Applicability of Cameriere's third molar maturity index on orthopantomograms and computed tomography scans from a French population

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.

Third molar eruption in dental panoramic radiographs as a feature for forensic age assessment - new reference data from a German population

Forensic age assessment in the living can provide legal certainty when an individual's chronological age is unknown or when age-related information is questionable. An established method involves assessing the eruption of mandibular third molars through dental panoramic radiographs (PAN). In age assessment procedures, the respective findings are compared to reference data. The objective of this study was to generate new reference data in line with the required standards for mandibular third molar eruption within a German population. For this purpose, 605 PANs from 302 females and 303 males aged 15.04 to 25.99 years were examined. The PANs were acquired between 2013 and 2020, and the development of the mandibular third molars was rated independently by two experienced examiners using the Olze et al. staging scale from 2012. In case of disagreement in the assigned ratings, a consensus was reached through arbitration. While the mean, median and minimum ages were observed to increase with each stage of mandibular third molar eruption according to the Olze method, there was considerable overlap in the distribution of age between the stages. The minimum age for stage D, which corresponds to complete tooth eruption, was 16.1 years for females and 17.1 years for males. Thus, the completion of mandibular third molar eruption was found in both sexes before reaching the age of 18. In all individuals who had at least one tooth with completed eruption and who were younger than 17.4 years of age (n = 10), mineralization of the teeth in question was not complete. Based on our findings, the feature of assessing mandibular third molar eruption in PAN cannot be relied upon for determining age of majority.

Skeletal maturation evaluation: which is the reliability of dental calcification Demirjian method versus hand-wrist X-ray in growing subjects? A systematic review

OBJECTIVES

This systematic review aimed at evaluating the reliability of dental maturation (DM) according to Demirjian method compared to hand and wrist maturation (HWM) to assess skeletal maturity (SM) in growing subjects, to identify the teeth and the corresponding mineralisation stages related to the pubertal growth spurt (PGS).

MATERIALS AND METHODS

PubMed, Scopus, and Web of Science were systematically searched until January 5th, 2024, to identify observational cross-sectional studies that assessed the reliability of Demirjian method compared to the HWM methods (i.e., Grave and Brown and Fishman) in growing subjects. The quality assessment was evaluated using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist.

RESULTS

Out of 136 papers suitable for title/abstract screening, 19 included studies. Of them, 17 papers showed the reliability of Demirjian DM method compared to HWM Fishman and Grave and Brown methods to assess SM in growing subjects. According to JBI Critical Appraisal Checklist, 12 papers were high-quality studies and 7 papers were medium-quality studies.  Conclusions: The mandibular second molar might be considered as the best indicator compared to other teeth and that the peak of growth occurs no earlier than stage F in females and stage G in males according to Demirjian method. Also, the mandibular canine might be analysed as indicator of SM in males, and results suggest that the peak of growth occurs no earlier than maturation stage F according to Demirjian method, only in male subjects. Further studies are needed to confirm these findings.

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.

Individual dental and skeletal age assessment according to Demirjian and Baccetti: Updated norm values for Central-European patients

PURPOSE

Chronological age often differs from dental and skeletal age. With orthopantomograms and lateral cephalograms, dental and skeletal development can be determined according to the methods published by Demirjian et al. and Baccetti et al. However, gender and skeletal class as possible confounders were frequently not considered and available norm values are not up-to-date. This retrospective cross-sectional study thus aimed to evaluate effects of skeletal class and gender on dental and skeletal age of growing patients and to generate updated norm values for contemporary Central-European patients.

METHODS

A total of 551 patients were included in the dental and 733 in the skeletal age assessment, respectively. Dental analysis was based on tooth mineralisation stages in orthopantomograms (Demirjian) and skeletal age was defined by cervical vertebrae maturation stages (CVMS) in lateral cephalograms (Baccetti). Skeletal class was determined by the individualised ANB angle of Panagiotidis/Witt. With nonlinear regression analysis a formula for determining dental age was established. Effects of gender and skeletal class were evaluated and updated norm values generated.

RESULTS

Inter- and intrarater reliability tests revealed at least substantial measurement concordance for tooth mineralisation and CVMS. Demirjian stages and CVMS significantly depended on gender with girls developing earlier. Skeletal class significantly affected skeletal age only, but without clinical relevance. Updated norm values for dental age differed significantly from the original values of Demirjian and the values for skeletal age differed from those published by Baccetti.

CONCLUSION

Optimised norms, separated by gender, increase precision in determining individual dental and skeletal age during orthodontic treatment planning. Further studies analysing the effect of skeletal class on dental and skeletal development are needed.

OPG-based dental age estimation using a data-technical exploration of deep learning techniques

Dental age estimation, a cornerstone in forensic age assessment, has been extensively tried and tested, yet manual methods are impeded by tedium and interobserver variability. Automated approaches using deep transfer learning encounter challenges like data scarcity, suboptimal training, and fine-tuning complexities, necessitating robust training methods. This study explores the impact of convolutional neural network hyperparameters, model complexity, training batch size, and sample quantity on age estimation. EfficientNet-B4, DenseNet-201, and MobileNet V3 models underwent cross-validation on a dataset of 3896 orthopantomograms (OPGs) with batch sizes escalating from 10 to 160 in a doubling progression, as well as random subsets of this training dataset. Results demonstrate the EfficientNet-B4 model, trained on the complete dataset with a batch size of 160, as the top performer with a mean absolute error of 0.562 years on the test set, notably surpassing the MAE of 1.01 at a batch size of 10. Increasing batch size consistently improved performance for EfficientNet-B4 and DenseNet-201, whereas MobileNet V3 performance peaked at batch size 40. Similar trends emerged in training with reduced sample sizes, though they were outperformed by the complete models. This underscores the critical role of hyperparameter optimization in adopting deep learning for age estimation from complete OPGs. The findings not only highlight the nuanced interplay of hyperparameters and performance but also underscore the potential for accurate age estimation models through optimization. This study contributes to advancing the application of deep learning in forensic age estimation, emphasizing the significance of tailored training methodologies for optimal outcomes.

Considerations for age estimation accuracy: Method-derived outcomes and practitioner interpretations

Recent research observed 92% accuracy for age-at-death estimations by U.S. forensic anthropologists. The present study compares this case report level accuracy to method level accuracy for the most commonly used methods in U.S. casework, drawing from the Forensic Anthropology Database for Assessing Methods Accuracy (FADAMA). Method application rate (i.e., how often a method is used in casework) was analyzed for n = 641 cases and identified 15 methods with an application rate >45 cases, and the present study focused further analyses on these 15 methods. Of the 15, only four yielded accuracies greater than or equal to the 92% documented for case-report level accuracy. The other 11 methods produced accuracy rates ranging from 54% to 91%, with six of these below 70% This disconnect between highly accurate age estimations at the case report level compared to the poor performance at method level suggests that practitioner interpretation and synthesis of the methods' outcomes is a critical step for increasing the accuracy rates of the age estimations as reported on the final case report. This inference was further supported by the study's results which indicated that practitioner interpretations of frequently used method combinations improve accuracy and age range width of age estimation. The study also performed a Fisher's Exact test to assess whether case report-level accuracy differed with the number of aging methods used in a case, and found no significant differences.

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.

Does third molar agenesis influence the second lower molar mineralization?

Different studies have established that the mineralization stages of the second mandibular molar can be used in forensic age estimation. Nowadays, the estimate's accuracy is an ethical concern, producing as few false positives (individuals incorrectly classified as older than a determined threshold) and false negatives (individuals incorrectly classified as younger than a determined threshold) as possible. Some have hypothesized that changes in teeth number may influence tooth mineralization, altering the age estimate process. This paper analyzes whether third molar agenesis affects the second mandibular molar mineralization time frame. To do so, 355 orthopantomograms were evaluated for third molar agenesis, and the second mandibular molar mineralization stage was assessed using the Demirjian stages. Student's t-test was used to compare the difference in the mean age at which the various stages of 37 mineralization were reached in the groups with and without third molar agenesis. The level of statistical significance was set at 5%. The results pointed to a delay in second mandibular molar mineralization in the case of agenesis, suggesting the need to consider this when estimating age using dental techniques.

Machine learning assisted 5-part tooth segmentation method for CBCT-based dental age estimation in adults

BACKGROUND

The utilization of segmentation method using volumetric data in adults dental age estimation (DAE) from cone-beam computed tomography (CBCT) was further expanded by using current 5-Part Tooth Segmentation (SG) method. Additionally, supervised machine learning modelling -namely support vector regression (SVR) with linear and polynomial kernel, and regression tree - was tested and compared with the multiple linear regression model.

MATERIAL AND METHODS

CBCT scans from 99 patients aged between 20 to 59.99 was collected. Eighty eligible teeth including maxillary canine, lateral incisor, and central incisor were used in this study. Enamel to dentine volume ratio, pulp to dentine volume ratio, lower tooth volume ratio, and sex was utilized as independent variable to predict chronological age.

RESULTS

No multicollinearity was detected in the models. The best performing model comes from maxillary lateral incisor using SVR with polynomial kernel ( = 0.73). The lowest error rate achieved by the model was given also by maxillary lateral incisor, with 4.86 years of mean average error and 6.05 years of root means squared error. However, demands a complex approach to segment the enamel volume in the crown section and a lengthier labour time of 45 minutes per tooth.

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Fully automated deep learning approach to dental development assessment in panoramic radiographs

BACKGROUND

Dental development assessment is an important factor in dental age estimation and dental maturity evaluation. This study aimed to develop and evaluate the performance of an automated dental development staging system based on Demirjian's method using deep learning.

METHODS

The study included 5133 anonymous panoramic radiographs obtained from the Department of Pediatric Dentistry database at Seoul National University Dental Hospital between 2020 and 2021. The proposed methodology involves a three-step procedure for dental staging: detection, segmentation, and classification. The panoramic data were randomly divided into training and validating sets (8:2), and YOLOv5, U-Net, and EfficientNet were trained and employed for each stage. The models' performance, along with the Grad-CAM analysis of EfficientNet, was evaluated.

RESULTS

The mean average precision (mAP) was 0.995 for detection, and the segmentation achieved an accuracy of 0.978. The classification performance showed F1 scores of 69.23, 80.67, 84.97, and 90.81 for the Incisor, Canine, Premolar, and Molar models, respectively. In the Grad-CAM analysis, the classification model focused on the apical portion of the developing tooth, a crucial feature for staging according to Demirjian's method.

CONCLUSIONS

These results indicate that the proposed deep learning approach for automated dental staging can serve as a supportive tool for dentists, facilitating rapid and objective dental age estimation and dental maturity evaluation.

Dental age estimation: A comparative study of convolutional neural network and Demirjian's method

The aim of this study is to compare a technique using Convolutional Neural Network (CNN) with the Demirjian's method for chronological age estimation of living individuals based on tooth age from panoramic radiographs. This research used 5898 panoramic X-ray images collected for diagnostic from pediatric patients aged 4-17 who sought treatment at Antalya Oral and Dental Health Hospital between 2015 and 2020. The Demirjian's method's grading was executed by researchers who possessed appropriate training and experience. In the CNN method, various CNN architectures including Alexnet, VGG16, ResNet152, DenseNet201, InceptionV3, Xception, NASNetLarge, InceptionResNetV2, and MobieNetV2 have been evaluated. Densenet201 exhibited the lowest MAE value of 0.73 years, emphasizing its superior accuracy in age estimation compared to other architectures. In most age categories, the predicted age closely matches the actual age. The most inconsistent results are observed at ages 12 and 13. The results highlight correspondence between the age predicted by CNN and the Demirjian's approach. In conclusion, the results show that the CNN method is adequate to be an alternative to the Demirjian's age estimation method. We suggest that convolutional neural network can effectively optimize the accuracy of age estimation and can be faster than traditional methods, eliminating the need for additional learning from experts.

Correlation between dental and skeletal maturity in Korean children based on dental maturity percentile: a retrospective study

BACKGROUND

The correlation between dental maturity and skeletal maturity has been proposed, but its clinical application remains challenging. Moreover, the varying correlations observed in different studies indicate the necessity for research tailored to specific populations.

AIM

To compare skeletal maturity in Korean children with advanced and delayed dental maturity using dental maturity percentile.

DESIGN

Dental panoramic radiographs and cephalometric radiographs were obtained from 5133 and 395 healthy Korean children aged between 4 and 16 years old. Dental maturity was assessed with Demirjian's method, while skeletal maturity was assessed with the cervical vertebral maturation method. Standard percentile curves were developed through quantile regression. Advanced (93 boys and 110 girls) and delayed (92 boys and 100 girls) dental maturity groups were defined by the 50th percentile.

RESULTS

The advanced group showed earlier skeletal maturity in multiple cervical stages (CS) in both boys (CS 1, 2, 3, 4, and 6) and girls (CS 1, 3, 4, 5, and 6). Significant differences, as determined by Mann-Whitney U tests, were observed in CS 1 for boys (p = 0.004) and in CS 4 for girls (p = 0.037). High Spearman correlation coefficients between dental maturity and cervical vertebral maturity exceeded 0.826 (p = 0.000) in all groups.

CONCLUSION

A correlation between dental and skeletal maturity, as well as advanced skeletal maturity in the advanced dental maturity group, was observed. Using percentile curves to determine dental maturity may aid in assessing skeletal maturity, with potential applications in orthodontic diagnosis and treatment planning.

Dental age assessment in the living: a comparison of two common stage classifications for assessing radiographic visibility of the root canals in mandibular third molars

After dentition is complete, degenerative tooth characteristics can be used for dental age assessment. Radiological assessment of the visibility of the root canals of the mandibular third molars in dental panoramic radiographs (DPRs) is known to be one such suitable feature. Essentially, two different stage classifications are available for evaluating the visibility of the root canals of mandibular third molars in the DPR. The aim of this study was to determine if one method outperforms the other. Therefore, the 2010 method of Olze et al. was directly compared to the 2017 method of Lucas et al. in the 2020 modification of Al Qattan et al. To this end, 233 DPRs from 116 females and 117 males aged 20.0 to 40.9 years were evaluated by three independent experienced examiners. In addition, one examiner ran two independent evaluations. Correlation between age and stage was investigated, and the inter- and intra-rater reliability was estimated for both methods. Correlation between age and stage was higher with the Olze method (Spearman rho 0.388 [95% CI 0.309, 0.462], males and 0.283 [95% CI 0.216, 0.357], females) than the Lucas method (0.212 [95% CI 0.141, 0.284], males and 0.265 [95% CI 0.193, 0.340], females). The intra-rater repeatability of the Olze method (Krippendorff's α = 0.576 [95% CI 0.508, 0.644], males and α = 0.592 [95% CI 0.523, 0.661], females) was greater than that for the Lucas method (intra-rater α = 0.422 [95% CI 0.382, 0.502], males and α = 0.516 [95% CI 0.523, 0.661], females). Inter-rater reproducibility was also greater for the Olze method (α = 0.542 [95% CI 0.463, 0.620], males and α = 0.533 [95% CI 0.451, 0.615], females) compared to the Lucas method (α = 0.374 [95% CI 0.304, 0.443], males and α = 0.432 [95% CI 0.359, 0.505], females). The method of Olze et al. was found to present marginal advantages to the Lucas et al. method across all examinations and may be a more appropriate method for application in future studies.

Age estimation in adults by canine teeth: a systematic review of the Cameriere method with meta-analysis on the reliability of the pulp/tooth area ratio

The age estimation of an adult using methods accessible to the forensic routine is a goal pursued by forensic experts. Cameriere, Ferrante and Cingolani (2004) proposed the use of the pulp/tooth area ratio of canine teeth as a promising variable, but its reliability has shown conflicting results in the scientific literature. This article aimed to carry out a systematic review with meta-analysis to verify whether the pulp/tooth area ratio of canine teeth includes a variable that can be used alone to estimate dental age in adults. A systematic search was carried out in six databases using keywords related to the theme in Portuguese, English, and Spanish. The study selection process followed pre-established eligibility criteria. Assessments were carried out regarding risk of bias and publication bias of selected studies, and meta-analysis was carried out considering Pearson's correlation coefficient between pulp/tooth area ratio and chronological age as effect measure. Most selected studies showed low risk of bias; no publication bias was found when all studies were considered, and potential publication bias was found when outliers were removed. Despite the high heterogeneity among studies and the need for more research, it could be observed that the pulp/tooth area ratio has strong negative correlation with chronological age, and the pulp/tooth area ratio could be derived from both periapical radiographs and orthopantomographs. Therefore, it is suggested that there is scientific evidence that the pulp/tooth area ratio obtained from canine teeth is reliable for dental age estimation in adults.

A comparison of estimated age based on pulp volume from cone beam computed tomography (CT) images and panoramic radiography data with chronological age

This retrospective study was conducted to evaluate different methods for dental age estimation in children and to examine the feasibility of using cone beam computed tomography (CBCT) data for age estimation. A total of 200 radiographic records (both digital panoramic radiographs and CBCTs) were acquired from 100 children aged 9 to 16 years, all taken on the same dates. Radiographic data was acquired from archived records and included both panoramic radiography and CBCT data belonging to the same individual. CBCT was used when panoramic radiographic data was insufficient. The pulp volume and pulp/tooth volume ratio of the left first molar teeth in the mandible were calculated from the CBCT data using MIMICS software. In addition, age was estimated by the Demirjian and Willems methods from data obtained from panoramic radiography images. Statistical analyses and linear regression analysis were performed as necessary. There was a statistically significant difference between the mean difference between the Demirjian method and chronological age, and between the Willems method and chronological age (p < 0.001). Statistically significance was achieved in a linear regression model created from pulp volume (R2 = 0.098) and pulp/tooth volume ratio (R2 = 0.395) data for the estimated dental age analysis (p < 0.001) and a negative correlation was observed with chronological age. When compared estimated dental age from CBCT data with chronological age, the pulp/tooth volume ratio method yielded results closer to chronological age than using only pulp volume data. When considering both panoramic radiographic age estimation methods and age estimation methods using CBCT data, we found that the results obtained with the Willems method, a panoramic radiographic age estimation technique, provided the closest results to the chronological age. More contributions should be made to the literature regarding the feasibility of age estimation using pulp and tooth volume as an alternative method.

Dental age estimation: development and testing of a reference data set for Qatari children, adolescents, and young adults aged between 5 and 25 years

The purpose of this study is to establish and test a reference data set of dental development of Qatari subjects aged between 5 and 25 years. Radiographs of individuals aged between 5 and 25 years were re-used to establish a reference data set (RDS). A scheme comprising 8 tooth development stages (TDS) was used to assess all the teeth on the left side of the maxilla and mandible. The accuracy of dental age estimation (DAE) was tested with a separate sample of radiographs - the validation sample (VS) comprised 50 females and 50 males of known chronological age (CA). Dental panoramic tomographs (DPT) of 1,597 Qataris were assessed. The summary data for the individual TDS comprising the number (n-tds), mean ( x ¯ -tds), standard deviation (sd-tds), 0th%-ile (the minimum), 25th%-ile, 50th%-ile (the median), 75th%-ile, and 100th%-ile (the maximum) were used to estimate the age of the VS subjects using the simple average method (SAM). There is a significant difference in dental age of 4.8 months in the female group when compared to the CA. The difference in the male group is 4.5 months. This shows similar differences to assessments of other ancestral or ethnic groups.

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

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

Three decades after the publication of the Lamendin method for adult age-at-death estimation: Methodological evolution of the procedure and interpretations

More than three decades have passed since the publication of Lamendin et al.'s proposal in 1992. Over this time, numerous investigations have been conducted to assess the applicability of the technique in different populations with acceptable results in terms of estimation errors. The proposal by Lamendin and colleagues remains relevant today, and has made a significant contribution to adult age-at-death estimation due to its simplicity, repeatability, replicability, and high performance. Indeed, significant progress towards systematizing and strengthening the procedure has been reported in the published literature. One noteworthy advancement is the development of an international database that supports the use of Bayesian statistics for age-at-death estimation. This resource plays a crucial role in standardizing the methodology and improving the reliability for obtaining more reliable results on a global scale. The aim of this study is to investigate the historical evolution of the technique, to assess the accuracy of the results obtained by different analytic procedures, and to explore its impact in forensic applications through a systematic analysis of the specialized literature on this field. The current state of research indicates that this type of methodological research is an ongoing process, far from being completed. Many questions and challenges that require further attention to address effectively these issues remain unanswered, such as the development of non-linear regressions and probabilistic approaches, the deepening of procedures that improve global approximations, and the intensification of research focused on achieving more accurate estimations among individuals over 70 years-old. However, studies generally agree that the Lamendin technique works well for individuals between the ages of 30-60 years. It is still in force today, although the method has been significantly perfected. Despite the degree of research development in this area, further efforts are needed to improve the understanding and performance of these kinds of procedures. This will ultimately lead to an improvement in the accuracy and reliability of forensic investigation results worldwide.

Automatic dental age calculation from panoramic radiographs using deep learning: a two-stage approach with object detection and image classification

BACKGROUND

Dental age is crucial for treatment planning in pediatric and orthodontic dentistry. Dental age calculation methods can be categorized into morphological, biochemical, and radiological methods. Radiological methods are commonly used because they are non-invasive and reproducible. When radiographs are available, dental age can be calculated by evaluating the developmental stage of permanent teeth and converting it into an estimated age using a table, or by measuring the length between some landmarks such as the tooth, root, or pulp, and substituting them into regression formulas. However, these methods heavily depend on manual time-consuming processes. In this study, we proposed a novel and completely automatic dental age calculation method using panoramic radiographs and deep learning techniques.

METHODS

Overall, 8,023 panoramic radiographs were used as training data for Scaled-YOLOv4 to detect dental germs and mean average precision were evaluated. In total, 18,485 single-root and 16,313 multi-root dental germ images were used as training data for EfficientNetV2 M to classify the developmental stages of detected dental germs and Top-3 accuracy was evaluated since the adjacent stages of the dental germ looks similar and the many variations of the morphological structure can be observed between developmental stages. Scaled-YOLOv4 and EfficientNetV2 M were trained using cross-validation. We evaluated a single selection, a weighted average, and an expected value to convert the probability of developmental stage classification to dental age. One hundred and fifty-seven panoramic radiographs were used to compare automatic and manual human experts' dental age calculations.

RESULTS

Dental germ detection was achieved with a mean average precision of 98.26% and dental germ classifiers for single and multi-root were achieved with a Top-3 accuracy of 98.46% and 98.36%, respectively. The mean absolute errors between the automatic and manual dental age calculations using single selection, weighted average, and expected value were 0.274, 0.261, and 0.396, respectively. The weighted average was better than the other methods and was accurate by less than one developmental stage error.

CONCLUSION

Our study demonstrates the feasibility of automatic dental age calculation using panoramic radiographs and a two-stage deep learning approach with a clinically acceptable level of accuracy.

Machine learning assessment of dental age classification based on cone-beam CT images: a different approach

OBJECTIVES

Machine learning (ML) algorithms are a portion of artificial intelligence that may be used to create more accurate algorithmic procedures for estimating an individual's dental age or defining an age classification. This study aims to use ML algorithms to evaluate the efficacy of pulp/tooth area ratio (PTR) in cone-beam CT (CBCT) images to predict dental age classification in adults.

METHODS

CBCT images of 236 Turkish individuals (121 males and 115 females) from 18 to 70 years of age were included. PTRs were calculated for six teeth in each individual, and a total of 1416 PTRs encompassed the study dataset. Support vector machine, classification and regression tree, and random forest (RF) models for dental age classification were employed. The accuracy of these techniques was compared. To facilitate this evaluation process, the available data were partitioned into training and test datasets, maintaining a proportion of 70% for training and 30% for testing across the spectrum of ML algorithms employed. The correct classification performances of the trained models were evaluated.

RESULTS

The models' performances were found to be low. The models' highest accuracy and confidence intervals were found to belong to the RF algorithm.

CONCLUSIONS

According to our results, models were found to be low in performance but were considered as a different approach. We suggest examining the different parameters derived from different measuring techniques in the data obtained from CBCT images in order to develop ML algorithms for age classification in forensic situations.

Prevalence of abnormalities seen on orthopantomograms performed for forensic age estimation in unaccompanied minor asylum seekers

OBJECTIVES

Evaluate the prevalence of radiological anomalies on orthopantomograms (OPT) performed as part of forensic age estimation in unaccompanied minors.

METHODS

This is a retrospective study conducted on 208 OPT examinations requested by a magistrate. These OPTs were interpreted independently by two readers to establish the number of missing teeth (MT), presence of dental fillings (DF), and dental anomalies (DA). The presence of radiolucent (RL), radiopaque, and mixed lesions was also assessed.

RESULTS

Most radiologic anomalies were RL, detected on 41% and 39% of the subjects evaluated for R1 and R2, respectively, with a mean of 1.3 ± 2.4 (1-16) and 1.1 ± 2 (1-13) RL lesions per subject. Among the RL identified, the majority were dental (70% for R1 and 65% for R2), all of which had a suspected infectious origin. Among readers, 43% and 41% of the subjects evaluated presented MT, 21% and 15% presented DF, and 22% and 20% presented DA for R1 and R2, respectively. The inter- and intra-observer reproducibility for OPT classification was considered excellent (Kappa = 0.84, 95% CI 0.78-0.90, and Kappa = 0, 95, 95% CI 0.86-0.99).

DISCUSSION

There was a non-negligible prevalence of radiological anomalies in OPT studies performed for forensic age estimation. Most of these lesions were suspected to be infectious in origin, potentially requiring medical care. This constitutes an ethical dilemma inherent in the judicial expertise injunction requiring a limited specific response.

CLINICAL RELEVANCE STATEMENT

This study highlights a non-negligible prevalence of supposedly infectious radiological abnormalities. The restricted possibility for the legal expert to declare these abnormalities raises ethical and medical questions.

KEY POINTS

• Orthopantomograms can be performed as part of forensic age estimation. • Results indicate the majority of radiological anomalies detected on OPTs were of suspected infectious origin. • These findings give rise to ethical and medical questions about the way in which these forensic examinations are carried out.

Using cementochronology to assess the seasonality of catastrophic events in medieval mass graves (Kutná Hora-Sedlec, Czechia, 14th century): Preliminary results

While season-of-death estimation using cementochronology is routine in archaeozoology, its use is much less frequent in bioarchaeology. Based on the character of the outermost increment (bright or dark), two seasons (spring/summer, autumn/winter) can be distinguished. Although many studies mention its potential and possible use in forensic anthropology or bioarchaeology, few exist with estimation results. This study aimed to apply cementochronology-a histological method based on counting and assessing regular circa-annual acellular cementum increments-to 42 individuals from medieval mass graves from Kutná Hora-Sedlec (Czechia, 14th century) to estimate the season-of-death. The mass graves belong to two stratigraphically distinct groups; written and archaeological sources relate them to two catastrophic events (the famine of 1318 and the plague epidemic of 1348-1350). Using cementochronology, we distinguished two distinct seasons corresponding to the two groups of graves, with individuals from the first group dying predominantly in spring/summer, while those from the second group died in autumn/winter. Taking into account the typical seasonal dynamics of epidemics, the results would be more in line with written sources. However, during the evaluation, we faced difficulties identifying the outermost increment and detecting the dark (thinner) increment; we recommend including only young and middle-aged adults in future studies, due to the difficulty of evaluation, and to consider the readability of the tissue (often affected by diagenesis). In conclusion, cementochronology has potential in the context of estimating the season-of-death, but the technical possibilities for enhancing the outermost increment need to be addressed, and the amount of data analysed expanded.

Estimating chronological age through learning local and global features of panoramic radiographs in the Korean population

This study suggests a hybrid method based on ResNet50 and vision transformer (ViT) in an age estimation model. To this end, panoramic radiographs are used for learning by considering both local features and global information, which is important in estimating age. Transverse and longitudinal panoramic images of 9663 patients were selected (4774 males and 4889 females with a mean age of 39 years and 3 months). To compare ResNet50, ViT, and the hybrid model, the mean absolute error, mean square error, root mean square error, and coefficient of determination (R2) were used as metrics. The results confirmed that the age estimation model designed using the hybrid method performed better than those using only ResNet50 or ViT. The estimation is highly accurate for young people at an age with distinct growth characteristics. When examining the basis for age estimation in the hybrid model through attention rollout, the proposed model used logical and important factors rather than relying on unclear elements as the basis for age estimation.

Skeletal, dental, and sexual maturation as an indicator of pubertal growth spurt

OBJECTIVES

The aims of this study were to determine the skeletal, dental, and sexual maturation stages of individuals at the peak of the pubertal growth spurt and to analyze the correlations between these parameters.

METHODS

The study included 98 patients, 49 females (mean chronological age 12.05 ± 0.96 years) and 49 males (mean chronological age: 13.18 ± 0.86 years), in the MP3cap stage. Skeletal maturation stages were determined using the cervical vertebral maturation (CVM) method on lateral cephalometric radiographs. The Demirjian index was used to determine dental maturation stages and dental ages on panoramic radiographs. The sexual maturation of the patients was evaluated in the pediatric endocrinology clinic by a pediatrician according to the Tanner stages. The frequencies of the variables were determined, and the Spearman rank correlation coefficients were used to analyze the correlations between the variables.

RESULTS

It was determined that the cervical vertebral maturation stage was CS3 in 81.6% (n = 40) of both female and male patients, and 81.6% of the female and 89.8% of the male patients were in stage G in terms of mandibular second molar tooth development. According to the Tanner pubic hair staging, 73.5% of the male and 51.0% of the female patients were in Stage 3. A significant correlation was found between the cervical vertebra stages and mandibular second molar tooth development stages in both sexes and between the cervical vertebra and Tanner pubic hair stages only among the male patients (r = 0.357; p < .05). There was also a significant and strong correlation between the Tanner pubic hair stages and breast development stages (r = 0.715; p < .05).

CONCLUSION

Cervical vertebral development in the CS3 stage and mandibular molar tooth development in the G stage can be considered the peak of the pubertal growth spurt. Tanner Stage 3 marks the peak of the pubertal growth spurt in males.

[Application of Demirjian and Chaillet method in age estimation of Uyghur and Han children and adolescents in Urumqi]

PURPOSE

To evaluate the applicability and accuracy of Demirjian and Chaillet method in estimating the actual age of Uygur and Han children and adolescents in Urumqi.

METHODS

A total of 1144 orthopantomograms were included in the study, and the seven permanent teeth in the left jaw were divided into different stages according to two dental age estimation methods, and the dental age was converted to tooth age after checking the table and assigning points, and the dental age and its chronological age were compared with t test or rank sum test using SPSS 21.0 software package, and the accuracy of the two methods was evaluated by comparing the mean absolute error of the two methods.

RESULTS

Demirjian method was overestimated by an average of 0.46 years (0.47 years for males and 0.43 years for women) in the Han population, 0.36 years for men and 0.26 years for women in Uyghur population, the difference was significant between Uyghur and Han boys (P＜0.05). Chaillet method yielded an average underestimate of 0.01 years (0.04 years for men and -0.08 years for women) in the Han population, and 0.08 years(0.02 years for men and -0.21 years for women) in the Uyghur population, there was no significant difference between Uyghur and Han boys and girls(P＞0.05).

CONCLUSIONS

When assessing the age of Uyghurhan children and adolescents in Urumqi, Chaillet method is more accurate than the Demirjian method. When applying dental age estimation method in different regions, it is necessary to evaluate the accuracy of the estimation method and revise it if necessary to improve the accuracy.

The accuracy of Cameriere methods in Turkish children: chronological age estimation using developing teeth and carpals and epiphyses of the ulna and radius

The aim of the present study was to develop a specific formula by measuring the developing teeth, carpal bones, and epiphyses of the ulna and radius to determine the chronological age in Turkish children. The left developing permanent mandibular teeth were evaluated, and the number of teeth with closed apex was recorded. The distance between the inner sides of open apex/apices was measured by using the ImageJ program and divided by the tooth length. The sum of the normalized open apices was also calculated. The carpal area (Ca), covering the epiphyses of ulna and radius and the carpal bones, was measured on the X-rays of left hand. The areas of each carpal bone and epiphyses of the ulna and radius were measured, and these measurements were added together to obtain the bone area (Bo). The Bo/Ca ratio between the total area of carpal bones and the carpal area was calculated to normalize the measurements. The accuracy of the equations formulated by Cameriere was evaluated, and a new regression equation was developed accordingly. The new formula showed no statistically significant difference between the chronological and the estimated age for females, males, and total sample. The new formula, which hit the age with 72.80% accuracy, was more successful in predicting chronological age than other adjusted regression equations. The new regression model, created for the Turkish children by using both developing teeth and hand-wrist bones, was considerably successful in estimating the chronological age.

Dental age assessment: scoring systems and models from the past until the present-how is it presented in the court?

OBJECTIVE

The aim of this study is to evaluate the accuracy of the methods from the past and present, such as Demirjian, Cameriere, and AlQahtani, as well as to determine the most reliable method for human age estimation under the request from the courts according to the effect size from each method in age estimation.

DESIGN

Four hundred eighty-three orthopantomographic images were selected from 318 patients from Centro Hospitalar Universitário Lisboa Norte aged between 6 and 15 years old. Several measurements of widths and lengths and classification of tooth development stages were performed, according to each age estimation method. The listing of patients and orthopantomographic images were consulted through SECTRA®. All data was entered and analysed using SPSS version 28. Observations' validity was verified through inter- and intraobserver validation.

RESULTS

The correlation coefficients between age and age estimates by the three methods on both sides were close to 90%. Regarding the estimation error correlation coefficient, Demirjian and AlQahtani values were low, whereas Cameriere's was significantly negative; i.e., underestimation increases as age increases. Between left and right, any significant difference in age estimation in AlQahtani and Cameriere methods was not observed, but there were great variability and large effect for the Demirjian method. Comparing females and males, the statistical analysis showed no significant differences and quite small effects in the precision of the estimates for any of the methods. Finally, although significant differences were detected when comparing estimated values and age, small effects were revealed except for the Demirjian method which attained a medium effect and, therefore, less consistency of estimation.

CONCLUSIONS

Since it was not possible to determine the most reliable method for age estimation, a combined application of different age estimation methodologies is recommended to be use in the courts with relevant statistical data such as effect size.

Association between dental and skeletal maturation in Scandinavian children born between 2005 and 2010

OBJECTIVE

The aim of this cross-sectional study was to analyse the association between dental and skeletal maturation in children born between 2005 and 2010.

MATERIALS AND METHODS

Dental and skeletal maturation of 117 ethnic Scandinavian children born between 2005 and 2010 (70 girls, 47 boys, mean age 11.48 years) was analysed. Dental maturation (DM) was assessed on orthopantomographs (OPs) by using Demirjian's and Haavikko's methods while skeletal maturation was assessed on hand-wrist radiographs by use of Helm's method. The correlation between skeletal and DM was analysed using Spearman's rho (Rs). Additionally, the most frequent DM stage in relation to the skeletal maturation stage was analysed by logistic regression adjusted for age and sex.

RESULTS

The correlation between dental and skeletal maturation was significant for all teeth (Rs = 0.071-0.562; p < .000-p = .035) except for the first incisor and the first molar. Logistic regression analysis showed that when the mandibular and maxillary canines are ¾ mineralized, this is significantly associated with the beginning of the adolescent period before peak height velocity (PHV) (PP2= p < .005-< .05). Likewise, when the mandibular second premolars are ¾ mineralized, this is significantly associated with the maturation stage PP2= or S (PP2= p < .05, S: p < .005-< .05), both of which are before PHV at the beginning of the adolescent period.

LIMITATIONS

Limited sample size and the X-rays were taken before orthodontic treatment, which may have introduced a selection bias.

CONCLUSIONS

When the root of the canines or second premolars is ¾ mineralized, it may indicate the beginning of the adolescent period with increased skeletal growth intensity.

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

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

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

ABSTRACT

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

Radiographic dental age estimation applying and comparing Demirjian's seven (1973) and four (1976) teeth methods

To apply Demirjian's seven (1973, D7) and four (1976, D4) teeth methods in a sample of Brazilian children and compare their performances for age estimation. Panoramic radiographs of 1200 children (600 females and 600 males) were collected from Southeast Brazil. The children were equally distributed (n = 60 females and 60 males) between age intervals of 1 year between 6 and 15.9 (mean age = 10.9; standard deviation [SD]: 2.9) years. D7 and D4 dental age estimation methods were applied by two observers and were compared based on their error rates (error = estimated age-chronological age). Both methods overestimated the chronological age (p < 0.0001). D7 led to overestimations of 0.71 (p < 0.0001) in females and 0.83 (p < 0.0001) in males, while the overestimations with D4 were 0.14 (p = 0.0067) and 0.73 (p < 0.0001) for females and males, respectively. The mean age estimated by D7 was 11.7 (SD: 3.1) years, while for D4, it was 11.3 (SD: 3.3) years. Intra- and interobserver agreement was ≥ 0.98. D4 optimized the performance of radiographic dental age estimation compared to D7. Improvements were reflected in the total sample and separately for female and male children from Southeast Brazil.

Age determination on panoramic radiographs using the Kvaal method with the aid of artificial intelligence

OBJECTIVES

This study aimed to assess and compare age estimation on panoramic radiography using the Kvaal method and machine learning (ML).

METHODS AND MATERIALS

554 panoramic radiographs were selected from a Brazilian practice. To estimate age using the Kvaal method, the following measurements were performed on the upper left central incisors and canines: tooth, pulp and root length; root and pulp width at three different levels: at the enamel-cementum junction (ECJ); midpoint between the enamel-cementum junction and; at the mid root level. For ML age estimation, radiomic, semantic and the radiomic-semantic attribute extractions were assessed. Nineteen semantic and 14 radiomic attributes and a single set of 33 semantic-radiomic attributes were extracted. Logistic Regression, Linear Regression, KNN, SVR, Decision Tree Reg, Random Forest Reg, Gradient Boost Reg e XG Boosting Reg were used for ML classification. For the Kvaal method, Mann-Whitney test, Spearman correlation coefficient, Student's t-test and linear regression with its respective coefficient of determination were used to estimate age and to assess data variability.

RESULTS

Mean absolute error (MAE) and standard error estimate (SEE) were assessed. For the Kvaal method, upper incisors presented higher precision than canines (R²: 0.335, SSE: 7.108). Males presented better MAE and SEE values (5.29,6.96) than females (5.69,7.37). The radiomic-semantic attributes presented superior precision (MAE: 4.77) than the radiomic and semantic (MAE: 5.23) attributes. The XG Boosting Reg classifier performed better than the other six assessed classifiers (MAE: 4.65). ML (MAE: 4.77 presented higher age estimation precision than the Kvaal method (MAE: 5.68).

CONCLUSION

The use of ML on panoramic radiographs can improve age estimation.

Application of the London Atlas of Tooth Development and Eruption in Panoramic Xrays for the Age Estimation

BACKGROUND

The age estimation of the individual by the forensic experts ascertains the chronological age of an individual. The possibility that the person being examined may be younger or older than a certain age threshold makes this process crucial, as it will establish whether or not the person is an adult under the law. The aim of this study was to test the applicability of the London Atlas of tooth development and eruption in Nepalese subset population.

METHODS

The London Atlas for age estimation was tested in 350 digital panoramic radiographs from the patients between four and twenty-four years visiting Tribhuvan University Teaching Hospital, Institute of Medicine, Nepal.

RESULTS

The mean values of the estimated age were higher in both the sexes, which was statistically not significant. Both the sexes showed an excellent positive correlation, and was significant with a p value of <0.001. The age estimation upto 10 years group classification was nearly accurate with less than 1 and 2.5 years variation in males and females respectively. The accuracy was good in 16-18 years group with maximum deviation of ±2.5 years. The accuracy was poor in more than 18 years group, as the variability was more than 5 years.

CONCLUSIONS

The London Atlas method was best suited for less than 18 years of age and was not very accurate in the age group of 13-14 and 14-15 years where most of the polymorphisms were noted.

Artificial Intelligence as a Decision-Making Tool in Forensic Dentistry: A Pilot Study with I3M

Expert determination of the third molar maturity index (I3M) constitutes one of the most common approaches for dental age estimation. This work aimed to investigate the technical feasibility of creating a decision-making tool based on I3M to support expert decision-making. Methods: The dataset consisted of 456 images from France and Uganda. Two deep learning approaches (Mask R-CNN, U-Net) were compared on mandibular radiographs, leading to a two-part instance segmentation (apical and coronal). Then, two topological data analysis approaches were compared on the inferred mask: one with a deep learning component (TDA-DL), one without (TDA). Regarding mask inference, U-Net had a better accuracy (mean intersection over union metric (mIoU)), 91.2% compared to 83.8% for Mask R-CNN. The combination of U-Net with TDA or TDA-DL to compute the I3M score revealed satisfying results in comparison with a dental forensic expert. The mean ± SD absolute error was 0.04 ± 0.03 for TDA, and 0.06 ± 0.04 for TDA-DL. The Pearson correlation coefficient of the I3M scores between the expert and a U-Net model was 0.93 when combined with TDA and 0.89 with TDA-DL. This pilot study illustrates the potential feasibility to automate an I3M solution combining a deep learning and a topological approach, with 95% accuracy in comparison with an expert.

Fetal Age Assessment From Primary Teeth and Long Bones

ABSTRACT

This study evaluated traditional and expedited methods for assessing the age of fetal remains. Because of their rare occurrence, the discovery of fresh, decomposing, disfigured, or skeletal fetuses engenders heightened awareness by forensic pathologists primarily tasked with age estimation in relation to viability. With decomposed complete or isolated fetal remains, dentists focus on primary molar mineralization, whereas anthropologists perform long bone measurements along with discernment of other indicators of skeletal maturity to obtain an age estimation.The results of this study are 4-fold: (1) The "best" technique for harvesting fetal tooth buds and long bones is the dissection of the developing tooth buds with maceration for the long bones. (2) Metric analysis was applied to the tooth buds and long bones for age estimation, and the findings were correlated. (3) There is a statistically significant difference between known age and dental age and between dental age and long bone age. The difference between known age and long bone age is not statistically significant, but a type II error exists because of the small sample size. (4) A central incisor staging technique for fetuses younger than 26 weeks was developed as a supplement to the molar staging system of Kraus and Jordan (1965).

Dental Age Assessment of United States Black and White Children: Performance Reliability of Harris and McKee (1990)

ABSTRACT

Medicolegal authorities use forensic dental age assessment of children to establish a biologic profile to assist in human identification, answer questions related to immigration, and answer questions used to substantiate eligibility for social benefits. The goal of this study was to assess the performance reliability of the child dental age assessment data previously published for White and Black children in the United States. A total of 432 dental panoramic radiographs were obtained from 3 geographic locations in the United States: Memphis, Tennessee, Knoxville, Tennessee, and Saint Louis, Missouri. Radiographs were staged, and the estimated age was calculated using the previously published data. Multiple age assessments were conducted to determine the effect of excluding certain teeth on estimated age. The results indicated estimated ages using the previously published reference data set were accurate and concordant with known chronologic age across the ancestral, sex, and geographic categories. The results also indicated that the known chronologic age fell within one standard deviation of the estimated age more than the statistical expectation for most categories. Excluding canines provided the most accurate estimation of known chronologic age.

[Chromatographic analysis of hard tooth tissue to determine the age of personality]

The biochemical approach for age assessment is most appropriate in forensic medicine, as racemization of aspartic acid in bones and teeth is closely related to human biological age. The aim of the study is to assess the biochemical parameters of aspartic acid in human teeth, which can be implemented into forensic practice in Russia. Samples of dentin in amount of 20, taken from the teeth of subjects aged between 16 and 76, were examined. Chromatographic analysis of the samples was performed on a gas chromatograph using chiral column. Statistical data processing showed that the relative squared peak of D-aspartic acid has a strong correlation with human biological age. Data, obtained from the Russian population study, demonstrate the applicability of chromatography for forensic purposes. It should be noted that the approach to the racemization rate estimation in the hard tooth tissue was performed using standard laboratory equipment, which allows to easily implement this method in forensic medical practice.

Age Estimation Using Maxillary Central Incisor Analysis on Cone Beam Computed Tomography Human Images

Forensic dentistry plays an important role in human identification, and dental age estimation is an important part of the process. Secondary dentin deposition throughout an individual's lifetime and consequent modification in teeth anatomy is an important parameter for age estimation procedures. The aim of the present study was to develop regression equations to determine age in adults by means of linear measurements and ratios on sagittal, coronal and axial slices of maxillary central incisors using cone bean computed tomography (CBCT). Multiplanar measurements of upper central incisors were taken for a sample of 373 CBCTs. Subsequently, one-way analysis of variance (ANOVA) and multivariate linear regressions were performed for age estimation. The equations obtained from axial linear measurements and ratios presented a standard error of the estimate (SEE) of ±10.9 years (R² = 0.49), and a SEE of ±10.8 years (R² = 0.50), respectively. The equation obtained for multiplanar linear measurements presented a SEE of ±10.9 years (R² = 0.52), while the equation for multiplanar ratios presented a SEE of ±10.7 years (R² = 0.51). Thus, CBCT measurements on upper central incisors were found to be an acceptable method for age estimation. Horizontal measurements, especially pulp measurements, improve the accuracy of age estimate equations.

Adapting Demirjian Standards for Portuguese and Spanish Children and Adolescents

Estimation of children's chronological age is highly important in human and forensic sciences. The Demirjian method has been reported as accurate for this purpose. The literature review shows some evidence that the accuracy of estimating chronological age via the Demirjian standards is not a straightforward process. The objective of this research is to analyze the reliability of the Demirjian standards in Portuguese and Spanish children and adolescents and adapt it to include sex and group age as contingent factors.

METHODS

Orthopantomographs of 574 Portuguese and Spanish male and female children and adolescents were employed to test the reliability of the Demirjian method. After testing for inter-rater consistency and age estimation using the Demirjian standards, multiple regression analysis was performed controlling for sex and age group.

RESULTS

The Demirjian standards overestimated chronological age for both sexes, mainly for females. Through the development of regression functions, more detailed dental age estimation was performed. The predictive capacities of the Demirjian method and the significant teeth varied as a function of children's age. The Demirjian global standard predicted over 65% of the variance of the chronological age. Taking a tooth-by-tooth approach, the predictive ability increased by over 70%.

CONCLUSIONS

The accuracy of estimating chronological age via the Demirjian method is not as reliable as it might appear, judging from the results found according to age group and according to sex crossed with age group.

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.

Does third molar impaction affect age estimation in adolescent and young adults? A radiographic population based study

Few studies consider the effects of impaction, resulting in inaccurate estimation of age using third molar. We aimed to assess the significance of impaction in estimating age using Modified Demirjian's method. 200 orthopantomograms of patients between 16-25 years were collected comprising 171 tests and 212 controls. Chronologic age (CA) and estimated age (EA) were calculated. Independent sample t-test, chi-square test, paired t-test and Kolmogrov-Smirnov test of normality were used. The mean difference between the CA and EA in both the tests and control samples were significant (mean difference test group = 2.6 ± 2.07, control group = 2.0 ± 1.8; p = 0.01). It provided a difference of 0.6 which is equal to 7.2 months. The results of our study indicate that impacted mandibular third molars are susceptible to undergo slower mineralization, leading to erroneous lower age estimation. These results in an Indian population are noteworthy. However further studies are needed.

Application of the ratio of the radiopaque calcified area to the dental follicle (RCA/DF) for dental age assessment on orthopantomograms

OBJECTIVES

This study aimed at exploring a new tooth development evaluation method for age assessment and investigating the dynamic alteration and potential trend of tooth development by orthopantomograms (OPGs), in order to provide references for tooth development prediction and forensic purpose.

MATERIALS AND METHODS

A total of 132 OPGs of children aged 3-8 years were collected. The developmental stages of the permanent mandibular second molar (M2)were evaluated by experienced examiners according to the Nolla method and Mimics software, respectively. Quantitative analysis of the ratio of the radiopaque calcified area to the dental follicle (RCA/DF) in different stages, ages, sexes and quadrants were evaluated and compared via descriptive statistics and Spearman's correlation coefficient analysis.

RESULTS

There was a strong, positive correlation between the examiners' evaluation and mimics analysis results. With the age increased, the Nolla stage of M2 observed by OPGs increased, and the RCA/DF showed increased trends both in males and females. There were significant differences of the RCA/DF of the M2 at various ages. The tooth calcification development of female was 9.08% earlier than that of male between 3 and 8 years old. However, teeth of male seemed to develop faster than that of female during this period. There was no significant difference between left and right quadrant either according to the Nolla stage or RCA/DF.

CONCLUSIONS

The RCA/DF value obtained from OPGs of the developmental mandibular second permanent molars could be used as a reliable indicator for tooth maturity and age estimation in children aged 3-8 years.

CLINICAL RELEVANCE

Age assessment based on radiographs is considered as a reliable and efficient indicator for judging different types of malocclusion, making suitable orthodontic treatment plan, deciding the extraction time of retained deciduous teeth in clinic practice.

Estimating the 18-Year Threshold with Third Molars Radiographs in the Southern Italy Population: Accuracy and Reproducibility of Demirjian Method

The estimation of the age of the majority of living subjects is widely required nowadays due to the presence of unidentifiable individuals, without documents and general information, involved in migration or legal procedures. Dental age estimation (DAE) is a valid method for investigating the age of subjects. The aim of this study was to evaluate the accuracy of the Demirjian method in a limited age group (16-24 years) in differentiating between older and younger than 18 years. From an initial sample of 17,594 radiographs, 460 were selected meeting the inclusion criteria. Two dentists provided the age estimate according to the Demirjian method, with a simplified approach based on the development of the third molars. The presence of a developmental stage of H for at least one third molar allowed to establish the major age if the other third molars, inferior or superior, have reached a stage equal or superior to F, with an accuracy of 90.2% and a predictive positive value of 91.6%. Thirty-three patients showed the development of at least one third molar (Stage H) before the age of 18 years while six patients showed the development of all four third molars with root completion (stage H) before the age of 18 years. When all third molars reached stage H an individual was over 18 years old in 97.4% of cases. In presence of one third molar on stage H and a stage equal or superior to F for the other third molars the probability of being of major age was 91.6%.

Accuracy of age estimation and assessment of the 18-year threshold based on second and third molar maturity in Koreans and Japanese

This study aimed to validate Lee’s age estimation method and assess the 18-year threshold in Korean and Japanese populations. We evaluated the maxillary and mandibular second (M2) and third molars (M3) in 2657 orthopantomograms of the Korean and Japanese populations aged 15–23 years (19.47±2.62 years for Koreans, 19.31±2.60 years for Japanese), using Demirjian’s criteria. Dental age was estimated, and correlations between chronological and dental ages were analyzed. Classification performance was calculated based on the 18-year threshold. The relationship between developmental stage and chronologic age was analyzed using multiple linear regression. Our results revealed that Lee’s method was appropriate for estimation in the Korean population. When the Lee’s method was applied to the Japanese population, a lower value of correlation coefficients between estimated and chronological age, and lower specificity were observed. Population differences were observed predominantly in the stages of root development (stages F and G) of M2s and M3s in both jaws and more frequently in females than in males. In the multiple linear regression between developmental stage and chronological age, lower values of adjusted r² were observed in the Japanese population than in the Koreans. In conclusion, the Lee’s method derived from the Korean population data might be unsuitable for Japanese juveniles and adolescents. To support the findings of this study, future studies with samples from multiple institutions should be conducted. Future studies with larger sample sizes are also warranted to improve the accuracy of dental age estimation and confirm the developmental pattern of teeth in the Japanese population.

Age Determination in Children Using Camirere's Indian Specific Formula: A Radiographic Study Using Orthopantomographs

AIM

Determination of age is a pivotal part of forensic dentistry. Since many dental age determination methods are invasive, Cameriere introduced a radiographic method where age evaluation was carried out using an orthopantomogram (OPG). An adaptation of the same formula was later formulated by Rai et al. for the Indian population. The aim of the study was to assess the age and to dictate the efficiency of the Indian version of Cameriere's formula in the Chennai subpopulation.

MATERIALS AND METHODS

This study consisted of radiographs belonging to 50 individuals with an age range of 5-15 years. Radiographs were taken using the OPG and the soft copies obtained were analyzed. The variables such as seven left and right permanent mandibular teeth and the number of teeth with closed apical, and with open apical, ends of roots were examined and measured. The obtained data, after substituting in the formula was statistically analyzed using paired and unpaired t-test and Pearson's correlation coefficient test.

RESULTS

On comparing dental age and chronological age, statistically significant results were obtained on both sides of the radiograph. Between genders, both sides of the radiograph showed non-significant results. On correlating the sides, the left side showed greater accuracy in age determination compared to the right side of the OPG.

CONCLUSION

Age estimation using Indian-specified formula provides a near good estimate and hence can be a reliable method to measure the chronological age of the participants.

CLINICAL SIGNIFICANCE

The Indian version of the Cameriere's formula can be used as a rational tool to assess the age of young children and adolescents.

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

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

Application of third molar maturity index for Indonesia minimum legal age of marriage: a pilot study

IBackground: Child marriage is recognised as a harmful practice. Recently, Indonesia enacted a new law to raise the minimum age of marriage from 16 to 19 years old for women, creating no minimum age difference between males and females. However, this improvement may be detrimental for individuals in remote areas with no legal documentation and the common practices of age falsification to reach the minimum age of marriage. Therefore, implementing an age estimation technique for juveniles is mandatory to reduce the risk of child marriage.

METHODS

this study used the third molar maturity index (I3M) to distinguish an individual under or over 19 years old. I3M values from 222 digital OPGs aged between 15 to 23.99 years were calculated. The sample was randomly assigned as a training dataset (n = 156) and testing dataset (n = 66). The logistic regression model was created using a 5-fold cross-validation method, and the Youden's Index Value was used to establish the I3M cut-off value.

RESULTS

the logistic regression model showed significance in both sex and I3M value for predicting the probability of minimum age of marriage. I3M cut-off values of 0.08 and 0.09 for males and females, respectively, were taken. The accuracy of this test was 80% for both sexes in the testing dataset.

CONCLUSIONS

the outcome of this pilot study showed a promising result of using I3M as a dental age estimation method to determine whether an individual is over or under 19 years old to comply with the newly enacted legal age of marriage in Indonesia. Future research should be carried out using a balanced age cohort for each sex and a more extensive training sample size to investigate the influence of sex in the cut-off value calculation.

Use of the Demirjian method to estimate dental age in panoramic radiographs of patients treated at the Buenos Aires University School of Dentistry

The aim of this study was to determine the difference between real age (RA) and dental age (DA) in boys and girls from the Autonomous City of Buenos Aires (C.A.B.A.) by analyzing digital panoramic radiographs from the database of the Imaging Department at the Buenos Aires University School of Dentistry, using the Demirjian Method (DM). The sample consisted of 508 panoramic radiographs of 6- to 14-year old Argentines (268 female and 240 male). The Demirjian method was used to estimate dental age from each panoramic radiograph, and the Wilcoxon test was applied to perform a comparative analysis with the real age recorded in the image database. Average RA was 9.36 years (SD 2.11), and average DA according to the Demirjian method was 10.45 years (SD 2.31). For females, RA was 9.25 (SD 2.12), and DA according to the DM was 10.40 years (SD 2.41). For males, RA was 9.46 (SD 2.10), and DA according to the DM was 10.50 years (SD 2.22). An inter-classcorrelationcoefficient(ICC) calculated as a correlation measure between dental age and real age was ICC = 1.09%. The ICC was 1.04% for the males and 1.15% for females. Significant differences were found between DA and RA (p<0.01) in general and according to sex. Real age was found to be lower than dental age in the study population from Buenos Aires City.