Numbness of lips after tooth extraction may be the effect of anesthesia or inferior alveolar nerve injury. 1. The effect of anesthesia: the extraction of mandibular teeth usually requires inferior alveolar nerve block anesthesia, the scope of anesthesia contains the ipsilateral corner of the mouth, the general anesthesia time of 2~4 hours, after the time has passed, the anesthesia feeling will disappear. 2. Inferior alveolar nerve injury: the anatomical variations of obstructed teeth are large, due to anatomical factors or extraction violence, etc., which can lead to inferior alveolar nerve injury and numbness of the lower lip. Usually half a year to two years can be gradually recovered, for the nerve damage is serious, can be life-long numbness. It is recommended to go to the regular hospital stomatology department for tooth extraction, especially for patients with blocked teeth, so as not to cause unnecessary damage.