Somewhere I read or heard that the reason kids have baby teeth ("milk" teeth) is because evolutionarily kids breastfed until 5 or 6. Milk is not great for teeth. After they weaned they would get a brand new set of teeth which would last them into their adult years. When folks were hunter gatherers (which is basically what our bodies have evolved for--according to an article in the last issue of "Mothering" we have been farmers for 10,000 years and hunter gatherers for 100,000.) they had no access to milk (or refined sugar for that matter) so their teeth were safe from cavaties.

Julie Brill, B.A., C.C.E.