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Major Research Update – The OPPERA Study: The Largest TMJ Disorder Study To Date

You may want to sit down, grab a cup of coffee or a smoothie 😉 and maybe even take some notes. This is one of the most important blog posts that you have ever read about TMJ disorder research.

I’m excited to be writing about this study – the OPPERA study – because it is by far the largest study to date about TMJ disorder, and they’ve uncovered some fascinating information that should really help each and every one of us.

The last time there was an update on the OPPERA study, we covered it, in May 2010. They had just a little bit of the results at that time. This time, however, is completely different. There is so much to report on this time that they have published an entire supplement to November’s issue of the Journal of Pain (meaning that this study was given a lot of attention and its own special issue in the well known peer-reviewed journal)!

So let’s start with a synopsis of what the OPPERA study is. Secondly, we will talk about what they found, and last (but not least!), I want to know what questions you have. Make sure you read to the end because I really need your feedback. If you ask a question, your question may be featured in an interview later this week! 🙂

1. What is OPPERA? The basics:


The OPPERA study (or Orofacial Pain Prospective Evaluation and Risk Assessment) followed 3,200 pain-free individuals ages 18-44 for three to five years. The results we are talking about today were part of the study in the very beginning, when they compared the 3,200 pain-free individuals to 185 patients who had chronic TMJ disorder. After that part of the study was over, they continued following the 3,200 pain-free individuals to see who developed their first bout of TMJD.

2. What did the researchers find about TMJ disorder?


They found a lot of very interesting information. Some of this information may seem basic to you as a TMJ disorder patient, but it is still extremely important because for the most part, this is the very first time we have had definitive data that actually proves these findings.

  • Most TMJ disorder patients are women, and the risk of developing TMJD is higher as women age. It seems to drop off after the late childbearing years.
  • Compared with pain-free individuals, those with TMJ disorder were more sensitive to pain, their heart rate increases during mild physical and psychological stress, and they are more aware of body sensations.
  • TMJ disorder patients have a higher rate of conditions like earaches, hearing loss, tinnitus, dizziness, fainting, and seizures – all neural or sensory related conditons.
  • Pain disorders are more common in those who have TMD, including headaches, low back pain, and fibromyalgia. Other disorders were also common: irritable bowel syndrome being one common one.
  • Abnormal jaw function was associated with clenching and teeth grinding. In later investigations, they will attempt to figure out whether clenching and grinding is caused by TMJ disorder, or is a consequence of it. At this point they believe that clenching and grinding are very likely both – a cause AND a consequence.
  • TMJ disorder does not seem to be tied to socio-economic status. This is a unique finding because many chronic pain conditions are tied to it (meaning that with other conditions they have found a higher incidence of the condition with a lower socio-economic status).
  • Chronic TMJ disorder patients have variations in several genes. These include genes that are known to influence inflammation, stress response, and psychological well-being.
  • Not one single risk factor was found to be the one, meaning that because the disorder is so complex, they doubt that there will ever be one singular cause of TMJ disorder. In the studies, they referred several times to what they call a “web of causation”.
  • Most of the 185 chronic TMD patients studied had both muscle pain and joint pain, while a very small percentage had just muscle pain (5%) or just joint pain (10%).
  • Past orthodontic treatment was only weakly associated with TMJ disorder. Just orthodontic treatment alone does not seem to improve or cause TMD.
  • One important item they will study more in the future is the idea that many of these factors that they’re measuring (for example, increased psychological distress, higher awareness of sensations) may actually be consequences or exacerbating factors of TMD rather than factors contributing to the actual onset of the disorder. This is an important distinction – are the issues we are facing as TMJ disorder patients the reason we’ve developed TMJ disorder, or are these issues consequences of having the disorder?
  • TMD patients have a higher number of sites on their body that are painful to palpation.

As you can see, these are very interesting findings that will influence our diagnosis and treatment in the very near future.

Personally, I think these are the biggest takeaways:

1. Other pain disorders are more common in people with TMJ disorder.

What does this mean? Do we have these conditions before we developed TMJ disorder? Or is it the opposite, that patients actually develop TMJ disorder first, then the other pain conditions?

2. TMD seems to be linked to a person’s perception of and ability to suppress pain.

3. Finally, it is becoming clearer through research like this that TMJ disorder is not just a head/neck/face pain disorder.

And last, but not least – what are your questions?
I’m happy to say that I will be talking with one of the lead researchers later this week, and I would love to incorporate some of your questions into the discussion.

What would you most like to know? Do these findings bring up new questions for you?


11 thoughts on “Major Research Update – The OPPERA Study: The Largest TMJ Disorder Study To Date”

  1. I have a couple of questions:

    First, I’m very interested about the sex differences and changes over a woman’s lifespan. I know other studies have shown relationships of estrogen/estrogen receptor to TMJ episodes; is this the mechanism thought to be related to the sex difference and change over lifespan? Is there translation of this to potential treatment mechanisms? How do TMJ episodes change during pregnancy with several hormone levels changing and new chemicals being introduced to the body?

    And second, a bigger more theoretical question: Is it possible that TMJ, fibromyalgia, IBS, etc. all involve some underlying mechanism instead of being distinct, comorbid conditions?

    Great write up, and great study. It’s wonderful to see a study tracking chronic TMJ patients and those who may develop TMJ in this data.

    1. Great questions, Jennifer.
      The pregnancy part of the question is particularly interesting because I’ve talked to several patients who have told me that when they are pregnant, they feel better. Of course I’ve also talked to several who *don’t* feel better, but there does seem to be some kind of correlation here.

      Thank you for your questions – I’m adding them to the list! 🙂

    2. I would also like to see some studies relating TMJ to pregnancy. I’ve talked to doctors who think this has to do with loosening of joints during pregnancy (and didn’t mention hormones) but I haven’t read any research to back their theories up.

  2. whats the connection between tmd and issues such as bladder problems/bowel problems?? there was a report written a few years ago about all of this but nothing since.

    1. Hi tisme! 🙂 Thanks for your question!
      IBS was mentioned several times in the studies. Specifically, in one part, the researchers stated that TMD patients reported more IBS symptoms than the controls, AND that they met the Rome criteria for IBS more often compared to controls.
      I don’t recall any mention of bladder issues. Thanks for asking, & I’ll add your question to the list for the researcher, too!

  3. I would love for them to look at other underlying factors such as are they stomach sleepers or side sleepers with pressure on their jaw or face, do those who develop symptoms have a tongue thrust or postural issues more often than those who do not develop TMD. 

  4. This is a wonderful article about a ground-breaking study!!!!  I’m really interested in finding out more about the genetic links between TMJD and other conditions, especially nerve damage.  I had bacterial spinal meningitis when I was a baby; I’m lucky I lived! I did however, end up with nerve damage and thus, nerve deafness, which means I’m also hearing impaired. As my TMJD has progressed (I’m currently preparing for bilateral total joint replacements-TMJ Concepts-with the fat grafts, etc…after already undergoing other surgeries and treatments), I’ve discovered I also have carpal tunnel (which is a nerve problem), migraines, a ton of aches and pains, and several of the comorbid conditions listed in the study.  I just never knew they were related. Now I have to have surgery on my wrists too (albeit much less serious surgery). Have they found any ties to people with early-occurring nerve damage to later developing severe TMJDs? Also, as new studies are coming out about Agent Orange (a non-related, Vietnam Veterans’ Illness), many researchers are considering if there is a tie between paternal genetic mutations from Agent Orange and nerve damage in their children; could TMJD be one of the results?  Just curious….

  5.  * I posted this comment on the may 2010 post, but just found this.  So coppied here as it’s more relevant:

    Of course every person is different, and with this disorder, often
    *very* different.  But personally, I’ve always felt like TMJ, not always, but is
    often a chronic pain as a result of another more acute cause.  Of course
    I’m only referring to the chronic cases, but like Fibro, IBS, and a
    whole bundle other, TMJ describes the symptoms, patterns, etc, but not
    the cause.  Thus this study supports my conclusions!

    Maybe the cause is so illusive because once it’s found, it’s attributed
    to a more acute ailment, treated, and the chronic pain diagnosis
    eventually heals with it.  Thus these chronic pains have a host of
    different causes, but once they get bad enough, with enough symptoms,
    they look the same.  Personally, I think this has a lot to do with all
    the chronic pain conditions, as they don’t necessarily have unique
    causes, nor each necessarily having single treatment.

    I have a lot more thoughts, but for later.  Thanks for posting this!

    (PS I’m in the trial, and didn’t know results were out, so it’s cool to see!)

  6. I would love to hear more about how TMJD relates to nerve conditions, such as facial neuralgias. I know that TMJ can cause trigeminal neuralgia and other pain conditions, but could it also work the other way round? I first developed TN and then my bite went off months later (although doctors say I may had had TMJD without knowing it). I didn’t grind my teeth until the TN. I would like to understand the correlation.

  7. Hi,
    Thank you for this! I am wondering if, they are saying that women are more prone, if it is estrogen related… What I mean is, I had a hysterectomy 5 yrs ago and developed the tmjd since then…So are they saying it’s related to the larger amounts we have or could there be anything to the fact that I have a lack of naturally produced estrogen and now take a supplement?

  8. This is thrilling. I could cry and hug the people doing this research. They are going to end up saving lives – because TMJD can take away life quality so easily. I had a feeling orthodontics couldn’t be a sole cause… for one my father had TMJD too (until he was in his forties or fifties I believe) and he never had orthodontics done. Secondly even though I am sure my braces and eventually the pulling of my wisdom teeth triggered something, my TMJD flare ups were never timed to seem consequences. I had my braces from age 12 to 13 – my TMJD started at 17. I had my wisdom teeth pulled in 2011 (without any extreme pulling or complications) and my TMJD flared up again over a year later. If anything my TMJD came back a few months after I had chest surgery and right after I emigrated… which to me seems like (especially since my dad has it) I have the genetics for it and it gets pulled out by something yet to be defined. I know I grind and clench but the 1,5 years I was gind/clench/TMJD-free inbetween cannot be explained just with that.

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