There are two types of large gaps in the teeth: one is due to natural gaps; the other is due to pathological reasons. For example, gum recession caused by periodontal disease or mechanical pressure, tooth displacement due to various reasons, excessive wear on the biting surface of the teeth to the point of breaking contact with adjacent teeth, cavities, etc. The presence of gaps in the teeth can cause food impaction when eating, causing discomfort and damage to the dentition and periodontal tissues, as well as affecting the overall aesthetics of the teeth in the front teeth and causing mental stress to some people. The causes of tooth gap are different, and the treatment methods are also different. The gap between the tooth and the neighboring teeth caused by the tooth defect caused by caries, generally after filling the tooth and restoring the normal contact with the neighboring teeth, there will be no more gaps that produce embedment. When the defect is larger, the stability and aesthetics are poor after simple filling, further crown restoration treatment is needed. In the case of larger and more gaps caused by congenital development, orthodontic treatment is best if younger, and if older, porcelain crowns can be considered to restore tooth contact. For more complex ones a combination of both methods should be applied. Periodontal disease caused by tooth loosening, displacement caused by the gap, should be first perfect periodontal treatment, after the periodontal condition improved, stable, in the corresponding restoration treatment, such as continuous crown, fixed bridge, etc..