Changing teeth earlier than children of the same age does not mean early development. There is no necessary correlation between the age of tooth replacement and developmental time. The timing of tooth replacement depends mainly on genetic factors and nutritional status. If a child’s parents or immediate family members within three generations have early tooth replacement, such a child is significantly more likely to have early tooth replacement than other children of the same age. Children who are well nourished and have no periodontal disease will have earlier tooth replacement. Early development is mainly influenced by genetics and certain endocrine diseases. Therefore, early tooth replacement does not mean early development. During the period of tooth replacement, children should pay attention to oral hygiene, eat less sweets, clean the mouth regularly, and consult a doctor in time if caries and other oral problems occur.