The best time for a child to have his or her teeth straightened is usually around the age of 12. When a child develops malocclusion, he/she needs to be corrected; malocclusion is roughly categorized into malocclusion, osseous malocclusion, functional malocclusion, etc.; the optimal time for different types of malocclusion is also different. 1. Malocclusion: When a child has malocclusion, the best age for treatment is around 12 years old. At this age, the child has just finished replacing his/her teeth, which makes him/her suitable for orthodontic treatment. 2. Bone malocclusion: The time for a child’s orthodontic treatment is during the pre-growth and developmental peak of a child’s orthodontic treatment at about 11 years of age, and as an adult, combined orthodontic and orthognathic treatment is required. 3. Functional malocclusion: The time for correction of functional malocclusion in children is around 8 to 12 years old. If the correction is delayed, it will develop into a bony malocclusion. If you find malocclusion in your child’s life, it is recommended to go to the hospital to do the relevant examination, to clarify the degree of malocclusion, and to choose the best time for treatment under the guidance of the dentist.