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Duanmu Z, Liu L, Deng Q, Ren Y, Wang M. Development of a biomechanical model for dynamic occlusal stress analysis. Int J Oral Sci 2021; 13:29. [PMID: 34493701 PMCID: PMC8423745 DOI: 10.1038/s41368-021-00133-5] [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: 02/15/2021] [Accepted: 07/06/2021] [Indexed: 02/08/2023] Open
Abstract
The use of traditional finite element method (FEM) in occlusal stress analysis is limited due to the complexity of musculature simulation. The present purpose was to develop a displacement boundary condition (DBC)-FEM, which evaded the muscle factor, to predict the dynamic occlusal stress. The geometry of the DBC-FEM was developed based on the scanned plastic casts obtained from a volunteer. The electrognathographic and video recorded jaw positional messages were adopted to analyze the dynamic occlusal stress. The volunteer exhibited asymmetrical lateral movements, so that the occlusal stress was further analyzed by using the parameters obtained from the right-side eccentric movement, which was 6.9 mm long, in the stress task of the left-side eccentric movement, which was 4.1 mm long. Further, virtual occlusion modification was performed by using the carving tool software aiming to improve the occlusal morphology at the loading sites. T-Scan Occlusal System was used as a control of the in vivo detection for the location and strength of the occlusal contacts. Data obtained from the calculation using the present developed DBC-FEM indicated that the stress distribution on the dental surface changed dynamically with the occlusal contacts. Consistent with the T-Scan recordings, the right-side molars always showed contacts and higher levels of stress. Replacing the left-side eccentric movement trace by the right-side one enhanced the simulated stress on the right-side molars while modification of the right-side molars reduced the simulated stress. The present DBC-FEM offers a creative approach for pragmatic occlusion stress prediction.
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Affiliation(s)
- Zheng Duanmu
- grid.443248.d0000 0004 0467 2584Key Laboratory of the Ministry of Education for Optoelectronic Measurement Technology and Instrument, Beijing Information Science and Technology University, Beijing, China
| | - Lu Liu
- grid.233520.50000 0004 1761 4404Department of Oral Anatomy and Physiology and TMD, School of Stomatology, Air Force Medical University, Xi’an, China
| | - Qi Deng
- grid.233520.50000 0004 1761 4404Department of Oral Anatomy and Physiology and TMD, School of Stomatology, Air Force Medical University, Xi’an, China
| | - Yuanyuan Ren
- grid.233520.50000 0004 1761 4404Department of Oral Anatomy and Physiology and TMD, School of Stomatology, Air Force Medical University, Xi’an, China
| | - Meiqing Wang
- grid.233520.50000 0004 1761 4404Department of Oral Anatomy and Physiology and TMD, School of Stomatology, Air Force Medical University, Xi’an, China
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Cao Y. Occlusal disharmony and chronic oro-facial pain: from clinical observation to animal study. J Oral Rehabil 2021; 49:116-124. [PMID: 34333797 DOI: 10.1111/joor.13236] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 06/24/2021] [Accepted: 07/17/2021] [Indexed: 12/21/2022]
Abstract
BACKGROUND Occlusion can be viewed as the most sensitive susceptor of the central nervous system in the oro-facial region. Its inalienable relationships to the temporomandibular joint, the muscles, the stomatognathic system and even the central nervous system are self-evident. Almost all the dental treatments inevitably change the occlusion, potentially or actually, locally or extensively, and immediately or gradually. OBJECTIVE The objective of this study was to present a narrative literature on occlusal disharmony and chronic oro-facial pain. METHODS Literature reviews focusing on clinical studies about the relationship between occlusal disharmony and myofascial oro-facial pain, and related preclinical studies about the animal models of, as well as the peripheral and central mechanisms underlying this condition related to, occlusal disharmony were used as starting point and guidelines to describe the topics mentioned. A search of the PubMed database was performed mainly with the following search terms: "occlusion," "occlusal interference," "occlusal disharmony," "occlusal change," "oro-facial pain" and "myofascial pain." RESULTS Relevant literature from the past 70 years until the present day was meticulously studied. The literature review together with three related characteristic clinical cases revealed an intimate association between occlusal disharmony and chronic oro-facial pain, involving pathological changes, extending from the peripheral tissues to the central nervous system. The patients suffered from psychological distress, sleep disturbance and poor life quality. CONCLUSION Occlusal disharmony-related oro-facial pain is a clinical problem that deserves attention, although there are no universally accepted clinical protocols. The existing literature provides some constructive suggestions, but further research is needed.
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Affiliation(s)
- Ye Cao
- Department of Prosthodontics, Center for Oral and Jaw Functional Diagnosis, Treatment and Research, Peking University School and Hospital of Stomatology, Beijing, China.,Center for TMD & Orofacial Pain, Peking University School and Hospital of Stomatology, Beijing, China.,National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, Beijing, China
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Xiang T, Tao ZY, Liao LF, Wang S, Cao DY. Animal Models of Temporomandibular Disorder. J Pain Res 2021; 14:1415-1430. [PMID: 34079358 PMCID: PMC8166243 DOI: 10.2147/jpr.s303536] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Accepted: 04/04/2021] [Indexed: 12/12/2022] Open
Abstract
Temporomandibular disorders (TMD) are a group of diseases in the oral and maxillofacial region that can manifest as acute or chronic persistent pain, affecting millions of people worldwide. Although hundreds of studies have explored mechanisms and treatments underlying TMD, multiple pathogenic factors and diverse clinical manifestations make it still poorly managed. Appropriate animal models are helpful to study the pathogenesis of TMD and explore effective treatment measures. At present, due to the high cost of obtaining large animals, rodents and rabbits are often used to prepare TMD animal models. Over the past decade, various animal models have been intensively developed to understand neurobiological and molecular mechanisms of TMD, and seek effective treatments. Although these models cannot carry out all clinical features, they are valuable in revealing the mechanisms of TMD and creating curative access. Currently, there are multitudinous animal models of TMD research. They can be constructed in different means and summarized into four ways according to the various causes and symptoms, including chemical induction (intra-articular injection of ovalbumin, collagenase, formalin, vascular endothelial growth factor, intramuscular injection of complete Freund’s adjuvant, etc.), mechanical stress stimulation (passive mouth opening, change of chewing load), surgical operation (partial disc resection, joint disc perforation) and psychological stress induction. Here, we summarize and discuss different approaches of animal models for determining neurophysiological and mechanical mechanisms of TMD and assess their advantages and limitations, respectively.
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Affiliation(s)
- Ting Xiang
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, Research Center of Stomatology, Xi'an Jiaotong University College of Stomatology, Xi'an, Shaanxi, 710004, People's Republic of China.,Department of Orthodontics, Xi'an Jiaotong University College of Stomatology, Xi'an, Shaanxi, 710004, People's Republic of China
| | - Zhuo-Ying Tao
- Discipline of Oral and Maxillofacial Surgery, Faculty of Dentistry, The University of Hong Kong, Sai Ying Pun, Hong Kong, 999077, People's Republic of China
| | - Li-Fan Liao
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, Research Center of Stomatology, Xi'an Jiaotong University College of Stomatology, Xi'an, Shaanxi, 710004, People's Republic of China
| | - Shuang Wang
- Department of Orthodontics, Xi'an Jiaotong University College of Stomatology, Xi'an, Shaanxi, 710004, People's Republic of China
| | - Dong-Yuan Cao
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, Research Center of Stomatology, Xi'an Jiaotong University College of Stomatology, Xi'an, Shaanxi, 710004, People's Republic of China
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Shi M, Liu X, Zhang C, Zhang H, Liu Q, Wang D, Liu X, Li J, Wang M. Effect of dental malocclusion on cerebellar neuron activation via the dorsomedial part of the principal sensory trigeminal nucleus. Eur J Oral Sci 2021; 129:e12788. [PMID: 33945647 PMCID: PMC8453929 DOI: 10.1111/eos.12788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 03/10/2021] [Accepted: 03/12/2021] [Indexed: 11/30/2022]
Abstract
Occlusion has been proposed to play a role for body posture and balance, both of which are mediated mainly by the cerebellum. The dorsomedial part of the principal sensory trigeminal nucleus (Vpdm) has direct projection to the cerebellum. The experimental unilateral anterior crossbite (UAC) has an impact on the motor nuclei in the brain stem via trigeminal mesencephalic nucleus (Vme). The current aim was to explore whether UAC has an impact on Vpdm‐cerebellum circuit. The inferior alveolar nerve was injected into cholera toxin B subunit (CTb), the cerebellum was injected into fluoro‐gold (FG), and the Vpdm was injected into biotinylated dextran amine (BDA) to identify the activation of Vpdm‐cerebellum circuit by UAC. Data indicated that there were more neuronal nuclei (NeuN)/CTb/FG triple‐labelled neurons and NeuN/CTb/vesicular glutamate transporter 1(VGLUT1) triple‐labelled neurons in the Vpdm, and more NeuN/BDA/ VGLUT1 triple‐labelled neurons in the cerebellum of rats with UAC than in control rats. The VGLUT1 expression in the Vpdm and cerebellum in the UAC group was higher than that in control rats. These findings indicate an excitatory impact of UAC on the Vpdm‐cerebellum pathway and support the role of occlusion for body posture and balance.
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Affiliation(s)
- Minghong Shi
- School of Stomatology, The Third Affiliated Hospital of Xinxiang Medical University, Xinxiang, China.,Department of Oral Anatomy and Physiology, School of Stomatology, The Fourth Military Medical University, Xi'an, China
| | - Xin Liu
- Department of Oral Anatomy and Physiology, School of Stomatology, The Fourth Military Medical University, Xi'an, China.,Department of Stomatology, The 960th Hospital of People's Liberation Army, Jinan, China
| | - Chunkui Zhang
- Department of Anatomy, Histology and Embryology and K.K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, China
| | - Hongyun Zhang
- Department of Oral Anatomy and Physiology, School of Stomatology, The Fourth Military Medical University, Xi'an, China
| | - Qian Liu
- Department of Oral Anatomy and Physiology, School of Stomatology, The Fourth Military Medical University, Xi'an, China
| | - Dongmei Wang
- School of Stomatology, The Third Affiliated Hospital of Xinxiang Medical University, Xinxiang, China
| | - Xiaodong Liu
- Department of Oral Anatomy and Physiology, School of Stomatology, The Fourth Military Medical University, Xi'an, China
| | - Jinlian Li
- Department of Anatomy, Histology and Embryology and K.K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, China
| | - Meiqing Wang
- School of Stomatology, The Third Affiliated Hospital of Xinxiang Medical University, Xinxiang, China.,Department of Oral Anatomy and Physiology, School of Stomatology, The Fourth Military Medical University, Xi'an, China
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Fast and accurate protocol for histology and immunohistochemistry reactions in temporomandibular joint of rats. Arch Oral Biol 2021; 126:105115. [PMID: 33819835 DOI: 10.1016/j.archoralbio.2021.105115] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 03/25/2021] [Accepted: 03/26/2021] [Indexed: 01/07/2023]
Abstract
OBJECTIVE Propose a standard, fast and accurate protocol for the processing of the temporomandibular joint (TMJ) of adults' rats for histology and immunohistochemistry reactions. DESIGN Wistar male rats were perfused with paraformaldehyde (4 %). The heads were fixed in formaldehyde 10 % solution for 48 h. After that, the heads were sectioned in a sagittal plane and fixed for plus 48 h. Decalcification was performed using 20 % formic acid for 96 h and delimitation of TMJ area was done. Detailed methodology to a standard extraction and processing of TMJ to histological sections is described. Different buffers, equipment, temperature and time were tested to optimize immunostaining. Morphological preservation and antigenicity were evaluated by hematoxylin and eosin staining and immunohistochemistry reaction. RESULTS The current findings demonstrated that TMJ fixed in 10 % formaldehyde and decalcified in 20 % formic acid optimized decalcification processing time with preservation of cell morphology. Antigen retrieval with citrate buffer in pressure cooker (2 min at 100 °C and 5 min at room temperature) demonstrated the best protocol to preservation of the structures of TMJ. CONCLUSIONS This work demonstrates in detail a methodology of a fast and accurate TMJ processing for histology and immunohistochemistry reactions that guarantee tissue integrity and quality of staining.
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Zhang HY, Duan J, Wang J, Xie MJ, Liu Q, Liu JQ, Yang HX, Wang MQ. Masseter response to long-term experimentally induced anterior crossbite in Sprague-Dawley rats. Arch Oral Biol 2020; 122:104985. [PMID: 33340921 DOI: 10.1016/j.archoralbio.2020.104985] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 10/30/2020] [Accepted: 11/01/2020] [Indexed: 12/13/2022]
Abstract
OBJECTIVE To detect the long-term response to unilateral anterior crossbite (UAC) in masticatory muscles and in molecular biomarkers of peripheral blood leukocytes. DESIGN Fifty-six six-week-old Sprague-Dawley rats were used. The gene-fold changes in peripheral blood leukocytes were detected by the microarray analysis to compare the rats that received 20-week UAC treatment with age-matched controls (n = 4). Muscle atrophy-related gene Fbxo32 was selected based on the data of the microarray analysis verified by using real-time PCR. The remaining 36 rats were randomly separated in the UAC and control groups at 12 and 20 weeks (n = 12). The protein expression of Fbxo32 and the muscle injury and myogenesis-related markers, αB-crystallin and desmin, were detected in the masseter and lateral pterygoid muscles by western blot assay. RESULTS In the 20-week UAC group, the masseter muscle weight was lower than that in the age-matched control group, and the expression level of Fbxo32 gene in peripheral blood leukocytes was increased according to the microarray analysis confirmed by real-time PCR detection. The increased protein expression levels of Fbxo32 were detected in the masseter in the 20-week UAC group, and the protein expression levels of desmin and αB-crystallin were decreased at this time point. No similar changes were detected in the lateral pterygoid muscle. CONCLUSIONS Masseter atrophy is induced by long-term stimulation of UAC. The increased expression of the Fbxo32 gene in peripheral blood leukocytes may be a candidate biological marker of masseter atrophy.
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Affiliation(s)
- Hong-Yun Zhang
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi International Joint Research Center for Oral Diseases, Department of Oral Anatomy and Physiology and TMD, School of Stomatology, the Fourth Military Medical University, 145 Changlexi Road, Xi'an, 710032, PR China
| | - Jing Duan
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi International Joint Research Center for Oral Diseases, Department of Oral Anatomy and Physiology and TMD, School of Stomatology, the Fourth Military Medical University, 145 Changlexi Road, Xi'an, 710032, PR China
| | - Jing Wang
- Department of Burns and Cutaneous Surgery, Xijing Hospital, the Fourth Military Medical University, Xi'an, PR China
| | - Mian-Jiao Xie
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi International Joint Research Center for Oral Diseases, Department of Oral Anatomy and Physiology and TMD, School of Stomatology, the Fourth Military Medical University, 145 Changlexi Road, Xi'an, 710032, PR China
| | - Qian Liu
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi International Joint Research Center for Oral Diseases, Department of Oral Anatomy and Physiology and TMD, School of Stomatology, the Fourth Military Medical University, 145 Changlexi Road, Xi'an, 710032, PR China
| | - Jin-Qiang Liu
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi International Joint Research Center for Oral Diseases, Department of Oral Anatomy and Physiology and TMD, School of Stomatology, the Fourth Military Medical University, 145 Changlexi Road, Xi'an, 710032, PR China; School of Stomatology, the Jiamusi University, Jiamusi, PR China
| | - Hong-Xu Yang
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi International Joint Research Center for Oral Diseases, Department of Oral Anatomy and Physiology and TMD, School of Stomatology, the Fourth Military Medical University, 145 Changlexi Road, Xi'an, 710032, PR China
| | - Mei-Qing Wang
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi International Joint Research Center for Oral Diseases, Department of Oral Anatomy and Physiology and TMD, School of Stomatology, the Fourth Military Medical University, 145 Changlexi Road, Xi'an, 710032, PR China.
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