Straight teeth are good for periodontal health maintenance because teeth that are lined up neatly are easier to clean, but teeth that are irregularly aligned can make brushing and cleaning difficult. It is easy to develop tartar deposits, gum redness and enlargement will have bleeding brushing and bad breath, etc. Periodontal lesions such as loose teeth and receding gums may occur over time, which will be more difficult to treat. And after aligning the teeth through orthodontics, it can be easy to clean and can prevent tooth decay and periodontal disease. Orthodontics can remove the bite trauma, unbalanced bite force will lead to tooth damage, making the teeth more prone to premature loosening and falling off, and through orthodontics to make the teeth alignment relationship, bite relationship to normal, to play a good protection of teeth. Straight teeth are good for enhancing personal self-confidence, increasing chewing function, and helping digestion and nutrient absorption. Abnormal bite in adults or middle-aged and elderly people will affect chewing and eventually other oral functions, such as pronunciation, lip closure, etc. It will also affect the temporomandibular joint, and all these problems can be relieved by orthodontics.