It is generally normal for babies to grow teeth within 13 months, and no tooth emergence beyond 13 months is considered late eruption of milk teeth. Those with delayed eruption of milk teeth should be examined to see if they are congenitally missing teeth or suffering from systemic diseases, and undergo relevant treatment. Preterm infants should be corrected for gestational age to due date. The first milk teeth of infants usually erupt at 6 to 8 months of age, and those who erupt their first milk teeth within 13 months of age belong to the normal eruption range, and those who have not erupted after 13 months of age are considered to have late eruption of milk teeth. X-rays should be taken to check for congenital tooth loss. Systemic diseases such as calcium deficiency, hypothyroidism and severe malnutrition are also considered. If systemic factors are involved, the disease can be treated. If congenital edentulous malformation, when the child is 4 or 5 years old, denture can be made to restore chewing function, which is conducive to nutritional intake and oral and maxillofacial development. When the baby is over 1 year old and still has no teeth, the parents should take him to the child health department or stomatology department of the hospital, and standardize the treatment under the guidance of the doctor.