Can Muscle Compensation Be a Long-term Effect of Botox?

Hi Chr021490. If your last Botox injection was over a year ago, it seems unlikely that the symptoms you are describing are related. We're also wondering what area of the face you had Botox injected.
For patients, it's above, in between or at the outside of the eyes. Are you relating these problems to "crow's feet" injections at the outer eye? This would seem to be the only possible related injection area, but the results would have worn off so long ago as to most likely rule this out.
The other possibility, which may be harder to accept is that you had some asymmetry before the injections. Your practitioner should have before and after photos to review with you to see if this is actually the case.
We suggest visiting him/her for a checkup to discuss your concerns. It is not uncommon to have a patient voice a concern over their appearance only to review the issue using the "before" photos to find out that it's nothing new. Good luck.

One thing is possible regarding your situation. Sometimes, people don't notice things about themselves until they actually get something done. This is a common thing that happens. When you get something done, like Botox, you tend to look at certain parts of your face more closely and notice things that used to be there before. That is why doctors have become used to pointing things out to people so that this doesn't happen after the particular procedure.
We are asymmetric for many reasons. One thing is really interesting though. When people look at others to asses beauty we tend to look at the right side of the person's face predominately. This is due to the fact that our right brains appreciate beauty more than the left brain. Our visual fields are crossed and asymmetric which leads to this phenomenon. You can find this out by searching on the web for visual field pathways in the brain. Hence, we select one another, from a sexual selection stand point, by concentrating more on the right side of the face.
In terms of the possibility that other facial muscles are working harder to compensate and then subsequently leading to asymmetric muscle movement and size differences, This is a possibility that hasn't been looked into as much from a scientific standpoint and could be happening. I would have to see pictures myself to really come to some assesment of the situation. Botox could help in this regard too. You could put Botox in those muscles that you think are bigger in a very conservative way. I would talk to your doctor or send me pictures.
I hope that helps!

The symptoms and findings you describe are quite unusual and should not be related to Botox. However, I am sure you have questions about this because the timeing seems right.
I would continue to see your physicians in close follow up to ensure that there are no other medical conditions which could be responsible for your current condition.
Generally, all effects of Botox should dissipate after 5 months. It seems very unlikely that it is responsible.