I've noticed with my daughter how, when she's excited (tho only when sitting and focused on something), she opens mouth as tho gasping for air, then calmly closes...repeats this behavior several times, still, only when sitting and suddenly excited. She rocks her body with hands clasped together as though a burst of sudden joy overcomes her, then relaxes again..until the next excitement overcomes her, repeats.
I never really thought that this behavior was out of the norm, (though what is normal?). She isn't on any meds to associate this behavior to. I just attributed this to how she is. I've never brought this observation of mine to her attention. I didn't want to make her feel uncomfy with how she is.

She also walks on the balls of her feet, sometimes on tip-toes, but never on her entire foot. Always walks leaning slightly forward, sometimes looks as though she's gunna tip over forward. (She has been dx'd with scoliosis, so that may be contributed to her posture while walking).

My entire family is known to use facial expression for emphasis of activity....lol. Especially my sister. Omg. The excessiveness of mouth movements...looooool...as though it assists to achieving her goal obtained, (usually when active in phsycial competition of some sort).

Shangrala