Wisdom teeth, worm teeth, gum recession …… For these “painful” toothaches, a simple extraction is not the answer. There are clear contraindications and indications for tooth extraction, and not everyone or any bad tooth can be extracted. There are also many precautions to take after tooth extraction, which may aggravate the pain if you are careless. Extraction is prudent if you are suffering from systemic diseases. Tooth extraction can cause bleeding, swelling, pain and other reactions, and can also lead to fluctuations in blood pressure, body temperature and pulse, so patients suffering from blood diseases, cardiovascular diseases, hyperthyroidism, diabetes, liver and kidney diseases and acute infectious diseases, or patients with local acute inflammation, malignant tumors and patients undergoing radiotherapy must be treated with caution, among which patients with cardiovascular diseases and blood diseases should pay particular attention. The reason is that tooth extraction can increase the risk of bleeding and infection, which can worsen the condition of these systemic diseases and seriously endanger the life and health. Therefore, teeth should not be extracted during the acute stage of these diseases, and preventive and curative measures should also be taken during the stable stage, so that teeth can be extracted carefully. In addition, women should also be cautious about tooth extraction during menstruation. Three kinds of cases require tooth extraction only. In the face of various dental problems of patients, doctors should first try to treat them, and only when the teeth have adverse health effects and there is no effective treatment to preserve them, extraction should be considered. This is because missing teeth can cause atrophy of the alveolar bone, displacement or elongation of neighboring and opposing teeth, resulting in chewing disorders. Missing front teeth also directly affect pronunciation and appearance. Premature loss of milk teeth in children can cause malformation of the developing jaws, so the indications for tooth extraction must be strictly controlled. There are three common cases that require tooth extraction: one is painful or affects other teeth, such as repeated inflammation and pain, crooked growth, no upper and lower alignment, always plugged, broken, deep cavities, and wisdom teeth that are invisible to the naked eye but seen on film to be buried deep in the bone and grow crooked and tilted. Secondly, there is no retention value of the residual roots and crowns, they are prone to repeated inflammation and pain, and destroy the dental bed, the doctor will recommend early extraction, and then set the teeth. The third is split teeth. For split teeth that cannot be retained, they should be extracted as early as possible. Eat some ice after tooth extraction. There are many precautions after tooth extraction: 1. The cotton ball or gauze bitten in the mouth must be spit out after 40 minutes, and after spitting out, you can eat some ice-cream, drink ice water or apply local ice; 2. Talk less on the day of extraction and try not to spit for 4 days, otherwise it will affect the healing of the wound and cause the wound to bleed; 5.