It is important for children to have their missing teeth set in time for their development and growth. The important function of teeth is to suck and chew food, children missing teeth, first of all, can not chew food well, affecting the absorption of nutrients, increasing the gastrointestinal burden, over time, can cause indigestion and other gastrointestinal diseases. Secondly, teeth have the function of assisting pronunciation, especially the front incisors, which are more important for children to learn accurate and clear pronunciation. Missing front teeth and leaking air in speech can form a lisp. Children’s jawbone is developing, if the back teeth are missing, the lower 1/3 re-straight distance of the lateral part of the missing teeth will become shorter, making the face shape left and right asymmetrical. If teeth are missing for too long, the upper and lower alveoli will lose the normal biting relationship for a long time, and the jaw bone will lack physiological functional stimulation, which can cause jaw bone resorption and atrophy if the development is serious. Therefore, regardless of when the missing teeth are caused, they should be set in time to restore their physiological functions. However, children’s teeth and face are not yet set, so they should be set with appropriate movable teeth, and with the development of jawbone and the expansion of dental arch, they should also be checked and replaced regularly in the future.