It is commonly believed that the best age for orthodontics is 11-13 years old, which is incomplete and has even caused delays for some patients. This is because there is an optimal time for orthodontics according to the different malocclusions. Commonly, for example: a. The orthodontic period of the baby teeth? 1, the mastodontic period of the jaw is characterized by the lower jaw will grow larger and larger as growth and development proceeds. 2, the protrusion of the upper jaw during the period of lactation is characterized by the growth and development of the lower jaw is hindered, more and more receding, smaller and smaller 3, the period of lactation deep overlap jaw and front teeth bite too deep, and even the upper and lower bite can not see the lower front teeth and so on. The best time to correct all kinds of conditions affecting the jaw and facial growth and development is 3-5 years old, usually in about 3 to 6 months can be corrected to complete, of course, can not be corrected for a long time. If you go past this age, its correction time is long and the effect can not achieve the desired results. Second, the orthodontic period 1, mild dental crowding and crowding degree in 3-5mm, if timely orthodontic intervention to take full advantage of the gap characteristics of its milk teeth – permanent teeth replacement, you can avoid the extraction of permanent teeth after the tooth replacement program. 2.Severe crowded teeth can also be intervened at an early stage according to the genetic factors and the estimated size of the teeth and the degree of crowding is about 10mm. By sequential extraction and pre-removal of individual baby teeth and permanent teeth, a perfect tooth alignment can be established without even orthodontic treatment. Third, the concept of the best age of 11-13 years old orthodontic teeth from this time should enter the permanent dentition, girls a little earlier, boys a little later, for various reasons of malocclusion, into the conventional orthodontic; but for the best time to miss the orthodontic jaw deformity can only wait until after 18 years of age for a comprehensive diagnosis of surgery and orthodontics. Therefore, it is reasonable and scientific not to generalize the best age, but to give the best time and age for orthodontics by a professional physician after detailed examination and analysis.