Problem:
In Skeptics.SE, a question regarding the skulls of children arose. Depicting a scary skull where the permenent teeth are "hidden" inside the jaws and the milk teeth are in the their place.
After all milk teeth fall out, and the permanent teeth "rise",
Required:
Question: Do the holes left by them filled up, or do we go around with holes in our jaws?
Any ideas? Or better yet, pointers to places where this has already been answered?