Awful smile following Botox in masseter. How long will this last & are results permanent?

The changes and asymmetry of the smile following Botox injection are secondary to unintended differential weakness of other muscles, but the good news is that the effect is temporary and will be gone in 3-4 months maximum time.

Thank you for your question!  I am sorry that you are having these difficulties after your Botox injections.  Botox injections into the masseter muscle help to sculpt the face, and reduce the width of these muscles.  You may be noticing some changes because of relaxation of the masseter muscle, which is not directly involved with smiling.  I would discuss your concerns with your injector, and possibly have a follow up visit. I hope that this helps!-David Gilpin

The problem is that the risorius muscles was hit with the Botox. This muscles lies in front of the masster. This will take 2-3 months to resolve and it will go back to normal. Don't worry. This is on the higher side of dosing. I start at 15 per side.

Botox is a neurotoxin designed to weaken or paralyze targeted muscle. when injected into the face it can affect intended and unintended muscles depending on technique and dosing. What ever may be attributable to Botox is temporary and should resolve in 10-12 weeks. May need to alter injection technique, dosing and dilution of Botox for the next treatment.

Thank you again for your question.  With an experienced injector you should not have any asymmetry of your smile.  Alll these effects should go away in 3-4 months though.  Thanks for your question. 

Have a recheck with your doctor about your smile and your results.  The dosing likely will need to be altered next time.

Sorry to hear about your experience. Botox injection into the masseter muscles is an advanced injection technique and should only be performed by injectors who know and understand facial muscle anatomy. That being said, honestly, I do not see asymmetry in your smile on the photos you have provided. If there is a smile asymmetry, it may take 3-4 months to resolve as the Botox wears off. The main complications with Botox injection into the masseters is diffusion of the Botox into the nearby muscles causing smile asymmetry. In experienced hands, this is rare.