Orthodontics is actually a kind of work to rearrange the position of the teeth, in the process of rearrangement often need enough space to align the teeth, in short, in the orthodontic treatment, the orthodontist will be extracted from the space used for: Uncrowding, so that the remaining teeth can be lined up in the appropriate position, to form a neat row of teeth, and to play the maximum function. Move back overly protruding maxillary front teeth to treat “buck teeth” and restore the protruding teeth to their normal position to improve appearance. By moving the overly protruding lower front teeth back, the appearance of the protruding teeth is improved. By moving the front and back teeth, a staggered occlusal relationship between the upper and lower teeth is formed to maintain the health of the root and periodontal environment. In short, orthodontic tooth extraction is the removal of a few teeth in exchange for the health and functionality of all remaining teeth.