Abstract: Objective To study the applicability of Demirjian's method for age estimation in teenagers of Shanghai Han population in China.Methods Paired t-test was performed between the chronological age and the age determined by Demirjian's method of 501 teenagers whose orthopantomograms were collected from the ninth hospital of Shanghai.There were 168 boys and 333 girls involved in this study with chronological age from 11 to 20 years.Uni-factor model was used to explore the relationships of the two kinds of age.Results For the marked difference between the chronological age and determined age,Demirjian's method was not suitable to the Chinese Han adolescents.The results of paired t-test between chronological age and predicted age from quadratic equation showed that there was no significant difference in boys aged 12-16 years,in girls aged 12-14 years and 15-17 years repectively.The uni-factor model could make the error of determined age less than 1 year to 81.04% of the samples.Conclusion The age between 11 and 17 years can be well estimated by our method,except for the 17 years of age and above.

Key words: forensic dentistry, age determination, teeth, Demirjian's method, adolescent, Han nationality