Malocclusion (also known as malocclusion) has a prevalence of more than 50% in our population and is one of the three most common diseases in dentistry. Malocclusion not only affects the beauty of the face, but also causes harm to the oral cavity and even the whole body. For example, misalignment of teeth can cause a decline in chewing function, and also induce dental caries (commonly known as worm teeth), periodontal disease, etc.; poor bite of teeth can cause temporomandibular joint disease, craniofacial pain, etc.; if there are more serious malocclusions in childhood, such as anterior anterior teeth (commonly known as enameled teeth), posterior anterior teeth, anterior teeth deep overlap, deep overlap and other malocclusions, may also have a negative impact on the normal development of the face. As there are many types of malocclusion, the timing and treatment methods for different types of malocclusion are different, so we will elaborate on them according to the different stages of growth and development of children. Orthodontic treatment of malocclusion during the milking period The milking period is the period from the beginning of milk teeth eruption to the loss of milk teeth and the beginning of permanent teeth eruption. On average, the period before the age of 6 is the molar period. The chance of malocclusion during this period is very low, and even if malocclusion occurs, it is often mild and does not require treatment. However, if any of the following conditions occur, it is advisable to consult an orthodontist as soon as possible for treatment recommendations. The orthodontist will decide whether orthodontic treatment is needed based on the severity of the anterior anterior teeth and whether it will affect the facial growth and development. For milder anterior anterior teeth, the patient can be observed and temporarily left untreated. For patients with heavy anterior teeth, they should be treated early, otherwise it will affect the normal eruption and alignment of permanent teeth, and even the normal development of the facial jaws. If you find that your child has bad oral habits, such as finger-biting, lip-biting and object-biting habits, you should consult the orthodontics department. If a child has mild bad oral habits during the teething period, no orthodontic treatment can be done, and parents can usually pay attention to remind correction. If there are serious oral habits, it will have a negative impact on the eruption of permanent teeth, alignment, facial and jaw development, and should be treated early, and the common treatment method is to wear a bad habit-busting orthodontic appliance. Orthodontic treatment of malocclusion during the period of teething The period of teething refers to the period from the beginning of the eruption of permanent teeth to the completion of the replacement of all milk teeth by permanent teeth. The age of children in this period is from 6 to 12 years old. Due to the factors such as dental caries, trauma and bad oral habits, the normal loss of milk teeth can affect the normal eruption of permanent teeth, and at the same time, the incidence and types of malocclusion during the period of teeth replacement increase greatly as the jaw bone development accelerates. The first category is dental malocclusion, mild malocclusion can be treated without orthodontic treatment, but if the replacement of milk teeth and permanent teeth is abnormal, if not treated will affect the normal eruption of subsequent permanent teeth and the establishment of a good occlusal relationship, then timely treatment should be provided, such treatment is also known as occlusion induction, that is, through early orthodontic treatment during the period of dentition, so that after the eruption of permanent teeth to establish a good alignment and occlusal relationship. The second category is serious dental malocclusion, if not treated in time, it will affect the normal development of the upper and lower jaws as well as the face, such as severe anterior anterior teeth, posterior anterior teeth, anterior atresia, etc. These malformations should be detected and treated early. The third category is bony malocclusion, which is caused by abnormal development of the upper and lower jaws, and has a greater adverse effect on facial development and appearance, and is also a more difficult malocclusion to treat. The timing and method of treatment are different for different bony malocclusions. For anterior anterior malocclusion caused by the underdevelopment of the maxilla, the soft tissue side appearance is concave, the maxillary anterior traction orthodontic treatment should be selected, the best time for orthodontic treatment is about 8 years old, although 10 to 12 years old can also be treated, but the efficacy is not as good as at the age of 8 years old. For maxillary protrusion deformity caused by overdevelopment of the maxilla, the soft tissue side appearance is convex, the best time for treatment is 10 to 12 years old, the treatment method is to use the head cap orthopedic force to inhibit the growth of the maxilla. For mandibular malocclusion caused by underdevelopment of the lower jaw (also known as small mandibular malocclusion), although the soft tissue side cap is also convex, the timing of treatment needs to be based on the bone age of the child’s growth and development, and the treatment should be chosen to start one year before the burst of youth. In conclusion, the probability and types of malocclusion increase significantly during the period of dentition, so if parents find that their children have malocclusion, they should take them to orthodontics for an early examination and choose the best time for proper orthodontic treatment so as not to delay the best time for treatment. Early permanent dentition orthodontic treatment Early permanent dentition refers to the period from the eruption of the second molar to the eruption of the third molar, also known as the period of young permanent dentition. This period is the period when most of the malocclusions can be treated with more satisfactory results. Among them, 12-14 years old is the best orthodontic period for all kinds of dental malocclusion, with a short course of treatment and good results. During this period, children with anterior malocclusion with hypertelorism or mandibular deviation must be carefully selected for orthodontic treatment, especially not for tooth extraction. For these malocclusions, if extraction is necessary, it is best to start at the age of 14 to 16 years, when the adolescent growth period is about to end.