Teenagers have many dental diseases, the most common of which are caries, periodontal disease, etc., and the source of its disease-causing enemy is “plaque”. Plaque is a dense non-calcified film-like bacterial group, which firmly adheres to the surface of the teeth, acid production caused by dental decalcification and caries, but also because of its poisons or metabolites to stimulate periodontal tissues and cause periodontal disease. Because the plaque is stored in the teeth fossa, neighboring surfaces and the neck of the teeth, it is not easy to eliminate, and bacterial decomposition of food, corrosion of the dentin process, in the three minutes after the meal to start, therefore, we should advocate oral hygiene “three-three system”, that is, after the meal three minutes to brush your teeth, brush three times a day, each time brushing for three minutes. Once caries and periodontal disease should be timely to the hospital to prevent the continued development of lesions. Another problem with teenage teeth is misalignment, crowding, misalignment and so on. This period, dental arch, jawbone is in the development stage, plasticity is very large, is suitable for malocclusion correction, patients and orthodontic is a very high technical content of the treatment, so the choice of orthodontics must go to the regular place, choose orthodontic qualifications of the doctor, orthodontics not only make the teeth beautiful, the main thing is that the occlusal function is reasonable, easy to clean, and can reduce caries and periodontal disease, thus prolonging the periodontal disease, and thus reduce the incidence of caries. The occurrence of periodontal disease, thereby extending the life of the teeth, clinical often encountered elsewhere in the orthodontic failure of patients, serious may cause the whole mouth teeth loose, or even individual teeth off, teeth alignment is not good, the bite is disorganized, resulting in difficult to recover from the damage, some patients even psychological burden, seriously affecting the daily life and learning, it is a pity and helpless.