Hi, KiddKaydii, and welcome to Psych Central! I've read that losing teeth is a fairly common dream theme. I used to dream about it, too.

I'm not sure about their being keys, but it's interesting that we lose teeth when we get to be a certain age--and then we grow new ones. So, maybe there's some level of growth that has to be reached to meet certain goals--and then new goals always come along.