Botox Revisited: May be Useful but not without Risks

I want to be clear from the beginning that I am not against Botox injections in clinical practice. In the right setting, and for the right person, they may have a role. That is especially true when treatment is provided by a medically trained professional, such as a maxillofacial specialist or an appropriately trained dentist, and when it is planned carefully.

My caution is not ideological as such. It is clinical. Botox is not always a quick fix, it is not right for every jaw problem, and it should be planned carefully with a qualified provider so that it is given safely, accurately, and for the right reason. Patients should also know what it may help, what it may not help, and what the possible downsides are.

This research-based blog explains why I am careful about recommending Botox for TMD, while at the same time accepting that it may help in selected cases.

Why people use Botox for TMD

Botox is sometimes used when the main problem is mostly because of overactive or painful jaw muscles. This is most relevant in myogenous TMD. “Myogenous” simply means that the pain is thought to come mainly from the jaw muscles, rather than mainly from the jaw joint itself. The term myofascial pain (MFP) is also used. So if someone has sore, tight, overworking chewing muscles, Botox may be considered because it ‘weakens’ those muscles and may reduce pain or heavy clenching. (pubmed.ncbi.nlm.nih.gov)

That is the attraction of Botox. If the muscles are driving the problem, weakening or inhibiting them may seem like a logical answer.

Some earlier research reviews and trials have reported benefit in selected patients, but the picture is mixed. A 2022 review described “equivocal evidence for myogenous TMDs”, meaning the evidence was uncertain and inconsistent. A 2024 randomised placebo-controlled crossover trial found that 50 units of BoNT-A "might improve MFP symptoms", but the authors also said the specific effect compared with placebos "is not obvious". (helda.helsinki.fi)

That is not a strong green light. It is more of a yellow light.

What the bigger picture says

The wider evidence has become more cautious.

The 2023 BMJ clinical practice guideline for chronic painful TMD, meaning pain present for 3 months or more, made a conditional recommendation against botulinum toxin injection. That means Botox should generally not be routine treatment for most people with long-standing painful TMD. It does not mean never use it. It means the evidence is not strong enough to support it as a standard go-to option for most patients. (pubmed.ncbi.nlm.nih.gov)

Then in 2024, Saini and colleagues published a systematic review and meta-analysis. Their conclusion was very direct: “Botox was not associated with better outcomes” for pain reduction, adverse events, maximum mouth opening, bruxism events, and maximum occlusal force compared to a placebo. That is a strong statement because these are the very outcomes usually used to justify giving Botox in TMD. (pubmed.ncbi.nlm.nih.gov)

So the current high-level message is this: Botox may help some people, but the best recent summary of the evidence does not show that it clearly performs better than placebo or other treatments on the outcomes that matter most. (pubmed.ncbi.nlm.nih.gov)

What worries me most is what it may do to the muscles

This is where my caution becomes stronger.

A 2024 systematic review in Annals of Anatomy looked at the histological and functional effects of botulinum toxin A in the chewing muscles. “Histological” means what happens to the tissue itself under the microscope. “Functional” means what happens to how the muscles actually work. The authors concluded that botulinum toxin injection into the chewing muscles “altered its histological structure and functional properties" (pubmed.ncbi.nlm.nih.gov)

They found that even one injection was linked with:

• Ultrastructural change - microscopic changes inside the muscle fibres

• Atrophy - the muscle becomes smaller or thinner

• Fibre type modification – the muscle may change the kind of fibres it relies on

• Reduced bite force – the person may not be able to bite as strongly

• Reduced muscle activity – the muscle is not working with the same output as before

  
  

The same review also stated that muscle “recovery was uncertain." Which means we cannot confidently assume the muscle always returns to normal after the effect wears off. The authors then gave a very important warning: "Multiple injections should be avoided." (pubmed.ncbi.nlm.nih.gov)

That is the point many discussions skip over. Botox is not just a pain treatment. It is also a muscle-weakening treatment. If a patient may feel less pain, but the price is muscle thinning, weaker biting, and uncertain recovery, that trade-off needs to be explained honestly.

What about the jaw bones?

There is also a bone question.

The 2024 muscle review said that masticatory muscle paralysis changes mechanical stress on bones. If you weaken the jaw muscles, you change the forces those muscles place on the facial skeleton. That matters because bone health depends on loading. (pubmed.ncbi.nlm.nih.gov)

This does not mean major bone damage happens in every patient. The bone evidence is less clear than the muscle evidence.

A separate 2024 systematic review looking at mandibular bone resorption and density found “no clear pattern” linking Botox injections in the chewing muscles to bone resorption, and most included studies did not show major consistent changes in jawbone measures. So at this stage, the bone evidence is mixed and limited. (pubmed.ncbi.nlm.nih.gov)

So the fairest summary is that the evidence for muscle change is stronger than the evidence for bone change, but bone loading is still part of the concern. (pubmed.ncbi.nlm.nih.gov)

Why I stay cautious

My hesitation about Botox for TMD comes down to a few practical points.

First, TMD is usually not one single problem. Some people mainly have muscle pain. Some mainly have joint pain. Some have disc problems, arthritis, headache overlap, poor sleep, stress-related clenching, or a mix of several things. A treatment that inhibits muscle may help some muscle-driven cases, but it will not fix every type of TMD.

(pubmed.ncbi.nlm.nih.gov)

Second, the best current guideline does not support routine Botox use for chronic painful TMD. (pubmed.ncbi.nlm.nih.gov). Instead, the guidelines recommend cognitive behavioural therapy (CBT), therapist-assisted mobilisation, manual trigger point therapy, supervised postural exercise, supervised jaw exercise and stretching with or without manual trigger point therapy, and usual care (such as home exercises, stretching, reassurance, and education). As well as conditional recommendations for manipulation, supervised jaw exercise with mobilisation, manipulation with postural exercise, and acupuncture. These are all treatments we offer here at the clinic. 

Third, the best recent meta-analysis found that Botox was not associated with better outcomes. (pubmed.ncbi.nlm.nih.gov)

Fourth, the newer tissue-level evidence raises a real concern that the muscles themselves may change in ways that are not insignificant and where full recovery cannot simply be assumed. (pubmed.ncbi.nlm.nih.gov)

Fifth, patients are sometimes given the impression that Botox is a fast, easy answer. I think that is risky. It may be useful in some cases, but it should not be sold as a magic shortcut.

A balanced view

This doesn't rule out Botox's usefulness.

It may still be considered in selected difficult cases, especially where the pain seems clearly muscle-driven, where other comprehensive conservative care has already been tried, and where the patient fully understands the possible benefits, limits, and risks. That is very different from presenting it as a routine answer for clenching, bruxism, or chronic jaw pain. (pubmed.ncbi.nlm.nih.gov)

So my position is balanced but careful.

I am not anti-Botox. I believe it has a role. But I think patients should know that:

• it is not always a quick fix

• it is not right for every TMD

• the best recent evidence does not strongly support routine use

• the muscle effects deserve serious attention

• treatment should be planned carefully with an appropriately trained provider

  
  

Final thought

The real question is not whether Botox is good or bad.

The real question is whether it is being recommended with enough care, enough diagnostic accuracy, and enough honesty about what the evidence actually says.

For some patients, Botox may be reasonable. But it is not always simple, and it is not risk-free. That is why I remain cautious.

By Simon Coghlan

References

Busse, J. W., Casassus, R., Carrasco-Labra, A., Durham, J., Mock, D., Zakrzewska, J. M., Palmer, C., Samer, C. F., Coen, M., Guevremont, B., Hoppe, T., Guyatt, G. H., Crandon, H. N., Yao, L., Sadeghirad, B., Vandvik, P. O., Siemieniuk, R. A. C., Lytvyn, L., Hunskaar, B. S., & Agoritsas, T. (2023). Management of chronic pain associated with temporomandibular disorders: A clinical practice guideline. BMJ, 383, e076227. https://doi.org/10.1136/bmj-2023-076227

Delcanho, R., Val, M., Guarda-Nardini, L., & Manfredini, D. (2022). Botulinum toxin for treating temporomandibular disorders: What is the evidence? Journal of Oral & Facial Pain and Headache, 36(1), 6-20. https://doi.org/10.11607/ofph.3023

Guignardat, J.-F., Raoul, G., Ferri, J., Sciote, J. J., & Nicot, R. (2024). Systematic review of the histological and functional effects of botulinum toxin A on masticatory muscles: Consideration in dentofacial orthopedics and orthognathic surgery. Annals of Anatomy, 256, 152302. https://doi.org/10.1016/j.aanat.2024.152302

Saini, R. S., Almoyad, M. A. A., Binduhayyim, R. I. H., Quadri, S. A., Gurumurthy, V., Bavabeedu, S. S., Kuruniyan, M. S., Naseef, P. P., Mosaddad, S. A., & Heboyan, A. (2024). The effectiveness of botulinum toxin for temporomandibular disorders: A systematic review and meta-analysis. PLOS ONE, 19(3),e0300157. https://doi.org/10.1371/journal.pone.0300157

Sitnikova, V., Kämppi, A., Kämppi, L., Alvesalo, E., Burakova, M., Kemppainen, P., & Teronen, O. (2024). Clinical benefit of botulinum toxin for treatment of persistent TMD-related myofascial pain: A randomized, placebo-controlled, cross-over trial. Pain Practice, 24(8), 1014-1023. https://doi.org/10.1111/papr.13396

Wojtovicz, E. L., Martinez Alvarez, O., Lopez-Davis, A., & Armijo-Olivo, S. (2024). Botulinum toxin type A injection into the masticatory muscles and its effects on mandibular bone resorption and density: A systematic review. Clinical Oral Investigations, 28, 477. https://doi.org/10.1007/s00784-024-05838-5