Not changing teeth at 6 1/2 years old may be normal. Under normal circumstances, children change their teeth at about 6 years old, and there are individual differences in the exact time, some children may start to appear around 4~5 years old, and some may appear at 7 years old or later, and at the same time, there is also a certain relationship with the child’s dietary habits and nutritional status. The order of tooth replacement is usually incisors first, followed by molars last. During the period of tooth replacement, avoid eating hard and stimulating foods, eat a balanced diet, pay attention to oral hygiene, and develop a good habit of brushing and rinsing frequently to avoid dental caries, periodontitis and other dental diseases.