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Metal Implants and Dental Amalgam: The FDA Announces Public Meeting and Paper

The U.S. Food and Drug Administration (FDA) announced a paper on metal-containing implants and a panel meeting as part of ongoing efforts to evaluate materials in medical devices to address potential safety questions.

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.

Cervical Muscle Tenderness in Temporomandibular Disorders and Its Associations with Diagnosis, Disease-Related Outcomes, and Comorbid Pain Conditions

To analyze cervical tenderness scores (CTS) in patients with various temporomandibular disorders (TMD) and in controls and to examine associations of CTS with demographic and clinical parameters.

You, Your Esophagus and TMD

The esophagus is a roughly ten-inch hollow tube that descends from your throat through the diaphragm into the stomach. Normally, it is a one-way street transporting food you swallow to the stomach for digestion. But in GERD— Gastroesophageal Reflux Disease— the flow can reverse so that stomach contents (including gastric acids) are regurgitated upwards to cause a burning sensation (heartburn), nausea, pain and other distressing symptoms.

It's Time to Be Part of the Solution

The National Academy of Medicine (NAM) Study on Temporomandibular Disorders (TMD) is well underway. We strongly encourage everyone affected by TMD to write to the NAM committee letting them know what it is like to live with TMD and your experiences with getting care.

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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In Treating TMJ

To view or order a free booklet about TMJ Disorders, visit the National Institutes of Health website.

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