Dear Linda,

I have had some limited personal experience with this phenomenon.  My grandmother
(fathers mother) was effected by this.  She was born in 1894 and passed away in
1974.  Her eye would open and close with each chew of her food to the day she died.
I asked her about it when I was a child and she said that she had done that from
the day she was born even when she nursed as a baby.  She never showed any other
signs of the problem as far as when she spoke or did any other facial movements
(only when chewing to eat).  She gave birth to and breastfed 10 children, has
numerous grandchildren, great-grandchildren, and great-great grandchildren none of
whom are effected.

Hope this helps.

Cheryl Leipold BS, IBCLC
mother of 9
Newnan, GA