The tooth extraction operation (especially the extraction of obstructed wisdom teeth) is a surgical operation in itself, and there are bound to be different degrees of pain, swelling, bleeding, and even other complications such as infection, nerve damage and root fracture during or after the operation, so it is very important to prepare well before the operation, and to be familiar with the precautions to be taken after the tooth extraction and strictly comply with them to reduce postoperative complications. 1. Psychological preparation. Psychological preparation is the most important, because if you cannot accept the postoperative pain, bleeding, swelling, which will definitely happen, or complications such as root fracture, infection, nerve damage, which have a certain chance of occurrence, or if you are afraid of the extraction environment and do not trust the doctor, it is recommended to withhold the tooth extraction. Good psychological preparation can reduce the postoperative discomfort, and negative emotions such as psychological fear may magnify the postoperative pain and other discomfort. 2. Control the inflammation of teeth, that is to say, teeth cannot be extracted when there is toothache and teeth can only be extracted when there is no pain. 3. Women should avoid menstruation and pregnancy. 4. You should not fast before surgery and eat to avoid fainting caused by low blood pressure and low blood sugar. 5. Avoid staying up late, fatigue and drunkenness before surgery. 6.If you have serious systemic diseases, such as hypertension, heart disease, diabetes, blood diseases, etc., you should inform the doctor in advance. 7.A history of drug allergy or other special conditions should also be explained to the doctor in advance.