<prompt> At what age the first permanent teeth appear in a child?2 years4 years6 years8 years  <response>: Ans. is c i.e., 6 years Rule of six:- Primary temporary dentition begins 6 months. Secondary permanent dentition begins 6 years.Eruption of temporary teethPrimary dentitionToothAge in range monthsAverage age monthsLower CI6-87Upper CI7-98Uppler LI7-98Lower LI10-12111 molar12-1413Canine17-1817-5II molar20-3025 Eruption of permanent teethSecondary dentition Age in range yearAverage age yearFirst molar6-76?5Central incisor7-87Lateral incisor8-98First PM9-1110Second PM10-1211Canine11-1211?5Second molar12-1413Third molar17-2517 