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This study explores the reliability of four established legal age threshold estimation approaches in a Croatian sample. We applied Haavikko stages, Demirjian stages, Olze's third molar eruption stages, and second and third molar maturity indices measurement in 593 orthopantomograms of Croatian children and adolescents aged 11.00-20.99 years old. The left mandibular second and third molar were assessed. Logistic regression analysis was conducted to test the significance of predictive variables. Logistic Receiver operating characteristic (ROC) curves were performed to evaluate the classification ability of variables for estimating 14- and 16-year-old thresholds. The areas under the ROC curve (AUC), accuracy (Acc), sensitivity (Se), specificity (Sp), Positive Likelihood Ratio (LR +), Negative Likelihood Ratio (LR-), and Bayes post-test probability (Bayes PTP) were calculated to evaluate classification performance. Results suggest that the combination of I 2M &I 3M is the best classifier for the 14-year-old threshold (AUC = 0.879); for males alone, I 2M is an even better classifier (AUC = 0.881). The highest Acc 80.1% (95%CI, 75.9%-83.9%), Bayes PTP 86.5% (95%CI, 82.8%-89.7%) and Sp 88.9% (95%CI, 83.0%-93.3%) were by I 3M  < 0.81 & I 2M  < 0.03 in total samples; the highest Acc 86.1% (80.6%- 90.6%), Bayes PTP 87.2% (95%CI, 81.7%- 91.4%) and Sp 87.8% (95%CI, 78.2%- 94.3%) were by I 2M  < 0.01 in males, Acc of Haavikko Ac and Demirjian H stage in second molar is very close with slightly lower Bayes PTP and Sp. I 3M is a good classifier for 16-year-old threshold (AUC = 0.889). The cut-off value I 3M  < 0.34 can be used to classify the 16-year-old threshold with Acc of 80.6% (95%CI, 77.2%-83.7%), Sp of 83.4% (95%CI, 79.0%-87.3%), and 81.7% (95%CI, 78.4%-84.8%) Bayes PTP. In conclusion, to classify the 14-year-old threshold, a pair of cut-off values I 3M  < 0.81 & I 2M  < 0.03 can be used in Croatian females; I 2M  < 0.01, Demirjian H stage, Haavikko Ac stage in second molar, and the pair I 3M  < 0.81 & I 2M  < 0.03 can all be used in Croatian males. I 3M  < 0.34 can classify the 16-year-old threshold in Croatian populations., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objectives: To estimate the joint correlations among cervical vertebrae maturation (CVM), spheno-occipital synchondrosis (SOS), midpalatal suture maturation (MPS), and third molar mineralization (TMM) and to assess the predictive potential of SOS on CVM and MPS., Materials and Methods: 570 pretreatment cone-beam computed tomogram (CBCT) scans from three private practices were analyzed, and MPS, CVM, SOS, and TMM stages were categorized and recorded by two independent investigators. Intra- and inter-rater reliability tests were evaluated with weighted Cohen's kappa tests. Spearman correlation coefficients for ordinal data were used to estimate the pairwise correlations among SOS, CVM, MPS, and TMM. To evaluate if SOS could predict CVM and MPS, ordinal regression models were estimated and cross-validated., Results: The analysis demonstrated a robust positive correlation between SOS and CVM (r = 0.845) and between SOS and MPS (r = 0.742). A significant correlation was also observed between CVM and MPS (r = 0.659). Further correlations were identified between TMM and SOS (r = 0.444), TMM and MPS (r = 0.392), and TMM and CVM (r = 0.358). Ordinal regression models indicated the potential of using SOS as a predictive marker for CVM and MPS stages., Conclusions: With a comprehensive analysis, SOS is strongly correlated with CVM and MPS, and SOS stage can be used to predict CVM and MPS using ordinal regression. Since MPS stages are challenging to categorize due to their anatomy, this finding suggests a diagnostic tool using SOS stages or when more information on skeletal maturity of the patient is desired., (© 2024 by The EH Angle Education and Research Foundation, Inc.)

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., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Introduction: Evaluation of the eruption of mandibular third molars in orthopantomograms (OPGs) is a method of forensic age assessment. The objective of our study was to provide valid reference data for this trait within a population of black South Africans. The study was guided by the criteria for reference studies in age assessment., Materials and Methods: A study population from Pretoria, South Africa comprising 670 OPGs obtained from 338 black females and 332 black males aged between 15.00 and 25.97 years was analysed. All OPGs were performed for medical indication during the period from 2011 to 2022 and were retrospectively evaluated. From the 670 OPGs, a total of 1021 mandibular third molars were evaluated. The assessment of mandibular third molars was conducted using the staging scale presented by Olze et al. in 2012. Two experienced dentists evaluated the OPGs independently of each other. If the two examiners diverged in their assessments, a consensus stage was assigned., Results: As expected, the mean, median and minimal age increased with higher stages for both teeth and both sexes. The minimum age recorded for stage D, indicating complete tooth eruption, was 15.79 years in females and 16.62 years in males., Conclusion: As it is the case for previous reference studies in other countries, placing exclusive reliance on the evaluation of mandibular third molar eruption is inadequate for ascertaining the age of majority among Black South Africans. Future studies need to examine if our results are transferable to other countries in Sub-Saharan Africa., (© 2024. The Author(s).)

Traditionally, dental identification techniques are used to establish identity or assist in reconstructing an individual's biological profile. However, other aspects of identity, namely socioeconomic status (SES), can be estimated through teeth. This work aims to evaluate the influence of SES on third molar agenesis in a Portuguese population. X-rays from 448 subjects (223 belonging to a high and 225 to a low socioeconomic status) were assessed and demographic data (age, sex) and dental history were registered. Frequencies and associations between the variables were analyzed using the chi-square test. For each group, differences between third molar agenesis were studied using the Wilcoxon test. The significance level was 5%. X-rays displaying at least one agenesis were more common in females (in both SES groups). Differences between socioeconomic status were found in female subjects' upper right and lower left third molars, with a higher frequency of agenesis in the lower SES group. Agenesis of lower third molars displayed fluctuant asymmetry in both groups, whereas agenesis of upper third molars was also present in the lower SES group. These results suggest that socioeconomic status can affect third molar agenesis prevalence, and fluctuant asymmetry seems more prevalent in the lower SES, as it affects all third molars., (© 2023. The Author(s).)

Introduction: Age Estimation has been considered as a human basic right, carried out through the use of tables for dental age assessment based on the chronology of tooth eruption. As such, the final aim of this investigation is to create tables with applicability to the Portuguese population, for the different scoring systems used and combined different statistical approaches., Materials and Methods: For this purpose, dental age assessment was achieved in all four third molars, using different scoring systems, in a total sample of 626 orthopantomograms (324 females, 302 males), aged between 12 and 25 years old, from the database population of Lisbon North University Hospital Center, approved by the Ethic Committee., Results: The values of validation showed excellent results both on precision and on reproducibility. Mostly all methods showed statistically significant differences between the estimated age and the chronological age and, therefore, the presence of estimation errors. Kullman's and Mincer's methods are the ones with best applicability in the Portuguese population, in the lower third molars. The reliability measures (sensitivity, specificity and accuracy) values decrease as age increases., Conclusion: A combination of the scoring systems as a protocol for dental age assessment in Portuguese nationality was established. Tables, for all the scoring systems used, were made with applicability in the Portuguese population., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Various staging scales have been proposed for the assessment of the visibility of the periodontal ligament space of mandibular third molars on dental panoramic radiographs (PANs) for forensic age assessment in living individuals. However, up to now, there has been no systematic comparison between these staging scales available. We directly compared the 2010 staging scale proposed by Olze et al. with the 2017 staging by Lucas et al. and the 2020 staging by Guo et al. in a German study population. We evaluated 233 PANs from 115 females and 118 males aged 20.0 to 40.9 years using three independent examiners, with one examiner conducting two assessments. We examined the correlation between age and stage, as well as the inter- and intra-rater reliabilities. While the point estimates for the correlation coefficient and the reliability measures were lowest for the Guo scale and highest for the Olze scale, confidence intervals showed a large overlap, particularly for the scales of Olze et al. and Lucas et al. The correlation coefficients between stage and age were consistently lower in females than in males across all methods. In summary, we showed that the staging scales of Olze et al. and Lucas et al. were very similar. The Olze method showed higher point estimates across all analyses, and because there are more reference data available for this method, we argue that it should be preferred as the method of choice for further studies in the field. However, Guo method could be considered for instances, in which the inter-radicular periodontal ligament is not evaluable., (© 2024. The Author(s).)

Accurate classification of tooth development stages from orthopantomograms (OPG) is crucial for dental diagnosis, treatment planning, age assessment, and forensic applications. This study aims to develop an automated method for classifying third molar development stages using OPGs. Initially, our data consisted of 3422 OPG images, each classified and curated by expert evaluators. The dataset includes images from both Q3 (lower jaw left side) and Q4 (lower right side) regions extracted from panoramic images, resulting in a total of 6624 images for analysis. Following data collection, the methodology employs region of interest extraction, pre-filtering, and extensive data augmentation techniques to enhance classification accuracy. The deep neural network model, including architectures such as EfficientNet, EfficientNetV2, MobileNet Large, MobileNet Small, ResNet18, and ShuffleNet, is optimized for this task. Our findings indicate that EfficientNet achieved the highest classification accuracy at 83.7%. Other architectures achieved accuracies ranging from 71.57 to 82.03%. The variation in performance across architectures highlights the influence of model complexity and task-specific features on classification accuracy. This research introduces a novel machine learning model designed to accurately estimate the development stages of lower wisdom teeth in OPG images, contributing to the fields of dental diagnostics and treatment planning., (© 2024. The Author(s).)

Cameriere developed a method on orthopantomograms (OPG) to assess adult age of 18 years based on the relationship between age and the third molar maturity index I3M. The aim of this study was to evaluate whether Cameriere's method could be applied to computed-tomography scans (CT-scans) from a population of French juveniles and young adults and compare the results obtained from OPG of the same individuals. Our sample comprised 200 examinations that had been performed at the radiological department of a French University hospital between 2007 and 2020. Each patient had received an OPG and a cranial CT scan for medical purposes, and we used a similar adaptation of I3M based on OPG to determine the I3M based on CT scans. Due to exclusion criteria, our final sample comprised 71 OPGs and 63 CT scans. Based on the 71 OPGs, there was concordance between chronological age and estimated age, with a sensitivity of 78.57%, a specificity of 89.47%, and a misclassified rate of 18.03% based on tooth 38, and a sensitivity of 78.79%, a specificity of 91.67%, and a misclassified rate of 17.78% based on tooth 48. Our results based on CT scans presented concordance between chronological age and estimated age for tooth 38 described by a sensitivity of 77.78%, a specificity of 94.12%, and a misclassified rate of 16.98%. The concordance between chronological age and estimated age based on 48 had a sensitivity of 75.00%, a specificity of 93.75%, and a misclassified rate of 19.23%. The > 90% ICC indicate an excellent similarity between measurements of teeth 38 and 48 based on OPGs and CT scans. This study has revealed the applicability of the Cameriere's method to calculate the I3M based on CT scans from a French population. The results based on CT scans are similar to results based on OPGs from the same individuals., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The assessment of majority age is important for determining legal responsibility. The definition of the 3rd molar maturity index (Im3) have proven to be a simple and effective method of majority age establishment, the accuracy of which has been tested in different populations. There is a clear lack of studies in this scientific area in Russia., Objective: To test diagnostic accuracy of majority age assessment method by 3rd molar (Cameriere index) in the Ufa sample., Material and Methods: The number of orthopantomograms equal 120 from males and females aged from 14 to 23 years without apparent pathological changes of the pulp of teeth 38 and 48 was examined. The measures were conducted using the standard R. Cameriere method. The method of logistic regression, determination of predictive values of sensitivity and specificity were used., Results: The Im3 cut-off point, that was equal 0.08, had a sensitivity of 89% and specificity of 95% in the male sample, accuracy of age group determination was 93%. In the female sample the method sensitivity was 93%, specificity - 97%, accuracy - 97%., Conclusion: The study results confirmed the absence of population variability of the Cameriere index value, that makes it possible to use the majority age determination method by 3rd molar for practical application in the examination of a living person at the territory of the Russian Federation.

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 3M L and I 3M R), 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 3M L and I 3M R, respectively. In addition, all these quantities were high when only the I 3M R 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 3M L and I 3M R 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., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Estimation of age of majority has important applications in the forensic daily practice because of the increasing demand for age estimates of unaccompanied minors. Diagnostic accuracy of I 3M to assess legal adult age of 18 years has been already tested in several specific population samples. The aim of this work was to compare the available data about sensitivity and specificity of the third molar maturity index (I 3M ) from five different regional groups' radiographic samples to study possible ethnical difference. For this purpose, a sample of 6157 orthopantomograms (OPGs), coming from 15 countries, was analysed. Data about sensitivity and specificity were pooled using a bivariate modelling approach. The one-way MANOVA analysis was applied to assess the likelihood that sensitivity and specificity of the five regional groups are sampled from the same population. The result of the one-way MANOVA showed that both sensitivity and specificity did not depend from the regional groups. The obtained sensitivity was 84% (95% CI: 82% and 85%), and its specificity was 94% (95% CI: 93% and 95%). Based on these results, the I 3M was a useful statistical tool to identify whether a subject has reached the legal age of 18 years old, regardless of his or her ethnicity., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The South African Bill of Rights and the Children's Act define a 'child' as a person under the age of 18 years. The age of 18 years is therefore significant for legal purposes in South Africa. The third molar is an important indicator in determining the 18-year threshold. Human biological growth markers are accepted indicators of a subject attaining the age of 18 years. A recent study by Roberts et al. suggested that the relative width of the distal root canals (RCW) of the lower left permanent molars (Fédération Dentaire Internationale notation 36, 37 and 38) as visualised on dental panoramic radiographs can be used as such a growth marker. This study aimed to validate this human biological growth marker in both black and white populations living in South Africa according to Roberts' method. The findings of this validation study were in agreement with this method which showed that individuals with Demirjian stage H left molars and category RCW-C were indeed over the 18-year threshold. Important aspects regarding the rationality and application of Roberts' method are discussed. The authors conclude that this method should not be used in isolation but as an adjunct with other age estimation methods.

It has already been proposed that a combined use of different molecular and morphological markers of aging in multivariate models may result in a greater accuracy of age estimation. However, such an approach can be complex and expensive, and not every combination may be useful. The significance and usefulness of combined analyses of D-aspartic acid in dentine, pentosidine in dentine, DNA methylation in buccal swabs at five genomic regions (PDE4C, RPA2, ELOVL2, DDO, and EDARADD), and third molar mineralization were tested by investigating a sample of 90 oral surgery patients. Machine learning models for age estimation were trained and evaluated, and the contribution of each parameter to multivariate models was tested by assessment of the predictor importance. For models based on D-aspartic acid, pentosidine, and the combination of both, mean absolute errors (MAEs) of 2.93, 3.41, and 2.68 years were calculated, respectively. The additional inclusion of the five DNAm markers did not improve the results. The sole DNAm-based model revealed a MAE of 4.14 years. In individuals under 28 years of age, the combination of the DNAm markers with the third molar mineralization stages reduced the MAE from 3.85 to 2.81 years. Our findings confirm that the combination of parameters in multivariate models may be very useful for age estimation. However, the inclusion of many parameters does not necessarily lead to better results. It is a task for future research to identify the best selection of parameters for the different requirements in forensic practice., (© 2021 The Authors. Journal of Forensic Sciences published by Wiley Periodicals LLC on behalf of American Academy of Forensic Sciences.)

Context: Dental age, one of the indicators of biological age, is inferred by radiological methods. Two of the most commonly used methods are using Demirjian's radiographic stages of permanent teeth excluding the third molar (Demirjian's and Willems' method). The major drawbacks of these methods are that they are based on population-specific conversion tables and may tend to over- or underestimate dental age in other populations. Machine learning (ML) methods make it possible to create complex data schemas more simply while keeping the same annotation system. The objectives of this study are to compare (1) the capacity of ten machine learning algorithms to predict dental age in children using the seven left permanent mandibular teeth compared to reference methods and (2) the capacity of ten machine learning algorithms to predict dental age from childhood to young adulthood using the seven left permanent mandibular teeth and the four third molars., Methods: Using a large radiological database of 3605 orthopantomograms (1734 females and 1871 males) of healthy French patients aged between 2 and 24 years, seven left permanent mandibular teeth and the 4 third molars were assessed using Demirjian's stages. Dental age estimation was then performed using Demirjian's reference method and various ML regression methods. Two analyses were performed: with the 7 left mandibular teeth without third molars for the under 16 age group and with the third molars for the entire study population. The different methods were compared using mean error, mean absolute error, root mean square error as metrics, and the Bland-Altman graph., Results: All ML methods had a mean absolute error (MAE) under 0.811 years. With Demirjian's and Willems' methods, the MAE was 1.107 and 0.927 years, respectively. Except for the Bayesian ridge regression that gives poorer accuracy, there was no statistical difference between all ML tested., Conclusion: Compared to the two reference methods, all the ML methods based on the maturation stages defined by Demirjian were more accurate in estimating dental age. These results support the use of ML algorithms instead of using standard population tables.

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

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., Competing Interests: Declaration of Competing Interest The authors report no declarations of interest., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Age estimation is an important procedure in the forensic practice, especially when it comes to the criminal imputability of juvenile offenders. This study aimed to compare two radiographic methods for dental age estimation in a population of subadults from Northeast Brazil considering their performance on allocating individuals below or above the age threshold of 18 years. A cross-sectional observational study was designed. The sample consisted of 1200 panoramic radiographs of Northeastern Brazilian females (n = 600) and males (n = 600) aged between 16 and 21 years. Dental age estimation was performed using the London Atas technique and Cameriere's third molar maturity index (I 3M ). Statistical tests were performed to assess the sensitivity, specificity and accuracy of the two methods on distinguishing individuals below or above the legal age threshold of 18 years. Considering the total sample, the London Atlas technique reached sensitivity of 92.3%, specificity of 56% and accuracy of 79.9%. I 3M revealed sensitivity of 94.1%, specificity of 55.4% and accuracy of 79.8%. Specificity rates systematically decreased when the sample was progressively stratified based on age groups that narrowed close to 18 years. The methods performed very similar (0.878). The combination of methods did not improve the performance on dental age estimation. The London Atlas and the I 3M methods similarly distinguished Brazilian individuals as minors or not. Their performance, however, was suboptimal because of the low rates of specificity that could negatively influence on Court decisions. In other words, the methods could wrongly classify minors into the age of legal majority (culminating in false positives). In practice, the misleading classification could restrict individual rights (in the civil scenario) or even support more severe penalties (in the criminal scenario)., Competing Interests: Declaration of Competing Interest The authors report no declarations of interest., (Copyright © 2020. Published by Elsevier B.V.)

Third permanent molars (M3s) are the last tooth to form but have not been used to estimate age at dental maturation in early fossil hominins because direct histological evidence for the timing of their growth has been lacking. We investigated an isolated maxillary M3 (SK 835) from the 1.5 to 1.8-million-year-old (Mya) site of Swartkrans, South Africa, attributed to Paranthropus robustus. Tissue proportions of this specimen were assessed using 3D X-ray micro-tomography. Thin ground sections were used to image daily growth increments in enamel and dentine. Transmitted light microscopy and synchrotron X-ray fluorescence imaging revealed fluctuations in Ca concentration that coincide with daily growth increments. We used regional daily secretion rates and Sr marker-lines to reconstruct tooth growth along the enamel/dentine and then cementum/dentine boundaries. Cumulative growth curves for increasing enamel thickness and tooth height and age-of-attainment estimates for fractional stages of tooth formation differed from those in modern humans. These now provide additional means for assessing late maturation in early hominins. M3 formation took ≥ 7 years in SK 835 and completion of the roots would have occurred between 11 and 14 years of age. Estimated age at dental maturation in this fossil hominin compares well with what is known for living great apes.

Staging third molar development is commonly used for age assessment in sub-adults. Current staging techniques are, at most, semi-automated and rely on manual interactions prone to operator variability. The aim of this study was to fully automate the staging process by employing the full potential of deep learning, using convolutional neural networks (CNNs) in every step of the procedure. The dataset used to train the CNNs consisted of 400 panoramic radiographs (OPGs), with 20 OPGs per developmental stage per sex, staged in consensus between three observers. The concepts of transfer learning, using pre-trained CNNs, and data augmentation were used to mitigate the issues when dealing with a limited dataset. In this work, a three-step procedure was proposed and the results were validated using fivefold cross-validation. First, a CNN localized the geometrical center of the lower left third molar, around which a square region of interest (ROI) was extracted. Second, another CNN segmented the third molar within the ROI. Third, a final CNN used both the ROI and the segmentation to classify the third molar into its developmental stage. The geometrical center of the third molar was found with an average Euclidean distance of 63 pixels. Third molars were segmented with an average Dice score of 93%. Finally, the developmental stages were classified with an accuracy of 54%, a mean absolute error of 0.69 stages, and a linear weighted Cohen's kappa coefficient of 0.79. The entire automated workflow on average took 2.72 s to compute, which is substantially faster than manual staging starting from the OPG. Taking into account the limited dataset size, this pilot study shows that the proposed fully automated approach shows promising results compared with manual staging.

In China, forensic age estimation in the living has become increasingly important in these few years. Due to increasing juvenile crimes, the age of 16 years has become the legal age threshold for determining whether the juvenile criminal law or adult criminal law applies to the citizen. This study aimed to assess new cut-off values of the third molar maturity index (I 3M ) and second molar maturity index (I 2M ) at the legal age threshold of 16 years in Southern Chinese population and then to compare the applicability of the cut-off values of I 3M and I 2M we set for discriminating whether a subject is ≥ 16 years. Orthopantomograms (OPGs) of 671 healthy Southern Chinese subjects (332 males and 339 females), aged between 10 and 20 years, were studied. Logistic regression analysis was performed with chronological age (below 16 years and over 16 years) as a dichotomous dependent variable and, I 3M , I 2M , and sex as predictive variables. The high p-value for sex (p = 0.861) reveals that this factor was not statistically significant in assessing the legal age of 16. The cut-off values of I 3M  < 0.38 and I 2M  < 0.03 were identified and used to distinguish between individuals who were or were not aged ≥ 16 years. Compared with a single predictor (I 3M ) alone, combining I 3M and I 2M can be more reliable for determining whether an individual is aged more than 16 years. We found that accuracy was 88.52% (95% confidence interval CI, 86.11-90.94%) and sensitivity and specificity were 77.96% (95% CI, 74.82-81.10%) and 97.28% (95% CI, 96.04-98.51%), respectively. The estimated Bayes post-test probability was 99.12% (95% CI, 98.41-99.83%). In conclusion, combining I 3M and I 2M may be useful in legal and forensic practices to determine the legal age of 16 years in Southern Chinese individuals., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Purpose: This study investigated the third molar mineralization in patients with cleft lip and palate. Materials and methods: From a total of 253 digital panoramic radiographs from patients with cleft lip and palate within the age range of 7-21 years, 97 radiographs were selected (cleft group). A control group was formed from same sex individuals, without malformation and chronological age matched within 30 days. The analysis of third molar mineralization was carried out by three calibrated examiners using Demirjian's and Nolla's methods. McNemar and Wilcoxon test for paired samples were used for pairwise comparisons between the groups. The Likelihood Ratio test was used to check for an association between the type of cleft and tooth calcification. Results: In both methods, the mineralization means were smaller in the case group than in the control, with significant differences for all third molars ( p  < .05). The type of cleft affected dental mineralization. There was no significant difference when comparing the left or right sides, but maxillary molars showed earlier mineralization. Conclusions: A significant delay in third molar mineralization was observed in patients with cleft lip and palate according to Demirjian's and Nolla's methods.

Objectives: This study was carried out to correlate chronological age of the patients with dental age using to Demirjian's method and to evaluate if orthopantamogram examination of third molar development correlates with age estimation., Study Design: The study was designed as a radiological cross sectional study. Simple random sampling method was used to obtain study subjects., Methods: Total of 231 patients between the age group of 10 to 25 years, visiting the Department of Oral Medicine and Radiology were selected. The digital orthopantomogram was obtained for these patients., Results: Our data showed that, in the maxilla, the stages of tooth developments A to E were reached earlier in men than in women, whereas stages F to H were reached earlier in women than men. In mandible stages B, C, E to F were reached earlier in men than women, whereas stages A and D were reached earlier by the female counterparts. There was a statistically significant difference noted between right and left third molar teeth in all the stages of tooth development., Conclusions: Our study showed that between the sexes in maxilla, men reached stages A to E earlier than women, whereas for stages F to H, women reached the stage earlier than men. For mandible, all stages except stage D were reached earlier by male subjects than female subjects. Our study showed that the third molar development can be affected positively by the chronological age of the patient, being developed either in maxilla or mandible, right or left side.

Staging third molar development is commonly used for age estimation in subadults. Automated developmental stage allocation to the mandibular left third molar in panoramic radiographs has been examined in a pilot study. This method used an AlexNet Deep Convolutional Neural Network (CNN) approach to stage lower left third molars, which had been selected by manually drawn bounding boxes around them. This method (bounding box AlexNet = BA) still contained parts of surrounding structures which may have affected the automated stage allocation performance. We hypothesize that segmenting only the third molar could further improve the automated stage allocation performance. Therefore, the current study aimed to determine and validate the effect of lower third molar segmentations on automated tooth development staging. Retrospectively, 400 panoramic radiographs were collected, processed and segmented in three ways: bounding box (BB), rough (RS), and full (FS) tooth segmentation. A DenseNet201 CNN was used for automated stage allocation. Automated staging results were compared with reference stages - allocated by human observers - overall and per stage. FS rendered the best results with a stage allocation accuracy of 0.61, a mean absolute difference of 0.53 stages and a Cohen's linear κ of 0.84. Misallocated stages were mostly neighboring stages, and DenseNet201 rendered better results than AlexNet by increasing the percentage of correctly allocated stages by 3% (BA compared to BB). FS increased the percentage of correctly allocated stages by 7% compared to BB. In conclusion, full tooth segmentation and a DenseNet CNN optimize automated dental stage allocation for age estimation., (© 2019 American Academy of Forensic Sciences.)

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.

Introduction: Age assessment based on dental development is often requested in order to assess whether an individual is older or younger than 18 years of age. There are several statistical approaches to estimate age based upon third molar development. The aim of this study was to apply the principles of transition analysis (TA) to a Danish reference material and to evaluate whether it was indicated to include a model that allows for logistic non-linearity as opposed to applying a model only allowing for logistic linearity. For this we chose to use the generalized additive model (gam) and the generalized linear model (glm), respectively., Material and Method: A cross-sectional sample comprising 1302 panoramic radiographs of Danish subjects in the chronological age range of 13-25 years was included. All present third molars had been scored according to the 10-stage method of Gleiser and Hunt. Each transition from one stage to the subsequent stage was analyzed according to the statistical approach of TA and fitted with both the generalized linear model (glm) and the generalized additive model (gam). In order to assess whether gam or glm was more parsimonious for each transition individually, the Akaikon information criterion (AIC) was applied., Results: The results emphasized the importance of applying a statistical model that sufficiently captures the spread of the age estimate. The AIC values showed that some transitions were sufficiently described by glm whereas for others the gam curves fitted significantly better., Conclusion: We recommend that for an age assessment tool based on TA, both a fitting allowing for non-linearity and one allowing only for linearity should be included., (Copyright © 2020 Elsevier B.V. All rights reserved.)

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., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The purpose of the present study was to test whether a new stage classification based on radiographic visibility of the periodontal ligament in lower third molars in a Chinese population can be used for the 18- and 21-year thresholds. A total of 1300 orthopantomograms, including equal numbers of northern Chinese males and females evenly distributed between the ages of 15 and 40 years, were analyzed. The stages were defined according to the visibility of periodontal ligament for the outer parts of lower third molar roots because the visibility status of the periodontal ligament between the roots of lower third molars is none valuable in many Chinese individuals. Stage 0 was first achieved at the age of 17.05 years in males and 17.46 years in females. The earliest appearance of stage 1 was 17.47 years in males and 17.86 years in females. Stage 2 was first observed in males at the age of 21.43 years and in females at the age of 21.96 years. The onset of stage 3 was first observed at the age of 25.83 years in males and 23.14 years in females. Compared with the stage classification of Olze et al., which also considers the mesial parts of the roots, the number of assessable cases could be significantly increased. Therefore, our novel approach is effective for age estimation in the Chinese population.

Introduction: The determination of age of majority (the 18-year-old threshold) using the popular Demirjian tooth staging method is unreliable, so other maturity markers are required. This study examines whether the Root Pulp Visibility (RPV) of the mandibular third molar is a useful indicator of age., Methods: One thousand six dental panoramic radiographs (DPTs) were examined and the left mandibular third molar assessed according to the RPV stages using the method of Olze et al. (Int J Legal Med 124:183-186, 2010) as modified by Lucas et al. (Forensic Sci Int 270:98-102, 2017). Six hundred sixty-two DPTs, 288 males and 374 females, satisfied the inclusion criteria., Results: Individuals who had reached stages RPV-A and RPV-B were represented in a wide range of ages spanning the 18-year-old threshold. Individuals who had reached stages RPV-C and RPV-D were all above the 18-year-old threshold. It was not possible to analyse a large number of DPTs for various reasons., Discussion: Individuals whose mandibular third molar exhibited stages RPV-C and RPV-D may be deemed to have reached the age of majority. These results are consistent with other published studies. Variation in the rate of development of the third molar limits the applicability of this method., Conclusions: RPV staging is an accurate method of determining the 18-year-old threshold. Substitute methods are required in a large number of cases.

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., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Ethical and safety issues have rendered mesenchymal stem cells (MSCs) popular candidates in regenerative medicine, but their therapeutic capacity is lower than that of induced pluripotent stem cells (iPSCs). This study compared original, dental tissue-derived MSCs with re-differentiated MSCs from iPSCs (iPS-MSCs). CD marker expression in iPS-MSCs was similar to original MSCs. iPS-MSCs expressed higher in pluripotent genes, but lower levels in mesodermal genes than MSCs. In addition, iPS-MSCs did not form teratomas. All iPSCs carried mtDNA mutations; some shared with original MSCs and others not previously detected therein. Shared mutations were synonymous, while novel mutations were non-synonymous or located on RNA-encoding genes. iPS-MSCs also harbored mtDNA mutations transmitted from iPSCs. Selected iPS-MSCs displayed lower mitochondrial respiration than original MSCs. In conclusion, screening for mtDNA mutations in iPSC lines for iPS-MSCs can identify mutation-free cell lines for therapeutic applications. [BMB Reports 2019; 52(12): 689-694].

The estimation of the age of majority is crucial to determine the legal accountability of an individual. With this purpose, the analysis of the dental development process has proven to be an effective, elucidatory method. This study investigated the applicability of the Third Molar Maturation Index (I 3M ), proposed by Cameriere et al. (2008), to estimate the age of majority in a sample of Northeastern Brazilians using panoramic radiographs. Adobe® Photoshop® CS4 (Adobe Systems Incorporated, San Jose, California, USA) software was used to obtain the I 3M index measurements in a sample of radiographs from a dental radiology clinic located in Northeastern Brazil. Radiographs of individuals aged between 14 and 23 years were included in the sample, except if showing absence, distortions, pathological alterations or suspected pulp impairment of the tooth #38 (third lower left molar), as the method applies exclusively to this element. Of the total sample of radiographs previously obtained for diagnostic and/or orthodontic purposes (n=394), 185 were from males and 209 from females, of which 217 corresponded to 18 year-olds or older and 177 were from minors. Logistic regression and predictive values of sensitivity, specificity and Receiver Operating Characteristic (ROC) curve (α=0.05) were used. The cutoff point originally proposed for the I 3M index (0.08) presented a sensitivity of 88.4% and a specificity of 73.2%, with accuracy (area under the ROC curve) of 80.8% (95%CI: 76.4-85.3%) for the Northeastern Brazilian population, as well as a correct age classification in 80.2% of the sample. The method estimated accurately 73.7% of the cases corresponding to "18 years or older" and 88.1% of the cases "under 18years" (p=0.000). Among the sexes, the correct age classification rate of the method was 84.3% for males and 76.6% for females, with no statistically significant difference between the match and error rates and between the sexes (p≥0.05). In conclusion, the Third Molar Maturation Index could accurately distinguish the age of adolescents and young adults of both sexes aged 18 years or under/older in a Brazilian population., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The main criterion of dental age assessment in living adolescents and young adults is the evaluation of third molars' mineralization. Concerning forensic age assessment after the completion of third molars' mineralization, apposition of secondary dentine and narrowing of the periodontal membrane as seen as decreasing radiolucent areas in the radiographs for mandibular third molars have already been described as regressive features. The present study examines the combination of both these features for the purpose of age assessment in regression analyses after rescaling the data to make it on the interval scale. To this end, a total of 1245 orthopantomograms was evaluated, taken from 606 females and 639 males in the age group of 15-40 years. The apposition of secondary dentine and narrowing of the periodontal membrane as seen as decreasing radiolucent areas in the radiographs were determined for the lower third molars. The correlation of the features with the chronological age was assessed by means of rescaled regression analyses. Furthermore, regression formulas for age assessment were established. The values of the standard error of estimate ranged between 3.55 and 4.52 years. In general, the rescaled regression of the examined features appears to be suited for forensic age assessment. A limitation of the present study is the comparatively low number of evaluable teeth in the examined age group. Due to an incomplete development or a lack of the mandibular third molars, only a mere half of the respective teeth could be included in the statistical analysis.

Introduction: The multifactorial aetiology of third molar (M3) impaction remains puzzling. While short retromolar jaw space is a well-established risk factor in young adults, space alone does not explain how impaction develops. Here we investigated in children and adolescents a potential new factor, delayed M3 development. We hypothesized that two important impaction correlates - lack of jaw space, and delayed M3 development - are also positively correlated with each other, and may together help suggest from early ages subsequent possible M3 impaction., Material and Methods: We studied 689 M3 regions on retrospective CBCT images of 179 Canadian patients aged 8-13 years, using multiple linear mixed-effects (LME) modeling to predict M3 development (using Demirjian's stages) in both upper and lower jaws based upon available distal jaw space while also accounting for age, sex, jaw, and oral quadrant., Results: Lack of distal jaw space was associated with less-developed M3s in upper and lower jaws (t = 3.209, p = .001). If space availability fell below a given threshold, absence of M3 development was predicted. Upper M3s developed more than lower M3s for each additional millimetre of retro-M1 space gained. Between-sex differences were not found., Conclusion: Retromolar jaw space and M3 development are two positive correlates of M3 impaction that co-associate as early as childhood. Our results suggest that delayed initial M3 development merits investigation as a potential prognosticator for late M3 eruption relative to when jaw growth ceases - an outcome known to increase the likelihood of impaction., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

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.

Three-dimensional imaging has improved the method of analysis in many forensic science investigations. The study aimed to derive regression equation for age estimation by investigating the relationship between chronological age and surface area of the developing mandibular 3rd molars apices. Furthermore, other predictor variables: ethnicity (Malay and Chinese), gender and status of the root development completion (open/closed apices) were also investigated in terms of fit to the age estimation model. One hundred and twenty eight training and 55 validation samples of intact mandibular 3rd molars were selected from 183 CBCT scans. The samples comprised of 93 Malays and 90 Chinese, ranging in age from 13 to 24 years. Three-dimensional image modeling and surface area analysis of the developing mandibular 3rd molars apices were performed using Mimics and 3-Matics software. Multiple linear regression analysis was used to derive age estimation model using chronological age as a dependent variable and surface area of the apices, ethnicity, gender and status of the root development completion (open/closed apices) as predictor variables. A strong inverse correlation (r = 0.95, SD = 1.144) was observed between chronological age and all the predictor variables. The results showed that 89.6% of the variation in age can be explained by the predictor variables. Mean absolute error (MAE) value of 0.8223 was observed when the derived regression equation was tested on the independent validation sample. In conclusion, three-dimensional surface area analysis of the developing mandibular 3rd molars apices can be used as a reliable method for age estimation., (Copyright © 2019 Elsevier B.V. All rights reserved.)

This paper concerns a method to estimate age in children using third molar maturity index (I 3 M) as independent variable and age as the dependent variable. Total of 1283 digital orthopantomograms (OPTs) of south Indian children aged between 7 and 22 years was included. Training sample of 933 OPTs was used to derive regression formulae, and validation sample of 350 OPTs used to verify accuracy of newly derived regression models. Regression analysis performed revealed that cubic function gave the best correlation between the studied variables. The models exhibited a high correlation coefficient for third molar development in both sexes (0.81 for boys and 0.84 for girls). When new models were verified, slight overestimation of dental age i.e., 0.2 years in boys and 0.13 years in girls was observed. Therefore, we conclude by recommending newly derived regression models as they provided better age predicting performances., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Providing appropriate legal mechanisms, that evaluate the progression of development from the age of childhood innocence to maturity and full responsibility, considered one of the difficult areas of criminal justice policy. The minimum age of criminal responsibility (MACR) in children varies among countries and differs widely owing to history and culture. Due to rising and brutality of criminal offenses, particularly by juveniles, few countries have lowered the minimum age of criminal responsibility, and many have considered/considering to do the same. India is one such country in which is under the proposal of lowering the age of criminal responsibility to 16 years. As there is lack of useful age assessment methods, that can indicate whether if the individual in question is younger (<16 years) or older than MACR (≥16 years), the present study was undertaken to derive a specific cut-off value of the third molar maturity index (I 3M ) for this purpose. The sample consisted of 1078 orthopantomograms (OPTs) from Andhra Pradesh, India, aged between 11 and 20 years (45.4% males and 54.6% females). The reproducibility of I 3M was calculated by intra-class correlation coefficients, which showed an intra-rater and inter-rater agreement of 0.912 and 0.891, respectively. The sample was divided into training dataset (819 OPTs), to test I 3M and gender as independent variables and MACR as a dependent variable by logistic regression analysis, and test dataset (259 OPTs). A receiver operating curve (ROC) analysis was performed to evaluate the specific cut-off value of I 3M for predicting MACR status. A logistic regression analysis showed that gender was not statistically significant for predicting MACR status while ROC analysis indicated a cut-off value of I 3M  = 0.293 as best for predicting MACR status. The performance of derived cut-off value was tested in a test data set. The sensitivity of the test was 90.6% and 90%, while specificity was 86% and 87.1% in males and females, respectively. The proportion of correctly classified individuals was 88.0% and 88.7% in males and females, respectively. The estimated Bayes post-test probability in males was 87.2% and while in females it was 88.3%. The results highlight the contribution of the derived cut-off value of I3M for discriminating individuals around MACR and should be evaluated in other populations., (Copyright © 2019 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.)

Aims: To evaluate the cut-off value of third molar maturity index (I 3M ) = 0.08 for discriminating minors from adults in Japanese population., Material and Methods: 276 panoramic radiographs of healthy Japanese subjects (139 girls and 137 boys) age range from 14 to 24 years were evaluated., Results: ICC (Intra-class correlation coefficient) for intra-rater and inter-rater agreement of I 3M was 99.6% (95% CI 98.6-99.9%) and 98.9% (95% CI 98.8-99.9%) respectively. The proportion of correctly classified in girls was 87% (95% CI 81-93%) and in boys was 91% (95% CI 87-96%). The sensitivity of the test in girls and boys was 84% (95% CI 77-92%) and 89% (95% CI 83-95%) respectively and specificity was 93% (95% CI 85-100%) and 96% (95% CI 90-100%) in girls and in boys. The PPV (Positive Predictive Value) was 87% (95% CI 69-95%) in girls and 92% (95% CI 74-98%) in boys., Conclusion: The results of the study show that I 3M is capable of discriminating adults and minors in subjects around legal age of 18 years old in Japanese population., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The completion of the third molar roots has played an important role in ascertaining whether individuals may be at or over a legal threshold of age, often taken as 18 years. This study demonstrates that root apex completion in the third molar is relatively uninformative regarding the threshold of age 18 years in a sample of 1184 males, where mean age-of-attainment of root apex completion for third mandibular molars is about 19.4 years. This paper also considers the legal age threshold problem for cases where the third mandibular molar is not completely formed, and outlines the use of parametric models and Bayes' factors to evaluate dental evidence in statistically appropriate ways. It attempts to resolve confusion over age-within-stage versus age-of-attainment, likelihood ratios versus other diagnostic tests, and prior odds for a case versus the prior density for an age distribution., (© 2018 American Academy of Forensic Sciences.)

Forensic age estimation has recently become an important topic due to a steady increase of cross border migration. Dental age assessment is one pillar of the forensic age estimation in living persons. Currently it is done by evaluating an orthopantomogram, which is generated using ionizing radiation. Nevertheless, the use of X-ray without medical indication is ethically questionable. Therefore, the aim of the study was to provide reference values for dental MRI to have an alternative radiation-free method for the assessment of dental age. In this cross-sectional study, 316 adolescent, male individuals were investigated. Two dentists evaluated the stage of mineralization and eruption of the third molars of the upper and lower jaws, according to the staging systems established by Demirjian and Olze. Following data analysis and the creation of reference tables, the likelihood ratios to be over specific age limits were calculated. In the mineralization evaluation mainly stages D-H were seen (range A-H); regarding eruption, all four stages (A-D) appeared. A significant difference between the teeth was only found for eruption stage A. However, the evaluation of participants who had all four third molars, showed partly different stages for the individual teeth as well for mineralization as for the eruption. Therefore, it seems to be important to include all available teeth in the age estimation. The likelihood ratios showed about 99% probability to be 18 years or older for stage H (mineralization), but only about 93% for stage D (eruption). In summary, it can be concluded that dental MRI holds promise as an alternative to conventional orthopantomogram based age assessment., (Copyright © 2019 Elsevier B.V. All rights reserved.)

During 2014-2015, Sweden received asylum applications from more than 240,000 people, of which more than 40,000 were termed unaccompanied minors. In a large number of cases, claims by asylum seekers of being below 18 years were not trusted by Swedish authorities. To handle the situation, the Swedish national board of forensic medicine (Rättsmedicinalverket, RMV) was assigned by the government to create a centralized system for medical age assessments. RMV introduced a procedure including two biological age indicators; x-ray of the third molars and magnetic resonance imaging of the distal femoral epiphysis. In 2017, a total of 9617 males and 337 females were subjected to this procedure. No validation study for the procedure was however published, and the observed number of cases with different maturity combinations in teeth and femur were unexpected given the claims originally made by RMV. We present a general stochastic model enabling us to study which combinations of age indicator model parameters and age population profiles are consistent with the observed 2017 data for males. We find that, contrary to some RMV claims, maturity of the femur, as observed by RMV, appears on average well before maturity of teeth. According to our estimates, approximately 15% of the tested males were children. These children had an approximate 33% risk of being classified as adults. The corresponding risk for an adult to be misclassified as a child was approximately 7%. We determine uncertainties and ranges of estimates under reasonable perturbations of the prior.

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.

Purpose: To compare the Ghent and Graz magnetic resonance imaging (MRI) protocols for third molars, focusing on the assessment of apical closure. To study the influence of (1) voxel size and (2) head fixation using a bite bar. To compare both protocols with a ground truth of apical development., Materials and Methods: In 11 healthy volunteers, 3T MRI was conducted, including four Ghent sequences and two Graz sequences, with and without bite bar. After removal, 39 third molars were scanned with 7T μMRI and μCT to establish the ground truth of apical development. Three observers in consensus evaluated assessability and allocated developmental stages., Results: The Ghent T2 FSE sequence (0.33 × 0.33 × 2 mm 3 ) was more assessable than the Graz T1 3D FSE sequence (0.59 × 0.59 × 1 mm 3 ). Comparing assessability in both sequences with bite bar rendered P = 0.02, whereas comparing those without bite bar rendered P < 0.001. Within the same sequence, the bite bar increased assessability, with P = 0.03 for the Ghent T2 FSE and P = 0.07 for the Graz T1 3D FSE. Considering μCT as ground truth for staging, allocated stages on MRI were most frequently equal or higher. Among in vivo protocols, the allocated stages did not differ significantly., Conclusion: Imaging modality-specific and MRI sequence-specific reference data are needed in age estimation. A higher in-plane resolution and a bite bar increase assessability of apical closure, whereas they do not affect stage allocation of assessable apices.

Objective: To assess the genetic and environmental influences on the variability of human third molar (M3) root mineralization stages via a twin study., Design: The study sample consisted of 162 same-sex twins (66 dizygotic and 96 monozygotic, mean age: 17.9 years) with normal growth and development. Panoramic radiographs were evaluated to assess root mineralization stages of the upper and lower third molars, using the method of Demirijian et al. (1973). Zygosity was established using 15 specific DNA markers., Results: Females developed their third molar roots earlier in life than males. Monozygotic twins (MZ) demonstrated higher intra-pair correlations for M3 root development stages than did DZ twins. An ACE model with additive genes, as well as common and specific environmental factors, provided the best explanation of variation in M3 root development. The mineralization of M3 roots showed highly additive genetic determination, varying from 60 to 63%, whereas a common environment contributed from 25 to 27%, and a specific environment only accounted 14% of the total variation, at most., Conclusions: A considerable proportion of the total variability of the third molar root mineralization rate can be attributed to additive genetic effects, while common and specific environmental effects have a smaller, yet significant, impact., (Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Objective: To analyse the accuracy of a meta-analysis-based dental age assessment (DAA) method in Finnish paediatric patients and to compare the dental development between two generations of Finnish children., Methods: Panoramic radiographs of Finnish Caucasian healthy children from two generations (early: born 1981-1984; subsequent: born 1996-2008) were analysed. All developing teeth on the left maxilla and mandible as well as the third permanent molars were analysed following Demirjian's classification. For each patient, dental age was calculated and compared with chronological age. Dental maturation patterns between the two groups were compared., Results: The study included 200 Finnish Caucasian healthy children from two generations (early: aged 7-13 years; subsequent: aged 6-15 years). In the early generation, DAA underestimated the chronological age by a mean of 3.15 years. The underestimation was only 0.11 years in patients < 10 years, but 3.86 years in patients ≥ 10 years. In the subsequent generation, the dental age was overestimated by a mean of 0.34 years; by 0.40 years in patients < 10 years and by 0.08 years in patients ≥ 10 years., Conclusions: The present DAA method is applicable to current Finnish children. Differences in dental development between two generations of Finnish children were detected.

Third molar development and eruption are two related areas of major interest in dental research into the etiology of "wisdom tooth" impaction. Third molars are not only an excellent model for studying dental development but also of fundamental clinical importance because they are very frequently impacted. Because the third molar is located in the distal-most region of the oral cavity, clinical access is relatively challenging. With the increasingly widespread use of cone-beam computed tomography (CBCT) in dentistry, studies and measurements of the third molar and its eruption area have become considerably easier to do. Here we present a novel CBCT-based measurement methodology we developed for our recent investigations that we hope will also be useful for the broader dental research community.

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., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Aim: This study examines the open apices of third molars indiscriminating between individuals who are or are not 18 years of age or older and to assign a cut-off for estimation of the age of 18 years. Furthermore, this method was compared to those based on Demirjian's stages 8 and 9., Methodology: Orthopantomographs (OPGs) of 1062 individuals (14 and 23 years) were assessed, to verify Cameriere's third molar maturity index (I3M). The apical ends of the roots of the left mandibular third molar were analysed. Mineralization of the third molar was also evaluated., Results: A cut-off value of I3M =0.08 was taken. The sensitivity of this test was 70.76% and specificity was 82%. The results of the test showed a better specificity for Stage 9 and better sensitivity for stage 8 for adult age. Accuracy was 74.58% for third molar maturity index as compared to 72.41% for stage 9.