Third molar maturity index (I3M) assessment according to different geographical zones: a large multi‑ethnic study sample

Nikolaos Angelakopoulos 1-2;Stefano De Luca 2-3;Inês Oliveira‑Santos 4;Isabella Lima Arrais Ribeiro 5;Ilenia Bianchi 6;Sudheer B. Balla 2-7;Hatice Cansu Kis 8;Lourdes Gómez Jiménez 9;Galina Zolotenkova 10;Mohd Yusmiaidil Putera Yusof 11;Aida Hadzic Selmanagic 12;Hemlata Pandey 13;Palmela C. Pereira 14;Johnys Berton Medeiros da Nóbrega 15;Hettiarachchi Kalani 16;Sylvia M. Mieke 17;Akiko Kumagai 18;Ayse Gulsahi 2-19;Ksenija Zelić 20;Nemanja Marinković 21;Jeta Kelmendi 22;Ivan Galic 2-23;Israel Soriano Vázquez 24;Enrico Spinas;Ymelda Wendy Velezmoro‑Montes 26;Maria Moukarzel 27;Jorge Pinares Toledo 28-29;Amal Abd El‑Salam El‑Bakary 30;Roberto Cameriere 2.

2023-01-01

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Abstract

Identification of living undocumented individuals highlights the need for accurate, precise, and reproducible age estimation methods, especially in those cases involving minors. However, when their country of origin is unknown, or it can be only roughly estimated, it is extremely difficult to apply assessment policies, procedures, and practices that are accurate and child-sensitive. The main aim of this research is to optimize the correct classification of adults and minors by establishing new cut-off values for four different continents (Africa, America, Asia, and Europe). For this purpose, a vast sample of 10,701 orthopantomographs (OPTs) from four continents was evaluated. For determination and subsequent validation of the new third molar maturity index (I3M) cut-off values by world regions, a cross-validation by holdout method was used and contingency tables (confusion matrices) were generated. The lower third molar maturity indexes, from both left and right side (I3ML and I3MR) and the combination of both sides (I3ML_I3MR) were calculated. The new cut-off values, that aim to differentiate between a minor and an adult, with more than 74.00% accuracy for all populations were as follows (I3ML; I3MR; I3ML_I3MR, respectively): Africa = (0.10; 0.10; 0.10), America = (0.10; 0.09; 0.09), Asia = (0.15; 0.17; 0.14), and Europe = (0.09; 0.09; 0.09). The higher sensitivity (Se) was detected for the I3ML for male African people (91%) and the higher specificity (Sp) of all the parameters (I3ML; I3MR; I3ML_I3MR) for Europeans both male and female (> 91%). The original cut-off value (0.08) is still useful, especially in discriminating individuals younger than 18 years old which is the goal of the forensic methods used for justice.