Wisdom teeth that are rotten to the gums and have only a little root can be extracted by forceps extraction, tapping method, ultrasonic bone knife extraction and other methods. 1. Pincer extraction: If the roots of wisdom teeth are relatively small, or even have floated out of the gum surface, you need to go to the stomatology department for local infiltration anesthesia or surface anesthesia, and then use the stump clamp to hold the stump and extract it. 2. Extraction method: If the remaining roots of the wisdom teeth are in the alveolar bone and there is a root bifurcation, the extractor can be placed at the alveolar spacing, and the proximal, distal and intermediate roots can be loosened and extracted respectively. 3. Ultrasonic scalpel extraction method: If the wisdom tooth residual root has adhesion with the surrounding alveolar bone and is close to the maxillary sinus or mandibular neural tube, in order to prevent damage to the important physiological structures of the human body, it is necessary to use an ultrasonic scalpel to slowly remove part of the bone tissue to increase the gap before extracting the residual root. In order to reduce the risk, it is recommended to go to a specialized hospital for treatment.