Controversies in Dental Age Estimation

It has long been assumed that population differences exist in dental maturity but most reference data describe tooth formation in children of European origin. This research is part of a comparative study of tooth formation in world groups and the application of reference data to estimate age. Objective: To investigate if population differences and sex differences in dental maturity influence the average age of tooth stages. Methods: The developing permanent mandibular teeth were assessed from archived dental radiographs (N=8221) of individuals in UK, Nigeria, South Africa, Japan, Malaysia, New Zealand, Australia and Canada. Age range was 2-25 years. Average age of individual tooth stages was calculated and compared between ethnic groups and males and females. Results were compared with a collaborative study of tooth formation in children of European origin in seven countries (N=9002). Results: Population differences in dental maturity were small and the age variation for each tooth stage within each group was considerable. Sex differences were also small, except for canine and third molar roots. Estimating dental age is always done at the individual level and the 95% confidence interval of estimated age is calculated using the standard deviation. Increasing the sample size tenfold did not reduce the standard deviation of mean age of individual tooth stages. These findings show that accuracy and precision of age estimation are hampered by the large age variation in dental maturity. Conclusion: Population specific and sex specific dental maturity reference data do not reduce the age variation in tooth formation and are unlikely to improve accuracy or precision of age estimation.