Orthodontics needs to choose whether to extract teeth according to the arrangement of teeth. If the tooth width is greater than the alveolar bone width, it is generally necessary to choose tooth extraction for orthodontics. If the position of individual teeth is incorrect, and the amount of teeth and bone are coordinated, it can be corrected without tooth extraction.

And some of them are corrected because the tooth arrangement is too sparse. This only needs to arrange the teeth closely and adjust the occlusion of the upper and lower teeth, without tooth extraction. There is also an abnormal face caused by bone, which can only be corrected by surgery.