Children begin getting primary, or "baby", teeth at about six to eight months of age, although it is not abnormal for some children to reach their first birthday before getting a single tooth.
Your child will produce ten primary teeth on the top jaw and ten primary teeth on the bottom. These teeth start to form before birth, and usually will all be present by three years of age.
Permanent, or "adult", teeth begin to appear in the mouth between five and eight years of age. Generally, the first permanent tooth to erupt is a molar that appears behind all the primary teeth. The next teeth are the lower incisors, in the front.
By the time your child turns fourteen years old they should have all their permanent teeth.