Hurry Humans develop teeth in two different stages of their lives. The first set of teeth develop in the first two years of a person’s life. They will keep that set of teeth for a few years until they begin to become loose. This loosening process makes space for a new set of teeth that the person will use for the rest of their life. What is the function of having two different stages of teeth development in a person’s lifetime? It allows the person time to learn good brushing habits before they get their permanent set of teeth. It allows the person to grow larger teeth in the second stage that they would not be able to form as a baby. It provides the person a chance to have a full set of teeth in case they lost a tooth as a kid. It allows the person to try new foods when they are more mature and can taste more flavors in food.