structures that are exposed to external forces or torques. The numerical results such as stress or strain distributions obtained from finite element analysis (FEA) enable dental researchers to evaluate the bone tissues subjected to the implant or prosthesis fixation from the viewpoint of (i) mechanical strength, (ii) material properties, (iii) geometry and dimensions, (iv) structural properties, (v) loading or boundary conditions, and (vi) quantity of implants or prostheses. This review paper evaluates the process of the FEA of the oral and maxillofacial structures step by step as followings: (i) a general perspective on the techniques for creating oral and maxillofacial models, (ii) definitions of material properties assigned to oral and maxillofacial tissues and related dental materials, (iii) definitions of contact types between tissue and dental instruments, (iv) details on loading and boundary conditions, and (v) meshing process.
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Affiliation(s)
- SUZAN CANSEL DOGRU
- Department of Mechanical Engineering, Faculty of Engineering, Istanbul University, Avcilar, Istanbul 34320, Turkey
| | - EROL CANSIZ
- Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Istanbul University, Capa, Istanbul 34093, Turkey
| | - YUNUS ZIYA ARSLAN
- Department of Mechanical Engineering, Faculty of Engineering, Istanbul University, Avcilar, Istanbul 34320, Turkey
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Lin M, Liu SB, Genin GM, Zhu Y, Shi M, Ji C, Li A, Lu TJ, Xu F. Melting Away Pain: Decay of Thermal Nociceptor Transduction during Heat-Induced Irreversible Desensitization of Ion Channels. ACS Biomater Sci Eng 2017; 3:3029-3035. [DOI: 10.1021/acsbiomaterials.6b00789] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
| | | | - Guy M. Genin
- Department
of Neurological Surgery, Washington University School of Medicine,
NSF Science and Technology Center for Engineering Mechanobiology,
and School of Engineering, Washington University, St. Louis, Missouri 63110, United States
| | | | | | - Changchun Ji
- Department
of Acupuncture, Shaanxi Hospital of Traditional Chinese Medicine, Xi’an 710003, PR China
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KE MINGJEN, HUANG KUICHOU, LEE CHENGHUNG, CHU HENGYI, WU YUNGTSAN, CHANG SHINTSU, CHIANG SHANGLIN, SU KUOCHIH. INFLUENCE OF THREE DIFFERENT CURVATURES FLEX-FOOT PROSTHESIS WHILE SINGLE-LEG STANDING OR RUNNING: A FINITE ELEMENT ANALYSIS STUDY. J MECH MED BIOL 2017. [DOI: 10.1142/s0219519417500555] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Flex foot device was one of the most common prosthesis for the athletes with the transtibial amputation on the recent market. Thus, the results of investigation with biomechanics on the flex foot would be a considerable impact on the performance of disabled athletes wearing the flex foots. This study was designed to investigate the biomechanical condition of the flex foot prosthesis with different curvatures while standing and running by finite element analysis. This study demonstrated finite element models of flex foot established with three different curvatures 20[Formula: see text] (small bending), 35[Formula: see text] (medium bending) and 50[Formula: see text] (big bending). Besides, it simulates and investigates the condition of flex foot while a person is wearing it with single-leg standing or running. The evaluation indices were selected as von Mises stress and displacements at top of socket surface. The results show that the big-bending flex foot generated the higher stress and the larger deformed displacement. Without exceeding the material tolerance of the flex foot, the larger displacement of big-bending flex foot could generate more energy, which possessed larger resilient potential energy and enabled the athletes to have better performance after using the flex foot. As a result, due to its beneficial property of energy storage and return, the large-bending flex foot user could have better effect. In the future, more innovative designs of the flex foot prosthesis can be laid out with the reference of the result in this study.
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Affiliation(s)
- MING-JEN KE
- Department of Physical Medicine and Rehabilitation, Tri-Service General Hospital, School of Medicine, National Defense Medical Center, Taipei, Taiwan
| | - KUI-CHOU HUANG
- Department of Physical Medicine and Rehabilitation, Tri-Service General Hospital, School of Medicine, National Defense Medical Center, Taipei, Taiwan
- Department of Occupational Therapy, Asia University, Taichung, Taiwan
- Department of Orthopedics, Asia University Hospital, Taichung, Taiwan
| | - CHENG-HUNG LEE
- Department of Orthopedics, Taichung Veterans General Hospital, Taichung, Taiwan
- Department of Biotechnology, Hung Kuang University, Taichung, Taiwan
| | - HENG-YI CHU
- Department of Physical Medicine and Rehabilitation, Tri-Service General Hospital, School of Medicine, National Defense Medical Center, Taipei, Taiwan
| | - YUNG-TSAN WU
- Department of Physical Medicine and Rehabilitation, Tri-Service General Hospital, School of Medicine, National Defense Medical Center, Taipei, Taiwan
| | - SHIN-TSU CHANG
- Department of Physical Medicine and Rehabilitation, Tri-Service General Hospital, School of Medicine, National Defense Medical Center, Taipei, Taiwan
- Department of Rehabilitation, Taichung Veterans General Hospital, Taichung, Taiwan
| | - SHANG-LIN CHIANG
- Department of Physical Medicine and Rehabilitation, Tri-Service General Hospital, School of Medicine, National Defense Medical Center, Taipei, Taiwan
- Department of Physical Therapy and Assistive Technology, National Yang-Ming University, Taipei, Taiwan
| | - KUO-CHIH SU
- Department of Medical Research, Taichung Veterans General Hospital, Taichung, Taiwan
- Department of Biomedical Engineering, Hung Kuang University, Taichung, Taiwan
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Role of the compression screw in the dynamic hip-screw system: A finite-element study. Med Eng Phys 2015; 37:1174-9. [PMID: 26521645 DOI: 10.1016/j.medengphy.2015.10.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2015] [Revised: 06/04/2015] [Accepted: 10/01/2015] [Indexed: 11/22/2022]
Abstract
The dynamic hip-screw (DHS) system is a common implant for fixation of proximal femur fractures. During assembly, it has been recommended to remove the compression screw after initial compression has been obtained; however, related complications had been reported. So far, the role of compression screw in the reconstructed stability of hip fractures as well as the mechanical strength of the DHS system has rarely been mentioned. This study investigated the function of this screw in the DHS system during fracture healing. Based on the FE method, six numerical models of proximal femur were employed to analyze the mechanical response of a DHS implant with various fracture types and different fixation strategies (with or without a compression screw). The displacement of the femur head and peak von Mises stress were selected as indices of the stability of a fractured femur stabilized by a DHS device and of the risk of implant failure, respectively. Our results showed that a retained compression screw increased reconstructed structural stiffness, reducing the displacement of the femur head. This screw also helped to lessen mechanical failure of side plate by reducing the peak von Mises stress around the connection between the barrel and side plate. Both findings were evident in the proximal femur fracture involving the intertrochanteric part, and even more obvious in the setting of bony defects. Thus, we recommend the maintenance of compression screw in the DHS system while treating the intertrochanteric fracture, particularly in cases with bony defects.
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CHANG WENJEN, CHANG YENHSIANG, WANG HSUAN, LIN CHUNLI. COMPARISON OF PROXIMAL IN VITRO TOOTH CONTACTS IN CLASS II RESTORATIONS WITH DIFFERENT RESTORATIVE MATERIALS AND CAVITY SIZES USING A NEW MEASUREMENT DEVICE. J MECH MED BIOL 2015. [DOI: 10.1142/s0219519415500578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
This study used a newly developed proximal contact strength (PCS) device to evaluate the tightness of proximal tooth contact for Class II cavity size restoration with different materials using an auxiliary separation ring system. A measurement device based on the equilibrium of forces acted on the clamp rod converts a pull-out force between interdental spaces on a force sensing resistor to express the PCS. This device was designed using dental floss as the test end and can be moved with constant speed during measurement through a bevel gear that transforms the rotation of motor shaft into linear movement of clamp rod. A manikin model was used with 60 artificial first molars in which an mesial occlusal (MO) preparation was ground. Samples were divided into six groups (each n = 10) for simulating amalgam and resin composite restoration with three different cavity sizes. The different cavities were defined using the ratio of the actual isthmus width to the intercuspal width (W) to 1/3, 2/3 and 1. The PCS value in each sample was measured after restoration. The result showed that the mean PCS value and standard deviation were 2283.1 ± 216.5 gf, 2419.1 ± 375 gf and 1737.6 ± 372.7 g for 1/3 W, 2/3 W and W cavities of the amalgam restoration, respectively. The corresponding PCS values were 1178.0 ± 230.4 gf, 1205.8 ± 249.1 gf and 1247.0 ± 157.5 gf for 1/3 W, 2/3 W and W cavities of the resin composite restoration. PCS values with amalgam restoration were larger than those for resin composite restorations under the same cavity size. Large cavity (W) PCS might be lost with amalgam restoration. No significant difference was found in resin composite restoration PCS among the different cavity sizes.
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Affiliation(s)
- WEN-JEN CHANG
- Department of Information Management, Chang Gung University, 259 Wen-Hua 1st Road, Kwei-Shan, Tao-Yuan 333, Taiwan
| | - YEN-HSIANG CHANG
- Department of General Dentistry, Chang Gung Memorial Hospital, 123, Ding-Hu Road, Kuei-Shan, Tao-Yuan 333, Taiwan
| | - HSUAN WANG
- Department of Biomedical Engineering, National Yang-Ming University, 2 No.155, Sec. 2, Linong Street, Taipei 112, Taiwan
| | - CHUN-LI LIN
- Department of Biomedical Engineering, National Yang-Ming University, 2 No.155, Sec. 2, Linong Street, Taipei 112, Taiwan
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Orrego S, Romberg E, Arola D. Synergistic degradation of dentin by cyclic stress and buffer agitation. J Mech Behav Biomed Mater 2015; 44:121-32. [PMID: 25637823 PMCID: PMC4499057 DOI: 10.1016/j.jmbbm.2015.01.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2014] [Revised: 01/05/2015] [Accepted: 01/05/2015] [Indexed: 11/30/2022]
Abstract
Secondary caries and non-carious lesions develop in regions of stress concentrations and oral fluid movement. The objective of this study was to evaluate the influence of cyclic stress and fluid movement on material loss and subsurface degradation of dentin within an acidic environment. Rectangular specimens of radicular dentin were prepared from caries-free unrestored 3rd molars. Two groups were subjected to cyclic cantilever loading within a lactic acid solution (pH = 5) to achieve compressive stresses on the inner (pulpal) or outer sides of the specimens. Two additional groups were evaluated in the same solution, one subjected to movement only (no stress) and the second held stagnant (control: no stress or movement). Exterior material loss profiles and subsurface degradation were quantified on the two sides of the specimens. Results showed that under cyclic stress material loss was significantly greater (p ≤ 0.0005) on the pulpal side than on the outer side and significantly greater (p ≤ 0.05) under compression than tension. However, movement only caused significantly greater material loss (p ≤ 0.0005) than cyclic stress. Subsurface degradation was greatest at the location of highest stress, but was not influenced by stress state or movement.
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Affiliation(s)
- Santiago Orrego
- Department of Mechanical Engineering, University of Maryland Baltimore County, Baltimore, MD, USA
| | - Elaine Romberg
- Department of Endodontics, Prosthodontics, and Operative Dentistry, Dental School, University of Maryland, Baltimore, MD, USA
| | - Dwayne Arola
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA; Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, WA, USA.
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FAN HONGYI, GAO SHANSHAN, LIU YANG, ZHU ZHUOLI, YU HAIYANG. THE MICROMECHANICAL AND TRIBOLOGICAL FEATURE OF MILD MOTTLED ENAMEL. J MECH MED BIOL 2014. [DOI: 10.1142/s021951941450050x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The relationships between the basic mechanical and wear properties of mottled enamel, especially during the mastication process, are important factors and must be explored. This study evaluated mottled enamel's micro-tribological behavior under artificial saliva conditions in vitro. The basic mechanical properties were determined by nanoindentiation testing. A conical diamond nanoindenter tip was used to scratch mottled enamel and normal enamel. The scratches were sliding with a constant normal load of 2 mN, with different cycles during the tests. The hardness, elastic modulus and friction coefficient were obtained to analyze the mechanical properties. The results showed that the hardness and elastic modulus of mottled enamel were 10% and 14.6% less, respectively, than those of normal enamel. Mottled enamel showed a lower friction coefficient and a higher wear rate, compared to normal enamel. The friction coefficient did not appear to be related to the wear rate for either type of enamel. The wear mechanism for normal enamel was plastic deformation for early wear, while the combination of plastic deformation and delamination was the main damage feature of mottled enamel.
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Affiliation(s)
- HONGYI FAN
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, NO. 14, 3rd Section of Ren Min Nan Road, Chengdu, P. R. China
| | - SHANSHAN GAO
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, NO. 14, 3rd Section of Ren Min Nan Road, Chengdu, P. R. China
| | - YANG LIU
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, NO. 14, 3rd Section of Ren Min Nan Road, Chengdu, P. R. China
| | - ZHUOLI ZHU
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, NO. 14, 3rd Section of Ren Min Nan Road, Chengdu, P. R. China
| | - HAIYANG YU
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, NO. 14, 3rd Section of Ren Min Nan Road, Chengdu, P. R. China
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Lin M, Genin GM, Xu F, Lu T. Thermal Pain in Teeth: Electrophysiology Governed by Thermomechanics. APPLIED MECHANICS REVIEWS 2014; 66:0308011-3080114. [PMID: 25516631 PMCID: PMC4240033 DOI: 10.1115/1.4026912] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 02/01/2014] [Indexed: 05/12/2023]
Abstract
Thermal pain arising from the teeth is unlike that arising from anywhere else in the body. The source of this peculiarity is a long-standing mystery that has begun to unravel with recent experimental measurements and, somewhat surprisingly, new thermomechanical models. Pain from excessive heating and cooling is typically sensed throughout the body through the action of specific, heat sensitive ion channels that reside on sensory neurons known as nociceptors. These ion channels are found on tooth nociceptors, but only in teeth does the pain of heating differ starkly from the pain of cooling, with cold stimuli producing more rapid and sharper pain. Here, we review the range of hypotheses and models for these phenomena, and focus on what is emerging as the most promising hypothesis: pain transduced by fluid flowing through the hierarchical structure of teeth. We summarize experimental evidence, and critically review the range of heat transfer, solid mechanics, fluid dynamics, and electrophysiological models that have been combined to support this hypothesis. While the results reviewed here are specific to teeth, this class of coupled thermomechanical and neurophysiological models has potential for informing design of a broad range of thermal therapies and understanding of a range of biophysical phenomena.
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Affiliation(s)
- Min Lin
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University , Xi'an 710049 , China
| | - Guy M Genin
- Department of Neurological Surgery, and School of Engineering, Washington University , St. Louis, MO 63110
| | - Feng Xu
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University , Xi'an 710049 , China
| | - TianJian Lu
- Bioinspired Engineering and Biomechanics Center, Xi'an Jiaotong University , Xi'an 710049 , China e-mail:
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Su KC, Chuang SF, Ng EYK, Chang CH. An investigation of dentinal fluid flow in dental pulp during food mastication: simulation of fluid-structure interaction. Biomech Model Mechanobiol 2013; 13:527-35. [PMID: 23913183 DOI: 10.1007/s10237-013-0514-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2013] [Accepted: 07/10/2013] [Indexed: 11/28/2022]
Abstract
This study uses fluid-structure interaction (FSI) simulation to investigate the relationship between the dentinal fluid flow in the dental pulp of a tooth and the elastic modulus of masticated food particles and to investigate the effects of chewing rate on fluid flow in the dental pulp. Three-dimensional simulation models of a premolar tooth (enamel, dentine, pulp, periodontal ligament, cortical bone, and cancellous bone) and food particle were created. Food particles with elastic modulus of 2,000 and 10,000 MPa were used, respectively. The external displacement loading (5 μm) was gradually directed to the food particle surface for 1 and 0.1 s, respectively, to simulate the chewing of food particles. The displacement and stress on tooth structure and fluid flow in the dental pulp were selected as evaluation indices. The results show that masticating food with a high elastic modulus results in high stress and deformation in the tooth structure, causing faster dentinal fluid flow in the pulp in comparison with that obtained with soft food. In addition, fast chewing of hard food particles can induce faster fluid flow in the pulp, which may result in dental pain. FSI analysis is shown to be a useful tool for investigating dental biomechanics during food mastication. FSI simulation can be used to predict intrapulpal fluid flow in dental pulp; this information may provide the clinician with important concept in dental biomechanics during food mastication.
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Affiliation(s)
- Kuo-Chih Su
- Department of Biomedical Engineering College of Engineering, National Cheng Kung University, 1 University Road, Tainan City, 701, Taiwan
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