Secondary Teeth

The second set of teeth, called "secondary" or "permanent" teeth, consists of thirty-two teeth - sixteen in each jaw - and they are arranged from the midline of the mouth as follows: central incisor, lateral incisor, cuspid, first bicuspid (premolar), second bicuspid, first molar, second molar, and third molar. The permanent teeth usually begin to appear at six years of age, but the set may not be completed until the third molars appear between seventeen and twenty-five years of age. Sometimes these molars, called "wisdom teeth," become wedged in abnormal positions within the jaws and fail to erupt. Such teeth are said to be "impacted." Different teeth are adapted to handle food in different ways. "Incisors" (front teeth) are chisel-shaped, and their sharp edges bite off relatively large pieces of food. The "cuspids" (canine teeth) are cone-shaped, and they are useful in grasping or tearing food. The "bicuspids" and "molars" have somewhat flattened surfaces and are specialized for grinding food.