Chris Penlington, Charlotte Bowes, Greig Taylor, Adetunji Adebowale Otemade, Paula Waterhouse, Justin Durham, Richard Ohrbach
The overall results are mixed, but indicate that psychological therapies may be a useful approach for painful TMD as there is some limited evidence that they can reduce the pain. Our review suggests that they may do this at least as well as other available treatments. Any negative effects of psychological therapies are unclear, and more research is needed before we can know whether they provide a noticeable benefit while causing no or few problems.
What is the condition?
Temporomandibular disorders (TMDs) are conditions that affect the jaw joint and the muscles that move it. They are often associated with pain that lasts more than 3 months (known as chronic pain). Other symptoms include limited mouth opening, and jaw clicking and locking. All symptoms can interfere with quality of life and mood.
What did we want to know?
We wanted to find out how effective psychological therapies are for adults and young people over the age of 12 years who have painful TMD that has lasted at least 3 months.
What did we do?
We searched databases of medical and dental journals and research studies. We only selected studies known as 'randomised controlled trials (RCTs)'. In this type of study, participants are allocated to groups randomly. One group receives the intervention and the other receives a different treatment or no treatment at all. RCTs aim to reduce the risk of introducing bias in clinical studies.
We looked for reports of RCTs of psychological therapies compared to different treatments or no treatment in people over 12 years of age. Most of the reports we found compared psychological therapy to medication or the use of a special mouthguard.
We chose to focus on three measures of success. These were reduction in pain intensity, interference with activities caused by pain ('pain disability'), and psychological distress. We looked for details of these measures immediately after treatment and a few months later. We also looked for information on any 'adverse effects' (negative side effects of the treatments).
We used standard Cochrane methods to decide which studies to include, collect the key information from the studies, judge whether or not the studies were biased in any way, and judge how certain we can be about the results.
What did we find?
Overall we found 22 relevant studies. Most of the studies reported on one particular form of psychological therapy called cognitive behaviour therapy (CBT). We did not have enough information to draw any conclusions about any other psychological therapies.
The results told us that CBT was no different to other treatments (e.g. oral splints, medicine) or usual care/no treatment in reducing the intensity of the TMD pain by the end of treatment. There was some evidence that people who had CBT might have slightly less pain a few months after treatment.
There was some evidence that CBT might be better than other treatments for reducing psychological distress both at the end of treatment and a few months later. This was not seen in the one study that compared CBT against usual care.
In terms of how much pain interfered with activities, there was no evidence that there was any difference between CBT and other treatments.
There was too little information to be sure about whether psychological treatments cause adverse effects (problems caused by treatment such as feeling unwell or worse pain or unexpected effects). Only six of the 22 studies measured what adverse effects participants experienced. In these six studies, adverse effects associated with psychological treatment seemed to be minor in general and to occur less often than in alternative treatment groups.
What are the limitations of the evidence?
We have little confidence in the evidence because many of the studies had design limitations. There was also variation in the length of treatment and in how it was delivered. This means that we need to be cautious in interpreting the results that we found and they may not be reliable.
How up-to-date is the evidence?
We searched for studies up to 21 October 2021.
Penlington C, Bowes C, Taylor G, Otemade AA, Waterhouse P, Durham J, Ohrbach R. Psychological therapies for temporomandibular disorders (TMDs). Cochrane Database of Systematic Reviews 2022, Issue 8. Art. No.: CD013515. DOI: 10.1002/14651858.CD013515.pub2.