The average adult has 32 teeth, with each tooth serving a specific purpose. The incisors in the front of your mouth tear food into small pieces to make them easier to chew. Your molars grind the food to make it small enough to swallow. Adults have 3 sets of molars on the top and bottom; however, the third set doesn’t appear until the late teen years. Wisdom teeth erupt between the ages of 17 and 21, but many people need to have them removed. 5 million people annually have them extracted. With so many extractions each year, why do we even have wisdom teeth? Believe it or not, they once served an important purpose, but nowadays they are more of a nuisance, and here’s why.