Babies’ teeth growth after birth may be caused by premature eruption of milk teeth and horse teeth. 1. Premature eruption of milk teeth: mainly because in the developmental period, milk teeth are located in a very superficial position under the mucous membrane and do not develop normally in the alveolar bone, then it will be manifested as teeth in the mouth at birth. This kind of teeth is very loose, easy to fall off will cause the baby sucking, accidental swallowing and other dangers. 2. Horse teeth: Horse teeth are not real teeth but are caused by the accumulation of epithelial cells. It does not affect the baby’s condition of breastfeeding, nor does it affect the development of milk teeth. There may be other reasons for babies to grow teeth after birth, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, and then give targeted treatment or treatment.