The whiteness, brightness, strength, integrity, and alignment of teeth are important aspects of cosmetology. After middle age, the periodontal tissues begin to slowly shrink toward the root tip of the tooth. In old age, the atrophy becomes more obvious, and the teeth appear longer than before, and the roots are exposed and the gaps between the teeth increase. This change in the teeth often leads to a series of pathologies. For example, the heavy wear of teeth may cause allergic symptoms such as cold, hot, sour and sweet, and when the condition is aggravated, it may also cause pulpitis, periodontitis and tooth fracture, etc.; the exposed roots and widened gaps of teeth may accumulate food and form tooth decay. The occurrence site of tooth decay is different between the old people and the teenagers, and it is much more serious. Once the tooth root surface is decayed, it will rapidly expand horizontally and form bad-shaped caries, and expand vertically and lead to pulpitis, which will cause great pain, so it should be actively prevented. Therefore, knowing some common sense of dental beauty and health care can not only keep the beauty of teeth, but also increase the interest of life. To maintain healthy and beautiful teeth, brush your teeth at least once a day in the morning and once in the evening, and eat dessert during the day, even if you do not brush your teeth, you should rinse your mouth with water to avoid tooth decay. When brushing your teeth, choose a brown-bristled toothbrush and brush your teeth gently and vertically, avoid brushing horizontally or using a stiff-bristled brush. If the gap between the teeth is large, you can use a toothpick to clean the gap between the teeth and the roots of the teeth after meals, but the action should be gentle. When we brush our teeth, not necessarily every crevice can be brushed, no matter how carefully when brushing, after brushing with a mirror, you will find that there are still many scum in the teeth, and these scum cling very tightly, therefore, every 3 to 4 months to the dentist to clean teeth is necessary, not only to maintain the health of the teeth, but also to make the teeth white and bright. If your teeth bleed when you brush them, it means that you lack vitamin C. You should eat more fruits and vegetables, preferably two oranges rich in vitamin C every morning on an empty stomach. If you still need to supplement, you can take vitamin C pills. Bad breath and dental abscesses are big enemies of female dental beauty and must be treated early. The following foods are the most harmful to teeth: peanuts, buttered bread, fried potato chips, icing sugar, sugar-free coffee, chocolate cookies, chocolate hard candy, apples, butter cookies, ice cream, sweet chocolate, sweet chewing gum, ordinary sweet cookies, sweet orange drinks, cream sugar, boiled sweets, sweet coffee.