The gap between the teeth and the incisors after the children’s tooth replacement is relatively large, usually due to physiological reasons, lower attachment of the upper lip tie, and supernumerary teeth, and it is recommended to consult a doctor to find out the situation, and to carry out orthodontics, lip tie correction, extraction and correction of supernumerary teeth and other treatments. 1. Physiological reasons: As children at the age of 6 to 12 years old belong to the stage of tooth replacement, there will be a mixed dentition, with the appearance of milk teeth or permanent teeth at the same time, the jawbone development leads to the gap between teeth and teeth is relatively large, which belongs to the normal physiological phenomenon, and there is no need to carry out special treatments, with the replacement of the teeth eruption, the gap between the incisors will be closed naturally. 2. Upper lip tie attachment is relatively low: hinder the growth of incisors, resulting in the gap between the patient’s door becomes larger, it is recommended that patients undergo lip tie correction treatment. 3. Multiple teeth: due to the patient’s multiple teeth, resulting in the gap between the incisors become larger, it is recommended that the patient to remove the extra teeth, and at the same time for orthodontic treatment. There may also be other reasons, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or treatment.