The hazards of mandibular teeth mainly include: 1, affect the normal function of the mouth: reduce the chewing function, affect the pronunciation function, resulting in inaccurate pronunciation, serious jaw recession can affect normal breathing, serious jaw protrusion can cause abnormal swallowing; 2, affect the beauty of the appearance: serious anti-jaw will cause facial incongruity to affect the beauty of the face, affecting career choice, social communication. This can lead to a heavy burden of thought and a sense of inferiority in children, which can be seen in the adverse effects of malocclusion on the mental health of children and adolescents; 3. The chewing function is reduced and the food is not chewed sufficiently to increase the burden on the stomach and intestines. Long-term will cause indigestion or gastrointestinal diseases, affecting nutrient absorption, which is detrimental to health.