Underage childhood caries (ECC) has become an important public health problem. The American Academy of Pediatric Dentistry (AAPD) and the American Academy of Pediatrics (AAP) jointly developed a strategy for the classification, impact, and prevention of ECC, which has been in place since 1978 and has been revised in 1993, 1996, 2001, 2003, 2007, 2008, 2011, and 2014 (with the 2014 revision limited to the use of fluoride toothpaste in children in relation to the use of fluoride toothpaste in children). What is in the latest version of the U.S. Prevention Strategy? About ECC: The concept of “bottle caries” was first introduced by the AAPD in 1978. However, it was later recognized that this unique clinical disease was not only related to improper feeding, but that caries was a bacterial infection. Therefore, the AAPD adopted the term ECC to better reflect the diversity of the disease’s etiology. Classification of ECC:In children under 6 years of age, the presence of one or more caries (whether or not it becomes a cavity), lost (due to caries), or filled surfaces on any of the milk teeth is considered ECC. In children under 3 years of age, the presence of caries on any smooth tooth surface is an indication of severe low grade childhood caries (S-ECC). In children 3 to 5 years of age, the presence of one or more carious, missing (due to caries), or filled tooth surfaces (smooth surfaces) on any maxillary milk anterior tooth, or the number of carious missing filling surfaces (dmfs) ≥ 4 (3 years), dmfs ≥ 5 (4 years), or dmfs ≥ 6 (5 years) also constitutes S-ECC. Impact of ECC:Epidemiologic data indicate that ECC is very common and is present in poor and ECC is more harmful to children than to adults, and the effects are both local and systemic, especially in the case of papillary caries and its secondary lesions, which are sometimes more extensive and severe than in the case of permanent caries. The main effects of ECC include: higher risk of new caries in the milk and permanent dentition; increased risk of hospitalization and emergency visits, which in turn increases the cost of treatment; higher risk of physical growth and developmental delay; reduced school time and increased restricted activities; reduced learning ability; and reduced oral health-related quality of life. Prevention of ECC: ECC is an important public health issue and oral health care providers and caregivers are encouraged to take preventive measures to reduce the risk of ECC in children. The main prevention recommendations are as follows: ① Reduce the level of Streptococcus pyogenes in parents/siblings’ mouths to reduce the transmission of cariogenic bacteria; ② Minimize the occurrence of salivary cross-activities (e.g., sharing utensils) to reduce the transmission of cariogenic bacteria; ③ Take oral immunization measures before the first milk teeth erupt in young children’s mouths; have parents help or assist children to brush twice a day and choose toothbrushes with soft bristles and brush head sizes appropriate for the child’s age-appropriate toothbrush. When brushing, all children under 3 years of age should use a “thin layer” or “rice-grain size” amount of fluoride toothpaste; all children 3 to 6 years of age should use a “pea-grain size” amount of fluoride toothpaste. All children aged 3-6 years should use a “pea-sized” amount of fluoride toothpaste. ④For children at risk of ECC, fluoride varnish treatment is recommended. ⑤ Within 6 months after the first milk tooth erupts in the mouth and no later than 1 year old, take the child to the dentist and establish a family file to assess the risk of caries in young children and to educate parents about oral health, including some precautionary instructions for oral disease prevention. (6) Avoid sugary liquid or solid foods at high frequencies. In particular: Avoid using bottles or sealed children’s cups to consume sugary drinks (e.g., fruit juices, beverages) Work with your dentist to ensure that every infant and toddler has the opportunity for an oral exam, health consultation, and preventive measures.