Figuratively speaking, it is mainly to improve face shape, align teeth and improve chewing efficiency. Judging from the situation of the yellow race, about 50% of corrective patients need to have their teeth pulled out, usually four teeth are pulled out. The main reason is the deterioration of jaw development, which can't accommodate so many teeth and can only reduce the number of teeth. If the patient's dentition is crowded beyond a certain amount, the teeth protrude forward and the lips cannot cover the teeth. In these cases, it is often necessary to extract teeth to make room for teeth to be aligned or retracted, so as to achieve the beauty of face and teeth. Orthodontics does not always require tooth extraction. Whether tooth extraction is necessary in orthodontic treatment depends on the patient's own situation, generally depending on the child's face, the abnormal degree of dentition and the abnormal degree of bone. If the child's face is prominent, his lips are not closed properly in a relaxed state, his teeth are leaning forward, his lips are upturned, and his lips are open to expose his teeth, he must pull out the bad teeth. The number and location of specific tooth extraction will be adjusted according to the specific situation. Generally speaking, we will adhere to the principle of symmetrical tooth extraction and pull out the bad teeth first. Some patients, it is not only through observation that they can judge whether to extract teeth. For this kind of patients, doctors usually adopt conservative treatment principle, first adopt the plan of not extracting teeth, and then consider whether to extract teeth according to the improvement degree of dentition and patient satisfaction. Therefore, orthodontists do not absolutely advocate tooth extraction. If you can take the treatment without tooth extraction and get satisfactory results, then try to choose the treatment scheme without tooth extraction. However, if some patients who should have their teeth extracted but haven't decided to do it first and then correct them, they will have some unstable effects because they barely keep the extracted teeth, so they are often prone to rebound in the treatment, and the treatment effect is not ideal, and it often takes time and money to make secondary correction. Experts remind: It is recommended to pull out the extracted teeth, choose a regular orthodontic institution, and follow the orthodontic treatment plan designed by doctors through scientific measurement and calculation, so as to completely correct them and obtain stable results.