Forensic Validity of the Third Molar Maturity Index (I 3M) for Age Estimation in a Russian Population

Dental Age Assessment Based on Developmental Stages and Maturity Index of Third Molars for Medico-Legal Purposes

As results may vary depending on the method of examination, this paper analyzes methods of age estimation based on the maturation index of third molars (I3M) and Kohler's developmental stages in living individuals. A total of 1475 orthopantomograms were analyzed. The results showed that the development of third molars tended to be more advanced in males than in females. Regression equations that included the value of the developmental stage of the left third molar most accurately predicted chronologic age in males and females. Using the I3M method, there were no statistically significant bilateral differences between the mandibular right and left third molars. Overall, 82.92% of males and only 72.82% of females were correctly classified with the cut-off value (0.08) for the left mandibular third molar index. In addition, 81.97% of individuals were correctly classified as minors and adults using the Kohler method, while only 78.62% of individuals were correctly classified as minors and adults using the I3M method. Based on the misclassification of minors as adults, both methods should be used with caution and overestimation of age should be considered, especially for those close to 18 years of age.

[Validation of method for estimation age of majority by the third molar maturity index on the sample of Ufa population]

The assessment of majority age is important for determining legal responsibility. The definition of the 3rd molar maturity index (Im3) have proven to be a simple and effective method of majority age establishment, the accuracy of which has been tested in different populations. There is a clear lack of studies in this scientific area in Russia.

OBJECTIVE

To test diagnostic accuracy of majority age assessment method by 3rd molar (Cameriere index) in the Ufa sample.

MATERIAL AND METHODS

The number of orthopantomograms equal 120 from males and females aged from 14 to 23 years without apparent pathological changes of the pulp of teeth 38 and 48 was examined. The measures were conducted using the standard R. Cameriere method. The method of logistic regression, determination of predictive values of sensitivity and specificity were used.

RESULTS

The Im3 cut-off point, that was equal 0.08, had a sensitivity of 89% and specificity of 95% in the male sample, accuracy of age group determination was 93%. In the female sample the method sensitivity was 93%, specificity - 97%, accuracy - 97%.

CONCLUSION

The study results confirmed the absence of population variability of the Cameriere index value, that makes it possible to use the majority age determination method by 3rd molar for practical application in the examination of a living person at the territory of the Russian Federation.

[Review of age assessment methods of children and adolescents by teeth X-rays]

Interest in the topic of age assessment for forensic medical identification of personality has not decreased for over the past decade. Establishing an exact age have a critical importance for law enforcement authorities, for example in case of wrongdoing by illegal migrants without identity documents. The search and systemic analysis of published researches devoted to age assessment by dental status in children and adolescents with subsequent updating of the directions of development in this scientific subject theme and the possibility of their realization in practice in the Russian Federation were carried out in order to have an objective concept of used methods of dental status assessment in the world practice.

Medico-legal indicators and cut-offs in different age classes through quantitative analysis of epiphyseal fusion segments on knee CT scans

Scientists are interested in determining age in subadults for several forensic purposes. High- resolution instrumental techniques are being increasingly used for age estimation, driven by the need to minimize errors; in this context, several studies have focused on the knee joint, recognized as a potential site for age examination in late adolescence. We analyzed 200 CT scans performed on Russian subjects (106 males and 94 females) between 13 and 20 years, without growth diseases, endocrine disorders, or osteodystrophy. Each subject underwent two scans, one for each leg. Two indicators were measured for each bone (femur, tibia and fibula): the entire length of the epiphyseal scar and the length of the part/s that is/are fused with metaphysis. Intra class Correlation Coefficient (ICC) was performed to evaluate the intra-operator reproducibility. The ratio between the two lengths was calculated for each bone (FemurR, TibiaR and FibulaR). The first aim was to evaluate a correlation between the ratios of the three bones and the three bones treated as a single parameter (given by the sum of the ratios) versus age. The results showed good correlations in both cases (τ a = 0.74, 0.64, 0.57 and 0.67). The second aim was to estimate the cut-offs derived from the sum of the three ratios respect to four age classes (14-15 years: cut-off ≤ 0.63, 15-16 years: cut-off ≤ 1.19, 16-17 years: cut-off ≥ 0.68 and 17-18 years: cut-off ≥ 1.49. The results from this research encourage further studies of the knee joint as an indicator of legal adult age.

Operational Health Pavilions in Mass Disasters: Lessons Learned from the 2023 Earthquake in Turkey and Syria

The massive earthquake that hit Turkey and Syria in February 2023 killed tens of thousands of people, and most of the deceased have not yet been identified. Many victims were pulled from the rubble hours or days later, injured and in need of assistance, treatment, and food, and many have not yet been connected with their families. Armed forces, volunteers, technicians, and health workers must cooperate in synergy in these situations to ensure effective interventions and to improve resilience. Based on the lessons learned from the response efforts to this recent natural catastrophe, this brief report proposes, for the first time, an organisational model structured around five functional pavilions that can be safely set up at the edge of a disaster area. Each pavilion should run its own activities to make a vital contribution to the overall coordinated emergency response. Looking to the future, it is extremely important to apply a technical approach that leads to maximum operational synergy at a disaster site and during the first phase of a sudden-onset emergency.

A systematic overview of dental methods for age assessment in living individuals: from traditional to artificial intelligence-based approaches

Dental radiographies have been used for many decades for estimating the chronological age, with a view to forensic identification, migration flow control, or assessment of dental development, among others. This study aims to analyse the current application of chronological age estimation methods from dental X-ray images in the last 6 years, involving a search for works in the Scopus and PubMed databases. Exclusion criteria were applied to discard off-topic studies and experiments which are not compliant with a minimum quality standard. The studies were grouped according to the applied methodology, the estimation target, and the age cohort used to evaluate the estimation performance. A set of performance metrics was used to ensure good comparability between the different proposed methodologies. A total of 613 unique studies were retrieved, of which 286 were selected according to the inclusion criteria. Notable tendencies to overestimation and underestimation were observed in some manual approaches for numeric age estimation, being especially notable in the case of Demirjian (overestimation) and Cameriere (underestimation). On the other hand, the automatic approaches based on deep learning techniques are scarcer, with only 17 studies published in this regard, but they showed a more balanced behaviour, with no tendency to overestimation or underestimation. From the analysis of the results, it can be concluded that traditional methods have been evaluated in a wide variety of population samples, ensuring good applicability in different ethnicities. On the other hand, fully automated methods were a turning point in terms of performance, cost, and adaptability to new populations.

Anthropometric analysis of orbital and nasal parameters for sexual dimorphism: New anatomical evidences in the field of personal identification through a retrospective observational study

Orbital and nasal parameters among modern humans show considerable variation, which affects facial shape, and these characteristics vary according to race, region, and period in evolution. The aim of the study was to ascertain whether there are sex differences in the orbital and/or nasal indexes and/or the single measurements used to calculate these in a Kosovar population. The following parameters were taken into consideration: orbital height (OH), orbital width (OW), nasal height (NH), and nasal width (NW). The ratios between orbital index/nasal index (RONI) were calculated. All measurements were obtained from a population sample comprising 408 individuals. The accuracy in sex prediction was 52.86% (CI95% = 45.05%-60.67%) for NW and 64.96% for NH (CI95% = 57.50%- 72.42%). The difference between male and female indexes was statistically significant (P < 0.05). The anthropometric study revealed that only NW and NH are configured as predictors of sexual dimorphism. It could be useful to increase the number of samples to test the discriminant function in other population groups.

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.

Correlation of chronological age with dental age estimated using modified Cameriere’s method and UT-age estimation software — a cross-sectional study

Background

Estimating age is essential in both the analysis of human skeletal remains and assessing live persons. The third molar develops over a longer period and is hence used in age estimation for subadults. Since dental age correlates with chronological age better than other growth markers, this study aims to assess the reliability of dental age assessed using the University of Texas (UT) age estimation method and modified Cameriere’s method.

Methods

It is a retrospective cross-sectional study in which the development and maturation of mandibular third molars were examined in 600 orthopantomograms (264 males and 336 females) of South Indian individuals (16–23 years). Dental age was estimated by using an Indian-specific formula based on maturity index value and the UT-age estimation  software program. The results were evaluated using the Student’s t-test for both methods and Pearson’s correlation test to compare chronological age with estimated dental age.

Results

Positive correlation was noted between chronological age and estimated dental age for males, females, and the total sample with highly statistically significant differences (p = 0.000). Modified Cameriere’s method underestimated dental age in samples ranging from less than 1 year to more than 2 years. UT-age estimation method underestimated age in samples above 20 years and overestimated age in samples below 20 years. The predictive classification of utilizing the maturity index was 79.17% accurate.

Conclusions

Dental age was negligibly over and underestimated in UT software method whereas it was overestimated in the modified Cameriere's method. To evaluate the reliability of these two methods, studies with larger sample sizes and population-specific data sets should be performed.

Graphical Abstract

An Effective Model for Estimating Age in Unaccompanied Minors under the Italian Legal System

This article presents an effective model for estimating the age of subjects without identification documents, in accordance with Italian legislation covering unaccompanied minors, using instrumental methods recognized by the scientific community for age estimation. A decision-making tree has been developed, in which the first step is a physical examination. If secondary sexual characteristics are fully developed and there are no obvious signs of abnormal growth, dental X-rays are the next step. If the roots of the seven left mandibular teeth between the central incisor and the second molar are completely developed, the focus then moves to the third molar. If the index of the third molar (I3M) value is less than 0.08, or if third molars are not assessable, the following step is to study the clavicle which, if fully formed, indicates that the subject is an adult with 99.9% probability; otherwise, the probability is 96%. In all other cases (where the I3M is over 0.08), the probability that the subject has reached 18 years is less than 60%. The research, carried out initially on x-rays of the wrist, teeth and clavicle, highlighted the uselessness of the x-ray of the wrist for determining the age of majority, because in our sample, all subjects with incomplete maturity of hand/wrist bones were under 16 years of age; thus, OPT was necessary anyway. What we propose is a practical, easily feasible, fast, economical, and extremely reliable method, which can be used on Caucasian populations and beyond for multiple forensic purposes.

[Research and development of Sechenov University forensic medicine department within the program «Priority-2030» implementation]

A comprehensive analysis of research and development results of Sechenov University forensic medicine department for the last 5 years (from 2018 to 2022) was performed. The thematic structure and citation indices of scientific publications were presented. The most promising directions of the department's research activities were identified.

[Forensic medical examination of the age of living persons in Russia: problematic aspects and solutions]

The article presents the results of the study of quantitative indicators and analytical compilation of forensic medical expert practice data in terms of the age of living persons in Russia examination as a whole and in individual federal districts and subjects of Russia in the period from 2003 to 2021. It has been established that against the background of the rather low number of expert examinations, performed to determine the living persons age, there has been an increase in this indicator since 2018, mainly due to the Central Federal District. Regional differences in the studied indicators were identified. A systematic survey study of literature (electronic search of publications in PubMed, Science Direct Scopus and eLIBRARY databases) was conducted on the issue of forensic medical assessment of living persons' age, including the methodical support of this examination type, to form an idea of existing scientific clusters. Search modes allowed to form an array of 184 publications indexed in the database Scopus, PubMed, and 8 publications presented in Russian Science Citation Index. The study results were used as a predictor of the efficacy of the package of measures to modernize this type of expert study. The proposed set of measures to improve the scientific and methodical support of forensic medical examination for age establishment will optimize practical activities and increase the evidential efficacy of expert opinions.

[Forensic medical diagnostics of age by the Cameriere method]

THE AIM OF THE STUDY

Was to conduct the comparative analysis of the age groups' separation accuracy (<18 years old; ≥18 years old) by orthopantomogram depending on the examination's side in Russian population sample. The number of orthopantomograms equal 600 (190 of male and 410 of female) aged from 14 to 23 were investigated. Index value of third molar (Im³) was calculated by the R. Cameriere method, in female and male, on the right and left sides. Index of third molar on the right and left sides shows a high correlation. In the male sample the result specificity was 0.97 on the left and 1.0 on the right, the sensitivity was 0.96 on the left and 0.94 on the right. In the female sample the values were as follows: the specificity was 0.96 on the left and 0.98 on the right, the sensitivity was 0.92 on the left and 0.94 on the right. The results showed the possibility of Im³ (0.08) use to determine the target age group for Russian citizens of both sexes regardless of examination side.

Testing international techniques for the radiographic assessment of third molar maturation

BACKGROUND

To assess the radiographic third molar maturation with internationally developed techniques for age estimation.

MATERIAL AND METHODS

The study analyzed 1,062 panoramic radiographs of patients treated at the School of Dentistry of the University of Passo Fundo/RS/Brazil, between 2009 and 2020. The patients were separated into ages between 15.00 and 23.99 years and, for each radiograph, the third molars were classified into stages from 1 to 10, with the subsequent application of one of the formulae proposed by Gunst et al. A dichotomous variable indicating whether each individual was younger or older than 18 was calculated from the chronological age of the individuals. A logistic regression model was adjusted to assess whether the third molar stages are correlated with the age of individuals.

RESULTS

The error indicators between estimated and chronological ages showed that mean errors closer to zero are seen in the 18-18.9 and 17-17.9 age groups, respectively. Male individuals were earlier in terms of dental mineralization but there were no significant differences between sexes regarding the applicability of the method. The ROC curve shows that the analysis of a single third molar for age estimation gives a maximum of 70.4% reliability.

CONCLUSIONS

The moderate performance of the technique tested in the present study justify future country-specific corrections to improve age estimation from the radiographic assessment of third molar maturity. Key words:Dental age estimation, forensic dentistry, radiology, third molar.

A new analytical cut-off point for determining 18 years of age using MRI on medial clavicular epiphysis

Evaluation of the ossification of the medial clavicular epiphysis plays a key role in forensic age estimation. The purpose of the present study was to assess a new numerical cut-off at the age of 18 years, taking into consideration Magnetic Resonance (MR) images of the medial clavicular epiphysis. We analyzed 163 MR scans of Italian subjects aged between 14 and 25 years. Using the data obtained we calculated two ratios: REM-1 (ratio between the length of the whole epiphysis and the length of the metaphysis) and REM-2 (ratio between the length of epiphyseal-metaphyseal fusion and the length of the metaphysis). In 68 out of 163 cases it was not possible to measure REM-2. The reproducibility was demonstrated using the Intraclass Correlation Coefficient (ICC) (Cronbach's alpha > 0.80). REM-1 and REM-2 were compared in each category of age (adult and minor) by the Wilcoxon signed-rank test. The cut-off points for measurements of REM-1 and REM-2 were determined by logistic regression. For REM-1, the cut-off scores were 0.83 for all individuals (accuracy = 94.77%) and males (accuracy = 96.05%), and 0.86 for females (accuracy = 92.30%). For REM-2, the cut-off values were 0.40 for all individuals and males (accuracy = 100.00%), and 0.41 for females (accuracy = 100.00%). Finally, receiver operating characteristic (ROC) curves for age classification based on REM-1 and REM-2 were constructed, showing that REM-2 had the highest discriminative power. Thus, a new cut-off model for predicting the age of majority has been introduced, conducting a quantitative analysis thanks to the use of a high-resolution imaging tool.

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.