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Liu Y, Jia F, Li K, Liang C, Lin X, Geng W, Li Y. Critical signaling molecules in the temporomandibular joint osteoarthritis under different magnitudes of mechanical stimulation. Front Pharmacol 2024; 15:1419494. [PMID: 39055494 PMCID: PMC11269110 DOI: 10.3389/fphar.2024.1419494] [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: 04/18/2024] [Accepted: 06/14/2024] [Indexed: 07/27/2024] Open
Abstract
The mechanical stress environment in the temporomandibular joint (TMJ) is constantly changing due to daily mandibular movements. Therefore, TMJ tissues, such as condylar cartilage, the synovial membrane and discs, are influenced by different magnitudes of mechanical stimulation. Moderate mechanical stimulation is beneficial for maintaining homeostasis, whereas abnormal mechanical stimulation leads to degeneration and ultimately contributes to the development of temporomandibular joint osteoarthritis (TMJOA), which involves changes in critical signaling molecules. Under abnormal mechanical stimulation, compensatory molecules may prevent degenerative changes while decompensatory molecules aggravate. In this review, we summarize the critical signaling molecules that are stimulated by moderate or abnormal mechanical loading in TMJ tissues, mainly in condylar cartilage. Furthermore, we classify abnormal mechanical stimulation-induced molecules into compensatory or decompensatory molecules. Our aim is to understand the pathophysiological mechanism of TMJ dysfunction more deeply in the ever-changing mechanical environment, and then provide new ideas for discovering effective diagnostic and therapeutic targets in TMJOA.
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Affiliation(s)
| | | | | | | | | | - Wei Geng
- Department of Dental Implant Center, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, Beijing, China
| | - Yanxi Li
- Department of Dental Implant Center, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, Beijing, China
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Wang Y, Gao W, Liang C, Jia F, Geng W. Influence on the temporomandibular joint induced by mandibular malpositioning caused by vertical dimension elevation and occlusal loss in adult rats: An imaging, histological and immunohistochemical study. J Oral Rehabil 2024. [PMID: 38783585 DOI: 10.1111/joor.13739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 04/26/2024] [Accepted: 05/06/2024] [Indexed: 05/25/2024]
Abstract
BACKGROUND Mandibular malpositioning may result in an abnormal concentration of stresses within the temporomandibular joint (TMJ) in adult rats, which may further lead to a series of pathological changes, such as articular cartilage wear, subchondral bone sclerosis and osteophyte formation. However, the pathological and adaptive changes in condylar cartilage caused by different stress distributions are still controversial. OBJECTIVE The aim of this study was to observe the effect of sagittal changes in mandibular position on condylar cartilage by changing the occlusal vertical dimension (OVD) in adult rats. METHODS Fifteen-week-old female rats were divided into three groups: control (CON), increased OVD (iOVD) and loss of occlusion (LO) groups. An occlusal plate and tooth extraction were used to establish the animal model. TMJ samples of the experimental and CON groups were observed and investigated by bone morphological, histomorphological and immunohistochemical staining analyses at 3 days, 1 week, 2 weeks, 4 weeks and 8 weeks. Weight curves were plotted. RESULTS Micro-computed tomography showed that, compared with the CON group, cartilage destruction followed by repair occurred in both experimental groups, which was similar to the trend observed in haematoxylin-eosin staining. All experimental results for the iOVD group showed an approximately similar time trend. Compared with the iOVD group, the toluidine blue and immunohistochemical staining results in the LO group showed no obvious change trend over time. CONCLUSION Compared with occlusal loss, an increase in OVD caused faster and more severe damage to condylar cartilage, and subchondral bone repair occurred later.
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Affiliation(s)
- Yue Wang
- Department of Dental Implant Centre, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, Beijing, China
| | - Wenmo Gao
- Department of Dental Implant Centre, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, Beijing, China
| | - Chao Liang
- Department of Dental Implant Centre, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, Beijing, China
| | - Fangwen Jia
- Department of Dental Implant Centre, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, Beijing, China
| | - Wei Geng
- Department of Dental Implant Centre, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, Beijing, China
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Zheng H, Liu Z, Wang H. Research progress in effect of chewing-side preference on temporomandibular joint and its relationship with temporo-mandibular disorders. Zhejiang Da Xue Xue Bao Yi Xue Ban 2023; 52:386-397. [PMID: 37476950 PMCID: PMC10409910 DOI: 10.3724/zdxbyxb-2023-0066] [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: 02/15/2023] [Accepted: 05/15/2023] [Indexed: 07/22/2023]
Abstract
Chewing-side preference is one of the risk factors for temporomandibular disorders (TMD), and people with chewing-side preference is more prone to have short and displaced condyles, increased articular eminence inclination and glenoid fossa depth. The proportion of TMD patients with chewing-side preference is often higher than that of the normal subjects. Clinical studies have shown a strong correlation between chewing-side preference and TMD symptoms and signs; and animal studies have shown that chewing-side preference can affect the growth, development, damage and repair of the mandible. After long-term unilateral mastication, changes in the stress within the joint cause the imbalance of temporomandibular joint (TMJ) structural reconstruction, the transformation and even destruction of the fiber structure of masticatory muscle, resulting in uncoordinated movement of bilateral muscles. The joint neurogenic diseases caused by the increase of neuropeptide substance P and calcitonin-gene-related-peptide (CGRP) released locally by TMJ may be the mechanism of TMD. This article reviews the research progress of the influence of chewing-side preference on the structure of TMJ, the relationship between chewing-side preference and TMD, and the related mechanisms.
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Affiliation(s)
- Huiyun Zheng
- The Stomatology Hospital, Zhejiang University School of Medicine, Zhejiang University School of Stomatology, Zhejiang Provincial Clinical Research Center for Oral Diseases, Zhejiang Provincial Key Laboratory of Oral Biomedical Research, Cancer Center of Zhejiang University, Hangzhou 310006, China.
| | - Zhichao Liu
- The Stomatology Hospital, Zhejiang University School of Medicine, Zhejiang University School of Stomatology, Zhejiang Provincial Clinical Research Center for Oral Diseases, Zhejiang Provincial Key Laboratory of Oral Biomedical Research, Cancer Center of Zhejiang University, Hangzhou 310006, China
| | - Huiming Wang
- The Stomatology Hospital, Zhejiang University School of Medicine, Zhejiang University School of Stomatology, Zhejiang Provincial Clinical Research Center for Oral Diseases, Zhejiang Provincial Key Laboratory of Oral Biomedical Research, Cancer Center of Zhejiang University, Hangzhou 310006, China.
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Nguyen MS, Saag M, Jagomägi T, Nguyen QH, Voog-Oras Ü. The impact of occlusal support on temporomandibular disorders: a literature review. PROCEEDINGS OF SINGAPORE HEALTHCARE 2021. [DOI: 10.1177/20101058211023779] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Temporomandibular disorders are a multifactorial disease. Occlusal support and the number of teeth in dentition have significant effects on the masticatory system. The current study aims to review the role of occlusal support in association with findings of temporomandibular disorders. Data sources were PubMed, Web of Science and Google Scholar, with 1411 citations published over the period 1992–2019. The selection criteria stipulated that articles must have reported the association between the number of teeth, occlusal unit, occlusal support and temporomandibular disorders. A total of 15 full-text articles was finally accessed for eligibility in the current review. The studies on temporomandibular disorders were collected from various sources, including articles reporting temporomandibular disorder symptoms ( n=1), temporomandibular disorder signs ( n=5), temporomandibular joint osseous changes ( n=1), temporomandibular joint dysfunction using the Helkimo index ( n=2), and temporomandibular disorder classification ( n=6). Of these articles, significant associations were found between: the number of missing teeth and temporomandibular disorders ( n=5); the number of occlusal units and occlusal supports and temporomandibular disorders ( n=3); the position of the lost occlusal units and temporomandibular disorders ( n=1). Loss of the occlusal unit has more impact on temporomandibular disorders than the loss of posterior teeth. The total loss of unilateral occlusal support seems to be an aetiological factor for temporomandibular disorders, and maintenance of balanced posterior occlusal support has a role in the prevention and management of temporomandibular disorders.
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Affiliation(s)
- Minh Son Nguyen
- Faculty of Dentistry, Danang University of Medical Technology and Pharmacy, Vietnam
| | - Mare Saag
- Institute of Dentistry, University of Tartu, Estonia
| | | | - Quang Hai Nguyen
- Department of Surgery – Anesthesia and Resuscitation, Danang Hospital of Odonto-Stomatology, Vietnam
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Nakamura A, Ogi N, Sugita Y, Maeda H, Nagao T, Kurita K. Effects of Vascular Endothelial Growth Factor (VEGF) on the Progression of Osteoarthritis in the Mouse Temporomandibular Joint. J HARD TISSUE BIOL 2021. [DOI: 10.2485/jhtb.30.137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Arihiro Nakamura
- Department of Oral and Maxillofacial Surgery, School of Dentistry, Aichi Gakuin University
| | - Nobumi Ogi
- Department of Oral and Maxillofacial Surgery, School of Dentistry, Aichi Gakuin University
| | - Yoshihiko Sugita
- Department of Oral Pathology, School of Dentistry, Aichi Gakuin University
| | - Hatsuhiko Maeda
- Department of Oral Pathology, School of Dentistry, Aichi Gakuin University
| | - Toru Nagao
- Department of Maxillofacial Surgery, School of Dentistry, Aichi Gakuin University
| | - Kenichi Kurita
- Department of Oral and Maxillofacial Surgery, School of Dentistry, Aichi Gakuin University
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Effects of Twin Inclined Plane Device on Adaptation and Ultrastructure Variations in Condyle of Growing Rats. BIOMED RESEARCH INTERNATIONAL 2019; 2019:3069347. [PMID: 31815128 PMCID: PMC6877931 DOI: 10.1155/2019/3069347] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 09/21/2019] [Accepted: 10/23/2019] [Indexed: 11/17/2022]
Abstract
Objective This study investigates the effects of using a twin inclined plane device (TIPD) on the remolding and ultrastructure variation of mandibular condyle in growing rats. Materials and Methods Forty-eight male Wistar rats (six weeks old, body weight of approximately 190–210 g) were divided into experimental group (wearing appliance, n = 32) and control group (no appliance, n = 16). Samples were collected on days 3, 14, 30, and 60. The immunohistochemical analysis for vascular endothelial growth factor (VEGF) and type II collagen was carried out. Tartrate-resistant acid phosphatase (TRAP) reaction was performed to evaluate the osteoclastic activity. Three-dimensional morphometric images were reconstructed for morphometric analysis by microcomputed tomography (micro-CT). The ultrastructure of the condylar surface was observed by scanning electron microscopy (SEM). Results The expression of VEGF significantly increased, while the expression of type II collagen decreased in the experimental group at days 30 and 60. Furthermore, the enhanced osteoclast activity was observed under the subchondral bone, which was highest at day 30, and decreased to the lowest at day 60 in the experimental group. In addition, adaptive subchondral bone remolding in the posterior part of the condyle was observed at day 60 in the experimental group, and the SEM revealed the ultrastructure variations after installation of the TIPD. However, these changes began to reverse after 30 days. Conclusion Condylar tissue changes point to the osteoclastic activity in the posterior region of the condyle. These adaptive changes point to bone resorption in the posterior condyle. Type II collagen and VEGF contribute to the MCC remolding induced by the TIPD. The ultrastructural changes in the posterior condylar area in response to mechanical stresses are recoverable at the initial stage.
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Stojić V, Glišić B, Djukić L, Prokić B, Janović A, Stamenković Z, Milutinović-Smiljanić S, Danilović V, Brković B, Roganović J. Mandibular lateral deviation induces alteration in vascular endothelial growth factor expression and oxidative stress/nitric oxide generation in rat condyle, synovial membrane and masseter muscle. Arch Oral Biol 2019; 110:104599. [PMID: 31734543 DOI: 10.1016/j.archoralbio.2019.104599] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 10/25/2019] [Accepted: 10/30/2019] [Indexed: 11/17/2022]
Abstract
OBJECTIVE We aimed to investigate alteration in cellular signaling mediated by vascular endothelial growth factor (VEGF) and parameters of oxidative stress/nitric oxide generation, superoxide dismutase (SOD) and neuronal nitric oxide synthase (nNOS), underlying altered functional mechanical loading of TMJ (temporomandibular joint) during lateral mandibular deviation. DESIGN Thirty-eight 5-week-old male Wistar rats were divided into experimental group, which received acrylic resin appliance that shifted mandible to the left during closure, and control group. Computed tomography and histomorphometry were used for condyle analyses, while samples of condyle, synovial membrane and m. masseter were analyzed with enzyme-linked immunosorbent assay and spectrophotometry to determine VEGF and nNOS protein concentrations, and SOD activity. RESULTS Experimental group of rats developed smaller and asymmetrical mandibles. Less of new bone and cartilage formation and larger bone marrow cavities area were found in the experimental group. Higher VEGF expression in condyle and m. masseter as well as higher nNOS expression in m. masseter and synovial membrane were found in the experimental compared to the control group. Alteration of SOD activity was found in m. masseter and synovial membrane in the experimental group. CONCLUSIONS Lateral mandibular deviation induces mandibular and condylar morphological changes as well as significant cellular signaling alterations in condyle, synovial membrane and masticatory muscle. Cellular VEGF protein overexpression and oxidative stress/nitric oxide disbalance could be the mechanisms underlying unbalanced functional TMJ loading due to mandibular deviation.
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Affiliation(s)
- Vanja Stojić
- Department of Orthodontics, School of Dental Medicine, University of Belgrade, Belgrade, Serbia
| | - Branislav Glišić
- Department of Orthodontics, School of Dental Medicine, University of Belgrade, Belgrade, Serbia
| | - Ljiljana Djukić
- Department of Pharmacology in Dentistry, School of Dental Medicine, University of Belgrade, Belgrade, Serbia
| | - Bogomir Prokić
- Department for Surgery, Orthopedics and Ophtalmology, Faculty of Veterinary Medicine, University of Belgrade, Belgrade, Serbia
| | - Aleksa Janović
- Department of Diagnostic Radiology, School of Dental Medicine, University of Belgrade, Belgrade, Serbia
| | - Zorana Stamenković
- Department of Orthodontics, School of Dental Medicine, University of Belgrade, Belgrade, Serbia
| | | | - Vesna Danilović
- Department of Histology, School of Dental Medicine, University of Belgrade, Belgrade, Serbia
| | - Božidar Brković
- Department of Oral surgery, School of Dental Medicine, University of Belgrade, Belgrade, Serbia
| | - Jelena Roganović
- Department of Pharmacology in Dentistry, School of Dental Medicine, University of Belgrade, Belgrade, Serbia.
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Jiang L, Xie Y, Wei L, Zhou Q, Li N, Jiang X, Gao Y. iTRAQ-based quantitative proteomic analysis on differentially expressed proteins of rat mandibular condylar cartilage induced by reducing dietary loading. Front Med 2017; 11:97-109. [DOI: 10.1007/s11684-016-0496-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 09/13/2016] [Indexed: 12/24/2022]
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Jiang L, Xie Y, Wei L, Zhou Q, Shen X, Jiang X, Gao Y. Identification of the vascular endothelial growth factor signalling pathway by quantitative proteomic analysis of rat condylar cartilage. FEBS Open Bio 2016; 7:44-53. [PMID: 28097087 PMCID: PMC5221432 DOI: 10.1002/2211-5463.12155] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 10/03/2016] [Accepted: 10/24/2016] [Indexed: 02/05/2023] Open
Abstract
Angiogenesis mediated by vascular endothelial growth factor (VEGF) is known to play an important role in regulating cartilage remodelling and endochondral ossification. However, the details of how VEGF signalling mechanisms affect condyle remodelling in response to alterations in functional loading remains unclear. To explore this, eighty 16‐day‐old male SD rats were divided into two equal groups which were fed either a soft/powdery diet or a hard diet for 4 weeks; the stiffness of the diet results in alteration of mastication force and hence temporomandibular joint (TMJ) development. We performed a proteomic analysis of rat condylar cartilage using isobaric tags for relative and absolute quantification (iTRAQ) labelling, followed by 2D nano‐high performance liquid chromatography and MALDI‐TOF/time‐of‐flight technology. After protein identification, we used biological information analysis to identify the differentially expressed proteins associated with the VEGF signalling pathway. Among the identified differentially expressed proteins, we found VEGF signalling mainly via the p44/42 MAPK and p38 mitogen‐activated protein kinase (MAPK) pathways in condylar cartilage, including VEGFD, VGFR2, KPCB, KPCT, KPCZ, ARAF, RASN, PLCG2, PLCG1, JUN and M3K12. Furthermore, four representative protein candidates, VEGF, p38 MAPK and p44/42 MAPK/phospho‐p44/42 MAPK, were confirmed by immunohistochemical staining and western blot. Our data suggest that VEGF might play an important role in TMJ development and remodelling in response to alterations in functional loading through the p44/42 MAPK and p38 MAPK signalling pathway. This study provides new clues to the understanding of the signalling mechanism responsible for VEGF production in response to different masticatory functions at the protein level.
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Affiliation(s)
- Liting Jiang
- Department of Stomatology Ruijin Hospital Affiliated to Shanghai Jiao Tong University, School of Medicine China; Department of Prosthodontics Shanghai Key Laboratory of Stomatology Ninth People's Hospital Affiliated to Shanghai Jiao Tong University, School of Medicine China
| | - Yinyin Xie
- State Key Laboratory of Medical Genomics Shanghai Institute of Hematology Ruijin Hospital Affiliated to Shanghai Jiao Tong University, School of Medicine China
| | - Li Wei
- Shanghai Institute of Traumatology and Orthopaedics Ruijin Hospital Affiliated to Shanghai Jiao Tong University, School of Medicine China
| | - Qi Zhou
- Shanghai Institute of Traumatology and Orthopaedics Ruijin Hospital Affiliated to Shanghai Jiao Tong University, School of Medicine China
| | - Xing Shen
- Shanghai Institute of Traumatology and Orthopaedics Ruijin Hospital Affiliated to Shanghai Jiao Tong University, School of Medicine China
| | - Xinquan Jiang
- Department of Prosthodontics Shanghai Key Laboratory of Stomatology Ninth People's Hospital Affiliated to Shanghai Jiao Tong University, School of Medicine China
| | - Yiming Gao
- Department of Stomatology Ruijin Hospital Affiliated to Shanghai Jiao Tong University, School of Medicine China
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Da Costa FF, Santos GSMQ, Farias-Neto A, Sanchez-Ayala A, Rizzatti-Barbosa CM. The relationship between occlusal support and maxillary development: An animal study. Eur J Dent 2015; 9:400-403. [PMID: 26430370 PMCID: PMC4569993 DOI: 10.4103/1305-7456.163230] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Objective: To test the hypothesis that maxillary development may be affected by occlusal support. Materials and Methods: The sample was composed by Wistar rats (5 weeks old) divided into three groups: Control (n = 10), extraction of mandibular molar teeth – left side (n = 10), extraction mandibular molar teeth – left and right sides (n = 10). The rats were sacrificed 8 weeks postextraction. Cone beam computed tomography scan images were taken for posterior measurement of maxillary length and width. Data were analyzed by one-way analysis of variance (Tukey test as post-hoc test). Results: Maxillary length was significantly shorter (P < 0.005) in both groups after tooth extraction. No difference was observed regarding maxillary width and body weight. Conclusion: Reduced occlusal support may impair the development of the maxilla in rats.
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Affiliation(s)
- Fabricio F Da Costa
- Department of Dentistry, Health School, Potiguar University - Laureate International Universities, Natal, RN, Brazil
| | - Gabriela S M Q Santos
- Department of Dentistry, Health School, Potiguar University - Laureate International Universities, Natal, RN, Brazil
| | - Arcelino Farias-Neto
- Department of Dentistry, Health School, Potiguar University - Laureate International Universities, Natal, RN, Brazil
| | - Alfonso Sanchez-Ayala
- Department of Dentistry, Ponta Grossa State University, School of Dentistry, Ponta Grossa, Paraná, Brazil
| | - Célia M Rizzatti-Barbosa
- Department of Dentistry, Piracicaba Dental School, Campinas State University, Piracicaba, São Paulo, Brazil
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The influence of altered occlusion on pro-inflammatory cytokine levels in the TMJ synovial tissues of rats. Arch Oral Biol 2014; 59:1164-71. [PMID: 25103542 DOI: 10.1016/j.archoralbio.2014.07.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 06/17/2014] [Accepted: 07/13/2014] [Indexed: 11/20/2022]
Abstract
OBJECTIVE The aim of this study was to evaluate whether altered occlusion affects both the condylar cartilage thickness and the cytokine levels of the TMJs of rats. DESIGN Thirty adult-male rats (n=30) were randomly assigned to three experimental conditions: a control group that underwent sham operations with unaltered occlusion; an FPDM group that underwent functional posterior displacement of the mandible that was induced by an incisor guiding appliance; and an iOVD group in which the increased occlusal vertical dimension was induced in the molars. The rats were subjected to the FPDM or iOVD model for 14 days and then killed. Both the right and left TMJs were removed and randomly assigned to examination with staining or immunoassay techniques. Toluidine blue staining was used to measure the thicknesses of the four layers of the articular cartilage (i.e., the fibrous, proliferating, mature, and hypertrophic layers). ELISA assays were used to assess the concentrations of the pro-inflammatory cytokines IL-1α, IL-1β, IL-6, and tumour necrosis factor (TNF-α). The measurements of the articular cartilage layers and cytokine concentrations were analyzed with ANOVA and Tukey's tests and Kruskal-Wallis and Dunn tests, respectively (α=5%). RESULTS The thickness of articular cartilage in the FPDM group (0.3±0.03mm) was significantly greater than those of the control (0.2±0.01mm) and iOVD (0.25±0.03mm) groups. No significant difference was observed between the control and iOVD groups. The four articular cartilage layers were thicker in the FPDM group than in the control and iOVD groups, and the latter two groups did not differ one from each other. Both the FPDM and iOVD groups exhibited higher cytokine levels than did the control (p<0.05) group. Compared to the FPDM group, the iOVD group exhibited significantly higher levels of IL-1β and TNF-α. CONCLUSION Both models induced inflammation in the TMJ and caused significant structural changes in the TMJ and surrounding tissues.
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Li Z, Lu H, Li ZB. The PI3K/Akt signalling pathway may play an internal role related to abnormal condylar growth: a preliminary study. Int J Oral Maxillofac Surg 2014; 43:1477-83. [PMID: 24929453 DOI: 10.1016/j.ijom.2014.05.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 05/17/2014] [Accepted: 05/19/2014] [Indexed: 10/25/2022]
Abstract
Developmental deformity of the mandible is one of the most common craniofacial malformations and is closely related to abnormal condylar growth. In this study, the role of PI3K/Akt signalling in the regulation of chondrocyte proliferation and hypertrophic differentiation in the condylar cartilage was studied. Immunohistochemical staining was used to investigate the expression of PI3K and p-Akt in the rat condyle cartilage. Rat condylar chondrocytes were cultured for the investigation of chondrocyte proliferation and hypertrophic differentiation when PI3K/Akt was inhibited. In addition, organ culture of the rat mandibular condyle was performed to evaluate the condyle cartilage growth while PI3K/Akt was inhibited. PI3K-positive cells and p-Akt-positive cells showing cytoplasmic staining were found to be present in the condylar cartilage. Reduced cell proliferation was observed in the culture of rat condylar chondrocytes when PI3K/Akt was inhibited; however, the hypertrophic differentiation level was increased. The proliferative zone thickness of condylar cartilage in the experimental group was less than that in the control group (P=0.00185), but the hypertrophic zone was greater than that in the control group (P=0.01048). PI3K/Akt signalling exerts opposite influences on chondrocyte proliferation and hypertrophic differentiation of the condylar cartilage, and these data suggest that PI3K/Akt is a potential intracellular regulation signal pathway in condylar cartilage development.
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Affiliation(s)
- Z Li
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory for Oral Biomedical Engineering of the Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China; Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Wuhan University, Wuhan, China
| | - H Lu
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory for Oral Biomedical Engineering of the Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China; Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Z-B Li
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory for Oral Biomedical Engineering of the Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China; Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Wuhan University, Wuhan, China.
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