New teeth have come in, but the old ones have not fallen out yet, a condition called retained milk teeth, which often occurs during the period of tooth replacement in children. The main reason is that children nowadays have a more refined diet and eat less coarse grains, mixed grains and other nutty foods, so it often happens that new permanent teeth erupt and the milk teeth do not fall out. In this case, the outside milk teeth can be extracted and the new teeth will naturally adjust their position and erupt naturally, so parents do not need to worry. In addition, tooth replacement itself is a natural physiological replacement process, if the new teeth have just erupted and the milk teeth are not loose, you can encourage your child to eat more nutty foods at this time, and try to let the milk teeth fall out on their own better. If there is a loose tooth has not fallen off, help the child to pull out the milk teeth can be.