Unsure, I can relate. I can tell what kind of a day it is going to be by looking in the mirror and trying to smile. If my right corner lip turns up, it is going to be an OK day. If the right side turn down ward, it is going to be a bad day.

I use to have dimples on both sides of my face, now I only have them on the left. My face appears stroke like most of the day, so I do not make eye contact or even try to smile so it is less noticeable. Of course all these symptoms are better after mestinon and get worse as it wears off.

Early in my MG days, I had no problems with my smile. It only happened as my symptoms progressed. My eyes on the other hand are a constant bother. They tremble and quiver all day long. I have no doubt it is muscle weakness.
Don't let the docs stress you out. I always schedule my mestinon so it is wearing off at the time of my doctor appointment so they can see what I am really like.
kathie