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New Report on Temporomandibular Disorders: Priorities for Research and Care

Over a year and half ago, the National Academy of Medicine (NAM) began the most comprehensive study ever undertaken on Temporomandibular Disorders (TMD). The study assessed the current state of TMD research, education and training, the safety and efficacy of clinical treatments, and associated burden and costs.

Statement by NIDCR Acting Director on the National Academies of Sciences, Engineering, and Medicine Report on Temporomandibular Joint Disorders

I am pleased to announce the release of the National Academies of Sciences, Engineering, and Medicine (NASEM) report, Temporomandibular Disorders: Priorities for Research and Care. As underscored by the comprehensive report, temporomandibular joint disorders (TMJDs) are a diverse and still poorly understood set of complex, painful conditions affecting the jaw muscles and tissues, temporomandibular joints, and associated nerves. Clearly, there is much more to be understood, and these conditions continue to confound medical and dental health care providers and researchers.

Have you seen the film Dark Waters?

The Film. Dark Waters is about attorney Robert Billott's real-life 20 year legal battle against DuPont chemical for releasing toxic waste - perfluorooctanoic acid, or PFOA - into Parkersburg, West Virginia's water supply, with devastating health effects on the townspeople and livestock. PFOA, also known as C8, is a man-made chemical. It is used in the process of making Teflon and similar chemicals known as fluorotelomers.

Online TMD Diet Diary Research Project

Online TMD Diet Diary Research Project The TMJ Association received the following request from Professor Justin Durham and his research team at Newcastle University. We encourage TMJ patients to participate in this project as it is an under researched

Drug Induced Bruxism

The authors of this article state that orofacial movement disorders (bruxism) are treated typically by dental professionals and not by those specialists (neurologists) researching and treating the other movement disorders (Parkinson's disease, Huntington's disease, tremors, etc.). Again, this is more evidence of the complexity of TMD and the need for multidisciplinary research and treatment in TMD.

Sustained and Repeated Mouth Opening Leads to Development of Painful Temporomandibular Disorders Involving Macrophage/Microglia Activation in Mice

  • May 30, 2018

The following was published in the March 2018 issue of Pain. This research was conducted by Guan Yun Frances Wang; Xiang Qun Shi; Wenjia Wu; Maria Gueorguieva; Mu Yang; Ji Zhang, Faculty of Dentistry, McGill University, Montreal, QC, Canada.  

Abstract: Temporomandibular disorder (TMD) is a set of heterogeneous musculoskeletal conditions involving the temporomandibular joint (TMJ) and/or the masticatory muscles. Up to 33% of the population has had at least one symptom of TMD with 5-10% of them requiring treatment. Common symptoms include limited jaw movement, joint sound, and pain in the orofacial area. Once TMD becomes chronic, it can be debilitating with comorbidities that greatly reduce one's overall quality of life. However, the underlying mechanism of TMD is unclear due to the multicausative nature of the disease.  

Here, we report a novel mouse model of TMD where a bite block was placed in between the upper and lower incisors such that the mouth was kept maximally open for 1.5h per day for 5 days. Following sustained mouth opening, mice developed persistent orofacial mechanical allodynia and TMJ dysfunction. At the cellular level, we found masseter muscle dystrophy, and increased proteoglycan deposition and hypertrophic chondrocytes in the mandibular condyle. Increased F4/80 macrophages were also observed in the masseter muscles and the TMJ posterior synovium. We also found ATF3 neuronal injury and increased F4/80 macrophages in the trigeminal ganglia. Microglia activation was observed in the trigeminal subnucleus caudalis. Inhibiting macrophage/microglia activation with a colony stimulating factor-1 receptor inhibitor prevented the development of orofacial mechanical allodynia, but not TMJ dysfunction.

This study suggests that mouth opening for an extended period of time during dental treatments or oral intubations may risk the development of chronic TMD and inflammation associated with macrophage/microglia in the tissue and trigeminal system contributes to the development of TMD pain. 

TMJ Disorders

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