Due to the difficulty of extraction of obstructed wisdom teeth, the postoperative reaction is often more obvious than that after extraction of ordinary teeth, mainly manifesting the following aspects: 1. Facial swelling. The main manifestation is the swelling of the soft tissue of the cheek or submandibular area corresponding to the tooth extraction, which generally reaches its peak 72 hours after the extraction. Then it starts to subside and is completely eliminated in about 1 week. It is recommended to start icing immediately after tooth extraction, which can be done for 24 hours. 48 hours later hot packs are applied to promote absorption. If the swelling is very obvious or causes difficulty in breathing, promptly follow up with the surgeon or see an emergency dentist. 2. Bleeding. Within 24 hours after tooth extraction, there will be a small amount of blood oozing from the wound and blood in the saliva, which is normal. If there is obvious bleeding and spitting out large mouthfuls of blood, it is necessary to seek follow-up consultation with the surgeon or visit the emergency room. 3. Difficulty in opening the mouth after tooth extraction. Most patients are caused by post-operative swelling, and the degree of mouth opening will generally improve significantly after the swelling subsides; some are caused by difficult tooth extraction, prolonged mouth opening, and over-opening of the mouth, which causes damage to the temporomandibular joint, which can be improved by applying heat to the joint and physical therapy. 4. Wound infection. Redness, swelling, overflowing pus at the extraction site, or a salty taste in the mouth. This may be related to factors such as difficult tooth extraction, long operation time, patients not taking antibiotics as prescribed, and poor resistance to recent fatigue, etc. Patients need timely follow-up. 5. Numbness in the lower lip or tongue. It is usually caused by the root of the tooth being too close to the nerve and the damage to the lower alveolar nerve or lingual nerve during the surgery. If there is still numbness of the lower lip or tongue on the next day after tooth extraction, timely consultation is needed to use nerve-nourishing drugs.