Crown formation times of human permanent anterior teeth

One gap in knowledge of human dental-growth standards is the age at which crown fractions of anterior permanent teeth are attained. The aim of this study was to document stages of crown formation for permanent incisors and canines from a small skeletal collection of known age. The source was C18th and C19th coffin-buried skeletal material from Spitalfields in London; developing teeth from 50 individuals with recorded age-at-death (range 0-5.40 years) and 56 unaged individuals were assessed. Teeth were dissected and crown height measured directly. Each developing crown was assigned to the nearest average fraction (C14, C12, C34, Cc). These fractions were calculated from the total crown height of unworn completed teeth from this sample. Median age for C12 of the permanent upper central incisor was 1.34 years (n=16) and for the canine was 2.52 years (n=16). Data on crown formation are also presented in relation to permanent lower first molar stages C12, C34 and Cc. When M(1) was at stage C34 the modal stage for I(1) was C34 and for other incisors and canines was C12. Although the sample is small, these results fill an important gap in tooth chronology and add to knowledge of growth variation in early childhood.