Positive Secular Changes in Dental Maturation Over a 30-year Period

Objectives: Secular change refers to the changes in rate of growth and development over successive generations. Evidence of secular change has been described across a multitude of populations. Logan and Kronfeld (1933) is currently used to assess dental age in the clinic and we wanted to test whether new up-to-date Canadian standards need to be developed.
Methods: A retrospective chart review was carried out in 440 children. Panoramic radiographs were examined for children ages 6 to 13 in a historical group born between 1969 and 1980 and a modern group born between 2004 and 2011 (220 per group). Root development on seven mandibular teeth was staged using the Demirjian system (1973). The median age-of-attainment for each stage of maturation was calculated using logistic regression. Significant differences in median age-of-attainment in each group separated by gender were determined by logistic regression using the Wald statistic. This work was approved by the UBC Clinical Ethics committee, H1702181.
Results: The modern sample was statistically significantly younger than the historical sample for a given tooth type and stage. Modern girls were on average 1-year ahead for the first premolar root completion and up to 17-months ahead for completion of the first molar root. Modern boys were almost 17-months ahead for the first premolar root completion and 1year ahead for first molar root completion. The modern boys and girls mature on average 0.61 years and 0.90 years earlier than their historical counterparts, respectively (P<0.05).
Conclusions: Secular changes have taken place in British Columbia during the last 30 years with earlier dental maturation. Tooth maturation is a sensitive way to measure childhood dental development. Furthermore, there may be certain teeth more susceptible to environmental factors such as the first premolar. These indicator teeth may be used to gauge shifts in the pace of childhood development.