Re: bottom lip throbbing
saz33: this could be a magnesium deficiency. I had throbbing going on under my eyes and a doctor told me it was a sign of magnesium deficiency. I had a test done to see if I was deficient and I was. I take a supplement now and the twitching is gone. You can also try eating dark chocolate, nuts, more green veggies, and cut down on caffeine if you drink it. Caffeine depletes the magnesium out of your body. Another thing you could try is adding Vit B6 and B12 to your diet because the B vitamins help with the nervous system too.
See if your doctor will do a whole work-up on you to see where your vitamin levels are.
I wish you luck.