Eruption of the Maxillary First and Second Molar Teeth in Cattle as a Method of Estimating Age

Abstract

Several studies have been undertaken into the age at which varying degrees of intra-oral eruption of the maxillary first and second molar teeth occur. As the rostral part of the tooth erupts before the caudal part it was possible to divide molar development into nine different stages starting with absence of the tooth and ending with both the rostral and caudal parts being fully up. Combination of these results for first and second molar eruption allowed the range of ages over which each stage of development occurred to be determined. The information obtained showed that molar codes 0 to 2 in the first molar were present at times before stage 6 in the same tooth. Additionally an animal with no eruption of the second molar was younger than one with both rostral and caudal parts of the tooth fully erupted. Stages of development in both the first and second molar took place before there was eruption of the permanent rostral teeth, and the age range at all but two stages of eruption was less than that for the rostral teeth.