3 months post op sliding genioplasty, wiped toothpaste from below lip but accidentally wiped the chin really hard could i have moved it back?

Genioplasty: Highly unlikely that one incident moved anything, especially 3 mos post treatment. If it failed to heal in the first place you would have likely known due to pain ,swelling etc... If still concerned, contact surgeon who performed.

Not likely..l: it should have been stabilized with small bone screws.

No: That said, if your even the least bit concerned call your Oral Surgeon and schedule a look-see.

Not likely: Three months time is long enough for biological union to take place.