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 six-year molars also help. determine the shape of the lower face and affect the. position and health of other permanent teeth. Most children have 28 of their permanent teeth. by age 13 years. These include four central incisors, four lateral incisors, eight premolars, four canines. and eight molars. The last of the permanent teeth to appear are. called âthird molars,â or âwisdom teeth.â They usu-. ally begin to eruptâpushing their way through the. gumsâbetween ages 17 and 21 years.