Buck teeth should first be photographed to see if it is a bone problem, that is, alveolar bone problem. Look at the degree of tooth protrusion and the position of alveolar bone to analyze the activity space of teeth and judge whether the ideal treatment effect can be achieved after correction. Orthodontics includes three stages: deciduous teeth, mixed teeth and adult permanent teeth. Generally speaking, the age of 12- 16 is the best period for orthodontics, and orthodontics can be carried out. The older you get, the longer it takes.