Is it possible for masseter Botox to cause lasting harm to nerves or muscles?

Question

Dear medical professionals, I seek your assistance. I received masseter Botox treatment, and nearly six months have passed, yet my smile has not fully returned to its previous state. Is it possible that the injection process may have caused damage to my muscles or nerves? What steps can I take at this point to address this issue?

Metin Kerem · Accepted Answer

I can happily announce that no effect related to Botox injection is permanent. Sometimes mimic muscles can be affected from masetter injections, but just like any other complications of toxin injection, this is completely reversible. There is nothing you can do at the moment, just wait and see. No worries.

belo2510979881 · Answer

Hi, I have been getting botox in my masseters for many years but after an an injection at a new clinic I had not gone to before back in 2023, the same thing happened to me. The injected quantity was higher than usual even though I specified the number of units I wanted. My smile significantly closed, causing asymmetry and the corners don't lift as high as before. It's been 2.5 years and it never went back to normal. What are the possible causes? Could a nerve has been effected causing a lasting damage. Did yours go back to normal in the end?