Premolar teethare between the canine front teeth and the molars. These are transitional teeth; teeth that transition between the tearing function of the canines and the grinding function of the molars. In other words, the primary functions of these teeth during chewing overlap with the functions of both molars and canines.
名为第一前磨牙和第二前磨牙牙齿premolar and there are two per quadrant, or eight per adult mouth. These quadrants split the upper and lower areas of the mouth in half and are referred to as lower left, lower right, upper left, and upper right.
These teeth will have at least two cusps, or elevations in the crown (top surface) portion of the tooth. The first premolar will have two cusps. The second premolar may have two lingual cusps, or smaller cusps that are unequal in size. Premolar teeth are permanent teeth and can be called bicuspids.
Primitive man had four premolars per quadrant, or 16 per person. Over time, the mesial premolars — those nearest the front of the mouth — have been lost. Paleontologists refer to these mesial premolars as premolar 3 and premolar 4.