Orthodontic treatment is a highly specialized, multidisciplinary and clinically complex technique. Patients with malocclusion should choose a qualified orthodontist who has been formally trained by a dental school and has received special training in the clinic when receiving treatment. Many parents or patients themselves are not very careful in choosing orthodontic treatment because they do not know the situation, which is very dangerous. Improper orthodontic treatment may cause some harm to the oral cavity as follows (1) Caries. Fixed orthodontic appliances are stuck on the teeth and cannot be removed during the treatment period, and the orthodontic treatment time is too long, which may lead to tooth surface caries because wearing orthodontic appliances is not conducive to the maintenance of oral hygiene. (2) Periodontal damage. In orthodontic treatment, tooth movement is accomplished through appropriate orthodontic force to induce alveolar bone remodeling. Excessive orthodontic force may cause periodontal damage, causing root resorption and shortening, and even premature loosening and loss of teeth. (3) Occlusal dysfunction. Due to the lack of control over the movement of teeth, the teeth that should move do not move, should not move instead, losing the original cusp-socket relative occlusal relationship, poor occlusal contact, chewing efficiency decreased. In addition, excessive occlusal force of individual teeth can also cause periodontal damage and lead to loosening of teeth. (4) Temporomandibular joint disorder. Poor occlusal contact often causes unstable occlusal position and long-term swaying of the mandible from side to side. Early contact of individual teeth, which causes occlusal interference, also puts the mandible in an incorrect position for a long time, all of which are detrimental to the temporomandibular joint and will lead to popping and pain in the temporomandibular joint over time. (5) Produce improper consequences and bring a lot of difficulties to the future remedial treatment. It is common for some patients with anterior protrusion deformity to have 4 premolar teeth extracted and then, due to lack of control, the posterior teeth move forward to occupy the extraction gap, while the anterior teeth do not get a significant backward and inward movement. In this case, it is difficult to perform remedial treatment because no more teeth can be extracted. Therefore, when choosing orthodontic treatment, you should try to go to a regular hospital, and do not regret for the rest of your life for the sake of cheapness.