I. Notes after tooth extraction 1. Please bite down firmly on the cotton ball or gauze cotton roll at the tooth extraction and spit out gently after 30 minutes. 2. You can eat only two hours after tooth extraction. On the day of surgery, it is advisable to eat warm, cool and soft food, not to overheat and drink alcohol, and avoid chewing with the side of the extracted tooth. 3. You should not rinse your mouth and brush your teeth on the day of tooth extraction (you can brush your teeth the next day), and you should not pick, lick and touch your tongue and suck the wound repeatedly to prevent infection and bleeding of the wound. 4. Within 2 days after tooth extraction, there may be a small amount of blood or slightly blood-colored in the saliva, which is a normal phenomenon, please do not worry about it. If the saliva contains more blood or blood clots, do not panic, please come to the hospital immediately to check and stop the bleeding, you can first bite with clean cotton or gauze placed on the wound to avoid continued bleeding on the way. 5. There are often swelling, pain and difficulty in opening mouth after complex tooth extraction, which usually improves after 3-5 days, please follow up if there is any abnormality. 6. The sutures at the extraction site will be removed about 5 days after the operation 7. Extraction of complex teeth is a more complex, traumatic, postoperative local reaction and complication dental surgery. The following situations may occur during and after the extraction: 1. 2. Postoperative bleeding, which requires exclusion of hematological system or jawbone hemangioma lesions and the use of hemostatic drugs or surgical sutures, and if necessary, observation in hospital or blood transfusion. 3.Facial swelling and pain, restricted opening, painful swallowing, etc. must be reviewed in hospital in several days after surgery, and symptomatic treatment should be taken, and the above symptoms may last for a longer time in special cases. 4.Postoperative infection, dry sulcus, need regular change of medicine, antibacterial and other treatment. 5, postoperative sometimes half side of the lower lip numbness or tongue numbness, the duration is variable, give drugs, physiotherapy, etc. 6, the posterior maxillary teeth and maxillary sinus close to the root, the root may enter the maxillary sinus need surgery to remove the root, and then perform maxillary sinus fistula repair. 7, other surgical accidents such as damage to adjacent teeth, adjacent tissues and complications, symptomatic treatment.