Misalignment of teeth is one of the three major diseases of the oral cavity, and its hazards are: 1. Usually manifested as “big whistling teeth” face and “pocket teeth” face. The uneven alignment of teeth affects the appearance of a person’s smile and cannot give a bright and confident smile. 2. Affect facial development. Usually, the human face is symmetrical, but if the teeth are not aligned and corrected in time, the jaw and facial bones will grow adaptively, eventually leading to asymmetrical facial development, commonly known as “crooked face”. 3, involving the health of the temporomandibular joint. The temporomandibular joint is the most complex joint among all joints in the body, and its function is also very important. If the teeth are not aligned, it will easily lead to damage to the joint, mainly manifesting as inconsistency in the mobility, morphological structure and size of the left and right joints, popping and pain in the joint area. In severe cases, headache, neck and back pain, improper standing posture, slanting neck, inability to open mouth, etc. may also occur. 4. Involvement of dental body and periodontal tissue health. If the teeth are not aligned properly, individual teeth may suffer from occlusal trauma, which may manifest as pain in individual teeth, cracks and/or neck defects in teeth, painful bite of teeth, etc. 5. Affects oral hygiene care. If the teeth are not aligned, food residues will easily accumulate between the teeth and brushing will not be easy to clean, which will eventually lead to calculus deposits, gum redness, gum recession and alveolar ridge resorption, and in serious cases, loose teeth, etc. 6, affect the psychological health of people. If the teeth are seriously uneven or the individual is too sensitive to the appearance caused by uneven teeth, it will produce a certain degree of psychological disorder, manifested as shyness to smile or hand covering the smile, reluctance to interact with others, a sense of inferiority, and in heavy cases, anti-social behavior.