Answer : A child’s primary teeth, sometimes called "baby teeth,” are as important as the permanent adult teeth. Children usually have 20 primary teeth which typically begin to appear when a baby is between ages six months and one year. Primary teeth help children chew and speak. They also hold space in the jaws for permanent teeth that are developing under the gums. Primary teeth start developing half way through pregnancy. The intake of systemic fluoride, usually present in tap water, is necessary for proper development of primary and permanent teeth.