Sparse teeth with gaps are common in three situations: 1. Sparse milk teeth with gaps, also called physiological gaps, the presence of these gaps is beneficial for the alignment of larger permanent teeth after eruption. This is a temporary malocclusion, which can be restored to normal after the teeth are replaced and a new occlusal relationship is established. 2. When the teeth are replaced, there is a gap between the two upper incisors, which is a temporary phenomenon in the process of tooth replacement. With the eruption of permanent lateral incisors and cuspids, the gap gradually decreases to completely disappear naturally, but when the gap between the upper incisors is large, it is necessary to ask the doctor to check whether there are multiple teeth. 3, the sparse gap of permanent teeth, one is the form of permanent teeth is small such as conical teeth or too small teeth. The other is that the permanent teeth have congenital missing teeth, both can go to the hospital and ask the doctor to close the gap by orthodontic or restorative methods.