There are two sets of teeth in a person’s life. The teeth that erupt during infancy and grow in during early childhood are called milk teeth. During preschool, the milk teeth are lost and replaced by new teeth. The newly erupted teeth will not be replaced and will remain with you for the rest of your life and are called permanent teeth. Schedule of eruption and loss of milk teeth Teeth Eruption time Eruption time Eruption time Lateral incisors 6 – 8 months 7 years Lateral incisors 6 – 10 months 8 years Cuspids 16 – 20 months 12 years 1st molar 12 – 16 months 10 years 2nd molar 20 – 30 months 11 – 12 years The first milk teeth begin to erupt around 6 months of age and 20 milk teeth are erupted by about 2.5 years of age. From the age of 6-7 to 12-13 years, the milk teeth are gradually lost and replaced by permanent teeth. The permanent teeth are the second set of teeth after the milk teeth, and if they are lost due to disease or accidental damage, there are no more teeth to replace them. In recent generations, the third molar has a tendency to degenerate, so the number of permanent teeth in general is between 28 and 32.