Teeth have different shapes for different jobs. When you eat, the upper teeth work together with the lower teeth of the same shape to bite, chew, and tear food. The names of these teeth are: Incisors There are eight incisors located in the front of the mouth (four on the top and four on the bottom). They have sharp, chisel-shaped crowns that cut food.         Different Teeth   Cuspids / canines The four cuspids are next to each incisor. Cuspids have a pointed edge to tear food.   Premolars Also called bicuspids, the four pairs of molars are located next to the cuspids. They crush and tear food.       Molars There are twelve molars, in sets of three, at the back of the mouth. They have wide surfaces that help to grind food.   Children have one set of 20 baby (primary) teeth used in early development. These are generally replaced by a second set of 32 larger permanent teeth. By the age of 6-10 months most infants cut their first tooth. By 10 months to 3 years, infants, toddlers and preschoolers continue to get their lower, then upper primary teeth starting in the centre of the mouth and working backwards. By 3 years of age, most of a child's 20 primary teeth are in. By the age of 5-6 years children begin to shed their primary teeth and permanent teeth begin to erupt. By 12-13 years, most baby teeth have been shed and almost all permanent teeth are in.