Periodontal disease is hardly taken seriously in China, in fact, it is a veritable “invisible killer”. ”Disease enters through the mouth, and if there is disease in the mouth, viruses are being imported into the body all the time. Medical research shows that there are more than 500 different kinds of bacteria active in the mouth. The scope of damage from these bacteria goes far beyond something as simple as an oral cavity. Take two examples that seem to be unrelated to periodontal disease. 1, periodontal disease is one of the causes of myocardial infarction U.S. experts to do a survey of a group of fifty to sixty-year-old myocardial infarction death cases, these patients have no previous history of cardiovascular disease, but for some reason the sudden onset of malady. After a long study, the experts found a common denominator in these patients, they all had relatively serious periodontal disease. Under the microscope, black bacteria enter the blood vessels and sludge on the walls of the blood vessels, which, over time, leads to atherosclerosis, and as more and more sludge is accumulated, the blood vessels eventually rupture, triggering myocardial infarction. 2, periodontal disease can lead to premature birth and miscarriage Periodontal disease can also lead to premature birth and miscarriage of pregnant women. A prospective study of 1,313 pregnant women by oral disease specialist Jeffcoat showed that periodontal disease in pregnant women is an independent risk factor for miscarriage and preterm delivery. After correcting for age, race, smoking, and maternal status, it was found that the risk of miscarriage and preterm delivery increased as periodontal disease worsened. When symptoms such as inflammation occur in the mouth, bacteria can enter the uterus with the bloodstream and cause lesions. It is advisable for women, before preparing for pregnancy, to visit a dentist.