Normally, all baby teeth are replaced by permanent teeth. Milk teeth are the first set of teeth that erupt in a newborn’s mouth, at about half a year of age, and all of them erupt between the ages of two and a half and three years, for a total of 20 teeth. The milk teeth are replaced by permanent teeth at about seven years of age. The first milk tooth to be replaced is the central incisor, which is replaced by the transverse incisor at about seven years of age. At the age of eight, the lateral incisors are replaced by the lateral equilibrium incisors, and the cuspids and first molars are replaced by the permanent cuspids and premolars at the age of 9-11. At the age of 12, the second molars are replaced by the permanent teeth, and generally at the age of 13, all the milk teeth are replaced by the permanent teeth.