Age estimation among Brazilians: Younger or older than 18?

Applying artificial intelligence to determination of legal age of majority from radiographic data

Forensic odontologists use biological patterns to estimate chronological age for the judicial system. The age of majority is a legally significant period with a limited set of reliable oral landmarks. Currently, experts rely on the questionable development of third molars to assess whether litigants can be prosecuted as legal adults. Identification of new and novel patterns may illuminate features more dependably indicative of chronological age, which have, until now, remained unseen. Unfortunately, biased perceptions and limited cognitive capacity compromise the ability of researchers to notice new patterns. The present study demonstrates how artificial intelligence can break through identification barriers and generate new estimation modalities. A convolutional neural network was trained with 4003 panoramic-radiographs to sort subjects into 'under-18' and 'over-18' age categories. The resultant architecture identified legal adults with a high predictive accuracy equally balanced between precision, specificity and recall. Moving forward, AI-based methods could improve courtroom efficiency, stand as automated assessment methods and contribute to our understanding of biological ageing.

Binary decisions of artificial intelligence to classify third molar development around the legal age thresholds of 14, 16 and 18 years

Third molar development is used for dental age estimation when all the other teeth are fully mature. In most medicolegal facilities, dental age estimation is an operator-dependent procedure. During the examination of unaccompanied and undocumented minors, this procedure may lead to binary decisions around age thresholds of legal interest, namely the ages of 14, 16 and 18 years. This study aimed to test the performance of artificial intelligence to classify individuals below and above the legal age thresholds of 14, 16 and 18 years using third molar development. The sample consisted of 11,640 panoramic radiographs (9680 used for training and 1960 used for validation) of males (n = 5400) and females (n = 6240) between 6 and 22.9 years. Computer-based image annotation was performed with V7 software (V7labs, London, UK). The region of interest was the mandibular left third molar (T38) outlined with a semi-automated contour. DenseNet121 was the Convolutional Neural Network (CNN) of choice and was used with Transfer Learning. After Receiver-operating characteristic curves, the area under the curve (AUC) was 0.87 and 0.86 to classify males and females below and above the age of 14, respectively. For the age threshold of 16, the AUC values were 0.88 (males) and 0.83 (females), while for the age of 18, AUC were 0.94 (males) and 0.83 (females). Specificity rates were always between 0.80 and 0.92. Artificial intelligence was able to classify male and females below and above the legal age thresholds of 14, 16 and 18 years with high accuracy.

Using machine learning to determine age over 16 based on development of third molar and periodontal ligament of second molar

BACKGROUND

Having a reliable and feasible method to estimate whether an individual has reached 16 years of age would greatly benefit forensic analysis. The study of age using dental information has matured recently. In addition, machine learning (ML) is gradually being applied for dental age estimation.

AIM

The purpose of this study was to evaluate the development of the third molar using the Demirjian method (Demirjian3M), measure the development index of the third molar (I3M) using the method by Cameriere, and assess the periodontal ligament development of the second molar (PL2M). This study aimed to predict whether Chinese adolescents have reached the age of criminal responsibility (16 years) by combining the above measurements with ML techniques.

SUBJECTS & METHODS

A total of 665 Chinese adolescents aged between 12 and 20 years were recruited for this study. The development of the second and third molars was evaluated by taking orthopantomographs. ML algorithms, including random forests (RF), decision trees (DT), support vector machines (SVM), K-nearest neighbours (KNN), Bernoulli Naive Bayes (BNB), and logistic regression (LR), were used for training and testing to determine the dental age. This is the first study to combine ML with an evaluation of periodontal ligament and tooth development to predict whether individuals are over 16 years of age.

RESULTS AND CONCLUSIONS

The study showed that SVM had the highest Bayesian posterior probability at 0.917 and a Youden index of 0.752. This finding provides an important reference for forensic identification, and the combination of traditional methods and ML is expected to improve the accuracy of age determination for this population, which is of substantial significance for criminal litigation.

Evaluation of Third Molar Maturity Index by Cone Beam Computed Tomography in Legal Age Estimation: A Preliminary Study

ABSTRACT

This retrospective study aimed to evaluate the accuracy and applicability of the third molar maturity index (I 3M ) for discriminating Turkish minors from adults, and its relationship with chronological age using cone beam computed tomography (CBCT). A total of 122 CBCT scans of Turkish individuals (55 boys and 67 girls) aged 13 to 23 years were evaluated using the I 3M cutoff value. Chronological age gradually decreased as the I 3M value increased. The overall accuracy was 95.9%. The sensitivity and specificity of this test were 93.5% and 97.4%, respectively. Positive predictive value was 95.6%. The intraclass correlation coefficient values of the I 3M for the intraobserver and interobserver agreements were 0.998 and 0.996, respectively. This study showed relatively higher reproducibility of measurements on CBCT scans than on panoramic radiographs in the literature. Cone beam computed tomography may be advantageous and preferred over panoramic radiographs in distinguishing the legal age threshold of 18 years according to Cameriere's method when a more extensive investigation is needed to support the solution of challenging and uncertain cases in forensic medicine.

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

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 (I_3M) 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 (I_3ML and I_3MR) and the combination of both sides (I_3ML_I_3MR) 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 (I_3ML; I_3MR; I_3ML_I_3MR, 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 I_3ML for male African people (91%) and the higher specificity (Sp) of all the parameters (I_3ML; I_3MR; I_3ML_I_3MR) 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.

Age estimation using London Atlas methodology: A systematic review and meta-analysis

Age estimation is a fundamental competence of Forensic Anthropologists and Odontologists. The London Atlas is a dental development chart by AlQahtani et al. (2010) that gained recent notoriety due to its applicability in forensic scenarios. This study aimed to answer, by a systematic review of literature and meta-analysis, the following question: "on average, what is the deviation between real and estimated ages, when applying the London Atlas method in sub-adults?". This study was carried out according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and registered in the International Prospective Register of Systematic Reviews (PROSPERO). Five electronic databases were screened (PubMed, SciELO, Scopus, Web of Science, and LILACS), and active search was carried out. The quality assessment was performed by means of Joanna Briggs Institute Critical Appraisal Tools for Systematic Reviews. The initial search resulted in 1021 studies, from which 24 filled the inclusion criteria. For the meta-analysis, 17 studies provided sufficient data. Out of these, eleven studies enabled meta-analysis of mean absolute difference values. Standardized mean differences were 0.02 years for MD and 0.78 for MAD. Analysis of subgroups was also accomplished by sex, and did not indicated heterogeneity between males and females. The London Atlas is an accurate age estimation method, presenting acceptable error and bias values worldwide. Despite the high heterogeneity of the studies, majority of studies presented a low risk of bias. Meta-analysis showed a non-significant and slight tendency of overestimating age, in total. Sub-group analysis showed modestly better results for boys than girls.

Application of Third Molar Maturity Index (I3M) for Assessing Adult Age of 18 Years in a Southern Italian Population Sample

OBJECTIVE

 Age estimation of living or dead individuals has a strategic importance in medicine, anthropology, and forensic science, in the context of mass disasters and in civil or criminal matters such as adoption or asylum. Teeth play a major role in this context in particular, the third molars are useful for determining whether an individual has reached the legal age of 18 years because they are still in development from the age of 14.

MATERIALS AND METHODS

 In this study, a sample of 307 panoramic radiographs performed on healthy subjects aged between 13 and 23 was analyzed to consider the correlation between the maturity index of the third molar (I3M) and age to verify the reliability of the cutoff 0.08 indicated by Cameriere et al in a sample of Italian subjects living in the Province of Messina (Sicily, South Italy) to discern the adult subjects from the minors.

STATISTICAL ANALYSIS

 The analysis of 307 panoramic radiographs resulted in a sensitivity of 89.2% with a confidence interval of 95%, a specificity of 96.5% with a confidence interval of 95%, and a positive predictive value of 96.7%.

RESULTS

 The method proved itself reliable in estimating adulthood in the population of the Messina- Sicily, but the I3M should not be used as the sole indicator to determine whether a person is younger or older than 18 years because age estimation based on dental methods alone has limitations as the third molars suffer from many variations related to their morphology, their location, and their development.

CONCLUSION

 We recommend a combination of several methods that are available to increase accuracy of age estimation, depending on the different legal requirements in civil or criminal cases.

Diagnostic accuracy of the third molar maturity index (I3M) to assess the age of legal majority in Northern Brazil-population-specific cut-off values

International guidelines for dental age assessment have recommended the use of methods based on available population-specific data. The Third Molar Maturity Index (I_3M) was previously validated in several populations worldwide. This was the first study to evaluate the I_3M in a northern Brazilian population and to test the diagnostic accuracy of the method to distinguish between minors and adults. The sample consisted of 1.070 panoramic radiographs retrospectively collected from females (n = 595) and males (n = 475) with ages between 16 and 22 years. I_3M's original cut-off value of 0.08 was used to classify individuals below and above the age of 18. Receiver operating characteristic (ROC) curves were plotted to assess the accuracy (ACC) of the method. In females and males separately, the overall ACC was 73.1% and 80%, respectively. The overall ACC for the combined sample was 76.1%. For northern Brazilian males, the best cut-off value remained 0.08, while for females, an adjustment to 0.12 showed optimal outcomes. The new cut-off value led to an ACC of 98.5% for females, which reflected an increase of 25.5% compared to the original cut-off value. The original cut-off value proposed by I_3M was applicable to the present sample of northern Brazilian individuals. Adjustments to 0.12, however, may be encouraged to enhance the performance of the method among females.

Accuracy of different dental age estimation methods for determining the legal majority of 18 years in the Turkish population

OBJECTIVES

Radiographic evaluation of the third molar maturation is used to estimate dental age, especially in adolescence. This study aimed to assess the application of three age estimation methods (Cameriere's third molar maturity index (I_3M), Demirjian's maturation stages, and The London Atlas) to determine whether an individual is 18 years or older (adult) or younger than 18 years (minor).

MATERIALS AND METHODS

The dental age was estimated using the I_3M, Demirjian's maturation stages, and The London Atlas methods on panoramic radiograms of a total of 500 Turkish individuals aged 14-22 years. A logistic model was derived with an individual's adult or minor status as the dependent variable, and each method and sex as predictive variables. The adult status was determined using dental age estimation methods and the performance of these methods in differentiating adults from minors was evaluated. The three methods were compared case-wise for their accuracy in predicting adult status.

RESULTS

Logistic regression analysis showed that sex and each estimation method were statistically significant in discriminating adults and minors (p < 0.05). In the case-wise comparison for estimate adulthood, both Demirjian's stages and I_3M methods tended to perform better than the London Atlas method, with this trend reaching statistical significance (p < 0.05).

CONCLUSIONS

Cameriere's I_3M and Demirjian's development stages are useful methods for adult age assessment in the tested population.

CLINICAL RELEVANCE

In forensic medicine and legal practices, Cameriere's I_3M and Demirjian's maturation stage methods based on the development of the third molar teeth can be used to determine whether an individual is a minor or an adult.

Demirjian and Cameriere methods for age estimation in a Spanish sample of 1386 living subjects

Currently, human identification is a challenge. Migration due to war, economic crisis or other factors is frequent. The wisdom teeth are the last teeth to initiate and complete development therefore, are fundamental for determining the legal age of majority in different countries. The aim of the study is to determine the validity of two methods based on mineralisation of the third molar to predict the ages of majority of individuals in a Spanish population. Orthopantomographies of 636 men and 750 women (mean age, 16.5 years) were analysed. The Demirjian and Cameriere methods were used, and each tooth was assigned a value according to the degree of mineralisation and maturation. The level of significance used in the analyses was 5% (α = 0.05), with a power of 96.2%. The predictive ability of the Demirjian method to determine 18 years of age in the lower wisdom teeth 93%, respectively. The Cameriere method has a predictive capacity of 88%. There are no statistically significant differences between men and women. Stage H and a cut-off point of 0.08 were the guiding values for determining the age of majority of the study population. For other proposed age ranges (14 and 16 years), both methods were useful in determining the actual age of individuals, with the Demirjian method having a sensitivity of 97.5% with and Cameriere having a predictive capacity of 95%. Both methods can be used with high reliability to determine the age of individuals where reliable documentation is unavailable. Stage H with the Demirjian method and a cut-off point of 0.08 with the Cameriere method can determine the age of majority of the Spanish population. The combination of the two methods does not substantially increase predictive ability.

Third molar maturity index as an efficient tool for prediction of age in a sample Indian population - A retrospective study

Introduction

The age of 18 years is an important milestone for legal matters, and developmental parameters of teeth are often used for estimation of this age. The aim of this study is to assess the efficiency of third molar maturity index (I3M) in establishing age of 18 years in Dakshina Kannada population.

Methods

A total of 700 orthopantomograms were retrieved from the archives of the radiology department of Manipal College of Dental Sciences, Mangalore. The length and the width of the open apex of the mandibular left third molar was assessed using Image J software and the Third molar maturity Index (I3M) was calculated and correlated with the age of the individual.

Results

Receiver operating characteristic (ROC) curve analysis showed the Area under curve of 0.94 and 0.96 in females and males, respectively, for prediction of age of 18 years. The cut-off of 0.08 predicted the 18-year cut-off with 97% specificity and 90.2% negative predictive value. The percentage of the accuracy was 80.23% if the I3M was <0.08.

Conclusion

The efficiency of the cut-off of 0.08 of I3M has been tested in various population including Kosovar, Peruvian, South Indian, Libyan, Montenegro, Croatian, African (Botswana), Albanian, and Serbian. Our study also shows the efficiency of the same in South Indian Dakshina Kannada population.

Sensitivity and Specificity of Mandibular Third Molar Calcification at Chronological Age and Hand Wrist Maturation Stage to Discriminate Between Female and Male at Pubertal Growth Period

Background:

The mandibular third molar is the last tooth that is not completely developed by the time pubertal growth has been finished. Maturation of the mandibular third molar is one of the physiological maturation indicators that can be used to determine the stage of pubertal growth.

Objective:

The aim of the study was to determine the sensitivity and specificity of mandibular third molar calcification at chronological age and hand wrist maturation stage to discriminate between female and male at pubertal growth period.

Methods:

It is a retrospective study with a cross-sectional approach using panoramic and hand-wrist digital radiographs of 279 females and 144 males, age 8-17 years, with a total of 423 panoramic radiographs and 423 hand-wrist radiographs. Statistical analysis was performed using Excel Mega Stat. ANOVA to analyze the differences between mandibular third molar calcification at chronological age and hand-wrist maturation stage, and t-test was used to analyze the differences between females and males. Spearman rank correlation was used for the analysis of the correlation between mandibular third molar calcification with chronological age and hand-wrist maturation stage; sensitivity and specificity were used to discriminate the pubertal growth period between mandibular third molar calcification and hand-wrist maturation stage.

Results:

There were significant differences found in mandibular third molar crown maturation stage B and C, but no significant difference was observed between mandibular third molar stage A, D, E, F, G and H, between females and males. The highest percentage of mandibular third molar crown formation in females was observed at stage D (6.68%) at MP3u, and in males, it was observed at stage D (8.83%) at SMI-4. The highest percentage of root formation in females was stage E (8.24%) at the SMI-10 stage, and males stage F (4.86%) at MP3u. The correlation was observed between mandibular third molar calcification with hand-wrist, females 0.22 and males 0.43, and chronological age 0.60 for females and 0.69 for males. The highest sensitivity of mandibular third molar calcification of 97.0% was observed in female at SMI-4 of hand-wrist maturation with specificity of 100%, while in male, a sensitivity of 94.5% was observed at SMI-2 stage with a specificity of 99.99%.

Conclusion:

There were significant differences found in mandibular third molar calcification between females and males except for stage B and stage C; weak correlation was observed between mandibular third molar calcification and hand-wrist, and moderate correlation was observed with chronological age. The sensitivity and specificity in females and males indicate that mandibular third molar calcification is only useful for diagnosing the pre-pubertal growth phase.

Comparison of the third molar maturity index (I3M) between left and right lower third molars to assess the age of majority: a multi-ethnic study sample

The diagnostic accuracy of the I_3M to assess the legal age of 18 years has already been tested in several specific-population samples. The left lower third molar has been extensively used for discriminating between minors and adults. This research aimed to compare the usefulness of lower third molar maturity indexes, from both left and right side (I_3ML and I_3MR), in samples originating from four distinct continents in order to examine possible differences in their accuracy values. For this purpose, a sample of 10,181 orthopantomograms (OPGs), from Europe, Africa, Asia and America, was analysed and previously scored in other studies. The samples included healthy subjects with no systemic disorders with both third molars and clear depicted root apices. Wilcoxon Signed Rank test for left and right asymmetry did not show any significant differences. Data about sensitivity, specificity, predictive values, likelihood ratio and accuracy were pooled together and showed similar results for I_3ML and I_3MR, respectively. In addition, all these quantities were high when only the I_3MR was considered to discriminate between adults and minors. The present referable database was the first to pool third molar measurements using panoramic radiographs of subjects coming from different continents. The results highlighted that both I_3ML and I_3MR are reliable indicators for assessing the legal age of 18 years old in those jurisdictions where this legal threshold has been set as the age of majority.

Radiographic assessment of third molar development in a Russian population to determine the age of majority

OBJECTIVE

To test the applicability of "Gleiser and Hunt dental staging system modified by Kohler" (GHK) to assess third molar (3 M) development in a Russian population in order to determine the age of majority.

DESIGN

The sample consisted of 918 panoramic radiographs from Russian females (n = 551) and males (n = 367) within the age interval between 8 and 23 years. On each radiograph, 3 M development was classified based on the GHK technique. Statistics tested the data for normality. Mean age and standard deviation were described for each 3 M position. Ordinal logistic regression tested the performance of the technique to classify individuals below or above the 18-year threshold. Receiver Operating Characteristic (ROC) curves were used.

RESULTS

The mean ages and standard deviation (SD) for apex closure in females were 21,11 (SD = 1,47), 21,11 (SD = 1,43), 21,24 (SD = 1,39), and 21,29 (SD = 1,28) years for the teeth #18, 28, 38, and 48, respectively. Among males, the same teeth showed mean closure ages of 20,57 (SD = 1,69), 20,64 (SD = 1,76), 20,68 (SD = 1,68), and 20,81 (SD = 1,62) years, respectively. Area under the curve (AUC) reached 0.904 and 0.915 for classifying females and males below or above the 18-year threshold.

CONCLUSION

The GHK technique was able to describe 3 M development in a Russian population. The statistic model was able to classify individuals below or above the 18-year threshold. However, the outcomes must be carefully interpreted, especially in borderline cases (17-19-year spectrum).

Age estimation in the living: A scoping review of population data for skeletal and dental methods

Age estimation of living individuals has become a crucial part of the forensic practice, especially due to the global increase in cross-border migration. The low rate of birth registration in many countries, hence of identification documents of migrants, especially in Africa and Asia, highlights the importance of reliable methods for age estimation of living individuals. Despite the fact that a number of skeletal and dental methods for age estimation have been developed, their main limitation is that they are based on specific reference samples and there is still no consensus among researchers on whether these methods can be applied to all populations. Though this issue remains still unsolved, population information at a glance could be useful for forensic practitioners dealing with such issues. This study aims at presenting a scoping review and mapping of the current situation concerning population data for skeletal (hand-wrist and clavicle) and dental methods (teeth eruption and third molar formation) for age estimation in the living. Two hundred studies on the rate of skeletal maturation and four hundred thirty-nine on the rate of dental maturation were found, covering the period from 1952 and 2020 for a total of ninety-eight countries. For most of the western and central African countries there are currently no data on the rate of skeletal and dental maturation. The same applies to the countries of the Middle East, as well as the eastern European countries, especially as regard the skeletal development.

Third molar maturity index and legal age in different ethnic populations: Accuracy of Cameriere's method

Molar development is widely accepted as a reliable indicator of chronological age in a forensic context. A quantitative method for age estimation has been proposed by Cameriere et al. based on the relationship between chronological age and the third molar maturity index (I_3M), which is the ratio between the two apical pulp widths and the total tooth length. Cameriere's cut off value of 0.08 was found to be a reliable tool in assessing the threshold of 18 years of age. The aim of this study was to evaluate the accuracy of the I_3M in different ethnic populations focusing on its specificity (subjects correctly classified as <18 years based on I_3M >0.08) and sensitivity (subjects correctly classified as ≥18 years based on I_3M <0.08). A review of 22 scientific articles was performed, representing data from panoramic radiographs of 12,286 individuals (5723 males and 6563 females) from all over the world, including some ethnical subgroups. The I_3M showed an overall sensitivity for both sexes ranging from 51.8% to 93.4% and a specificity ranging from 86.2% to 100%. The proportion of correctly classified individuals ranged from 74% to 95%. These results can be useful to refer the age estimation with the margin of error of subjects correctly classified as minors (specificity) or adults (sensitivity), according to sex, ethnicity and geographical distribution. The I_3M can be considered a suitable method for estimating adulthood in forensic settings, regardless of sex. However, ethnic group can affect the accuracy.

Validation of the Third Molar Maturation Index (I3M) to assess the legal adult age in the Portuguese population

Age estimation is a major step in forensic and legal procedures. Its relevance has been increasing due to growing society issues, such as identification of missing people, crimes against minors or lack of valid identification papers from locals or foreigners. Evaluation of the cut-off value of the Third Molar Maturation Index (I_3M) = 0.08 for discriminating minors from adults in the Portuguese population. The left lower third molars were analysed by applying a specific cut-off value of 0.08 determined by Cameriere et al. in 2008. A sample of 778 digital panoramic radiographs of a representative Portuguese sample (442 females and 336 males), in the age range of 12–24 years (mean age 17.7 ± 2.98 years in females and 18.1 ± 3.0 years in males), was retrospectively evaluated. I_3M decreased as the real age gradually increased in both sexes. The 0.08 cut-off score was valuable in discriminating adults from minors. According to the pooled results, the accuracy, by means of area under the curve, was 92.8% (95% confidence interval (CI) 91.0–94.6%). The proportion of correctly classified subjects (sensitivity) was 90.7% (95% CI 88.7–92.8%) and the specificity was 94.9% (95% CI 93.3–96.4%). The results show that I_3M is a valuable method to differentiate minors from adults in the Portuguese population.

A new model of classification of third molars development and its correlation with chronological age in a Brazilian subpopulation

The present study correlated the mineralization of third molars to chronological age using a modified classification based on Demirjian's stages in a Brazilian subpopulation and compared with the original classification. A total of 1082 patients with age ranging from 6 to 26 years were included in the sample, with at least one third molar on panoramic radiographs. The third molars were classified according to the original Demirjian classification (8 stages) and a new model based on the Demirjian method, where the original stages were grouped into four stages: AB-enamel mineralization; CD-crown dentin mineralization; EFG-root formation; and H-complete development. Statistical analyses were performed by Kruskal-Wallis/Dunn tests (α = 0.05) and the multinomial logistic regression model. Data were analyzed according to percentiles for the probability of an individual being over 18 years old. The mean ages of the stages in both classifications did not present a significant difference between superior and inferior arches (p < 0.05). The differences in mean ages between all the stages of mineralization were statistically significant (p < 0.001) only for the 4-stage classification. Males attained root formation and complete formation earlier than females (p < 0.05) in the 4-stage classification. The modified classification system showed dependence between chronological age and mineralization stages of third molars, simplifying the age estimation process. At stage H, females present a 95.7% chance of being over 18, while for males, this probability is 89.6%. This modified classification system simplifies the dental age estimation process based on third molars and can be used as a reference for future studies.

Estimating sex and age from a face: a forensic approach using machine learning based on photo-anthropometric indexes of the Brazilian population

The facial analysis permits many investigations, some of the most important of which are craniofacial identification, facial recognition, and age and sex estimation. In forensics, photo-anthropometry describes the study of facial growth and allows the identification of patterns in facial skull development, for example, by using a group of cephalometric landmarks to estimate anthropological information. Previous works presented, as indirect applications, the use of photo-anthropometric measurements to estimate anthropological information such as age and sex. In several areas, automation of manual procedures has achieved advantages over and similar measurement confidence as a forensic expert. This manuscript presents an approach using photo-anthropometric indexes, generated from frontal faces cephalometric landmarks of the Brazilian population, to create an artificial neural network classifier that allows the estimation of anthropological information, in this specific case age and sex. This work is focused on four tasks: (i) sex estimation on ages from 5 to 22 years old, evaluating the interference of age on sex estimation; (ii) age estimation from photo-anthropometric indexes for four age intervals (1 year, 2 years, 4 years, and 5 years); (iii) age group estimation for thresholds of over 14 and over 18 years old; and; (iv) the provision of a new data set, available for academic purposes only, with a large and complete set of facial photo-anthropometric points marked and checked by forensic experts, measured from over 18,000 faces of individuals from Brazil over the last 4 years. The proposed binary classifier obtained significant results, using this new data set, for the sex estimation of individuals over 14 years old, achieving accuracy values higher than 0.85 by the F₁ measure. For age estimation, the accuracy results are 0.72 for the F₁ measure with an age interval of 5 years. For the age group estimation, the F₁ measures of accuracy are higher than 0.93 and 0.83 for thresholds of 14 and 18 years, respectively.

Age estimation of Brazilian individuals using the London Atlas

OBJECTIVE

The objective of the present study was to evaluate, for the first time, the applicability of the London Atlas method for age estimation on a sample of Brazilian population.

DESIGN

The study consisted of archived dental panoramic radiographs (n = 288) of individuals aged between 5 and 23 years. Radiographs were assessed using the London Atlas method to determine the developmental and eruption stages of all teeth on each sides of each jaw separately, and also to make an age estimation.

RESULTS

There was no significant differences between the right and left sides of the jaws (p = 0.31 for males and p = 0.65 for females). An overestimation of age occurred more likely in the female sample when compared to the male sample. Three age groups, 20.5, 18.5 and 19.5 years, presented the highest values ​​of mean absolute difference found in the whole sample.

CONCLUSION

The London Atlas of age estimation performed well in general and good viability in an expert context, with most age groups showing age differences lower than two years of age, however it is necessary that it be applied with caution in certain age groups, especially when the third molar is used as a decision tooth for age estimation. Therefore, it is recommended to use more than one method for assessing the age in those age groups.

Validation of the third molar maturity index cut-off value of <0.08 for indicating legal age of 18 years in Eastern Chinese region

Having a reliable, inexpensive and simple method to estimate 18 years of age would be of help in the forensic field. This study aimed to test the accuracy of the third molar maturity index (I_3M) in indicating the legal adult age of 18 years. This retrospective cross-sectional study analysed 450 digital panoramic images of Eastern Chinese children and young adults (226 females and 224 males) aged between 14 and 22 years. A cut-off value of I_3M < 0.08 was tested in discriminating adults from minors for both sex. For females, the sensitivity of the test (Se) was 75.0%, with a 95% confidence interval (95%CI) of 67.5% to 82.5%. The specificity of the test (Sp) was 100%. The proportion accurately classified (Ac) individuals was 85.8% (95%CI, 81.3% to 90.4%). The Bayes post-test probability was 100% (93.6% to 100%). For males, Se, Sp and Ac were 91.9% (95%CI, 87.1% to 96.7%), 92.0%(95%CI, 86.7% to 97.3%) and 92% (95%CI, 88.4% to 95.5%), respectively. The Bayes post-test probabilities was 92% (95%CI, 88.4% to 95.5%). Males were ahead in the development of third molars comparing to females according to I_3M. A stepwise logistic regression analysis showed that both I_3M and sex contribute to the regression model to discriminate adults (≥18 years) from minors (<18 years), while a receiver operating curve (ROC) analysis indicated some better accuracy of I_3M < 0.12 in females, without statistically significant difference when compared to I_3M < 0.08. The results of this study show that the cut-off value of I_3M < 0.08 may help to discriminate Eastern Chinese adults from minors. However, further study should evaluate the usefulness and possible variability of I_3M cut-off value in a specific population before used for legal and forensic procedures.

Accuracy of the cutoff value of the third molar maturity index: an Egyptian study

Background

This study aimed to test the sensitivity and specificity of the third molar maturity index (I3M) cutoff value to discriminate between individuals above and below 18 years of age in an Egyptian sample.

Material and methods

Digital images of 247 orthopantographs (97 boys and 150 girls) were evaluated. The cutoff value of I3Mobtained from the results of Cameriere et al. (Int J Legal Med 122:493–497, 2008) was evaluated in both girls and boys.

Results

Sensitivity (the proportion of individuals being 18 years of age or older) was 95% and 73% in boys and girls, respectively. Meanwhile, specificity (the proportion of individuals younger than 18) was 100% in boys and 97% in girls. The proportion of correctly classified boys was 97% while it was 59% in girls.

Conclusion

It can be concluded that the third molar maturity index can discriminate between individuals who are 18 years and over and those under 18 with higher accuracy in boys.

Cameriere's third molar maturity index in assessing age of majority: a study of a French sample

Forensic age estimation is a challenging field in forensic sciences because of the increase of migratory flows. Medicolegal age assessment is a key point because it has many implications for authorities. Dental age estimation is an essential part of the global age assessment. The aim of this study was to evaluate and test the accuracy of Cameriere's cutoff values of the third molar maturity index (I3M) in assessing legal adult age of 18 years in a French population. The sample was constituted of 431 orthopantomograms performed between January 2014 and August 2017 on patients aged between 14 and 22 years. The reproducibility and repeatability of the method were high. Age distribution gradually decreases as I3M increases in both sexes. 0.08 seemed to be the best I3M cutoff. For females, the sensitivity and specificity of the test were 74.51% and 88.23%, respectively. The sensitivity and specificity for males were 92.19% and 88.35%, respectively. The accuracies were 80.74% for female, 90.57% for male. Estimated post-test probabilities were 0.879 for female and 0.899 for male. To conclude, the specific cutoff value of I3M ˂ 0.08 may be a useful additional tool in discriminating adults and minors in French population.

Validation of the Third Molar Maturation Index to estimate the age of criminal responsibility in Northeastern Brazil

The estimation of the age of majority is crucial to determine the legal accountability of an individual. With this purpose, the analysis of the dental development process has proven to be an effective, elucidatory method. This study investigated the applicability of the Third Molar Maturation Index (I_3M), proposed by Cameriere et al. (2008), to estimate the age of majority in a sample of Northeastern Brazilians using panoramic radiographs. Adobe® Photoshop® CS4 (Adobe Systems Incorporated, San Jose, California, USA) software was used to obtain the I_3M index measurements in a sample of radiographs from a dental radiology clinic located in Northeastern Brazil. Radiographs of individuals aged between 14 and 23 years were included in the sample, except if showing absence, distortions, pathological alterations or suspected pulp impairment of the tooth #38 (third lower left molar), as the method applies exclusively to this element. Of the total sample of radiographs previously obtained for diagnostic and/or orthodontic purposes (n=394), 185 were from males and 209 from females, of which 217 corresponded to 18 year-olds or older and 177 were from minors. Logistic regression and predictive values of sensitivity, specificity and Receiver Operating Characteristic (ROC) curve (α=0.05) were used. The cutoff point originally proposed for the I_3M index (0.08) presented a sensitivity of 88.4% and a specificity of 73.2%, with accuracy (area under the ROC curve) of 80.8% (95%CI: 76.4-85.3%) for the Northeastern Brazilian population, as well as a correct age classification in 80.2% of the sample. The method estimated accurately 73.7% of the cases corresponding to "18 years or older" and 88.1% of the cases "under 18years" (p=0.000). Among the sexes, the correct age classification rate of the method was 84.3% for males and 76.6% for females, with no statistically significant difference between the match and error rates and between the sexes (p≥0.05). In conclusion, the Third Molar Maturation Index could accurately distinguish the age of adolescents and young adults of both sexes aged 18 years or under/older in a Brazilian population.

Forensic anthropology and missing persons: A Brazilian perspective

The problem of the missing persons phenomenon in Brazil in the 21st century has become apparent, and the responses to the issue are still under development. The relatively new field of forensic anthropology and its trained professionals occupy an essential place in the investigation of cases of missing and unidentified individuals. The development of forensic anthropology in Brazil is unique among Latin American countries, who improved their expertise during the investigations of political crimes that occurred between the 1960s and 1980s in most places. The qualifications and the paths to become a forensic anthropologist in Brazil are different from other professionals who work in the field worldwide. This article addresses the issue of missing person investigations and details the work of forensic anthropologists in such cases in Brazil.

Third molar maturity index for indicating the legal adult age in southeastern France

The estimation of age in living subjects is today a significant issue because of the increase in the situations in which it arises and its legal consequences. In line with the Study Group on Forensic Age Diagnostics of the German Association of Legal Medicine's recommendations, it is based on the concomitant use of physical examination and methods for estimating bone age and dental age. Given the variations between the populations, the use of the latter requires their validation on all the ethnic groups on which they can be used. This aim of this study was to access the interest of the Cameriere's third molar maturity index (I_3M) to indicate if an individual had reached the age of 18 in a sample of individuals from southeastern France. The studied sample consisted of OPTs 339 (184 females and 155 males) subjects aged between 14 and 22 years old. A logistic regression analysis with the adult age and minor age as dichotomous dependent variable and gender and I_3M as predictor variables showed that gender was not statistically significant in discriminating adults and minors. The receiver operating curve (ROC) analysis showed the best discrimination performance of the specific cut-off value of I_3M<0.08 in discriminating adults from minors. The proportion of accurate classification was 0.897 and 0.916 for females and males, respectively. The specificity (Sp) and sensitivity (Se) results for females were 0.962 and 0.813, respectively. Sp and Se for males were 0.953 and 0.871, respectively. The Bayes post-test probability was 0.961 and 0.955 in females and males respectively. Obtained results showed that a cut-off value of I_3M<0.08 may be an additional tool for indicating adult age in the tested population.

The third molars for indicating legal adult age in Montenegro

AIM

From a medico-legal and penalty point of view, it is essential to conclude if an individual is a minor or an adult (18 years of age). Methods based on the third molar development have been used for this purpose. The present article aims to verify the Nolla's stages of mineralization of the third molars and a third molar maturity index (I3M) which is based on the measures of the projections of open apices normalized by their height in the sample of Montenegrins.

METHOD AND SAMPLE

The sample consisted of 683 panoramic radiographs (324 males and 359 females) between 13 and 24 years of age. The specific mineralization stages of Nolla and the cut-off value of I3M < 0.08 was used to discriminate adults and minors.

RESULTS

The best performance in discriminating adults and minors was for I3M < 0.08 followed by the Nolla stage 9. For I3M < 0.08 the results demonstrated high sensitivity of 0.92 and 0.82 and specificity of 0.94 and 0.96 in males and females, respectively. The proportions of correctly classified individuals were 0.93 in males and 0.89 in females. The Nolla stage 9 demonstrated the sensitivity of 0.95 and 0.85 and the specificity of 0.84 and 0.90 in males and females, respectively. The proportions of correctly classified individuals were 0.90 in males and 0.87 in females.

CONCLUSION

The suggested value of I3M < 0.08 followed by Nolla stage 9 can be used to discriminate adults from minors with high specificity.

Third molar maturity index (I3M) for assessing age of majority: study of a black South African sample

AIMS

The evaluation of the cutoff value of I_3M = 0.08 for discriminating black South African minors from adults, and its relationship with chronological age.

MATERIAL AND METHODS

A sample of 833 panoramic radiographs of healthy black South African subjects (500 females and 333 males), in the age range of 14 to 24 years (mean age 17.67 years in females and 17.42 years in males), was retrospectively evaluated.

RESULTS

ICC values were 99.10% (95% CI 97.70 to 99.70%) and 99.20% (95% CI 98.00 to 99.60%), for the intra- and inter-observer reliability, respectively. I_3M decreased as the real age gradually increased in both sexes. According to the logistic regression model, the variable sex was not significant when the probability that an individual is 18 years or older was calculated. The I_3M = 0.08 was valuable in discriminating between adults and minors. The overall accuracy (ACC = fraction of accurately classified subjects) is 0.90 (95% CI 0.87-0.91); the proportion of correctly classified subjects (Se = sensitivity) is 0.80 (95% CI 0.76-0.84), and specificity (Sp) is 0.95 (95% CI 0.93-0.97). The PPV (predictive positive value) is 0.96 (95% CI 0.95-0.97), and the negative predictive value is 0.76 (95% CI 0.72-0.80).

CONCLUSION

The results show that I_3M is a valuable method to distinguish subjects who are around legal adult age in South Africa.

Accuracy of the third molar maturity index in assessing the legal age of 18 years: a systematic review and meta-analysis

The age estimation is a complex procedure required in the daily practice of legal medicine. The maturity of third molars stands out by the age of 18 because these teeth are still in development. This systematic review aimed to assess the accuracy of the third molar maturity index (I _3M), proposed by Cameriere et al. (2008), in discriminating whether an individual is under or over 18 years. Seven electronic databases were screened: PubMed, Scopus, ISI Web of Science, Cochrane Library, LILACS, SIGLE, and CAPES. Eligible studies included an assessment of I _3M accuracy at the 0.08 cut-off value. The quality assessment was performed by using QUADAS 2. Three meta-analyses (MA) were accomplished: overall, one for males and another for females. From 2397 articles identified, 16 met the eligibility criteria. Of these, two showed high risk of bias, one in the reference standard domain and the other in the flow and timing domain. The percentage of individuals correctly classified ranged from 72.4 to 96.0%. The overall MA showed pooled sensitivity of 0.86 (0.84 to 0.87; p = 0.0000) and pooled specificity of 0.93 (0.92 to 0.94; p = 0.0000). The AUC (area under the summary receiver operator characteristics curve) and DOR (diagnostic odds ratio) values were, respectively, 0.9652 and 104.68, indicating an overall high discrimination effect. Separately, better results of accuracy were found for males. High heterogeneity was achieved for both sensibility (94.6%) and specificity (88.8%). We conclude that the I _3M is a suitable and useful method for estimating adulthood regarding forensic purposes, regardless of gender.

The third molar maturity index in indicating the legal adult age in Kosovar population

The third molar tooth, known as the "wisdom tooth," is the only tooth that can be used to determine legal adult age. This study aimed to test the accuracy of Cameriere's third molar maturity index (I_3M) in assessing the legal adult age of 18 years in the Kosovar population. Orthopantomographs (OPTs) of 1221 healthy living Kosovar individuals, aged between 12 and 23 years and with no congenital or developmental anomalies, were analyzed. Intra-class correlation coefficients were 0.858 (95% CI, 0.786 to 0.906) and 0.852 (95% CI, 0.779 to 0.903) for intra-rater and for inter-rater agreement, respectively. The sample was divided into training dataset (800 OPTs) and test dataset (421 OPTs). The training dataset was used to generate the logistic regression model, while the test dataset was used to study the performance of the model. I_3M and gender as independent variables and adult age (≥ 18 years) or minor age (< 18 years) as the dependent variable were used for logistic regression analysis. The receiver operating curve (ROC) analysis was used to determine the specific cut-off value of I_3M for predicting adult age. The results showed that only I_3M statistically significantly contributed to discriminating adults and minors. ROC analysis showed that the cut-off value of I_3M < 0.08 was the best in discriminating adults and minors. An analysis of the test dataset (421 OPTs) showed that as I_3M decreased the age gradually increased. The performance of the cut-off value of I_3M < 0.08, to discriminate between adults and minors, was analyzed by contingency tables for both sexes. In males, the accurate classification (Acc) was 0.968 (95% CI, 0.926 to 0.985), the sensitivity (Se) was 0.962 (95% CI, 0.925 to 0.978), and the specificity (Sp) was 0.976 (95% CI, 0.929 to 0.995). The Bayes post-test probability (Bayes PTP) was 0.975 (95% CI, 0.905 to 1.00). In females, Acc was 0.909 (95% CI, 0.870 to 0.917), Se and Sp were 0.826 (95% CI, 0.787 to 0.834) and 0.991 (95% CI, 0.953 to 1.00) respectively, while Bayes PTP was 0.989 (95% CI, 0.926 to 1.00). Our data support the usefulness of I_3M < 0.08 to indicate legal adult age in a Kosovar population.

Third molar cut-off value in assessing the legal age of 18 in Saudi population

Teeth plays a major role in forensic sciences especially in age assessment of an individual, which can be used to aid in criminal or civil matters. The importance of teeth comes from their ability to survive inhumation well and because they are hardly affected by exogenous and endogenous factors. Third molars are the only teeth still developing after the age of 14 years and during the legal age of adulthood, which is 18 years. The consequences of criminal violation can strongly affect the individual's life, it is important to set different parameters to decide whether an individual is a minor or an adult in the absence of documents. Depending on the different legal requirement, such parameters can set above 90% probability for criminal matters and from 51% to civil matters.

AIM

The aim of this research was to find the cut-off value of third molar development for the legal age of 18 amongst Saudi individuals using the third molar maturity index method by Cameriere et al. (2008) [17].

MATERIALS AND METHODS

This was a cross sectional study on 300 archived orthopantomogram (OPG) of healthy Saudi patients between the ages 14 and 22 years attending the Dental Hospital at King Saud University, Riyadh, Saudi Arabia. All OPGs were taken by PLANMECA - ProMax machine and evaluated by the Romaxis software. The inclusion criteria were good quality OPGs taken during the course of treatment. All patients were healthy with no systemic diseases or disorders with the presence of third molars and clear root apex. The lower left mandibular third molar (LL3rdM) was assessed using third molar maturity index (I3m) to determine if the individual is younger or older than 18 years old.

RESULTS

The cut-off value of I3m for the Saudi population was (I3m<0.08). The sensitivity of this method was 51.7% and the specificity was 98.5%. Early mineralization was found in males except when I3m was ranging from (0.0 to 0.4) and (0.9 to 1.7). Cameriere et al. (2014, 2008) [16,17] test was reproducible with good measure of reliability.

CONCLUSION

This method is suitable for assessing the attainment of legal age of adulthood in Saudi population and the cut-off value of I3m is similar to other populations. Although dental age assessment by means of third molar development is useful, it still has its limitation because of its variation in position, morphology and development.