Third molar assessment for legal age determination in Indonesian juveniles using Demirjian method

Third molar radiographic assessment can help determine the probability of an individual reaching the legal age of majority, typically 18 years old. This study aims to assess this probability using third molar development through the Demirjian staging system. The sample consisted of 429 panoramic radiographs (210 females, 219 males) from individuals aged 15–23.99 years. Upper right (FDI 18) and lower right (FDI 48) third molars were assessed following Mincer's adaptation of the Demirjian staging system. Logistic regression analysis was used to evaluate the probability of being over 18 years old, analysing both single and combined third molar stages. FDI 18 and 48 showed similar developmental stages, with FDI 18 generally developing at a faster rate. The probability of being 18 years or older (P ≥ 0.5) was reached at stage F for males (P = 0.58) and females (P = 0.54) in FDI 18, and for females in FDI 48 (P = 0.61). By stage H, it was almost certain that the individual was over 18 years old. When combining both upper and lower third molars, individuals were almost certainly over 18 if FDI 18 had reached stage H, regardless of FDI 48 stage. Third molar development assessment in Indonesian juveniles can serve as an effective tool for determining whether an individual is over or under 18 years old using Demirjian staging. Future research should aim to refine age estimation models within specific populations to enhance accuracy and reliability in legal age assessments.