We have a fixed number of teeth, but after a certain age, some people will grow teeth again, that is, we say wisdom teeth, long wisdom teeth will have gum swelling and pain, some wisdom teeth need to be extracted, what are the precautions after wisdom teeth extraction? 1, after wisdom tooth extraction to bite the sterile cotton ball or gauze pressed on the wound, in order to achieve the purpose of compression of the wound, to help stop bleeding, to insist on half an hour before spitting out. This is because the blood in the wound after tooth extraction may form a blood clot within half an hour. If you spit out the cotton ball or gauze in advance, bleeding will easily occur. 2. Generally do not rinse your mouth, let alone brush your teeth, for 24 hours after wisdom tooth extraction. Because about 24 hours after tooth extraction, the local fibroblasts just extend from the alveolar bone wall to the blood clot and gradually make the blood clot mechanized and become strong and solid. If you rush to rinse and brush your teeth, it is possible to rinse and brush off the blood clot and cause rebleeding, or cause “dry socket” with unbearable pain due to emptying of the tooth socket, which prolongs the healing time. You should also be careful not to lick the wound with your tongue or suck the wound with force. 3, two hours after wisdom tooth extraction can eat, but should pay attention to eat some liquid food, do not drink hot water or eat too hot, too hard food. Hot food will cause vasodilation and easy bleeding; too hard food is a mechanical stimulus to the wound, which can cause bleeding and aggravate the injury, so it should be avoided.