Journal of Temporomandibular Joint
Online ISSN : 1884-4308
Print ISSN : 0915-3004
ISSN-L : 0915-3004
Volume 31, Issue 1
Displaying 1-4 of 4 articles from this issue
proceedings
  • Makoto TSUDA
    2019 Volume 31 Issue 1 Pages 3-7
    Published: April 20, 2019
    Released on J-STAGE: May 20, 2019
    JOURNAL FREE ACCESS

    Neuropathic pain occurs after damage to the nervous system caused by cancer, diabetes, infection, or trauma. Studies on the mechanisms underlying neuropathic pain had long focused on the role of neurons in the nervous system. Accumulating evidence indicates that glial cells (in particular, microglia and astrocytes) in the spinal dorsal horn rapidly respond to peripheral nerve injury and become activated, with changing expression of a variety of genes. Because controlling the function of these glial cells suppresses the development or maintenance of neuropathic pain, glial cells are crucial for understanding the mechanisms of neuropathic pain and are potential targets for treating this pain. This review highlights recent advances in our understanding of somatosensory information processing in the spinal dorsal horn and the role of glial cells.

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original articles
  • Mayu SUZUKI, Naomi OGURA, Teruo YANO, Kosuke TAKAHASHI, Fumie YAMAZAKI ...
    2019 Volume 31 Issue 1 Pages 8-15
    Published: April 20, 2019
    Released on J-STAGE: May 20, 2019
    JOURNAL FREE ACCESS

    Metabolites of extracellular matrix have been shown to be one of the pathogens for chronic inflammation. Fibronectin, an extracellular matrix component, is degraded by enzymes such as matrix metalloproteinase. Fibronectin fragments (FN-Fs; 30-200 kDa molecular weight) are present at high levels in synovial fluid from osteoarthritis patients, and are associated with inflammatory conditions. In this study, we investigated the role of FN-Fs in inflammation pathogens of temporomandibular joint disorders (TMDs). Synovial fibroblasts were prepared from synovium of the temporomandibular joint (TMJ) with internal derangement using the outgrowth method. Synovial fibroblasts were treated with 30 kDa FN-F. Gene expression was examined using a real-time PCR method. The FN-F induced the gene expression of monocyte chemotactic protein (MCP) -1, -2, and -3 in synovial fibroblasts from human TMJ synovium. The protein level of MCP-1, one of the best-known MCP members, was measured using ELISA. The protein concentration of MCP-1 was increased in the conditioned medium from synovial fibroblasts treated with 30 kDa FN-F. Furthermore, signal inhibitor experiments indicated that 30 kDa FN-F mediated induction of MCP-1 was inhibited via activation of NF-κB. MCP production mainly modulates monocyte/macrophage recruitment in multiple inflammatory diseases. These results suggest that 30 kDa FN-F is associated with the progression of inflammation of TMDs.

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  • Atsushi DANJO, Kenji KAKUDO, Eiro KUBOTA, Hirofumi YATANI, Yoshihiro T ...
    2019 Volume 31 Issue 1 Pages 16-23
    Published: April 20, 2019
    Released on J-STAGE: May 20, 2019
    JOURNAL FREE ACCESS

    In 2013, the Japanese Society for the Temporomandibular Joint announced a new classification of temporomandibular disorders (2013) based on the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Three years later, we investigated how the classification was viewed by 153 chief medical instructors at Japanese training institutions involved in TMD treatments. We explored the usage situation, methods employed, diagnostic overlaps, treatment priorities, availability of clinical statistics, utility of the new classification, and education of students and residents. We found that 87% of facilities used the new classification. In terms of diagnosis, the new classification was used by 73% of facilities, while 13% used the original DC/TMD. Multiple diagnoses were made in 88% of facilities, many of which prioritized treatment of arthralgia and myalgia. Overall, 23% of facilities considered the DC/TMD "useful" and 67% considered it "somewhat useful". The new classification was used to educate students and residents in 76% of facilities. Thus, the new classification is spreading widely as a result of its usefulness. Guidance in terms of treatment priority and a Japanese version of the DC/TMD including imaging criteria are required.

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case report
  • Satoru HORI, Kazuhiro NAGATA, Tomoko YOKOE, Yojiro ATSUMI, Wataru NAGA ...
    2019 Volume 31 Issue 1 Pages 24-31
    Published: April 20, 2019
    Released on J-STAGE: May 20, 2019
    JOURNAL FREE ACCESS

    Progressive condylar resorption (PCR) or idiopathic condylar resorption is a disease that manifests as a rapid resorption of the condyles and condylar processes leading to posterior dislocation of the mandibula or anterior tooth opening without injury or fraction. In this paper, we report the treatment and progression of an PCR case that emerged after treatment for temporomandibular disorder (TMD) with disc displacement without reduction. The PCR patient was a 43-year-old woman who visited the TMD & Bruxism clinic in our hospital, complaining of open bite of an anterior tooth and masticatory disturbance. The patient had been treated for TMD 3 years earlier in our clinic for mouth-opening limitations, with manipulation and a stabilization splint. Magnetic resonance imaging (MRI) showed a distinct resorption on both condyles with erosion, which we diagnosed as PCR because of the short period and remarkable resorption. We planned splint therapy for occlusal stabilization, exercise therapy of the mandible and habit control to improve jaw function as the primary treatment in this case. Secondary treatment using orthognathic surgery with full arch prosthodontic treatment was to be implemented after occlusal stabilization had been obtained to acquire an ideal occlusion. However, we canceled the secondary treatment, because the patient achieved acceptable development for occlusion after the primary treatment. As there are no reports in the literature regarding the predictable progression of PCR, there are no clear treatment guidelines. If functional and aesthetic development can be achieved without orthognathic surgery, priority on conservative treatment should be considered.

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