Many people think that misaligned teeth only affect the aesthetics, but in fact, malocclusion is much more dangerous to patients than that. There are many risks associated with malocclusion, including local, psychological and systemic effects. Malocclusion can cause many oral health hazards. Many children themselves do not pay attention to oral hygiene, do not brush their teeth carefully, brush only once a day, or do not brush their teeth. Crowded teeth are not easily self-cleaned and are not easy to clean. Poor oral hygiene will cause more caries and periodontal damage. Severe malocclusion also affects the normal functions of the mouth, such as abnormal pronunciation, abnormal swallowing and low chewing function. Severe bony malocclusion affects the development of the hard and soft tissues of the jaw and face during the growth and development of the child, resulting in underdevelopment or overdevelopment of the upper or lower jaw, which affects the aesthetics of the face and has a psychological impact on the patient. Malocclusion is not only harmful for craniofacial malformation, but also affects digestion because of the reduced chewing function, which leads to malnutrition and affects general health.