Reliability of determining the age of majority: a comparison between measurement of open apices of third molars and Demirjian stages

This study examines the open apices of third molars indiscriminating between individuals who are or are not 18 years of age or older and to assign a cut-off for estimation of the age of 18 years. Furthermore, this method was compared to those based on Demirjian's stages 8 and 9. Orthopantomographs (OPGs) of 1062 individuals (14 and 23 years) were assessed, to verify Cameriere's third molar maturity index (I3M). The apical ends of the roots of the left mandibular third molar were analysed. Mineralization of the third molar was also evaluated. A cut-off value of I3M =0.08 was taken. The sensitivity of this test was 70.76% and specificity was 82%. The results of the test showed a better specificity for Stage 9 and better sensitivity for stage 8 for adult age. Accuracy was 74.58% for third molar maturity index as compared to 72.41% for stage 9.