Order and Age of Eruption for the Deciduous Dentition

Abstract

This paper treats order and age of eruption (gum perforation) of the deciduous teeth in North American children. Its purpose is twofold: to assemble the available research materials and to present a synthesis of these materials. The findings from 22 investigations are first reviewed. These findings are then ordered and integrated in a series of statements which epitomize present knowledge on the problem. Selected conclusions are: The mean age for eruption of the 1st tooth is 7.5 mos. 98% of infants erupt their first tooth between 4 and 12 postnatal months. The typical White infant has 3 erupted teeth at 9 mos., 6 at 1 yr., 12 at 18 mos., and 16 at 2 yrs. In 1-yr.-old infants the number varies from none to a full complement[long dash]50% have between 4 and 8. The usual eruption sequence is incisors (lower central, upper central, upper lateral, lower lateral), first molars, canines, second molars (lower before upper). Exceptions to the predominant pattern include the eruption of 1st molars before lateral incisors, canines before lateral incisors, canines before 1st molars, and 2d molars before canines. At all ages from 9 mos.-2 yrs. teeth tend to erupt earlier in [male][male] than in [female][female]. While materials on Negro subjects are limited, it appears there is no striking difference in avg. age of tooth eruption for White and Negro children.