 The second molars start protruding at the age of about six months, grow to a size of wide by long and are lost by the age of 6–7 years.The third molars protrude at the age of about one year, grow to a size of wide by long and are lost by the age of 8–10 years.The fourth molars show by the age of 6–7 years, grow to a size of wide by long and are lost by the age of 22–23 years.