I have three year old girls; one sucks her fingers and one sucks her thumb. This is having an effect on their baby teeth and seems to be making them buck toothed and in the case of the finger sucker, gappy. I tried to explain to them that sucking would ruin their teeth and make them look like Bugs Bunny. The look on their little faces made me feel so bad. Was I being unreasonable to say this? Should I just leave them in peace to suck away, even though it might ruin their teeth? Might it not even damage their adult teeth below?