Some patients with malocclusion have wisdom teeth that need to be removed before orthodontic treatment, so many patients have doubts about orthodontics. In fact, this perception is a misconception. Wisdom teeth, even without orthodontics, still need to be removed in most people. Especially those wisdom teeth that have not erupted to their normal position will have adverse effects on other teeth if they are not removed. Many patients believe that they are not willing to sacrifice healthy teeth to achieve aesthetics, and that health is more important than aesthetics. In fact, this is a misconception. Proper extraction of teeth not only does not harm health, but also promotes it. First of all, if the teeth are crowded, the teeth are difficult to clean and the oral hygiene is poor, the probability of gingivitis and periodontal disease will greatly increase in the long run, and even cause the loss of teeth. Secondly, orthodontic treatment establishes a good bite, avoiding the bad force on the teeth, which is conducive to the improvement of chewing efficiency; according to statistics, the chewing efficiency lost by removing four premolar teeth is only about three percent. In some patients, the upper and lower teeth cannot bite together due to the misalignment of teeth, but after the removal of the premolar teeth, the other teeth are aligned and can function as chewers again, and the total chewing efficiency is increased instead, so the advantages of such extraction outweigh the disadvantages.