Brushing morning and evening still grows worms this question in clinical work, many teenagers and adults will ask, now almost everyone can do morning and evening brushing, its has become a habit of life. Everyone is brushing, but the difference is still very big, such as the duration of brushing, the recommended brushing time for 3-5 minutes, but some teenagers, such as junior high school students or high school students, their brushing time is only 1-2 minutes, perfunctory. Also, the brushing method is incorrect, the international recommendation is now the pasteurized brushing method, not to mention teenagers and children, many adults brush incorrectly, some like to brush horizontally, brushing the teeth to the bad. Some teenagers brush their teeth at night and they are still eating or even eating sweets, so brushing their teeth is not very meaningful. In addition to the growth of insect teeth, is a comprehensive factor, first of all it has to do with the mouth of caries-causing bacteria, more importantly, there is a second related factors, is the diet, the main is sugar, like like like to eat sweets, like to drink drinks, drink cola, its teeth are prone to grow insect teeth. In one case, it is cola teeth, the patient drinks 1-2 bottles of Coca-Cola a day, and in a short time, his mouth full of teeth may grow worm teeth. The patient’s saliva and immune status can also be affected, such as nasopharyngeal cancer patients after radiotherapy, oral salivary gland destruction, saliva is very little, very viscous, it is also very easy to long insect teeth. In addition, it is also related to age, such as young adults have fewer teeth. There are also correlations with race, genetics and geography. In short, it is a combination of factors.