All about Teeth Write T if the statement is true and F if otherwise 1. Canines are large, wide teeth whose function is to crush and grind food while eating. 2. Incisors are located at the rear of the mouth. 3. Humans have a total of 52 teeth in their lifetime-20 primary teeth and 32 permanent teeth. 4. Impacted wisdom teeth can lead to problems, including gum disease and tooth decay. 5. The main reason wisdom teeth grow so late in life is the lack of space at the back of a child's jawbone.