The people said that the big teeth that molar teeth, the average person’s mouth will have 12 molar teeth, the first molar, second molar, third molar 4 each, the third molar for the wisdom teeth, the majority of people’s wisdom teeth often have no occlusal function, there will be no effect after the extraction. In addition to wisdom teeth, there are 8 remaining molar teeth in the mouth, with their cusps opposite each other. Molar teeth play an important role in grinding food, and once a molar tooth is extracted, the chewing efficiency will be lost by about 16%. In addition, missing teeth for a long time will also lead to the neighboring teeth tilt shift, the opposite jaw teeth elongation, and then appear in the gap between the teeth become bigger, food congestion and a series of problems. Food debris retained in the tooth gap can cause oral odor and dental caries, etc. Although the missing molar teeth will not affect the aesthetic appearance, but in view of the above oral problems that may occur, or should be as early as possible to choose reasonable restorative methods to restore chewing efficiency and function.