Not sure how to describe this. My dad is up from Florida and staying with us. I noticed when he is watching tv sometimes his bottom lip seems to go in...I know I'm not describing this exactly correctly. Anyone know what I am trying to describe? Thanks.

Does he have PD? Can you describe better? Does his lip tremble? Is he aware he's doing it? As we age many of us lose control of fine muscle movement and muscle tone. From your very brief description it's too hard to tell what the cause may be. My dad is almost 80 and he does hold his mouth open more than he used to. He doesn't have PD or anything wrong, it's just part of aging in his case.

If I were concerned I would ask. It's never a bad thing to have someone care.

Does he pull his bottom lip under his "bite" where his top teeth are almost. "Biting" the lower lip and sucking it in? I think that maybe a matter of one of the "chorionic dyskinesias" or if held in the odd way for a long time, and showing no "reverting to normal", it sounds like a "dystonia". This condition is more than an open mouth", not to be confused with drooling. I take it that dad is "clenching" that lower lip, and he knows what he is doing it sometimes but not others.you can't say what is his problem might be until a neurologist has given him tests which may lead to a dx