Children typically begin losing their primary teeth from around 6 years old. From 6-12 years, children have a mixture of grown-up as well as baby teeth. By about 12 years, a lot of children have all their adult teeth with the exception of the 3rd molars ( knowledge teeth). There are 32 adult teeth. If your child's baby teeth came late, the adult teeth will most likely be late also. If you're concerned concerning kids dentist as well as your child's teeth development, see your dentist.