Orthodontic extraction of 4 teeth is necessary for orthodontic treatment and has no effect. With the evolution of human beings, jaws, teeth, muscles are constantly degrading, in which the jaws are degrading faster than the teeth, resulting in the amount of teeth is greater than the amount of bone, the jaws can not provide enough space, so there are misaligned teeth and crowding. When crowding reaches a certain level, orthodontic treatment requires the removal of teeth to provide space, the removal of 4 teeth is for the symmetry of the teeth as well as the establishment of a stable occlusal relationship, orthodontists will use the rest of the teeth shifted to close the gap between the extracted teeth. Therefore orthodontic extraction of 4 teeth, is the need for treatment, 4 teeth less in the mouth, chewing function may be a slight decline, but compared to the crowding caused by chewing function is not good, extraction of orthodontic benefits far outweigh the disadvantages. It is recommended to go to the regular hospital stomatology department, before orthodontic, and good communication with the physician.