The massetter muscle is located at the lower and rear aspect of the cheek, running from the cheek bone down to the lower jaw on both sides of the face. The muscle is one of the muscles of mastication (chewing), and it’s function is to close the jaw while chewing.

In some people, the massetter muscle becomes enlarged if they clench or grind their teeth (bruxism). Unequal enlargement of the muscle may result in facial asymmetry and increased muscle bulk, creating an overly-square or masculine-looking jawline.

A popular treatment for non-surgical massetter muscle reduction is the use of Botox® or Dysport® injections directly into the muscle.

Why is it sometimes necessary to “revise” a Botox® massetter muscle reduction treatment?

Injecting Botox® or Dysport® into the massetter muscle requires an in-depth knowledge of the structure of craniofacial anatomy, along with an intimate understanding of how muscles and tendons work in the jaw. If Botox® or Dysport® are not placed in the massetter correctly, unintended and negative side effects may result that may take weeks or many months to resolve.

Patients who come to us for a revision Botox® or Dysport® massetter muscle reduction typically do so because they received Botox® treatment from an unqualified provider, resulting in an unsatisfactory outcome, or unintended side-effects which may include:

  • Crooked, lopsided or assymetrical smile, or unwanted changes to other facial expressions
  • No evident reduction in the massetter muscle (no visible result)
  • Inadvertant full- or semi-paralysis of jaw muscles leading to chewing problems
  • Asymmetrical results: massetter reduction in one side of the face, but not the other
  • Partial or full facial muscle paralysis from over-injection of Botox® or Dysport®

Most of the negative side effects mentioned above are typically caused by an unqualified provider injecting the Botox® or Dysport® in the wrong location, or at the wrong depth (too deep or too shallow) into the muscle.

We cannot emphasize this enough: always choose a highly qualified and trained provider for your Botox® treatment.

There are great risks if Botox® or Dysport® are not administered by a highly trained professional who understands the complexities of craniofacial anatomy. The small amount you may save by choosing an unqualified or ill-trained provider for treatment is far outweighed by the risk you take.

In our experience, and the experience of our patients, it is definitely not worth it.

If I need a revision Botox® treatment will I need to wait until the previously poorly-applied Botox® has worn off?

If you currently have muscle paralysis or jaw weakness from the use of too much Botox® or Dysport®, or it has been injected too deeply, unfortunately you may have to wait several weeks or months until the Botox® or Dysport® wears off before undergoing another treatment.

If you are suffering from a crooked or lopsided smile, or an asymmetrical result, we may be able to place additional injections of Botox® or Dysport® into the massetter muscle immediately. It depends on the previous treatment and your desired outcome.

Depending on your circumstances, you may need a series of several treatments to achieve the level of massetter muscle reduction you seek. But the greatest benefit of applying Botox® or Dysport® correctly is a gradual approach that ensures steady progress towards the degree of massetter muscle reduction that you’re happy with.

Typically, injections of Botox® may need to be repeated every 4-6 months for at least a year to see a significant and obvious reduction in massetter muscle size. Then the decreased size of the masseter may remain stable -- even without further injections. Read more about Botox use here.

Might I need surgical reduction of the massetter muscle?

Depending on your desired aesthetic outcome, Botox® may not be the answer for you. In fact, you may require a surgical option such as surgical reduction of the massetter muscle.