All of a child’s milk teeth are replaced with permanent teeth. A child’s early milk teeth, usually 20 in number, are gradually replaced as they develop, from milk teeth to permanent teeth. During this process, care must be taken to help your child through a healthy tooth replacement period. 1. Pay attention to the growth of milk teeth and permanent teeth, and review them regularly: if you find that permanent teeth are coming in next to milk teeth, but the milk teeth have not fallen out, forming a double row of teeth, then you should take your child to have the retained milk teeth extracted as soon as possible. 2. Supervise children to brush their teeth every day to prevent dental caries: children should use special toothpaste and toothbrush for brushing their teeth, and pay attention to rinsing their mouths after meals to maintain oral hygiene. 3. Correct bad habits in time: for example, spitting and biting the tongue, biting fingers or pencils, licking the teeth with the tongue, etc. These bad habits will affect the growth of children’s teeth and lead to tooth deformation. 4. Protect your child’s first permanent molars at the age of 6 or so: because the surface of newly erupted teeth is not sufficiently calcified, acid resistance is poor, and they are easy to decay. You can choose to do fissure sealing to prevent caries according to the condition of the teeth. In addition, children can eat more high fiber and have a certain degree of hardness of the food, can promote the development of the dental bed, jawbone and facial bone.