During menstruation, teeth cannot be extracted because the number of platelets produced in the body decreases and the resistance of the person decreases, so teeth cannot be extracted. In addition, the teeth should not be extracted during the first three months and the second three months of pregnancy; some people with mental diseases do not know their diseases clearly and strongly request to have their teeth extracted, which also cannot be extracted; some tumor patients have their teeth extracted, which may lead to tumor recurrence and metastasis; patients need to have their teeth extracted before radiation therapy, and if they have their teeth extracted after radiation therapy, it may cause radioactive jaw necrosis. Therefore, tooth extraction is not recommended for 5 years after radiotherapy; patients with serious heart disease, kidney disease, as well as serious infections and blood diseases, such as hemophilia, cannot have their teeth extracted casually.