Youngsters generally start losing their primary teeth from around 6 years old. From 6-12 years, youngsters have a combination of grown-up and also baby teeth. By about 12 years, the majority of youngsters have all their grown-up teeth except for the third molars ( knowledge teeth). There are 32 grown-up teeth. If your child's baby teeth came late, the adult teeth will most likely be late also. If you're worried about kids dentist as well as your child's teeth development, see your dental professional.