1.What is periodontal disease? Periodontal disease is a disease that occurs in the gums, periodontium, alveolar bone and other tissues around the teeth, and can affect most or even all of the teeth. It includes gingivitis, periodontitis, periodontal abscess, peri-implantitis and other diseases. It manifests as oral odor, gum swelling, bleeding, brittle texture, gum recession, periodontal abscess, alveolar bone resorption, root exposure, hot and cold sensitivity, tooth (or implant) loosening and displacement, etc. And as chronic lesions endanger the health of the whole body and increase the risk of major diseases such as stroke and heart attack. 2, the incidence of periodontal disease. Periodontal disease is one of the two major diseases of the oral cavity and has a high incidence rate in the world, and its incidence rate is higher than that of caries in China. According to the third national oral disease survey (2008), the incidence rate of periodontal disease in our population is as high as 80%-97%, and it can threaten all ages. 3.The susceptible group of periodontal disease. Including: ① stressful people (students, white-collar workers, high-end people) ② pregnant women; ③ adolescents (especially for orthodontic treatment); ④ fixed denture, implant denture in the mouth; ⑤ diabetic patients; ⑥ smokers; ⑦ genetic background, there is a family history of periodontal disease. 4, the consequences of periodontal disease without treatment Periodontal disease without treatment, the end result is loose teeth, displacement, and even loss. This course of disease usually occurs at an older age, so people mistakenly think that it is “old tooth loss”, but the essence is that periodontal disease destroys the dental bed and leads to the loosening and loss of teeth, and at present, tooth extraction due to periodontal disease accounts for 60%-80% of tooth extraction in maxillofacial surgery clinics. With the deepening of the understanding of periodontal medicine, the current evidence shows that periodontal disease as a chronic lesion can endanger the health of the whole body, and even increase the risk of major diseases such as stroke and heart attack.