First of all, it is necessary to find out what are the common maxillofacial deformities in children. Generally speaking, the common jaw deformities in children can be divided into two categories: dental deformities and bony deformities. The dental deformities are divided into general dental deformities and functional deformities. The best time for orthodontic treatment differs for different types of malformations. When is the best age for orthodontics in children? For general malocclusion, the best time for orthodontic treatment is in the early permanent period (i.e., 12 or 13 years old), when children have just finished replacing their teeth and are in a more vigorous growth spurt. As for functional malformations, since they often appear during the period of the replacement of teeth (i.e., 6-12 years old), if orthodontic treatment is delayed, they may develop into bony malformations, so the best time for orthodontic treatment should be during the period of the replacement of teeth. As for the correction of bony malformations, orthodontic treatment should be performed when the child is in the pre-growth phase (10-12 years old for girls and 11-13 years old for boys). The exception to this is the anterior backbite (commonly known as “encephalitis”). This deformity has a serious impact on the jaw development of children and should be corrected as soon as it occurs, starting as early as around 3.5 years old. It usually takes only 3-6 months to push out the upper milk front teeth that bite back on the inside of the lower jaw teeth.