Caries-causing bacteria can be transmitted from mother to newborn child Dental caries is one of the most common chronic diseases in children before the age of 6 years. The population distribution of dental caries is not uniform, 25% of children suffer from 80% of caries, mostly in disadvantaged groups, economically backward countries and regions. In the outpatient clinic, we met some children who were only 2 or 3 years old, and the teeth inside their mouths were so rotten that only the roots were left. Generally these parents have not good oral health care knowledge, and they have the mentality of ‘no need to fill the rotten milk teeth, they have to be replaced anyway’, not knowing that some children’s early caries progresses very fast, from chalky demineralized plaque to obvious cavities very soon, and sometimes the child has several more caries during the scheduled caries surgery. Caries is closely related to diet, and it is also an infectious and transmittable disease. Chen Ke introduced that the occurrence of caries needs to meet four conditions at the same time: caries-causing bacteria, fermentable carbohydrates, susceptibility of the host and time. Many women know that they should cure their dental problems before pregnancy, but doing so is actually beneficial to the baby’s oral health in addition to avoiding hormonal fluctuations in the body during pregnancy that aggravate dental problems. “This is because the causative agent of dental caries is mainly Streptococcus mutans, which can be transmitted vertically between mother and baby, that is to say, the mother infected with Streptococcus mutans will transmit to her newborn baby. Babies whose mothers have higher concentration of Streptococcus mutans in their saliva have a higher risk of developing early caries in their milk teeth.” There is also horizontal transmission of Streptococcus mutans, such as sharing utensils and mouth-to-mouth kissing with an infected person. In addition, the condition of dental caries must have fermentable carbohydrates, “including any food containing sugar, such as carbonated drinks, milk, juice, etc.” Susceptibility is also a necessary condition for growing caries. “Some children have not very good oral hygiene habits, but because they are not so sensitive to cariogenic bacteria, their teeth are not too bad.” Therefore, we should not pay attention to children’s oral health because “other children don’t brush their teeth and don’t have cavities”. Drinking “night milk” may cause children’s early caries Many diseases have “high-risk group”, the original caries can also be risk assessment, and is the key to caries treatment and prevention. Chen Ke introduced that the risk index of a child suffering from caries includes family history, previous caries experience, medical factors (such as medication), family caries experience (especially mother and siblings), diet, oral hygiene habits (brushing, flossing, etc.), fluoride use and some dental clinical examination and assessment means, etc. High-risk dietary habits are established as early as 12 months of a child’s life. Some parents will give their baby a pacifier for a long time to drink milk as a soothing effect, but doing so is equivalent to having the teeth in contact with milk at any time, which can be eroded by cariogenic bacteria at any time. Irregular breastfeeding, bottle feeding after 12 months, bottle holding at bedtime, bottle feeding with sugary substances, snacking more than 3 times a day, eating caries-causing snacks and drinks, etc. are all dietary risk factors for caries. The frequency of eating affects the risk of dental caries more than the total amount of food eaten: if one eats “non-stop” and irregularly throughout the day, it is equivalent to exposing the teeth to risk for a long time. Therefore, she suggested that breastfeeding should be regular, no bottle, comfort pacifier or duckbill cup at night, no juice or soda in the bottle, and milk in a cup after the child is 1 year old, and limit the frequency of eating starchy or sweet snacks or drinks. Don’t keep eating all day long. Poor oral habits of children are also the risk factor of tooth decay. It is basically impossible to expect two or three year old children to brush their teeth carefully automatically and consciously. Parents should do their responsibility to help their children to develop the habit, “Some children’s toothpaste contains fluoride and some does not, it is recommended to use fluoride toothpaste for children who have the risk of tooth decay, and each time the amount only needs to be the size of a green bean. If children always swallow toothpaste when they first brush their teeth, they can start without toothpaste, but parents should be firm in their attitude, and it is important to develop the habit first.” She said that the quality of brushing is more important than the frequency. After brushing, parents can help their children gently scrape their teeth with a toothpick, and if there is still a layer of white food residue, it means that it is not yet clean. Parents are advised not to wait until their children have problems with their teeth before looking at them. From the time the first milk teeth erupt around the age of 1, dental checkups should be done at least once every six months, and polishing and fluoride application for caries prevention can be done at every checkup during the age of two or three. If the child has poor oral hygiene, high risk of caries or abnormal tooth development and eruption, the frequency of checkup should be increased.