Applicability and accuracy of Demirjian and Willems methods in a population of Eastern Chinese subadults.

BACKGROUND

To assess the validity of the Demirjian and Willems dental age estimation methods in a population of Eastern Chinese 11-18-year-old subadults.

SAMPLES AND METHODS

A total of 1622 orthopantomograms (787 boys and 835 girls) aged from 11.00 to 18.99 years old from a Chinese Han population were evaluated in the study. Dental ages were calculated using both Demirjian and Willems method. Statistical significance was set at p<0.05 and for each method, discrepancies between chronological age (CA) and dental age (DA) were statistically analyzed by paired t-tests. Special age interval analysis was conducted by Chi-square tests to compare the accuracy of the Demirjian and the Willems methods.

RESULTS

Demirjian method underestimated CA 0.66±1.45 y (p<0.001) in boys and 0.62±1.61 y (p<0.001) in girls while Willems method underestimated 0.90±1.32 y (p<0.001) and 0.97±1.56 y (p<0.001) in boys and girls, respectively. The mean absolute error (MAE) value between the CA and the DA (CA-DA) using the Demirjian method and the Willems method were 1.31 and 1.29 y for boys, respectively, and 1.35 and 1.43 y for girls, respectively.

CONCLUSIONS

It is suggested that the Demirjian method was found to be more accurate compared with the Willems method. However, the Demirjian method may not be satisfactory for 11-18-year-old children of Eastern China. It is recommended that a modified Demirjian method for better dental age estimation for Eastern Chinese juvenile individuals.