When disc brakes for high performance cars arrived on the scene we began to hear of warped brake discs on road going cars, with the same analyses and diagnoses. Typically, the discs are resurfaced to cure the problem and, equally typically, after a relatively short time the roughness or vibration comes back.
As a result, the cheek teeth, like the incisors, have evolved to continuously grow throughout life. In other rodents, the diet of tubers, seeds, and grain requires little chewing, resulting in little wear of the cheek teeth.
Slowly, the permanent teeth grow in and take the place of the primary teeth. By about age 12 or 13, most kids have lost all of their baby teeth and have a full set of permanent teeth. There are 32 permanent teeth in all â 12 more than the original set of baby teeth. Most people have four teeth (called wisdom teeth) grow in at the back of the mouth when they're between 17 and 25 years old.