4hw.com.cn: tooth changing is a process that everyone has to go through. It's a very painful thing for many children. As a parent, we should take more care of their children's physical and mental health at this stage. A person's teeth grow twice, once are deciduous teeth, once are permanent teeth, that is, adult teeth. The permanent tooth germ begins to develop calcification after birth. Generally speaking, when the child is about six years old, the permanent teeth will replace the primary teeth gradually, and start to accompany the child for a lifetime. So it is really important to do a good job in the handover of the permanent teeth of the primary teeth.
It starts to sprout at the age of 6-7, with a total of 32, generally reaching the age of 20. When the permanent teeth erupt, the deciduous teeth fall off one after another, and the time sequence is as follows:
At the age of 6, two incisors came out, and the first molar came out behind the second primary molar, which is commonly said to be slotted teeth, one on the top, one on the bottom, one on the left and one on the right; the next two primary incisors fell off.
At the age of 7, the upper two incisors came out and the upper two primary incisors fell off.
At the age of 8, the upper and lower incisors came out, and the upper and lower primary incisors fell off.
At the age of 9-10, the lower canine and the first bicuspid (one at the top, one at the bottom and one at the left), the lower deciduous canine and the first deciduous molar (one at the top, one at the bottom and one at the left).
At the age of 10-ll, the upper canine teeth came out and the upper deciduous canine teeth fell off (one on the left and one on the right).
At the age of 12, the upper and lower second bicuspid teeth (one on the left and one on the right) and the upper and lower third primary molars fell off (one on the left and one on the right).
Generally, all the deciduous teeth fall off at the age of 12-13, and then the permanent teeth are the molars, the second molars at the age of 12, and the third molars at the age of 18, once every six years, hence the name of the six-year-old teeth. However, some people do not come out until they are about 30, and some others do not. When children change their teeth, if the deciduous teeth do not fall off and the permanent teeth erupt on the side of the deciduous teeth bed, the so-called double teeth will appear. They should be pulled out in the hospital as soon as possible, and the permanent teeth will be recovered quickly. In addition, if the deciduous teeth take off early and the permanent teeth don't sprout for a long time, the children are used to chewing food with gingiva, and the gingival keratosis is thickened, which makes it difficult for the permanent teeth to sprout. If the permanent teeth are close to the subgingiva, the gingival color becomes dark and white. When touching the hard subgingival cutting edge during palpation, the gingival slice at the cutting edge can be cut off, and the cutting edge will be exposed, which will accelerate the tooth eruption.
In addition, children should eat more hard and crisp food during tooth change, such as steamed bread, bread, wowowotou, vegetables, beans, etc., to stimulate the development of maxilla and mandible and promote the early eruption of permanent teeth. When the deciduous teeth are replaced, the root is absorbed first. After the deciduous teeth crown without root falls off, the permanent teeth crown erupts from the original alveolar position. The dentin of the newly sprouted teeth has not been completely formed, and the root still continues to develop. After about 11 / 2-3 years, the root tip is completely formed. During teething or tooth replacement, children must pay attention to good protection, avoid all trauma, pay attention to nutrition, especially mineral salt, calcium, phosphorus, or vitamin D, A1, C, etc., in order to promote the formation and calcification of tooth hard tissue.