Dry Socket: It may also be called fibrinolytic alveolitis. It is a common painful and severe complication after tooth extraction, most often occurring after the removal of mandibular impacted wisdom teeth. The main symptom is severe pain 2-3 days after tooth extraction, which may spread to the auriculotemporal region, mandibular region and the top of the head, and the pain cannot be relieved by general analgesic drugs; the extraction sockets may be empty, or there may be corrupted and degenerated blood clots with strong putrid odor. Pathologically, the main manifestation is osteitis of the alveolar bone wall or mild limited osteomyelitis. The incidence of postoperative dry socket in mandibular obstructive wisdom teeth is reported to be 4%-10% in China. I. Pathogenesis There are various theories of the cause of the disease, and none of them can fully explain the pathogenesis and clinical manifestations of dry socket. 1, infection: However, so far, a single pathogenic bacteria has not been found. Most scholars believe that dry socket is a mixed infection, and anaerobic bacteria play an important role. 2.Extraction trauma: complex extractions, which are traumatic and prolonged, have a higher chance of dry socket. 3.Gender: the prevalence of women is 5 times higher than that of men. 4.Age: the incidence increases with age. 5, oral contraceptives: the prevalence of oral contraceptives is 3 times higher than that of women who do not take oral contraceptives. 6. Smoking: the prevalence of smokers is 5 times higher than that of nonsmokers, and the rate of dry socket in smokers within 24 hours after tooth extraction is as high as 40%. 7. Pericoronitis: The incidence of dry socket is higher in teeth with pericoronitis than in those without pericoronitis. The main symptom is severe pain 2-3 days after tooth extraction, which can be discharged to the ear-temporal area, mandibular area and top of the head, and the pain cannot be relieved by general analgesic drugs; the extraction sockets can be empty or have corrupted and degenerated blood clots with strong putrid odor. C. Disease differentiation 1. Reactive pain after tooth extraction: reactive pain appears on the same day after surgery, the pain is generally not serious and tends to gradually decrease, and basically disappears within 3-5 days, and the examination of the blood clot of the extraction wound is basically normal. Dry socket, on the other hand, is a severe pain that reappears 2-5 days after tooth extraction, discharging pain and lasts for a long time. 2. Post-extraction infection: infection in the anterior space of the pharynx and cheek, post-operative pain, severe opening restriction, accompanied by swallowing difficulties, obvious pressure pain in the medial angle of the mandible, redness, swelling and pressure pain under the third molar Sheze, and pus in the puncture. In contrast, the clinical manifestation of dry socket is mainly severe spontaneous pain, without obvious soft tissue swelling and without pus. IV. Local treatment Thoroughly clear the wound under local anesthesia, use 3% hydrogen peroxide solution to repeatedly wipe, take out the corrupt necrotic material until the alveolar sockets are clean, without repeatedly scratching the extraction sockets, rinse repeatedly with saline, fill the iodoform gauze into the extraction wound, and can suture the gums. After the above treatment, most of them can basically stop the pain, and if there is no obvious pain, remove the iodine strip in about 10 days. If there is no obvious pain, the iodine strips can be removed in about 10 days. Those with severe pain can take oral painkillers. VI. Prevention methods Prevention of dry socket should pay attention to reducing surgical trauma, protecting blood clots, paying attention to oral hygiene and proper rest after surgery. After tooth extraction, filling the wound with various kinds of substances to fight infection, protect blood clot and reduce the volume of the wound can prevent the occurrence of dry socket. The fillings include iodoform sponges, gelatin sponges containing chlorhexidine and antibiotics, etc. Preoperative preparations such as clean oral hygiene, intraoperative disinfection, minimizing extraction trauma, and avoiding large amounts of saliva and other contaminants should be done. Postoperative care should be done to protect the extraction trauma blood clot, avoid sucking, quit smoking, and not rinse the mouth for 24 hours.