The whole tooth is beneficial to maintain periodontal health, because the teeth arranged neatly are easier to clean, but the teeth arranged irregularly will bring some difficulties to brushing and cleaning. It is prone to dental calculus deposition, gingival swelling and hyperplasia, bleeding from brushing teeth, bad breath and so on. After a long time, periodontal diseases such as tooth loosening and gingival recession may occur, which is more difficult to treat. After orthodontics, the teeth are arranged neatly, which can be easily cleaned and prevent dental caries and periodontal disease. Orthodontics can remove occlusal trauma. Unbalanced bite force will lead to tooth damage, which will make the teeth loose and fall off earlier. Orthodontics can make the tooth arrangement and occlusal relationship normal and protect the teeth well. Neat teeth are conducive to enhancing personal self-confidence, increasing chewing function and helping digestion and absorption of nutrients. Abnormal occlusion in adults or middle-aged and elderly people will affect chewing, and finally affect other oral functions, such as pronunciation and lip closure. These problems can be alleviated by orthodontic treatment.