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.
The standard number of primary teeth is 20 and the standard number of permanent teeth is 32. Primary teeth are the first set of teeth that erupt in a person's mouth, generally by the age of 36 months, and are shed by the time the person is about 12 years old. Permanent teeth then take the place of the primary teeth and are usually fully erupted by the time the person reaches 21 years of age.