Are you supposed to change them every 3-4 months or when the bristles start fraying out like we do for adults? DD pretty much chews her toothbrush for "her turn" and then I try to brush a bit for "my turn".... so needless to say, her brush looks awful. Should I change or just leave it since we're not really "brushing" just yet?
FWIW, she has 8 teeth completely out and it looks like 4 or more are on their way in right now!