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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.

Early Molecular Response and Microanatomical Changes in the Masseter Muscle and Mandibular Head After Botulinum Toxin Intervention in Adult Mice

  • May 30, 2018

We thank Dr. Susan Herring for providing our readers with this research summary. 

In this small study, young adult mice received an injection of Botox in the right masseter muscle, while the left masseter received the same volume of saline as a control. The authors examined gene expression in the mandibular condyles 2 days after the injections and in the muscles 7 days after the injections. Two weeks after the injections, they looked for structural changes in the condyles and masseters.

The results showed dramatic early changes in gene expression. Only 2 days after treatment, the Botox side condyles showed four times as much activity in a gene that promotes bone resorption (RankL) than the saline side condyles. The Botox-injected masseters had greatly increased expression of genes involved in muscle atrophy at the 1 week time point compared to the control side muscles. At the end of the study, 2 weeks after injection, the Botox-injected masseters were about 20% smaller than the control side masseters, and the Botox-side condyles had lost about 40% of relative bone area compared to the control side condyles.

This study is preliminary in many ways. Sample size was very small and only included male mice of one inbred strain. Each outcome was measured at just one time point. The findings that Botox treatment of the masseter cause atrophy of the paralyzed muscle and severe loss of bone in the TMJ region are not new. Nevertheless, the study illustrates how rapidly the tissues react to treatment with this powerful toxin. It is striking that bone loss in the condyles was already triggered by the second day, because this bone loss is likely not a direct effect of the toxin, but rather a response to the absence of muscle loading.

From the point of view of The TMJ Association, important questions that remain include (1) does the bone of the condyle eventually recover, and if so, how long does it take? and (2) does the loss of condylar bone threaten the integrity of the TMJ and make it more vulnerable to injury? To date, there are no studies that address these questions in either animals or humans.

Source: Balanta-Melo J, Toro-Ibacache V, Torres-Quintana MA, Kupczik K, Vega C, Morales C, Hernández-Moya N, Arias-Calderón M, Beato C, Buvinic S. Early molecular response and microanatomical changes in the masseter muscle and mandibular head after botulinum toxin intervention in adult mice Ann Anat. 2018 Mar;216:112-119. doi: 10.1016/j.aanat.2017.11.009. Epub 2017 Dec 28. 

TMJ Disorders

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