Baby teeth also known as deciduous teeth primary or milk teeth are the teeth that children have due to the fact that infant jaws are too small to accommodate adult-sized teeth. To over come the fact that children grow smaller teeth are necessary until the jaw grows to its mature size.
Between the ages of 6 months and 1 year the deciduous teeth begin to push through the gums. This process is called eruption or teething. At this point the crown (the portion of a tooth covered by enamel) is complete and the root is almost fully formed. By the time a child is 3 years old he or she has a set of 20 deciduous teeth 10 in the lower and 10 in the upper jaw. Each jaw has four incisors two canines and four molars. The purposes of the molars are to grind food and the incisors and canine teeth are used to bite into and tear food.
By the time the average child is six the jaws and jaw muscles have grown in size and strength paving the way for the arrival of permanent adult teeth. As the fundamentals of adult teeth form in the gums specialized cells called odontoclasts reabsorb the roots of the baby teeth. By the time the adult teeth start to push through the gums the rootless baby teeth are loose and ready to come out. The baby teeth help the permanent adult teeth to push through into their normal positions and most of the permanent teeth form close to the roots of the baby teeth. Permanent tooth development continues over the next 15 years as the jaw steadily grows into its adult form. From ages 6 to 9 the incisors and first molars start to come in. Between ages 10 and 12 the first and second premolars as well as the canines extend. From 12 to 13 the second molars come in. The wisdom teeth (third molars) erupt between the ages of 17 and 21. Sometimes there isn't enough room in a person's mouth for all the permanent teeth. If this happens the wisdom teeth may not come through at all which can lead to overcrowding of the teeth and is one of the reasons people get braces.
Recent research into baby teeth has led to the discovery by scientists that baby teeth from are also a good source of stem cells a type of cell that can transform into and generate other cells. These cells could help repair damaged teeth and perhaps even treat neural injuries or degenerative diseases.