Children with sparse teeth with gaps are generally divided into three cases: 1, 5-6 years old, sparse milk teeth with gaps, also called physiological gaps, is beneficial to the alignment of permanent teeth after eruption. 2. After the age of 7, when permanent teeth erupt, there is a gap between the two upper incisors, which may be a temporary phenomenon in tooth replacement. However, if the gap between the upper incisors is large, or if the gap does not become smaller after several months, it is necessary to ask the doctor to check and exclude the problem of multiple teeth or abnormal labial tie attachment. 3.The sparse gap of permanent teeth may be due to the small form of permanent teeth such as tapered teeth or too small teeth, or it may be due to the congenital missing teeth of permanent teeth, which needs to be examined and diagnosed by an orthodontist, not by a general dentist.