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National Academy of Medicine to Conduct a Study on Temporomandibular Disorders

We want you to be among the first to know that because of the advocacy efforts of The TMJ Association, the National Academy of Medicine (NAM) will conduct a first-ever study on Temporomandibular Disorders (TMD).

Dentists in Distress

Fear of the dentist is practically a rite of passage in youth. Growing up, I wasn't exactly afraid of the dentist; rather, any excuse to leave school early was a powerful incentive. These days, I have a more complicated relationship with dentistry: I go to get answers and try to feel better, but I always pop a prophylactic ibuprofen or two in case my jaw protests from the oral gymnastics.

Patients in Los Angeles or New York City Needed for Clinical Study - Comparative Study of Women Considering or Currently Receiving Botox© Injections for TMJ Pain

Are you a woman with "TMJ" pain in facial muscles, who has either: a. recently had Botox© injections for your pain or b. not had Botox© for your pain but has thought about such treatment? If either is true for you, you may qualify for an observational research study centrally administered by the NYU College of Dentistry. It is funded by the National Institutes of Health (NIH). The purpose of this study is to understand potential health risks that may be caused by treating "TMJ pain" with Botox© injections.

Patients Front and Center at the 2018 TMJ Patient-Led RoundTable

It is still all too fresh in the minds of many patients. Fifty years ago, between the 1970s and 1980s, some 10,000 TMJ patients received Vitek jaw implant devices.

Funding Opportunities now available for the NIH Common Fund’s Acute to Chronic Pain Signatures program

The NIH Common Fund's Acute to Chronic Pain Signatures program aims to understand the biological characteristics underlying the transition from acute to chronic pain and what makes some people susceptible and others resilient to the development of chronic pain.

Repeated Injections of Botox into the Masseter Muscle... A Longitudinal Study

  • Oct 5, 2017

We thank Dr. Susan Herring for writing the following article summary.

Lee HJ, Kim SJ, Lee KJ, Yu HS, Baik HS. Repeated injections of botulinum toxin into the masseter muscle induce bony changes in human adults: A longitudinal study.   Korean J Orthod. 2017 Jul;47(4):222-228. 

The authors of this study examined mandibular bone before and after subjects received Botox injections into each masseter muscle. These volunteers were healthy adults (22-48 years old), both male and female, who wanted injections to slim their faces. (This happens because the Botox causes temporary muscle paralysis and the masseters undergo atrophy when they are not used.) The 20 subjects were randomized into two groups. One group received a single dose of Botox in each muscle while the second group got two doses. The second dose was given 4 months after the first. The bone scans were cone-beam computed tomography (CBCT), a 3-D technique with relatively low radiation. The after-Botox CBCT scan was performed 6 months after the initial injection. The scans were directed at the mandibular angle, where the masseter attaches. The TMJ region was not examined.

Even 6 months after a single injection, the masseter muscles were much smaller than before injection (loss of about 70 mm2). Predictably, the shrinkage was much greater for the two-injection group (loss of about 140 mm2).

The very limited amount of mandibular bone examined is only part of the masseter's attachment, and an unaffected muscle, the medial pterygoid, attaches to it as well. Therefore, it is surprising that the authors were able to document a loss of bone volume which was statistically significant in the 2-injection group. The loss was due to thinning of the bone, because the mandible as a whole did not become smaller. The authors refer to this finding as an "unwanted side effect" of multiple Botox injections of the masseter muscles.

This study was not ideal and leaves many questions unanswered. Sample size was small, there were no uninjected control subjects, differences between the groups at the start were not reported, the bone examination was very restricted, and it is unknown whether full restoration of muscle and bone would eventually have occurred.  

Nevertheless, it is the first prospective, randomized, longitudinal study of the effects of Botox on the human jaw. The finding of bone loss is consistent with the only other human Botox study on jaws, a cross-sectional examination of the condylar bone of TMJ disorder patients who did or did not receive masseter injections (Raphael et al. 2014). The paper by Lee et al. reinforces the idea that thinned and weakened jaw bones are likely side effects of Botox treatment.

 Raphael, K. G., A. Tadinada, J. M. Bradshaw, M. N. Janal, D. A. Sirois, K. C. Chan and A. G. Lurie (2014). Osteopenic consequences of botulinum toxin injections in the masticatory muscles: a pilot study. J Oral Rehabil 41: 555-563.

Read the full article: https://synapse.koreamed.org/Synapse/Data/PDFData/1123KJOD/kjod-47-222.pdf

TMJ Disorders

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