A big gap between baby’s teeth may be a normal phenomenon, or it may be caused by low attachment of labial tie and supernumerary teeth, which can be treated by incision surgery of labial tie attachment and extraction of supernumerary teeth. 1. Mastodontic period: when babies are in the mastodontic period, the permanent teeth have not yet fully erupted, and the milk teeth have to reserve a certain amount of space for the permanent teeth, so the gap between the baby’s teeth will be very big. In this case, no special treatment is needed. 2. Lip tie attachment is too low: infant lip tie attachment is too low, will cause the gap between the upper incisors is too wide, it is recommended to ask the doctor in time under local anesthesia will be cut at the attachment of the lip tie, the two central incisors will gradually and automatically to the middle of the close together. 3. Multiple teeth: the normal gap between the front teeth is generally 1-2 millimeters, during the eruption of permanent lateral incisors, the normal gap can be closed basically by extrusion. Some infants have supernumerary teeth in the alveolar bone of permanent teeth, which will lead to larger gaps, sometimes up to 3-5 millimeters, and need to extract the supernumerary teeth in time. When the gap between the baby teeth is large, it is recommended to go to the hospital in time to identify the cause of the disease, and according to the cause of the standardized treatment.