Age Estimation - 18 Years old I3M Cutoff Value: Specificity Approach Resulting Confidence Increase

Abstract

Mazzilli Luiz Eugenio Nigro, Melani Rodolfo Francisco Haltenhoff, Lascala Cesar Angelo, Sakaguti Nelson Massanobu, Bruna Hernandes Rodrigues and Kaya Borges da Silva

Objectives: From an administrative or forensic point of view, the need to estimate the age of living people who do not have hold valid documents is crucial. In this sense 18 years, old cutoff values are of great importance due to civil and criminal imputability in the majority of countries. Different medicine and forensic dentistry methods are used to estimate age. Among them, the development of dental elements is one of the most reliable. This study aimed to apply and discuss sex-specific cutoff 18 years old discriminant ratios advantages over sex-pooled reference value to improve accuracy and specificity over Cameriere et al.’s (2008) method in a Southern Brazilian Sample.
Methods: After prior ethical authorization (CAAE: 82403918.0.0000.0075), three experienced examiners measured using Fiji-Image J software, 354 digital panoramic radiographs of individuals aged 14 to 23 years old, to obtain the dental maturity indices (I3m). Based on the sensitivity and specificity criteria (ROC curve), different cutoff values were tested for males and for females.
Results: The inter-examiner agreement verified by Intraclass Correlation Coefficient (ICC) was 0.89. Based on post-test results, the 18-year I3m accuracy ranged from 98% to 94% throughout the tested cutoff values, and was 98% for females (I3m =0.09), 96% for males (I3m = 0.07), and 94% for sex-pooled individuals (I3m = 0.08). Sex-pooled sensitivity values where higher when I3m = 0.09, whereas specificity values were higher when I3m = 0.08. Sex-specific cutoff values expressed an increase in female Specificity (+2%) at 0.09 considered the sex-pooled value of 0.08, while best male specificity was observed at 0.08 I3m values.
Conclusions: Considering the discriminating objective for estimating the age of 18 years old and its forensic impact, it must be observed the greater importance of the specificity of the test in order to minimize false positives than the overall accuracy. In this sense, we can conclude that even being a forensic reliable option the use of 0.08 sex-pooled I3m ratio, sex specific I3m ratios m

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