Clinically, there are certain criteria for judging the looseness of teeth, and it is not necessary to pull out the teeth if they are particularly loose. The first stage refers to the looseness of the tooth within 1mm, when the looseness of the tooth is mainly in the buccolingual direction. The second stage is a loosening of 1-2mm, when the tooth is loosened in the buccolingual direction as well as in the proximal and distal mesial directions. The third stage is the loosening of more than 2mm, when the teeth may be loosened in the vertical direction in addition to the buccolingual direction and the proximal and distal mesial directions. If there is a third degree of loosening that is difficult to reverse, the tooth needs to be extracted.