do humans lose all their baby teeth
A primary tooth falls out because it is being pushed out of the way by the permanent tooth that is behind it. Slowly, the permanent teeth grow in and take the place of the primary teeth. By about age 12 or 13, most kids have lost all of their baby teeth and have a full set of permanent teeth. There are 32 permanent teeth in all â 12 more than the original set of baby teeth. Most people have four teeth (called wisdom teeth) grow in at the back of the mouth when they're between 17 and 25 years old.