Could my crooked smile after Botox be caused by nerve damage? (photo)

Thank you for your photos. Your doctor is correct and the Botox was either injected or migrated to affect one side of your smile. Luckily it is very minimal and not noticeable but I am sure you feel a little "tight" when smiling and it Is bothersome. This can happen to anyone, even the most experienced injectors out there.Some people feel the effect of botox within minutes of it being injected and it takes 2 weeks for the best and final results to settle. There is no nerve damage here. Just sleepy muscle from botox.The good news is that it is not permanent and the effect will wear off in a few weeks to few months and you should be back to your normal self very soon. Time is your friend now.
Have a beautiful day.Best. Dr.Anna Avaliani, NYC

It’s very unlikely that your crooked smile is from nerve damage. Botox works by temporarily relaxing muscles, and when a neighboring muscle (like the risorius, which helps pull the corners of the mouth outward) gets affected, it can cause a lopsided or “frozen” smile.
A few key points:
Timing: Botox typically starts working within hours to days, so noticing it the same day isn’t unusual if some spread occurred quickly.
Migration vs. technique: It’s more often due to diffusion or placement rather than true migration weeks later.
Nerve damage signs: Permanent nerve injury is extremely rare with Botox and would usually come with other symptoms like numbness, weakness in unrelated muscles, or pain — not just a temporary asymmetric smile.
Recovery: Effects of Botox gradually wear off over 3–4 months, so your smile should return to normal as the product metabolizes.

Hello, our nurse injector reviewed your case.

The change in your smile is likely due to the Botox spreading slightly to the risorius muscle, which helps pull the corners of the mouth outward when you smile. This should not be nerve damage, and it doesn’t mean there is anything wrong with the nerves or muscles themselves. Rather, Botox temporarily weakens muscle activity, and in this case, the product has likely diffused into a nearby facial muscle unintentionally.

This can sometimes happen when treating TMJ with Botox, especially when injections are near the masseter muscle, which is close to muscles involved in facial expression. The effect is temporary and should gradually wear off as the Botox loses potency over the next few weeks to months. Your natural smile should return as the risorius muscle regains its normal function.

If this happens again or if you're concerned about it, your provider may adjust the placement or dose of Botox in future treatments to avoid affecting nearby muscles.

Thanks for sharing your question and posting your photo. Botox can change the shape of one’s smile. It should not be permanent and will likely resolve when the treatment wears off. Make sure an experienced oculofacial surgeon carefully evaluates your condition in person.
Good luck’

I agree with your Doctor, it probably was a migration to the Risorius muscle, it should recover 100% of the movement after the effect goes away with weeks.

Hello and thank you for the question. After Botox injections, it is possible that the neurotoxin can migrate and effect your smile muscles, which sounds like what you are describing. It would be unlikely to effect the facial nerve with an injection. Botox does not effect nerves themselves, rather it causes a paralysis of muscles by affecting the neruomuscular junction. I would recommend speaking with your initial provider to seek answers about what may have cause the asymmetry you have described.