Dental extractions are a surgical treatment in dentistry, and patients are generally advised not to brush their teeth or rinse their mouth for 24 hours after the extraction. Brushing and rinsing after 24 hours after a tooth extraction will usually make the bad breath inside the mouth go away. However, if the patient does not brush and rinse his/her teeth in time after 24 hours, the bad breath will remain in the mouth, mainly due to the slight oozing of blood from the extraction wound, as well as the presence of bacteria, food residue, soft dirt and so on around the teeth, which causes gingivitis and periodontitis. At this time you need to take the pasteurized brushing method, brush your teeth well, generally about a week bad breath will slowly disappear. Need to pay special attention to is in the extraction of teeth 3-4 days, if there is particularly obvious corruption necrotic bad breath, and accompanied by extraction of teeth trauma of severe pain, radiating caused by the same side of the head and face pain, is very likely to be the extraction of teeth trauma occurred in the post-surgical infection, that is, dry socket disease. Need to go to the hospital as soon as possible to take treatment measures, after a thorough debridement, about a week inside the mouth odor will completely disappear.