Botox Treatment for TMJ Pain
A New Remedy That Needs More Proof
Dear Doctor,
I’ve heard Botox is being used to treat TMD. Is this a good idea?
Dear Chris,
Temporomandibular Disorders (TMDs) are a group of conditions involving the temporomandibular jaw joint (TMJ), and the jaw muscles. Of these conditions, involvement of the jaw muscles is the most common problem. Although the exact cause is not known, stress — and the teeth grinding/clenching habits that may accompany it — can be important factors.
Proceed With Caution
The best way to treat jaw muscle pain initially is with conservative, reversible therapies. According to the American Association for Dental Research, “Studies of the natural history of many TMDs suggest that they tend to improve or resolve over time. While no specific therapies have been proven to be uniformly effective, many of the conservative modalities have proven to be at least as effective in providing symptomatic relief as most forms of invasive treatment.” Conservative therapies include: a temporary switch to a diet of softer, easier-to-chew foods; cold and heat packs; gentle therapeutic exercises; anti-inflammatory and pain-relief medications; and removable oral appliances (bite guards) to control tooth clenching and grinding habits.
Recently, Botox has been proposed as a possible treatment for jaw muscle pain. Botox is a drug containing botulinum toxin type A, a poisonous substance produced by the bacterium Clostridium botulinum, which can cause muscle paralysis. The FDA has approved Botox injection in small doses for certain medical and cosmetic uses. It has been suggested that the drug might help relieve jaw pain by paralyzing the muscles involved. While this is not presently approved for TMD by the federal Food and Drug Administration (FDA), it is currently being used by some doctors for this purpose.
There are a number of reasons why this may not be advisable. Most importantly, Botox is being used to treat the symptoms and not the cause of the problem. Therefore it is not a cure. There is at present no known mechanism that explains how Botox might address the underlying causes of TMD, only some anecdotal reports that such injections can help control its symptoms. However, the scientific evidence to support this view is slight. In fact, when taking into account only randomized, double-blind trials — the gold standard of scientific research — the results point in the opposite direction: The vast majority of these studies have found that Botox injections produce no clinically relevant effects.
Complications
There are also a number of potential complications associated with its use. One set of complications common to any intramuscular injection is pain, bruising and swelling at the injection site. What’s worse is that about one percent of patients develop severe headaches that can persist for weeks afterward. A small group may also develop antibodies against the toxin, meaning that it will take more and more of the drug to produce any noticeable effect.
Another drawback to Botox treatment is that rather than being a permanent solution, it offers at best a temporary fix. Botox injections typically become ineffective after a period of weeks or months, and generally need to be repeated. This can make them an ongoing — and costly — procedure; typically, medical insurance won’t cover non-FDA-approved treatments.
In some patients, the long period of decreased muscular activity resulting from repeated injections leads to muscle atrophy (wasting away) and even facial deformity.
Yet another potential problem with Botox injections results from its paralyzing effects on the muscles. In some patients, the long period of decreased muscular activity resulting from repeated injections leads to muscle atrophy (wasting away) and even facial deformity.
There is also some evidence that it can result in decreased density of the jaw bone (osteopenia). Studies have shown that Botox used to induce paralysis in animals can cause enduring bony (osteopenic) changes. Because of this, a recent clinical study in humans was undertaken to examine bone-related consequences of Botox injections in the masticatory (chewing) muscles. The study was controlled, meaning that one study population was given Botox and the other wasn’t. The Botox recipients showed evidence of bony changes consistent with osteopenia. Researchers noted decreased bone density in all participants exposed to Botox, but no bone-density decrease in the unexposed participants. These findings should be tested in a larger sample, and over a longer time period, to ensure safety of TMD patients receiving multiple Botox injections for their pain.
If there were no other treatments available for jaw muscle pain, the argument for trying Botox injections might be stronger. However, there are presently a number of less invasive treatments that have proven effective, especially if given enough time to work.
