The tooth next to the wisdom tooth is loose, that is to say, the second molar adjacent to the wisdom tooth is loose after the wisdom tooth is extracted, and the reasons for the loosening are as follows: 1) The second molar itself is in bad periodontal condition, and the alveolar bone atrophy has reached the apical 1/3 of the root, and the looseness will be increased when the wisdom tooth is extracted. 2) Wisdom teeth grow horizontally, and they are growing on top of the root of the anterior teeth before they are extracted, which is equivalent to a fulcrum in the second molar, and when the wisdom teeth are extracted, they will lack a fulcrum, and then the tooth will loosen. When wisdom teeth are removed, there is a lack of a fulcrum, then the tooth will be loose.