You don't need them to chew properly, but they pop up (erupt) when your jaw grows and elongates during your late teen years. Open your mouth wide and use a penlight to see the back of your mouth.
[header] How to tell between an erupting and impacted wisdom tooth [title] Know where to look in your mouth. [step] Your wisdom teeth are the last molars on each row of teeth-the uppers and lowers on both sides. They are meant for grinding food.