Teeths are divided mainly into two groups , that is milk teeth and permanent teeth Milk teeth fall off by the age of 10 and are replaced by permanent teeth A milk teeth is a set of 16 to 20 teeth , while permanent teeth is a set of 28 to 32 teeth _ ( mainly considered as a set of 32 teeth ) Now talking about permanent teeth _ mainly a set of 32 teeth _the set is now divided into four groups ( don't confuse about two and four groups In whole life _human gets two different sets of teeth _ permanent and milk teeth while permanent set of teeth is divided into four teeth ) So permanent set of teeth is divided into four groups_Insicors , front teeth _ canines _pre -molars and molars. If you know to want more please reply my answer_ I know my answer is long, but you will understand everything about you want to know _ Hope this helped you _ And happy and safe learning_