1. The child’s first milk teeth begin to erupt at about 6 months of age, and by the age of about 2.5 years, 20 milk teeth have erupted. Due to the different physique of the children, some children have gaps in their milk teeth and some children have no gaps in their milk teeth. However, as they get older, their jaws continue to grow and develop while the size of their teeth remains unchanged, resulting in gaps in their milk teeth. 2. Some children’s milk teeth have no gap at the beginning, which is a normal physiological phenomenon. The absence of gaps in the early stages of milk teeth will not affect the replacement of teeth in the future. Parents need to pay attention to the child’s oral hygiene, to avoid the occurrence of dental caries, from the age of 6 ~ 7 to 12 ~ 13 years old, milk teeth will gradually fall off, permanent teeth will gradually replace milk teeth.