Ohhhhhh yes, I'm exactly the same! Gnashing teeth, bending fingers, pinching my skin and worst of all this compulsion to roll my upper lip up to my nose. Looks really really stupid! Like you say, it was a lot worse when I was a child but I'm still doing it.
It's definitely an obsessive/compulsive thing with me, like an itch, like having to get up in the middle of the night if I notice a door or drawer that isn't closed. Obsessive/compulsive behaviour is quite typical for people with panic disorder, I think.
Marianne