Positive secular change in dental root maturation over a 30-year period in British Columbia, Canada

The purpose of this study is to determine whether a secular change in dental root maturation had occurred in Vancouver, British Columbia over a 30-year period.

Two cohorts of sex and age matched children ages 6-12 were selected from orthodontic pediatric patients treated in the Vancouver area. An earlier group of children were born between 1960 and 1980 (n = 220) and a recent group between 2004 and 2010 (n = 220). Stages of tooth mineralization were scored from panoramic radiographs according to Demirjian's method. Seven mandibular teeth on the left side were assigned a maturity score (A-H). To assess changes in the timing of dental root maturation, the median age-of-attainment for each maturity stage was calculated, using logistic regression. Differences in median age-of-attainment between the two time periods and between males and females was compared via logistic regression using the Wald statistic.

A significant positive secular change in dental root maturation was observed. Advancement in median age-of-attainment in the historical sample relative to the recent sample ranged between 0.06 and 1.43 years (mean = 0.61years) in boys and between 0.05 and 1.43 years in girls (mean = 0.79 years). Differences were most pronounced at later root-formation stages (F-H) and girls demonstrated greater acceleration than boys across most tooth types and stages.

These findings confirm that dental root maturation in British Columbian children has advanced substantially over a single generation, indicating greater developmental plasticity than previously recognized and underscoring the need to update or adjust standards used in clinical and forensic practice.