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Li A, Chong DYR, Shao B, Liu Z. An Improved Finite Element Model of Temporomandibular Joint in Maxillofacial System: Experimental Validation. Ann Biomed Eng 2024; 52:1908-1917. [PMID: 36689028 DOI: 10.1007/s10439-022-03124-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 12/25/2022] [Indexed: 01/24/2023]
Abstract
Finite element (FE) analysis has become a popular method of exploring the biomechanical characteristics of temporomandibular joint (TMJ). However, the FE model should be improved and its reliability should be verified further. This study developed a complete maxillofacial model by cone-beam computed tomography (CBCT) and magnetic resonance imaging (MRI). The integrity and physiological environment of TMJ were considered. Then the FE model and corresponding 3D printed model were developed and loaded under the same conditions. The strains on the mandible and upper surface of the left articular disc were measured on the experimental model and compared with the FE model. The differences of the strains on the mandible were less than 6%. The strain distributions on the disc were also approximate between the experimental and simulated results. It indicated that the strains calculated from the improved FE model were reliable on the mandible and inside the TMJ.
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Affiliation(s)
- Annan Li
- Key Lab for Biomechanical Engineering of Sichuan Province, Sichuan University, Chengdu, 610065, China
- Yinbin Institute of Industrial Technology/Sichuan University Yinbin Park, Yinbin, 644600, China
| | - Desmond Y R Chong
- Engineering Cluster, Singapore Institute of Technology, Dover, 138683, Singapore
| | - Bingmei Shao
- Yinbin Institute of Industrial Technology/Sichuan University Yinbin Park, Yinbin, 644600, China.
- Basic Mechanics Lab, Sichuan University, Chengdu, 610211, China.
| | - Zhan Liu
- Key Lab for Biomechanical Engineering of Sichuan Province, Sichuan University, Chengdu, 610065, China.
- Yinbin Institute of Industrial Technology/Sichuan University Yinbin Park, Yinbin, 644600, China.
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Cui SJ, Yang FJ, Wang XD, Mao ZB, Gu Y. Mechanical overload induces TMJ disc degeneration via TRPV4 activation. Oral Dis 2024; 30:1416-1428. [PMID: 37103670 DOI: 10.1111/odi.14595] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 03/07/2023] [Accepted: 04/13/2023] [Indexed: 04/28/2023]
Abstract
OBJECTIVE The temporomandibular joint (TMJ) disc cushions intraarticular stress during mandibular movements. While mechanical overloading is related to cartilage degeneration, the pathogenesis of TMJ disc degeneration is unclear. Here, we determined the regulatory role of mechanoinductive transient receptor potential vanilloid 4 (TRPV4) in mechanical overload-induced TMJ disc degeneration. METHODS We explored the effect of mechanical overload on the TMJ discs in a rat occlusal interference model in vivo, and by applying sustained compressive force in vitro. TRPV4 inhibition was delivered by small interfering RNA or GSK2193874; TRPV4 activation was delivered by GSK1016790A. The protective effect of TRPV4 inhibition was validated in the rat occlusal interference model. RESULTS Occlusal interference induced TMJ disc degeneration with enhanced extracellular matrix degradation in vivo and mechanical overload promoted inflammatory responses in the TMJ disc cells via Ca2+ influx with significantly upregulated TRPV4. TRPV4 inhibition reversed mechanical overload-induced inflammatory responses; TRPV4 activation simulated mechanical overload-induced inflammatory responses. Moreover, TRPV4 inhibition alleviated TMJ disc degeneration in the rat occlusal interference model. CONCLUSION Our findings suggest TRPV4 plays a pivotal role in the pathogenesis of mechanical overload-induced TMJ disc degeneration and may be a promising target for the treatment of degenerative changes of the TMJ disc.
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Affiliation(s)
- Sheng-Jie Cui
- Department of Orthodontics, Peking University School and Hospital of Stomatology & National Center for Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology & Research Center of Engineering and Technology for Computerized Dentistry Ministry of Health & NMPA Key Laboratory for Dental Materials, Beijing, China
| | - Fu-Jia Yang
- Department of Orthodontics, Peking University School and Hospital of Stomatology & National Center for Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology & Research Center of Engineering and Technology for Computerized Dentistry Ministry of Health & NMPA Key Laboratory for Dental Materials, Beijing, China
| | - Xue-Dong Wang
- Department of Orthodontics, Peking University School and Hospital of Stomatology & National Center for Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology & Research Center of Engineering and Technology for Computerized Dentistry Ministry of Health & NMPA Key Laboratory for Dental Materials, Beijing, China
| | - Ze-Bin Mao
- Department of Biochemistry and Biophysics, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Peking University Health Science Center, Beijing, China
| | - Yan Gu
- Department of Orthodontics, Peking University School and Hospital of Stomatology & National Center for Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology & Research Center of Engineering and Technology for Computerized Dentistry Ministry of Health & NMPA Key Laboratory for Dental Materials, Beijing, China
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Min Z, Li Y, Xiong Y, Wang H, Jiang N. Specific tissue engineering for temporomandibular joint disc perforation. Cytotherapy 2024; 26:231-241. [PMID: 38099894 DOI: 10.1016/j.jcyt.2023.11.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 06/28/2023] [Accepted: 11/15/2023] [Indexed: 02/26/2024]
Abstract
BACKGROUND The temporomandibular joint (TMJ) disc is a critical fibrocartilaginous structure with limited regenerative capacity in the oral system. Perforation of the TMJ disc can lead to osteoarthritis and ankylosis of the TMJ because of the lack of disc protection. Clinical treatments for TMJ disc perforation, such as discectomy, hyaluronic acid injection, endoscopic surgery and high position arthroplasty of TMJ, are questionable with regard to long-term outcomes, and only three fourths of TMJ disc perforations are repairable by surgery, even in the short-term. Tissue engineering offers the potential for cure of repairable TMJ disc perforations and regeneration of unrepairable ones. OBJECTIVES This review discusses the classification of TMJ disc perforation and defines typical TMJ disc perforation. Advancements in the engineering-based repair of TMJ disc perforation by stem cell therapy, construction of a disc-like scaffold and functionalization by offering bioactive stimuli are also summarized in the review, and the barriers developing engineering technologies need to overcome to be popularized are discussed.
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Affiliation(s)
- Ziyang Min
- West China School/Hospital of Stomatology, Chengdu, China
| | - Yibo Li
- West China School/Hospital of Stomatology, Chengdu, China
| | - Yichen Xiong
- West China School/Hospital of Stomatology, Chengdu, China
| | - Huayu Wang
- West China School/Hospital of Stomatology, Chengdu, China
| | - Nan Jiang
- State Key Laboratory of Oral Diseases and West China Hospital of Stomatology, Chengdu, China.
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Gao W, Lu J, Gao X, Zhou J, Dai H, Sun M, Xu J. Biomechanical effects of joint disc perforation on the temporomandibular joint: a 3D finite element study. BMC Oral Health 2023; 23:943. [PMID: 38031042 PMCID: PMC10685656 DOI: 10.1186/s12903-023-03521-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 10/10/2023] [Indexed: 12/01/2023] Open
Abstract
BACKGROUND Disc perforation (DP) is a severe type of Temporomandibular Disorder (TMD). DP may induce changes in the internal stresses of the temporomandibular joint (TMJ). Herein, this study attempts to investigate the biomechanical effects of different positions and sizes of DP on the TMJ using a biomechanical approach, to explore the mechanical pathogenesis of TMD. METHODS Eleven three-dimensional finite element (FE)models of the TMJ were constructed based on CBCT imaging files of a patient with DP on the left side. These models included the disc with anterior displacement and discs with different locations and sizes of perforations on the affected disc. FE methods were conducted on these models. RESULTS Anterior displacement of the disc leads to a significant increase in the maxim von Mises stress (MVMS) in both TMJs, with the affected side exhibiting a more pronounced effect. DP occurring at the posterior band and the junction between the disc and the bilaminar region has a greater impact on the MVMS of both TMJs compared to perforations at other locations. As the size of the perforation increases, both sides of the TMJs exhibit an increase in the magnitude of MVMS. CONCLUSIONS Unilateral disc anterior displacement results in an increased stress on both TMJs. Unilateral DP further affects the stress on both sides of the TMJs. TMD is a progressive condition, and timely intervention is necessary in the early stages to prevent the worsening of the condition.
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Affiliation(s)
- Wentong Gao
- Stomatological Hospital of Chongqing Medical University, No. 426 Songshi North Road, Chongqing, China
- Chongqing Key Laboratory for Oral Diseases and Biomedical Science, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Jie Lu
- Stomatological Hospital of Chongqing Medical University, No. 426 Songshi North Road, Chongqing, China
- Chongqing Key Laboratory for Oral Diseases and Biomedical Science, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Xiang Gao
- Stomatological Hospital of Chongqing Medical University, No. 426 Songshi North Road, Chongqing, China
- Chongqing Key Laboratory for Oral Diseases and Biomedical Science, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Jianping Zhou
- Stomatological Hospital of Chongqing Medical University, No. 426 Songshi North Road, Chongqing, China
- Chongqing Key Laboratory for Oral Diseases and Biomedical Science, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Hongwei Dai
- Stomatological Hospital of Chongqing Medical University, No. 426 Songshi North Road, Chongqing, China
- Chongqing Key Laboratory for Oral Diseases and Biomedical Science, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Min Sun
- Department of Orthopedics, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
- Department of Knee Joint Sports Injury, Sichuan Provincial Orthopedic Hospital, Chengdu, Sichuan Province, China.
| | - Jie Xu
- Stomatological Hospital of Chongqing Medical University, No. 426 Songshi North Road, Chongqing, China.
- Chongqing Key Laboratory for Oral Diseases and Biomedical Science, Chongqing, China.
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China.
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Duggal I, Singh N, Tripathi T. Queries regarding clinical finite element analysis of mandibular displacement model treated with Twin-block appliance. Am J Orthod Dentofacial Orthop 2023; 164:461-462. [PMID: 37758397 DOI: 10.1016/j.ajodo.2023.06.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Accepted: 06/29/2023] [Indexed: 10/03/2023]
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Zhang Y, Zheng X, Zhang Q, He Z, Huang W, Yan X, Lv T, Yuan X. Clinical finite element analysis of mandibular displacement model treated with Twin-block appliance. Am J Orthod Dentofacial Orthop 2023; 164:395-405. [PMID: 37029052 DOI: 10.1016/j.ajodo.2023.02.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 02/01/2023] [Accepted: 02/01/2023] [Indexed: 04/09/2023]
Abstract
INTRODUCTION The mechanical distribution of the mandible is an important factor that affects functional orthosis during Twin-block (TB) appliance correction. Changes in the mandible before and after TB appliance correction are also key factors in maintaining the therapeutic effect. Finite element analysis, a powerful numerical, analytical tool, is widely used to predict the stress and strain distribution of the craniofacial bone that orthodontics generates. METHODS The sample was a 14-year-old male patient with Class II malocclusion during growth. A cone-beam computed tomography scan was undertaken at pretreatment and posttreatment. In the Finite element analysis of the pretreatment model, the remote displacement model of the mandible was established with the sella point as the center. A mandibular model under TB appliance loading was established. Its mandibular displacement and von Mises stress were compared before and after loading. Three-dimensional registration was conducted on the pretreatment and posttreatment models to measure the sagittal displacement of the centrosome. RESULTS The force on the mandible occurred mainly in the condyle neck and medial mandible after the TB appliance moved the mandible. After displacement, the posterior upper margin of the condyle was farther away from the articular fossa. Three-dimensional registration results showed that new bone had formed behind and above the condyle after TB appliance treatment. CONCLUSION The TB appliance provides additional advantages in treating skeletal Class II malocclusions by helping to reduce the burden on the temporomandibular joint and promoting the adaptive reconstruction of the mandible.
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Affiliation(s)
- Yingyue Zhang
- Department of Orthodontics, The Affiliated Hospital of Qingdao University, Qingdao, China; School of Stomatology, Qingdao University, Qingdao, China
| | - Xinyu Zheng
- Department of Orthodontics, The Affiliated Hospital of Qingdao University, Qingdao, China; School of Stomatology, Qingdao University, Qingdao, China
| | - Qiang Zhang
- Department of Orthodontics, The Affiliated Hospital of Qingdao University, Qingdao, China; School of Stomatology, Qingdao University, Qingdao, China
| | - Zijing He
- Department of Orthodontics, The Affiliated Hospital of Qingdao University, Qingdao, China; School of Stomatology, Qingdao University, Qingdao, China
| | - Wenli Huang
- Department of Orthodontics, The Affiliated Hospital of Qingdao University, Qingdao, China; School of Stomatology, Qingdao University, Qingdao, China
| | - Xiao Yan
- Department of Orthodontics, The Affiliated Hospital of Qingdao University, Qingdao, China; School of Stomatology, Qingdao University, Qingdao, China
| | - Tao Lv
- Department of Orthodontics, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration & Shandong Provincial Clinical Research Center for Oral Diseases, Qingdao, China.
| | - Xiao Yuan
- Department of Orthodontics, The Affiliated Hospital of Qingdao University, Qingdao, China; School of Stomatology, Qingdao University, Qingdao, China.
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Feng SY, Lei J, Li YX, Shi WG, Wang RR, Yap AU, Wang YX, Fu KY. Increased joint loading induces subchondral bone loss of the temporomandibular joint via the RANTES-CCRs-Akt2 axis. JCI Insight 2022; 7:158874. [PMID: 36173680 PMCID: PMC9675482 DOI: 10.1172/jci.insight.158874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 09/21/2022] [Indexed: 12/15/2022] Open
Abstract
Early-stage temporomandibular joint osteoarthritis (TMJOA) is characterized by excessive subchondral bone loss. Emerging evidence suggests that TMJ disc displacement is involved, but the pathogenic mechanism remains unclear. Here, we established a rat model of TMJOA that simulated disc displacement with a capacitance-based force-sensing system to directly measure articular surface pressure in vivo. Micro-CT, histological staining, immunofluorescence staining, IHC staining, and Western blot were used to assess pathological changes and underlying mechanisms of TMJOA in the rat model in vivo as well as in RAW264.7 cells in vitro. We found that disc displacement led to significantly higher pressure on the articular surface, which caused rapid subchondral bone loss via activation of the RANTES-chemokine receptors-Akt2 (RANTES-CCRs-Akt2) axis. Inhibition of RANTES or Akt2 attenuated subchondral bone loss and resulted in improved subchondral bone microstructure. Cytological studies substantiated that RANTES regulated osteoclast formation by binding to its receptor CCRs and activating the Akt2 pathway. The clinical evidence further supported that RANTES was a potential biomarker for predicting subchondral bone loss in early-stage TMJOA. Taken together, this study demonstrates important functions of the RANTES-CCRs-Akt2 axis in the regulation of subchondral bone remodeling and provides further knowledge of how disc displacement causes TMJOA.
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Affiliation(s)
- Shi-Yang Feng
- Center for Temporomandibular Disorders & Orofacial Pain, and,Central Laboratory, Peking University School and Hospital of Stomatology, Beijing, China.,National Center of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Research Center of Oral Biomaterials and Digital Medical Devices, Beijing, China
| | - Jie Lei
- Center for Temporomandibular Disorders & Orofacial Pain, and,National Center of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Research Center of Oral Biomaterials and Digital Medical Devices, Beijing, China
| | - Yu-Xiang Li
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, China.,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, China
| | - Wen-Ge Shi
- Center for Temporomandibular Disorders & Orofacial Pain, and,National Center of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Research Center of Oral Biomaterials and Digital Medical Devices, Beijing, China
| | - Ran-Ran Wang
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, China.,School of Chemistry and Materials Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, China
| | - Adrian Ujin Yap
- Center for Temporomandibular Disorders & Orofacial Pain, and,Department of Dentistry, Ng Teng Fong General Hospital and Faculty of Dentistry, National University Health System, Singapore, Singapore.,National Dental Research Institute Singapore, National Dental Centre Singapore and Duke-NUS Medical School, Singapore Health Services, Singapore, Singapore
| | - Yi-Xiang Wang
- Central Laboratory, Peking University School and Hospital of Stomatology, Beijing, China.,National Center of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Research Center of Oral Biomaterials and Digital Medical Devices, Beijing, China
| | - Kai-Yuan Fu
- Center for Temporomandibular Disorders & Orofacial Pain, and,National Center of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Research Center of Oral Biomaterials and Digital Medical Devices, Beijing, China
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Bi S, Guo Z, Zhang X, Shi G. Anchorage effects of ligation and direct occlusion in orthodontics: A finite element analysis. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2022; 226:107142. [PMID: 36156441 DOI: 10.1016/j.cmpb.2022.107142] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 09/07/2022] [Accepted: 09/16/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND AND OBJECTIVE During orthodontic treatment, the figure-of-eight ligature and the physiological occlusion play an important role in providing anchorage effects. However, their effects on reaction forces of tooth and stress state in periodontal ligament (PDL) have not been quantitatively evaluated yet. In this study, we presented a finite element analysis process for simulating posterior molar ligature and direct occlusion during orthodontics in order to quantitatively assess their anchorage effects. METHODS A high precision 3D biomechanical model containing upper and lower teeth, PDL, brackets and archwire was generated from the images of computed tomographic scan and sophisticated modelling procedures. The orthodontic treatment of closing the extraction gap was simulated via the finite element method to evaluate the biomechanical response of the molars under the conditions with or without ligation. The simulations were divided into experimental and control groups. In the experimental group, orthodontic force of 1 N was first applied, then direct occlusal forces of 3 and 10 N were applied on each opposite tooth. While in the control group, occlusal forces were applied without orthodontic treatment. The tooth displacement, the stress state in the PDL and the directions of the resultant forces on each tooth were evaluated. RESULTS In the case of molars ligated, the maximum hydrostatic stress in the molars' PDL decreases by 60%. When an initial tooth displacement of several microns occurs in response to an orthodontic force, the direction of the occlusal force changes simultaneously. Even a moderate occlusal force (3 N per tooth) can almost completely offset the mesial forces on the maxillary teeth, thus to provide effective anchorage effect for the orthodontics. CONCLUSIONS The proposed method is effective for simulating ligation and direct occlusion. Figure-of-eight ligature can effectively disperse orthodontic forces on the posterior teeth, while a good original occlusal relationship provides considerable anchorage effects in orthodontics.
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Affiliation(s)
- Shaoyang Bi
- Department of Mechanics, Tianjin University, 135 Yaguan Road, Tianjin 300354, China.
| | - Ziyuan Guo
- Department of Orthodontics, Tianjin Stomatological Hospital, School of Medicine, Nankai University, Tianjin 300041, China
| | - Xizhong Zhang
- Department of Orthodontics, Tianjin Stomatological Hospital, School of Medicine, Nankai University, Tianjin 300041, China
| | - Guangyu Shi
- Department of Mechanics, Tianjin University, 135 Yaguan Road, Tianjin 300354, China
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He J, Ran J, Zheng B, Algahefi A, Liu Y. Finite element analysis of various thickness occlusal stabilization splint therapy on unilateral temporomandibular joint anterior disc displacement without reduction. Am J Orthod Dentofacial Orthop 2021; 161:e277-e286. [PMID: 34776321 DOI: 10.1016/j.ajodo.2021.09.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 09/01/2021] [Accepted: 09/01/2021] [Indexed: 12/22/2022]
Abstract
INTRODUCTION Occlusal stabilization splint is the most common treatment modality for temporomandibular joint disorders, but the optimal thickness is still uncertain. This study investigated the effect of the occlusal splint with different thicknesses on the stress distribution of the temporomandibular joint. METHODS Cone-beam computed tomography and magnetic resonance images were used to reconstruct the maxillofacial and disc, and the unilateral anterior disc displacement without reduction was established manually as the basic model. Occlusal splint with 5 different thickness levels (2, 3, 4, 5, and 6 mm) was added to the basic model as the study models. The displacement and stress distribution of the disc were evaluated. RESULTS The maximum von Mises stress of the condylar cartilage was the largest on the affected side, whereas the maximum von Mises stress of the disc was the largest on the unaffected side. The disc stress on the affected side was mainly distributed on the posterior zone and the intermediate zone for the unaffected side. The maximum von Mises stress of the bilaminar region on the affected side was greater than the unaffected side. The stress of the disc and bilaminar region was the lowest on the affected side in the 2 mm model. The disc displacement on the affected side gradually increased, whereas, on the unaffected side, it fluctuated. CONCLUSIONS These results showed that occlusal stabilization splint could decrease the stress of disc and bilaminar region, and 2 mm was considered the optimal thickness for the treatment of unilateral temporomandibular joint anterior disc displacement without reduction.
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Affiliation(s)
- Jia He
- Department of Orthodontics, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, Liaoning, China
| | - Junyi Ran
- Department of Orthodontics, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, Liaoning, China
| | - Bowen Zheng
- Department of Orthodontics, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, Liaoning, China
| | - Ahmed Algahefi
- Department of Orthodontics, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, Liaoning, China
| | - Yi Liu
- Department of Orthodontics, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, Liaoning, China.
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Shu J, Luo H, Zhang Y, Liu Z. 3D Printing Experimental Validation of the Finite Element Analysis of the Maxillofacial Model. Front Bioeng Biotechnol 2021; 9:694140. [PMID: 34336806 PMCID: PMC8322983 DOI: 10.3389/fbioe.2021.694140] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 06/18/2021] [Indexed: 11/29/2022] Open
Abstract
Contacts used in finite element (FE) models were considered as the best simulation for interactions in the temporomandibular joint (TMJ). However, the precision of simulations should be validated through experiments. Three-dimensional (3D) printing models with the high geometric and loading similarities of the individuals were used in the validation. This study aimed to validate the FE models of the TMJ using 3D printing models. Five asymptomatic subjects were recruited in this study. 3D models of mandible, disc, and maxilla were reconstructed according to cone-beam CT (CBCT) image data. PLA was chosen for 3D printing models from bottom to top. Five pressure forces corresponding to the central occlusion were applied to the 3D printing models. Ten strain rosettes were distributed on the mandible to record the horizontal and vertical strains. Contact was used in the FE models with the same geometries, material properties, loadings, and boundary conditions as 3D printing models to simulate the interaction of the disc-condyle, disc-temporal bone, and upper-lower dentition. The differences of the simulated and experimental results for each sample were less than 5% (maximum 4.92%) under all five loadings. In conclusion, it was accurate to use contact to simulate the interactions in TMJs and upper-lower dentition.
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Affiliation(s)
- Jingheng Shu
- Key Lab for Biomechanical Engineering of Sichuan Province, Sichuan University, Chengdu, China.,Yibin Institute of Industrial Technology, Sichuan University Yibin Park, Yibin, China
| | - Haotian Luo
- Key Lab for Biomechanical Engineering of Sichuan Province, Sichuan University, Chengdu, China.,Yibin Institute of Industrial Technology, Sichuan University Yibin Park, Yibin, China
| | - Yuanli Zhang
- Department of Medical Technology, Chongqing Three Gorges Medical College, Chongqing, China
| | - Zhan Liu
- Key Lab for Biomechanical Engineering of Sichuan Province, Sichuan University, Chengdu, China.,Yibin Institute of Industrial Technology, Sichuan University Yibin Park, Yibin, China
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