Reliability of the methods applied to assess age minority in living subjects around 18 years old

Radiologic assessment of third molar development and cervical vertebral maturation to validate age of majority in a Mexican population

An increase in irregular migration flows has further raised the importance of age estimation in forensic science. To improve the reliability of age of majority determination, one recommendation is to combine the evaluation of third molar development with age-related skeletal information. In the present study, we assessed mandibular third molar development and cervical vertebral maturation to evaluate the ability of these age indicators, alone and in combination, to accurately identify individuals 18 years of age or older. The study sample comprised 123 multi-slice computed tomography images of Mexican individuals (67 males and 56 females) aged between 14 and 22 years. Demirjian's stages of tooth development and Baccetti's stages of vertebral maturation were used. A fully developed mandibular third molar (stage H) indicated adult age with 100% certainty. However, around 70% of individuals older than 18 years had third molars that had not yet completed their development. Thus, immature third molars do not rule out the possibility that an individual has reached the age of majority. In the study sample, the combination of the maturity stages of teeth 38 and 48 or their combination with the cervical stages of maturation did not improve upon the prediction accuracy of either of the mandibular third molars alone (area under the ROC curve > 0.85). Therefore, these findings highlight the need to identify other complementary age estimation methods that minimize the number of false negatives (i.e., adults classified as minors) obtained with assessment of third molar development alone.

Root canal widths of mandibular molars in predicting the legal age threshold 18 years in a sample of juveniles and sub-adults of south-indian origin: an orthopantomographic study

Pursuing a proficient age estimation methodology introducing novel radiographic methods remains an ongoing and demanding aspect of forensic and medicolegal research. In 2017, Roberts GJ et al. (J Forensic Sci 62(2):351-4, 2017) described a new radiographic method, i.e., root canal width (RCW) patterns to assign a subject to above 18-year-age threshold. Since then, few researchers have investigated the validity of this radiographic method in other populations. The present study aimed to test the usefulness of these RCW patterns in predicting 18 years in a sample of South Indian juveniles and sub-adults aged between 16 and 23. Descriptive analysis revealed that pattern-A was initially observed at a minimum age of 16.08 and 16.22 years in males and females. Pattern-B at 16.31 years in males and 16.22 years in females, while pattern-C was initially recorded at 18.73 years in males and 19.01 years in females, respectively. In summary, if an individual, regardless of sex, exhibits a fully-formed (apex closed) mandibular first, second, and third molars and concurrently displays RCW-C, there is a strong likelihood that the person has exceeded the legally relevant age of 18 years. However, due to higher rate of technically unacceptable errors (adults wrongly identified as individuals below 18 years), reliance on this method alone should be restricted, and it is advisable to combine it with other methods.

Chronological age estimation based on dental mineralization for Syrian population

Dental age assessment based on evaluating dental mineralization status is one of the most common methods used in forensic practice. The aim of this study is to enhance the accuracy of age diagnostics and provide reference data from the Syrian population for forensic application. After several selection steps, a total of 280 orthopantomograms (OPGs) from 140 males and 140 females from the Syrian population divided into 14 age groups between 12 and 25 years were analysed. Based on Demirjian's classification system, the mineralization stages of third molars (18, 28, 38 and 48) as well as lower second molars (37 and 47) were evaluated. Statistical investigations and evaluations were carried out to estimate the marginal probabilities of the subjects having attained ages 14 and 18 by generalized estimating equation models. Our results show that no significant differences can be revealed in the mineralization status with respect to jaw side and sex. In the Syrian population, third molars showing mineralization stage G provide evidence of reaching the age of 14 years with the highest standard of proof ("beyond reasonable doubt"). A completed mineralization in lower second molars (stage H) provides very high marginal probabilities (more than 90%) of the subjects having attained age 14 years. Nevertheless, this cannot exclude an age under 14 years. For the age threshold of 18 years, third molars showing incomplete root development (G dental stage or lower) are associated with a low probability (less than 40%) of the subject having reached 18 years of age. A person's probability of having attained 18 years of age is very high (82- 95%) when the roots of third molars are fully developed (stage H). Nevertheless, third molars at stage H do not conclusively exclude an age under 18 years.

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.

Postmortem computed tomography assessment of skeletal and dental age in Polish children, adolescents, and young adults

This paper presents a retrospective analysis of postmortem computed tomography (PMCT) scans of secondary ossification centers in the medial clavicular epiphysis, iliac crest apophysis, proximal humeral epiphysis, distal femoral epiphysis, proximal tibial epiphysis, and distal tibial epiphysis. At the same time, we analyzed PMCT scans of the maxillary and mandibular incisors, canines, premolars, and molars. We assessed 203 corpses, whose age ranged from 2 to 30 years, including 156 males and 47 females. The purpose of our study was to compare the processes of secondary ossification center fusion and permanent tooth maturation. Our research hypothesis was that certain stages of skeletal and dental maturation occur along consistent timelines that can be related to the chronological age. Secondary ossification center fusion was evaluated based on Kreitner and also McKern and Steward's classifications. The process of permanent tooth maturation was evaluated with Demirjian's method. Spearman's correlation coefficients (Rho) were positive in all analyses, which indicates that epiphyseal fusion progresses with age. The strongest relationship between the age and the stages of ossification was observed in the proximal tibial epiphysis (p < 0.001; Rho = 0.93) in females and in the medial clavicular epiphysis (p < 0.001; Rho = 0.77) in males. Studies show the importance of concomitant analysis of skeletal and dental maturation with a subsequent comparison of the results to achieve a greater precision in age estimation. A comparison of the results obtained in the study population of Polish children, adolescents, and young adults with the results of other studies in populations of similar ages showed a number of similarities in the time windows of dental and skeletal maturation. These similarities may help in age estimation.

Evaluating legal age of 18 years through observation of third molars using Gambier et al. method in an orthopantomographic sample of subadults from South India

In forensic practice, medicolegal physicians are often tasked with estimating age using dental evidence. This calls for an uncomplicated, reliable, and reproducible method for dental age estimation, enabling physicians to proceed without specific odontological expertise. Among various dental methods, third molar eruption analyses are less complicated and easier to perform. In our study, we explored the effectiveness of Gambier et al.'s scoring system, which examines the eruption of all third molars. We retrospectively analysed 1032 orthopantomograms (528 males and 504 females) of individuals aged between 15 and 24 years. The mean chronological age increased with the progression of stages (1 to 3) and phases (A to D) of the third molar eruption for both sexes. In terms of stages, none showed significant discrimination between minors (<18 years) and adults (>18 years), especially for males. However, Gambier's phase D displayed a relatively high likelihood of being 18 years or older, with an overall 85.9 % of males and 95.7 % of females having all third molars in stage 3 being 18 years or older. While the tested method could be helpful in indicating the completion of the 18th year of life, caution is advised (due to a high percentage of false positives), and it should be used alongside other age assessment methods by experts.

Decision tree analysis for age estimation in living individuals: integrating cervical and dental radiographic evaluations within a South African population

Age estimation in living individuals around the age of 18 years is medico-legally important in undocumented migrant cases and in countries like South Africa where many individuals are devoid of identification documents. Establishing whether an individual is younger than 18 years largely influences the legal procedure that should be followed in dealing with an undocumented individual. The aim of this study was to combine dental third molar and anterior inferior apophysis ossification data for purposes of age estimation, by applying a decision tree analysis. A sample comprising of 871 black South African individuals (n = 446 males, 425 = females) with ages ranging between 15 and 24 years was analyzed using panoramic and cephalometric radiographs. Variables related to the left upper and lower third molars and cervical vertebral ring apophysis ossification of C2, C3, and C4 vertebrae analyzed in previous studies were combined in a multifactorial approach. The data were analyzed using a pruned decision tree function for classification. Male and female groups were handled separately as a statistically significant difference was found between the sexes in the original studies. A test sample of 30 individuals was used to determine if this approach could be used with confidence in estimating age of living individuals. The outcomes obtained from the test sample indicated a close correlation between the actual ages (in years and months) and the predicted ages (in years only), demonstrating an average age difference of 0.47 years between the corresponding values. This method showed that the application of decision tree analysis using the combination of third molar and cervical vertebral development is usable and potentially valuable in this application.

Greulich and Pyle atlas: a non-reliable skeletal maturity assessment method in the North Indian population

Forensic age assessments are crucial in the evaluation of criminal responsibility and preventing false age claims. Of all the methods available, the Greulich and Pyle (GP) atlas is most commonly used for age estimation purposes. Therefore, the current study sought to analyze the reliability and applicability of the GP standard and, additionally, to determine any possible association between the socioeconomic status (SES), food habits, and estimated skeletal maturity in the North Indian population. The study included 627 (334 males and 293 females) healthy children up to 19 years of age with varying SES and food habits. The skeletal age (SA) was estimated by three different evaluators using the GP atlas. The chronological mean age (CA) and SA were compared in different age cohorts. A paired t-test and a Pearson chi-square test were applied to show the difference between CA and estimated SA and the association of skeletal maturity with SES and food habits. The estimated skeletal age in males was retarded by 0.142 years or 1.72 months (p ≤ 0.05), whereas in females, it was retarded by 0.259 years or 3.12 months (p ≤ 0.05). In males, the GP method has significantly underestimated SA in age cohorts 3-4, 4-5, 6-7, 7-8, 8-9, and 12-13, whereas it overestimated in 10-11 and 18-19 years. However, in females, the SA was significantly underestimated in age groups 10-11, 12-13, and 14-15, respectively. Estimated skeletal maturity had no significant association with SES and food habits. The current study concludes that the GP atlas may not be applicable to North India's population. The observed difference in assessed skeletal maturity may be due to geographical region, genetics, hormonal effects, etc., which require further investigation. Hence, population-specific standards are necessary to determine the bone age of Indian children accurately.

Precision and Accuracy of Radiological Bone Age Assessment in Children among Different Ethnic Groups: A Systematic Review

AIM

The aim was to identify, evaluate, and summarize the findings of relevant individual studies on the precision and accuracy of radiological BA assessment procedures among children from different ethnic groups.

MATERIALS AND METHODS

A qualitative systematic review was carried out following the MOOSE statement and previously registered in PROSPERO (CRD42023449512). A search was performed in MEDLINE (PubMed) (n = 561), the Cochrane Library (n = 261), CINAHL (n = 103), Web of Science (WOS) (n = 181), and institutional repositories (n = 37) using MeSH and free terms combined with the Booleans "AND" and "OR". NOS and ROBINS-E were used to assess the methodological quality and the risk of bias of the included studies, respectively.

RESULTS

A total of 51 articles (n = 20,100) on radiological BA assessment procedures were precise in terms of intra-observer and inter-observer reliability for all ethnic groups. In Caucasian and Hispanic children, the Greulich-Pyle Atlas (GPA) was accurate at all ages, but in youths, Tanner-Whitehouse radius-ulna-short bones 3 (TW3-RUS) could be an alternative. In Asian and Arab subjects, GPA and Tanner-Whitehouse 3 (TW3) overestimated the BA in adolescents near adulthood. In African youths, GPA overestimated the BA while TW3 was more accurate.

CONCLUSION

GPA and TW3 radiological BA assessment procedures are both precise but their accuracy in estimating CA among children of different ethnic groups can be altered by racial bias.

High performance for bone age estimation with an artificial intelligence solution

PURPOSE

The purpose of this study was to compare the performance of an artificial intelligence (AI) solution to that of a senior general radiologist for bone age assessment.

MATERIAL AND METHODS

Anteroposterior hand radiographs of eight boys and eight girls from each age interval between five and 17 year-old from four different radiology departments were retrospectively collected. Two board-certified pediatric radiologists with knowledge of the sex and chronological age of the patients independently estimated the Greulich and Pyle bone age to determine the standard of reference. A senior general radiologist not specialized in pediatric radiology (further referred to as "the reader") then determined the bone age with knowledge of the sex and chronological age. The results of the reader were then compared to those of the AI solution using mean absolute error (MAE) in age estimation.

RESULTS

The study dataset included a total of 206 patients (102 boys of mean chronological age of 10.9 ± 3.7 [SD] years, 104 girls of mean chronological age of 11 ± 3.7 [SD] years). For both sexes, the AI algorithm showed a significantly lower MAE than the reader (P < 0.007). In boys, the MAE was 0.488 years (95% confidence interval [CI]: 0.28-0.44; r² = 0.978) for the AI algorithm and 0.771 years (95% CI: 0.64-0.90; r² = 0.94) for the reader. In girls, the MAE was 0.494 years (95% CI: 0.41-0.56; r² = 0.973) for the AI algorithm and 0.673 years (95% CI: 0.54-0.81; r² = 0.934) for the reader.

CONCLUSION

The AI solution better estimates the Greulich and Pyle bone age than a general radiologist does.

Use of third molar eruption based on Gambier's criteria in assessing dental age

The biological aspects of determining the dental age of subadults represent an important interdisciplinary scientific link with applications in criminal law and in forensic anthropology and dentistry. In criminal procedural law, it is necessary to determine the exact age of an undocumented person in view of the application of the provisions on juvenile offenders and minor victims. Chronological age can be estimated from the development of the third molars, as these are the only teeth that develop at the age of 18. The aim of this study was to verify the applicability of the Gambier method based on the eruption of the third permanent molars in the mandible and maxilla, to contribute to forensic age assessment. The analyzed group that met the criteria consisted of 811 orthopantomograms (OPGs) (339 females and 472 males) between the ages of 13 and 25 years. The OPGs were retrospectively analyzed according to the method of Gambier et al. (Int J Legal Med 133:625-632, 29), which refers to the eruption stages of the third molar. Differences between eruption stages of maxillary and mandibular third molars were statistically significant in both biological sexes. Intersexual differences in mean age were significant only at stage 3 for any M3 tooth and at stage 1 for mandibular M3. There were no statistically significant differences between the left and right mandibular and maxillary third molars, respectively. Differences between mandibular and maxillary M3 were significant only for stage 1 in males on the left side and for stage 2 in both sexes and sides. The method used allowed the best classification of individuals into minor and adult groups (based on phase D-90.41% of individuals, based on the third stage of the mandibular left third molar-86.29%). Based on the results obtained, we can assume that the method cannot be used alone in the initial examination of living individuals, since all four third molars must be assessed and there are no additional findings from practice.

Premolar maturity index (IPM) for indicating legal age 12 years in a sample of south Indian children - A digital pantomographic study

Legal age of 12 years has been set as the minimum age of criminal responsibility in many countries. This paper concerned a method for predicting the legal age 12 years based on the maturation of lower first and second premolars. The sample consisted of 900 digital pantomographs of south Indian children (450 males, 450 females) aged between 8 and 16 years. Among them, 580 DPTs were used as test sample and 320 DPTs as validation sample. New cut-offs at the age threshold 12 years were determined by using the measurement of open apices in first premolars (IPM1 < 0.10), second premolars (IPM2 < 0.14) and the combined method (IPM1 + IPM2 < 0.12). The sensitivity (Se), specificity (Sp) and posttest probability (PTP) were established. For IPM1 < 0.10, the Se, Sp and PTP were 92.4 %, 91.3 % and 91.1 % for males and 90.8 %, 87 % and 86.5 % for females. For IPM2 < 0.14, they were 92.6 %, 93.6 % and 93.4 % for males and 91.5 %, 83.1 % and 83.4 % for females. And, for the combined predictor (IPM1 + IPM2 < 0.12), these values were 92.6 %, 94.8 % and 94.6 % and 90.5 %, 84.9 % and 84.7 % in males and females respectively. The best score of positive predictive value and specificity was obtained for males with the combined predictor (IPM1 + IPM2 < 0.12) and with single predictor (IPM1 < 0.10) for females. To conclude, the combined predictor has resulted in better discrimination in males, while in females the single predictor (IMP1 < 0.10) did slightly better. Further studies are warranted to test the combination of dental and skeletal indicators for the prediction of 12 years in the studied population.

Forensic age assessments of alleged unaccompanied minors at the Medicolegal Institute of Montpellier: a 4-year retrospective study

Background

As many other European countries, France has to deal with a growing number of migrants including some who contend age minority entitling them to benefits and privileges reserved for children within the context of legal proceedings. In case of doubtful minority, medical examinations may be carried out to assess skeletal and dental age. Our objective was to analyse the age assessments regarding individuals of doubtful minority assertion at the Medico-legal Institute of the University Hospital of Montpellier since 2018.

Methods

Expert reports of forensic age assessments performed during the 2018–2021 period were reviewed. Demographic data and results from medical and radiological investigations based on AGFAD recommendations were recorded in each case. When available, conclusions of judicial investigations about the individuals’ actual age were collected.

Results

A total of 265 reports were compiled. Age assessments predominantly concerned males (97.7%) and the main reported country of origin was sub-Saharan Africa (80.4%). The mean reported age was 16.3 ± 0.8 years. The individual’s stated age was compatible with the age assessment in 31 cases (11.7%), while expert reports concluded that the age of majority had been reached in 131 cases (49.4%). In cases of discrepancies, the average difference between the stated and the assessed lowest possible age (= assessed minimum age) was 2.7 ± 2.3 years and 6.9 ± 3.8 years between the stated and the most probable age. Age assessments could be compared with actual ages determined by court proceedings in 27 cases, with established ages being systematically higher than the assessed minimum ages (mean difference = 4.4 ± 4.0 years). The difference between actual and stated ages ranged from 1.8 up to 18.9 years (mean difference = 6.4 ± 4.0 years). The used protocol never led to any age overestimation in this population.

Conclusion

Our study reinforces the relevance of AGFAD recommendations for forensic age assessment and calls for the harmonization of practices based on this methodology in the European countries.

The Application of Magnetic Resonance Imaging in Skeletal Age Assessment

METHOD

The study includes 80 patients identified from an endocrine clinic, two males and two females from each of 5 age groups (<5, 5 to 7, 8 to 10, 11 to 13, and 14 to 16 years). Skeletal age as determined from an open MRI scanner and radiographs performed on the same day was compared for each child. Two observers assess the skeletal age from radiographs and MRI images independently. After a period of at least three weeks, observers determined the skeletal age of all patients independently. All of the images were in different and random orders, on both of the assessment occasions. The agreement was assessed using the interclass correlation coefficient and Bland Altman plots. Problem Statement. The recurrent use of left-hand radiography in children with chronic conditions might result in the patient being exposed to the same image several times throughout the course of their lives. Use of radiation-free methods such as magnetic resonance imaging (MRI) may be able to assist in reducing the risks associated with radiation exposure, if done properly.

RESULTS

Patients' age ranged from 3 to 16 years, in which the mean of the chronological age was 9.3 years (±2.9) and 9.8 years (±2.7) in girls and boys, respectively. The interrater agreement for skeletal age determination was 0.984 for radiographs and 0.976 for MRI scans. Using the G&P technique, for Observer 1, intraobserver agreement for radiographs and DXA was 0.993 and 0.983, respectively, and 0.995 and 0.994, respectively, for Observer 2. Plotting the rater readings against the line of equality shows no significant differences between readings acquired from radiographs and MRI scans.

CONCLUSION

For the study contribution, it is possible to employ open compact MRI to determine the skeletal age of a person. Our results showed that left-hand MRI scans were of better quality than the radiographs.

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.

Comparison of Bone Age Assessments by Gruelich-Pyle, Gilsanz-Ratib, and Tanner Whitehouse Methods in Healthy Indian Children

BACKGROUND

There are several methods of bone age (BA) assessment, which include Gruelich-Pyle (GP), Gilsanz-Ratib (GR), and Tanner Whitehouse-3 (TW-3) methods. Although GP atlas is the most widely used, there are concerns about its accuracy in children of different ethnicities, making the use of the TW-3 method an attractive option in Indian children.

OBJECTIVES

1) To assess the relationship of BA with chronological age (CA) as assessed by different methods (GP, GR, and TW-3) in healthy Indian children 2) To assess which of the three methods of BA assessment is more suitable in Indian children.

METHODOLOGY

X-rays of 851 children (438 boys and 413 girls, aged 2-16.5 years) were analyzed by four independent observers using three different methods of BA estimation (GP, GR, and TW-3). Mean BAs were converted to Z-scores. For purpose of deciding which method of BA was most suitable in our cohort, a test of proportions and root mean square (RMS) deviations were computed.

RESULTS

Using the test of proportions, the TW-3 method was most suitable overall (P < 0.05). TW-3 method was again most applicable in prepubertal boys (P < 0.05), in prepubertal girls (although not significant, P > 0.1), and pubertal girls (P < 0.05). However, in pubertal boys, the GR atlas method was most suitable (P < 0.05). The same results were obtained when root mean square (RMS) deviations were computed. Interestingly, BA was underestimated in Indian boys irrespective of the method used. In Indian girls, however, the BA was underestimated till the pubertal growth spurt, after which there was rapid advancement of BA.

CONCLUSIONS

Among the three methods (GP, GR, and TW-3), the BAs estimated by the TW-3 method were closest to CAs. Hence, it seems reasonable to recommend the use of the TW-3 method for BA estimation in the Indian population till an Indian standard bone age atlas is developed.

Evaluation of Bone Age in Children: A Mini-Review

Bone age represents a common index utilized in pediatric radiology and endocrinology departments worldwide for the definition of skeletal maturity for medical and non-medical purpose. It is defined by the age expressed in years that corresponds to the level of maturation of bones. Although several bones have been studied to better define bone age, the hand and wrist X-rays are the most used images. In fact, the images obtained by hand and wrist X-ray reflect the maturity of different types of bones of the skeletal segment evaluated. This information, associated to the characterization of the shape and changes of bone components configuration, represent an important factor of the biological maturation process of a subject. Bone age may be affected by several factors, including gender, nutrition, as well as metabolic, genetic, and social factors and either acute and chronic pathologies especially hormone alteration. As well several differences can be characterized according to the numerous standardized methods developed over the past decades. Therefore, the complete characterization of the main methods and procedure available and particularly of all their advantages and disadvantages need to be known in order to properly utilized this information for all its medical and non-medical main fields of application.

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.

Age verification using random forests on facial 3D landmarks

Three-dimensional facial images are becoming more and more widespread. As such images provide more information about facial morphology than 2D imagery, they show great promise for use in future forensic applications, including age estimation and verification. This paper proposes an approach using random forests, a machine learning method, to develop and test models for classification of legal age thresholds (15 years and 18 years) using 3D facial landmarks. Our approach was developed on a set of 3D facial scans from 394 Czech individuals (194 males and 200 females) aged between 10 and 25 years. The dataset was retrieved from a sizable database of Central European faces - The FIDENTIS 3D Face Database. Three main types of input variables were processed using random forests: I) shape (size-invariant) coordinates of 3D landmarks, II) size and shape coordinates of 3D landmarks, and III) inter-landmark distances, angles and indices. The performance rates for the combinations of variables and age threshold were expressed in terms of sensitivity and specificity. The overall accuracy rates varied from 71.4%-91.5% (when the male and female samples were pooled). In general, higher accuracy was achieved for the age limit of 18 years than for 15 years. Whereas size-variant variables showed a better performance rate for the age limit of 15 years, the size-invariant variables (i.e., shape variables) were better for classifying individuals under 18 years. The verification models grounded on traditional variables (distances, angles, indices) yielded consistently higher performance rates on females than on males, whereas the inverse trend was observed for the models built on 3D coordinates. The results indicate that age verification based on 3D facial data with processing by the random forests method has high potential for further forensic or biometric applications.

Magnetic resonance imaging for forensic age estimation in living children and young adults: a systematic review

The use of MRI in forensic age estimation has been explored extensively during the last decade. The authors of this paper synthesized the available MRI data for forensic age estimation in living children and young adults to provide a comprehensive overview that can guide age estimation practice and future research. To do so, the authors searched MEDLINE, Embase and Web of Science, along with cited and citing articles and study registers. Two authors independently selected articles, conducted data extraction, and assessed risk of bias. They considered study populations including living subjects up to 30 years old. Fifty-five studies were included in qualitative analysis and 33 in quantitative analysis. Most studies had biases including use of relatively small European (Caucasian) populations, varying MR approaches and varying staging techniques. Therefore, it was not appropriate to pool the age distribution data. The authors found that reproducibility of staging was remarkably lower in clavicles than in any other anatomical structure. Age estimation performance was in line with the gold standard, radiography, with mean absolute errors ranging from 0.85 years to 2.0 years. The proportion of correctly classified minors ranged from 65% to 91%. Multifactorial age estimation performed better than that based on a single anatomical site. The authors found that more multifactorial age estimation studies are necessary, together with studies testing whether the MRI data can safely be pooled. The current review results can guide future studies, help medical professionals to decide on the preferred approach for specific cases, and help judicial professionals to interpret the evidential value of age estimation results.

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.

Applicability of the Greulich-Pyle Method in Assessing the Skeletal Maturity of Children in the Eastern Utter Pradesh (UP) Region: A Pilot Study

Background In forensic proficiency, the distinct model applied for age estimation includes physical examination, i.e., evaluation of somatic maturity and post pubescence peculiarities, dental development, and radiological assessment of skeletal maturity usually of the hand and wrist. The Greulich and Pyle (GP) method of skeletal age (SA) determination is considered quicker and easier with a lower error percentage of prediction. The specificity and applicability of the GP atlas have been recapitulated in many studies. This study aims to assess the applicability and reproducibility of the GP atlas on a sample of the eastern Utter Pradesh (UP) population. Results Considering the whole study population, the SA of the male subjects was retarded by 0.89 years or 9.03 months, whereas the SA of females were retarded by 0.36 years or 4.33 months than the chronological age, respectively. Conclusion According to this study, it is concluded that the GP atlas may not be applicable for both males and females in the eastern Uttar Pradesh region. The factors responsible for delayed skeletal growth and maturation may vary depending on demographics, ethnicity, and genetics. Further, a detailed study will be conclusive on a greater population size assessing more accurate and precise insights on the applicability and reproducibility of GP atlas.

Minor or adult? Introducing decision analysis in forensic age estimation

Nowadays, forensic age estimation takes an important role in worldwide forensic and medico-legal institutes that are solicited by judicial or administrative authorities for providing an expert report on the age of individuals. The authorities' ultimate issue of interest is often the probability that the person is younger or older than a given age threshold, which is usually the age of majority. Such information is fundamental for deciding whether a person being judged falls under the legal category of an adult. This is a decision that may have important consequences for the individual, depending on the legal framework in which the decision is made. The aim of this paper is to introduce a normative approach for assisting the authority in the decision-making process given knowledge from available findings reported by means of probabilities. The normative approach proposed here has been acknowledged in the forensic framework, and represents a promising structure for reasoning that can support the decision-making process in forensic age estimation. The paper introduces the fundamental elements of decision theory applied to the specific case of age estimation, and provides some examples to illustrate its practical application.

Die Aussagekraft sozialpädagogischer Altersschätzungen im Vergleich zur forensischen Altersdiagnostik

In der vorliegenden Studie sollte die Aussagekraft sozialpädagogischer Altersschätzungen im Vergleich zu forensischen Altersbegutachtungen, die entsprechend den Empfehlungen der Arbeitsgemeinschaft für Forensische Altersdiagnostik durchgeführt worden waren, analysiert werden. Hierfür wurden 47 Fälle ausgewertet, bei denen sowohl sozialpädagogische Altersschätzungen von in Jugendhilfeeinrichtungen betreuten unbegleiteten minderjährigen Flüchtlingen als auch forensische Altersgutachten zur Verfügung standen. In 44 Fällen, in denen die Einrichtungen von Minderjährigkeit ausgingen, bescheinigten die forensischen Altersgutachten in 12 Fällen zweifelsfreie Volljährigkeit und in 24 weiteren Fällen wahrscheinliche Volljährigkeit. In 2 Fällen, in denen die Einrichtungen die Minderjährigkeit anzweifelten, wurden im Ergebnis der forensischen Altersbegutachtung in dem einen Fall zweifelsfreie Volljährigkeit und in dem anderen Fall wahrscheinliche Volljährigkeit festgestellt. In einem Fall, in dem die Einrichtung von Volljährigkeit ausging, wurde auf der Grundlage der forensischen Altersbegutachtung wahrscheinliche Volljährigkeit mit noch möglicher Minderjährigkeit attestiert. Objektivierbare psychosoziale Kriterien, mit denen Volljährigkeit zweifelsfrei festgestellt werden kann, ließen sich nicht erkennen. Es ist davon auszugehen, dass der Anteil falsch-positiver Minderjährigkeitsfeststellungen bei sozialpädagogischen Altersschätzungen deutlich höher als bei forensischen Altersbegutachtungen ist. Ebenso scheint ein relevantes Risiko falsch-positiver Volljährigkeitsfeststellungen bei sozialpädagogischen Altersschätzungen zu bestehen. Es wurde geschlussfolgert, dass sozialpädagogische Altersschätzungen keine überzeugende Alternative zu forensischen Altersbegutachtungen darstellen.

Discriminatory ability of cervical vertebral maturation stages in predicting attainment of the legal age threshold of 14 years: A pilot study using lateral cephalograms

Purpose

In India, the age of 14 years is the legal age threshold for child labour. Therefore, in suspected instances of child labour, age assessment plays a crucial role in determining whether a violation of the law on the employment of children has occurred. The aim of this retrospective cross-sectional study was to assess the discriminatory ability of stages of cervical vertebral maturation (CVM) in predicting the legal age threshold of 14 years.

Materials and Methods

Routinely taken lateral cephalograms from 408 subjects aged 10 to 18 years were evaluated retrospectively using the CVM stages described by Baccetti et al. Descriptive statistics, accuracy, sensitivity, specificity, positive and negative predictive values, and likelihood ratios were calculated for stages 2, 3, and 4 of CVM.

Results

Real age increased as the CVM stage gradually increased. The results of 2×2 contingency tables showed that CVM stage 4 produced an accuracy of 71% and 73%, a false positive rate of 7% and 18%, and a post-test probability of 59% and 68% for boys and girls, respectively.

Conclusion

Based on these findings, it can be concluded that the stages of CVM are of limited use for predicting the attainment of the legal age threshold of 14 years. Future studies should investigate whether combinations of skeletal and dental methods could achieve better accuracy and post-test probability.

Multi-factorial age estimation: A Bayesian approach combining dental and skeletal magnetic resonance imaging

PURPOSE

To study age estimation performance of combined magnetic resonance imaging (MRI) data of all four third molars, the left wrist and both clavicles in a reference population of females and males. To study the value of adding anthropometric and sexual maturation data.

MATERIALS AND METHODS

Three Tesla MRI of the three anatomical sites was prospectively conducted from March 2012 to May 2017 in 14- to 26-year-old healthy Caucasian volunteers (160 females, 138 males). Development was assessed by allocating stages, anthropometric measurements were taken, and self-reported sexual maturation data were collected. All data was incorporated in a continuation-ratio model to estimate age, applying Bayes' rule to calculate point and interval predictions. Two performance aspects were studied: (1) accuracy and uncertainty of the point prediction, and (2) diagnostic ability to discern minors from adults (≥18 years).

RESULTS

Combining information from different anatomical sites decreased the mean absolute error (MAE) compared to incorporating only one site (P<0.0001). By contrast, adding anthropometric and sexual maturation data did not further improve MAE (P=0.11). In females, combining all three anatomical sites rendered a MAE equal to 1.41 years, a mean width of the 95% prediction intervals of 5.91 years, 93% correctly classified adults and 91% correctly classified minors. In males, the corresponding results were 1.36 years, 5.49 years, 94%, and 90%, respectively.

CONCLUSION

All aspects of age estimation improve when multi-factorial MRI data of the three anatomical sites are incorporated. Anthropometric and sexual maturation data do not seem to add relevant information.

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.

Is the Greulich and Pyle atlas applicable to all ethnicities? A systematic review and meta-analysis

OBJECTIVE

To determine whether the Greulich and Pyle (G&P) atlas is applicable when applied to populations of different ethnicity.

METHODS

A systematic review of studies published between 1959 and 15th February 2017 identified from the Embase, MEDLINE and Cochrane databases was undertaken. Quality of the studies was assessed using the National Institute for Health and Care Excellence tool. Meta-analysis used mean differences and standard deviations as summary statistics for the difference between bone age (BA) and chronological age (CA).

RESULTS

A total of 49 studies were included of which 27 (55%) were related to Caucasian populations. Of the 49 eligible studies, 35 were appropriate for further meta-analysis. In African females, meta-analysis showed a significant mean difference between BA and CA of 0.37 years (95% CI 0.04, 0.69). In Asian males, meta-analysis showed significant differences between BA and CA of -1.08, -1.35, -1.07, -0.80 and 0.50 years for chronological ages of 6, 7, 8, 9 and 17 years, respectively. Meta-analysis showed no significant differences between BA and CA in African males, Asian females, Caucasians and Hispanics.

CONCLUSIONS

The G&P standard is imprecise and should be used with caution when applied to Asian male and African female populations, particularly when aiming to determine chronological age for forensic/legal purposes.

KEY POINTS

• In African females, bone age is significantly advanced when compared to the G&P standard. • In Asian males, bone age is significantly delayed between 6 and 9 years old inclusive and significantly advanced at 17 years old when compared to the G&P standard. • The G&P atlas should be used with caution when applied to Asian and African populations, particularly when aiming to determine chronological age for forensic/legal purposes.

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.

Contribution of third molar eruption to the estimation of the forensic age of living individuals

Forensic age estimation of a living individual is frequently performed in clinical forensic medicine. Medicolegal physicians are usually called upon by the authorities to estimate the age of a living person requesting asylum or to determine whether a suspected offender is subject to juvenile or adult criminal law. Dental age is one of the parameters studied to estimate biological age. Several methods are used, and among these, analysis of the eruption of the third molar (M3) on an orthopantomogram (OPG) is one of the common methods. The objective of the study was to analyse the contribution of M3 eruption to age estimation, in particular with regard to the threshold of 18 years of age, in a sample of individuals examined in a French university hospital. The stage of wisdom tooth eruption of all individuals aged between 15 and 24 years, who had an OPG performed between 1 January 2013 and 31 December 2015, was interpreted using a three-stage scoring system. In total, 557 OPGs (340 males and 217 females) were included. None of the stage scores allowed a distinction between minors and majors, for either sex. Overall, 85% of females and 98% of males with four M3s in stage 3 (complete emergence in the occlusal plane) were majors.

Union of the medial clavicular epiphysis in a South African Black skeletal sample

Current research points to an increase in the interest in and focus on the age at which the medial end of the clavicle begins and completes union in various populations worldwide. As it currently stands, no information exists for the South African population detailing the age at which this skeletal developmental marker commences or completes union. The aim of this study was to establish the age at which partial and complete unions occur and to find if there is any correlation between the age and the assigned stage score in a South African Black skeletal sample. Paired clavicles of 211 males and females (M = 101, F = 110) with ages ranging between 12 and 45 years from the Raymond A. Dart Collection of Human Skeletons were included. A strong correlation between age and the assigned stage score was observed for both males and females (rs = 0.73). No statistically significant differences between the stage of union at the left and right clavicles were observed (p = 0.9). In this sample, partial union was commonly observed in individuals in their third decade of life; while complete union occurred more often in individuals older than 30 years of age. Assessing and recording the degree of union at the medial end of the clavicle can be a helpful additional age-at-death indicator to use when establishing an age-at-death range. However, overlap and variability between the ages of individuals categorized as either displaying signs of partial or complete union were evident.

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.

A systematic review and meta-analysis of the fully formed wisdom tooth as a radiological marker of adulthood

Assessment of third molar development on dental radiograms is one of the most commonly used methods of forensic age estimation. Despite widespread use and numerous studies, there is a paucity of aggregated data on how well a fully mature third molar identifies adulthood (> 18 years), the most important threshold in a medicolegal context. Therefore, a systematic review and meta-analysis was conducted. A total of 1229 studies were screened, and 82 studies were assessed for inclusion. Twenty-four studies, with a pooled cohort of 19,690 individuals, presented true positive (TP), true negative (TN), false positive (FP), and false negative (FN) outcomes, enabling meta-analysis. The outcomes were based on using the third molar in the fully mature stage as a diagnostic test to indicate age 18 years or above. The false positive rate (fall-out/1-specificity) was 3.1% (95% CI 2.1-4.6%), and the true positive rate (recall/sensitivity) was 51% (95% CI 44-58%). Diagnostic accuracy was 71%. These findings, while reassuring in terms of the low false positive rate, highlight the need for complementary age estimation methods to avoid a significant number of false negatives.