Third molar maturity index (I3M) for assessing age of majority in a black African population in Botswana

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.

Predicting chronological age of 14 or 18 in adolescents: integrating dental assessments with machine learning

AIM

Age estimation plays a critical role in personal identification, especially when determining compliance with the age of consent for adolescents. The age of consent refers to the minimum age at which an individual is legally considered capable of providing informed consent for sexual activities. The purpose of this study is to determine whether adolescents meet the age of 14 or 18 by using dental development combined with machine learning.

METHODS

This study combines dental assessment and machine learning techniques to predict whether adolescents have reached the consent age of 14 or 18. Factors such as the staging of the third molar, the third molar index, and the visibility of the periodontal ligament of the second molar are evaluated.

RESULTS

Differences in performance metrics indicate that the posterior probabilities achieved by machine learning exceed 93% for the age of 14 and slightly lower for the age of 18.

CONCLUSION

This study provides valuable insights for forensic identification for adolescents in personal identification, emphasizing the potential to improve the accuracy of age determination within this population by combining traditional methods with machine learning. It underscores the importance of protecting and respecting the dignity of all individuals involved.

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.

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.

The challenge of unidentified decedents in Africa: The need for training and research in forensic odontology to strengthen a multidisciplinary approach

Introduction

The management of unidentified decedents suspected to be undocumented migrants is a growing humanitarian crisis in Africa. Identification of the dead and the right of the family to know the fate of a decedent is a fundamental human right. Forensic odontology methods can provide helpful and assisting information in the identification even in challenging low-resource settings. South Africa and other countries that are part of significant migration routes face the problem of unidentified decedents.

Discussion

The fundamental application of forensic odontology relies on the availability of good antemortem dental records. The state of dental records was reported to be suboptimal in South Africa and other African countries. Incorporating forensic odontology into the undergraduate training in the 23 dental schools in Africa will increase the understanding of the value of maintaining accurate dental records and potentially facilitate collaboration with dentists and forensic odontologists in cases where dental features can be used for identification. South Africa offers postgraduate training in forensic odontology, and prospects for research in Africa need to be explored.

Conclusion

The development of a forensic odontology career path and research prospects will provide African countries with the potential for building multidisciplinary teams to assist in solving the challenge of unidentified decedents.

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.

Legal age determined by a new threshold value of third molar maturity index in subjects with impacted mandibular third molars: An orthopantomographic study in south Indian adolescents

Third molars are one of the few biological markers available for age estimation in juveniles, especially for the estimation of the 18-year-age threshold. Literature has indicated that impaction has an influence on the development of third molars, which could possibly result in age misclassifications. The present study is intended to identify an alternative cut-off value of the third molar maturity index (I3M) in impacted mandibular third molars and also to evaluate its applicability in estimating the major (≥ 18 years)/minor (< 18 years) status. A total of 1330 digital orthopantomograms (OPGs) of 665 male and 665 female south Indian adolescents aged from 15 to 22 years were collected and assessed. Eight hundred forty OPGs (63.1%) represented test sample, and 490 OPGs (36.9%) represented validation sample. I3M was measured for the total sample. Logistic regression, receiver operating characteristic (ROC) curve analysis, and Youden's index were used to test the performance of the method in the test sample. An alternative cut-off value of I3M < 0.17 was established for the highest value of the Youden's index of 0.598 for both sexes. When tested in validation sample, it has resulted in sensitivity and specificity values of 0.91 (95% CI; 0.86-0.95) and 0.90 (95% CI; 0.78-0.91) in males and 0.86 (95% CI; 0.80-0.92) and 0.90 (95% CI; 0.83-0.95) in females. In conclusion, cut-off value of I3M < 0.17 could accurately discriminate adults from minors with impacted mandibular third molars. However, more work is needed to be done among a more diverse sample to confirm these findings.

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.

Age Estimation Using the Cameriere Methods of Open Apices: A Meta-Analysis

Purpose: To evaluate the actual variability of the mean difference between chronological and dental age using the Cameriere method of open apices and to test its accuracy in variable age groups. Method: We selected studies that contained data about the mean, standard deviation, and number of cases for chronological age, dental age and gender. We used a random-effects model. Statistical significance was estimated, at a p < 0.05, using prediction intervals. For the analysis of publication bias we used the funnel plot and Egger’s regression test for plot asymmetry. I² was used to test the presence of heterogeneity between studies. The Z test was used to test for statistical differences between subgroups, with p < 0.05 being considered statistically significant. We also used 95% for confidence intervals and prediction intervals. Results: In boys, the average difference between chronological and dental age was 0.44 (0.26–0.63) years, while in girls the average difference between chronological and dental age was 0.34 (0.19–0.49) years. In the 6–7 years age group and in the 14–15 years age group, there was a statistically significant difference between dental and chronological age. Our study shows that the Cameriere method is useful for estimating the chronological age, with errors of less than one year. Conclusions: The Cameriere method of evaluating dental age using open apices is sufficiently accurate for forensic practice, at least in the 7–14 age-interval.

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

OBJECTIVES

The aim of this study is to estimate the cut-off points for the Portuguese legal ages through the I_3M, and to compare them with the methods of Demirjian, Nolla and Moorrees.

DESIGN

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.

RESULTS

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.

CONCLUSION

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.

Minor migrants' age estimation: Comparison of two dental methods

In case of minor migrants, absence of valid identification documents that clearly define age is a critical issue, because without these data the child cannot enjoy the rights provided by the Convention on the Rights of the Child. Differentiation between minors and adults is fundamental when age is disputed in human identification, asylum seeking, criminal liability, and child abuse fields. Few indications are available about qualitative/statistical agreement of different age estimation methods. Ages of 301 individuals were estimated through two dental methods in order to: determine quantitative and statistical agreements in legal age definition; identify practical recommendations. The study pointed out discrepancy between the two methods in 7/301 cases. From a statistical point of view, this finding corresponded to an almost perfect agreement. Thus, authors suggested that the two methods can be alternately used for legal age assessment, but operators should use both methods when the estimated age is 18.5 years.

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.

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.

Dental age estimation in Somali children and sub-adults combining permanent teeth and third molar development

Estimation of an individual’s age has important applications in forensics. In young individuals, it often relies on separate evaluations of permanent teeth (PT) and third molars (TM) development. Here, we analysed the age prediction performance of combined information from PT and TM in an unusual sample of healthy Somalis, born and living in Finland. PT development was staged according to Demirjian et al. (Hum Biol, 1973) and TM development according to Köhler et al. (Ann Anat, 1994), using panoramic radiographs from 803 subjects (397 males, 406 females) aged 3–23 years. A sex-specific Bayesian age-estimation model for the multivariate distribution of the stages conditional on age was fitted on PT, TM and PT and TM combined. The age-estimation performances were validated and quantified. The approach combining PT and TM only overestimated age with an ME of − 0.031 years in males and − 0.011 years in females, indicating the best age prediction performance.

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.

Is the third molar maturity index (I3M) useful for a genetic isolate population? Study of a Sardinian sample of children and young adults

This work aims to assess the validity of the cut-off value (0.08) of the third molar maturity index (I_3M) for discriminating minors from adults in Sardinian population. A sample of 336 digital panoramic radiographs of healthy Sardinian children and young minors (165 females and 171 males), aged between 15 and 23 years (mean age, 19.35 years in females and 18.80 years in males), was retrospectively evaluated. The left lower third molars were analysed by applying a specific cut-off value of 0.08 determined by Cameriere et al. in 2008. The reliability and reproducibility of the test was also studied: the intra-class correlation coefficients (ICC) were 0.91 (95% CI, 0.89-0.93) and 0.88 (95% CI, 0.86-0.90), for the intra- and inter-observer reliability, respectively. The I_3M gradually decreased as the real age gradually increased in both sexes. According to the pooled results of the diagnostic test, the accuracy (ACC) was 0.86 (95% CI, 0.82-0.89); the proportion of correctly classified subjects (Se = sensitivity) was 0.82 (95% CI: 0.76-0.86); and specificity (Sp = specificity) was 0.95 (95% CI, 0.89-0.97). The positive predictive values (PPV) and the negative predictive values (NPVs) were 0.97 (95% CI, 0.94-0.99) and 0.70 (95% CI, 0.62-0.77). The LR+ and the LR- were 17.12 (95% CI, 7.27 to 40.36) and 0.19 (95% CI, 0.14 to 0.25). In spite of this, significant differences in the early mineralisation of the third molar were found between sexes as well as in the results of the diagnostic test, showing a better sensitivity in males than in females. The results showed that, although the third molar teeth are highly variable in development, and with differences between females and males as compare to other teeth, the I_3M is a reliable method to distinguish between minors and adults even in such a genetic isolate population.

Dental age estimation in Somali children using the Willems et al. model

AIM

The aim of the current study was to retrospectively collect dental panoramic radiographs from Somali children living in Finland, to use the radiographic data to develop a new age estimation model based on the model established by Willems et al. (J Forensic Sci 46(4):893-895, 2001), and to compare the age prediction performances of the Willems et al. model (WM) and the newly developed model.

MATERIAL AND METHODS

Dental panoramic radiographs from 808 healthy Somalis born in Finland were selected. The development of the seven left mandibular permanent teeth, from the central incisor to the second molar, was staged according to Demirjian et al. (Hum Biol 45(2):211-227, 1973). Radiographs with all listed permanent teeth completely developed were excluded. The studied sample consisted of 635 subjects (311 females, 324 males) ranging in age from 4 to 18 years. Kappa and weighted Kappa statistics were used to quantify intra- and inter-observer agreement in stage allocation. The collected dataset was used to validate the WM, constructed on a Belgian Caucasian reference sample, and to establish a Somali-specific age estimation model (SM) based on the WM. Both models were validated and their age prediction performances quantified using mean error (ME), mean absolute error (MAE) and root mean squared error (RMSE).

RESULTS

The SM resulted in a slight underestimation of age when the sex groups were analysed separately or combined, with ME varying between 0.04 (standard deviation (SD) 1.01) and 0.05 (SD 1.04) years, MAE between 0.77 and 0.80 years and RMSE between 1.01 and 1.04 years. The WM statistically significantly underestimated the age of females, with an ME of 0.20 (SD 1.01) years (p = 0.0006). For males, and for females and males combined, no statistically significant ME was observed.

CONCLUSION

The WM and SM were similar in their age prediction performances, and the use of the WM in dental age assessment in the Somali population is justified.

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.