Botox for TMJ; the effect on clenching and grinding of teeth

TMJ syndrome is a disorder which often coexists with migraine and tension-type headaches and is characterized by pain in the jaw joint and surrounding muscles. It is very common, but the exact cause remains unclear. In many people TMJ is a sleep disorder, which can occur in the absence of overt stress, but stress definitely plays a role in most people. Headaches in patients with traumatic brain injury can be also worsened by bruxism (clenching and grinding of teeth), while treating bruxism contributes to the relief of headaches.

Dentists usually advise patients to sleep with a custom-made bite guard, but it only reduces grinding and may not stop clenching.

The standard injection protocol for migraines includes injections into the temples (temporalis muscles), which are involved in clenching, but my 25 years of using Botox suggests that many patients get much better results if lower jaw (masseter) muscles are also injected.

A study just published in Neurology tested the safety and efficacy of onabotulinumtoxin-A (Botox) injections into those muscles (masseter and temporalis) in patients with sleep bruxism.

This study included adults with sleep bruxism which was confirmed by an overnight sleep study. The study was randomized and placebo-controlled (half received Botox and the other half, placebo), with an open-label extension (when everyone receives Botox). Participants were injected with 200 units of Botox – 60 into each masseter and 40 into each temporalis muscle or placebo (by comparison, a total of 155 units is used to treat chronic migraine headaches). They were examined 4 to 8 weeks after the initial treatment. Global impression scale and perceived change in bruxism and in pain were assessed. .

Of the 22 participants who completed the study (19 women, mean age 47 years), 13 were given Botox and 9 received placebo. Global impression, pain and bruxism favored the Botox group. Two participants who received Botox reported a cosmetic change in their smile. No other side effects were reported. I find that many patients like the cosmetic effect of injections into the lower jaw muscles – they often acquire a more rounded face, instead of a square-jawed one. On the other hand, if temporalis muscles are injected too far towards the front of the temple, it can lead to an unattractive caved-in appearance.

In addition to Botox and an oral appliance, many patients with bruxism and headaches benefit from stress reduction techniques, such as meditation, biofeedback, progressive relaxation, yoga, and other. When medications are needed, we most often prescribe muscle relaxants and antidepressants.