In infants, milk teeth begin to erupt at 4~10 months after birth, but the exact time of eruption varies with the growth and development of each infant. In general, healthy infants in 4~10 months after birth milk teeth began to erupt, nutritional absorption or faster growth and development of infants milk teeth eruption earlier, on the contrary, some infants with poor nutritional absorption may milk teeth eruption later, this is due to each baby’s physique is different or by the influence of genetic factors, but in the birth of 4~10 months within the eruption of the normal. If the baby is not erupted 13 months after birth belongs to the delayed eruption of milk teeth, may be the manifestation of disease, most commonly caused by lack of vitamin D or lack of calcium caused by rickets, but also seen in cretinism, malnutrition and so on. If you find that your baby’s teething time is abnormal, you should go to the hospital in time.