<p>Cause of infringement of functional balance of chewing  system most often is teeth. Violation of natural parameters of tooth can lead to change of its function therefore chewing pressure goes not on a tooth axis. At the wrong arrangement and modeling of hillocks the chewed food can be distributed out of limits of an occlusive field. Plane contacts between teeth antagonists complicate uniform crushing of food, load of a periodontium thus increases, the erasing of teeth.</p>