Orthodontics is the correction of teeth and the release of malocclusion. Orthodontics is the study of the etiology of malocclusion, its diagnosis and analysis, as well as its prevention and treatment. The English name of orthodontics comes from the combination of three Greek roots, which mean “tooth”, “orthodontic” and “discipline”, that is, what we call “orthodontics”. Timing There are some malocclusions that need to be treated early (3-6 years old), such as “enamel” or lip biting, finger sucking and other bad habits caused by malocclusion, in order to avoid adverse effects on the jaws and face during the growth and development process. The rest of the malocclusion should be consulted and examined by the orthodontist when the permanent teeth start to erupt (8-10 years old). Because at this time, we can observe the process of permanent tooth eruption early and regularly, and find and solve problems in time. The best age for most orthodontic treatment is between 12 and 16 years old, and some orthodontists call this age the “golden period” for orthodontic treatment. The best time for orthodontic treatment, according to the different age groups have different considerations: 1, the period of milk teeth (3 ~ 5 years old). The purpose of orthodontic treatment is to promote the normal development of the jaw and face of children, the period is mainly aimed at the milk teeth (teeth together) (i.e., the ground), jaw protrusion, back teeth (teeth together) and other errors (teeth together) that prevent the normal development of the jaw and face, and timely correction of tongue, lip biting and other bad habits that affect the normal function of the oral cavity, to prevent the further occurrence of errors (teeth together) malformation. 2.Dental replacement period (girls: 8-10 years old, boys: 9-12 years old). However, for bad habits such as lip biting, tongue extension, jaw extension, or abnormal facial shape, anterior teeth retrusion, functional jaw recession and intermaxillary relationship, it is often necessary to go to the orthodontist for examination in time to determine whether it is dental, functional or bony malocclusion, so as to clarify the treatment plan. 3, permanent period (girls: 11-14 years old, boys: 13-15 years old). 12 years old or so permanent teeth began to form, at this time, once the teeth do not align will not automatically disappear, can only be corrected through the treatment of orthodontic specialists, this period is the best period of children’s orthodontic treatment, the best curative effect, a variety of Orthodontic treatment is available for all kinds of malocclusion. Don’t think that after putting on the brackets, you can be done with it once and for all. When orthodontics, diet and oral maintenance should be paid attention to, improper diet and oral maintenance habits may affect the time needed for treatment and the final result at the end of treatment. The orthodontic brackets are attached to the surface of the teeth with a special bonding agent, and then the archwire is fixed to it and a certain force is applied to achieve the purpose of orthodontic treatment. Therefore, the brackets themselves need to be easy to attach and remove. The archwire also needs to have the ability to generate the right amount of force and withstand a certain amount of chewing force. Since the appliance is to be removed later, the aligners cannot be so tightly attached to the teeth that we can eat with impunity, and the thinner archwires cannot withstand excessive biting forces. Therefore, during the orthodontic process, we should eat less: (1) foods that are too hard, such as ice, nuts, hard cookies, sugar cane, hard candy, crabs, lobster shells, etc. We should also quit the bad habits such as biting pens and nails; (2) foods that are too sticky, such as milk sugar, maltose and some cookies, etc.; (3) foods that are too big, such as apples and pears, etc. should be cut into small slices before eating. At the same time, in order to avoid tooth decay, the intake of sweet food and carbonated drinks should be reduced as much as possible during the orthodontic period. The mouth should be thoroughly cleaned with correct brushing method after each meal, supplemented with oral cleaning products such as dental floss and gap brush to avoid tooth enamel demineralization, dental caries, gingivitis or other complications.