I’ve noticed that when I grin, the right side of my mouth comes up far more than the left side (my right, my left, not the viewer’s). Of course, I CAN smile normally, it’s just that it’s easier for me to smile on one side.
Also when I’m making a speech, or acting, or whatnot, I do that grin. The right corner of my mouth comes up involuntarily. The same for lying–my mother and my best friends, once they know my secret, always know if I’m fibbing because of my grin.
It’s okay, some people just do that! Besides, sometimes it can be really cute! If it’s how you usually smile, make a full smile something special. For example, when you really like someone, then you can put forth a conscious effort to smile fully. It will make a big difference to that person. Say cheese!
You have a mild dysfunction of the levator anguli oris, according to the House-Brackmann classification of facial function.
Disclaimer: That was complete bullshit, I think.
I copy-and-pasted it while googling around without result, because I vaguely remembered seeing on TV that there is a medical term for the nerves or muscles on one side of the face being less excitable, yet fully functional. Sorry.
But maybe it irritated our docs enough to make one of them visit this thread, if only to kick me.
Say cheese!