Cut-off for the legal ages in the Portuguese Population by Third Maturity Index: Measures of Accuracy

• Published in: Archives of oral biology 2021-05, Vol.125, p.105089-105089, Article 105089
• Main Authors: Palmela Pereira, Cristiana, Rodrigues, Ana, Santos, Adriana, Salvado, Francisco, Santos, Rui, Cameriere, Roberto
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Age Determination by Teeth; Bayes Theorem; Child; Cut-off points for Portuguese legal ages; Dental age assessment; Dentistry; Humans; Molar, Third - diagnostic imaging; Portugal; Portuguese Civil Code; Portuguese Penal Code; Radiography, Panoramic; Reproducibility of Results; Third Molar Index; Young Adult
• ISSN: 0003-9969; 1879-1506
• DOI: 10.1016/j.archoralbio.2021.105089

•Third Molar Index and Demirjian’s stages showed a stronger correlation with chronological age.•When comparing the age group classification there are no significant differences between these methods.•The third molar index provides the best accuracy, establishing cut-off value to increase the sensitivity or specificity.•The use of third molar index for the legal ages in the Portuguese population is reliable and with medical-legal application The aim of this study is to estimate the cut-off points for the Portuguese legal ages through the I3M, and to compare them with the methods of Demirjian, Nolla and Moorrees. The lower third molars were analyzed on 348 orthopantomography’s aged between 12 and 23 years in a Portuguese Population. The images were analyzed by ImageJ and the cut-off points were calculated for the respective legal ages of 14, 16, 18 and 21 years old. The correlation between age and the I3M was 0.862, whereas with Demirjian’s stadiums, Nolla’s stages, and Moorrees’ stages the correlation coefficients were 0.863, 0.842 and 0.844, respectively. For the cut-off point of 0.08 for the age of 18, a sensitivity of 78.99 %, specificity of 93.48 %, an accuracy of 88.54 %, a positive predictive value of 86.24 % and a posteriori Bayes probability of 92.82 %. The cut-off points established for the ages of 14, 16, 18 and 21 years for the Portuguese population achieved an accuracy of 83.67 %, 85.67 %, 88.54 % and 87.11 %, respectively. Demirjian’s method and Cameriere’s method attain quite similar results. In certain ages, the methods of Nolla and Moorrees show higher sensitivity or higher specificity when compared to Cameriere’s method, however this last method is more stable in terms of reliability and more suitable to use in the Portuguese population.