Effects of ethnicity on skeletal maturation: consequences for forensic age estimations

Comparison of original and new South African formulae for age estimation in African Black and white children and adolescents using dental and hand-wrist methods

BACKGROUND

Methods for age estimation in children involve measurements of: (1) the projections of open apices and tooth heights (T), (2) the total area of the carpal bones and the epiphyses of the ulna and radius (HW), and (3) a combination of these parameters (THW). This study aimed to compare the accuracy of the original formulae for T, HW, and THW in Black South African (BSA) and White South African (WSA) samples of children and adolescents.

MATERIALS AND METHODS

The sample comprised 556 subjects, 164 BSA (71 males and 93 females) and 392 WSA (171 males and 221 females) aged 6 to 16 years. The main sample comprised 556 subjects and was divided into two parts. The first part was used to develop new formulae specific to the South African population, while the second part, consisting of 183 subjects and referred to as the test sample, was used to evaluate the accuracy of these formulae and to quantify their uncertainty when applied to real cases. Adjusted R2 and standard errors of the estimate (SEEs) were calculated for each regression model. The mean absolute difference or error (MAE) between estimated and chronological age and the percentage of individuals within specific age ranges of ± 0.25, ± 0.5, ± 1, and ± 2 years of chronological age was used to compare the accuracy of formulae.

RESULTS

Teeth showed the most significant underestimation in the training sample, -0.49 years in males and - 0.29 years in females, as much as -0.70 years in WSA males, while BSA males were overestimated by + 0.03 years. Combining teeth and hand-wrist, the new formula showed the best performance in age estimation compared to only teeth or hand-wrist, except in WSA males (-0.51 years). New South African-specific formula improved accuracy, especially in males, suggesting their suitability alongside the original Cameriere et al. methods for precise age estimation.

CONCLUSION

The original regression formulae by Cameriere et al., along with the newly developed formulaespecific to South African populations, shows promise for age estimation, considering potential estimation errors and the accuracy rates demonstrated in this study.

CT-assisted age estimation from the medial clavicular epiphysis in the Greek population according to Schmeling and Kellinghaus classification

Examining the clavicle by macroscopic or radiologic techniques is a well-established method in forensic age estimation in living and dead individuals. The present study examined 196 CT (computed tomography scan) images of native patients from the archive of the medical imaging laboratory of the University Hospital in Heraklion, Crete, in Greece. The ossification of the medial clavicular epiphysis was classified according to Schmeling et al. and the extended amplified staging system of Kellinghaus et al. Next, a stage transition analysis was carried out according to the Bayesian model. Probability density functions were calculated using informative priors for age distribution in the total population, deceased and violently deceased individuals. Our study showed that when the medial clavicular epiphysis' ossification is sorted in stages 4 and 5 in Greek males and females, the cumulative probability of adulthood (≥18 years) is nearly 1. As far as Greek males are concerned, in stage 3c, the cumulative probability of adulthood (≥18 years) is 0.86, and in Greek females in stage 3c, the cumulative probability of adulthood (≥18 years) is 0.97. This is the first study of age estimation based on the ossification of the sternal clavicular end using CT in a Greek population.

Bone age and dental age to assess criminal responsibility: Part II

INTRODUCTION

Age estimation is vital in dentistry and legal contexts to determine minors' criminal responsibility. This study aimed to estimate and classify bone and dental age in a Portuguese population, using the Greulich-Pyle method and the Moorrees Fanning and Hunt method, comparing the accuracy of both methods.

MATERIALS AND METHODS

597 left hand and wrist radiographs and 184 orthopantomographs were selected, and the methods were applied.

RESULTS

Cohen's weighted kappa coefficient ranged between 0.890 and 1. Both methods underestimate age. The linear regression formulas showed strong correlations between estimated and real age (0.902 for bone age assessment and 0.894 for dental age assessment). For the bone assessment the accuracy is highest at 14 and 18 years, with similar values to those at 12 and 16. The AUC shows that the method is more reliable at 12 and 14 years. For the dental age assessment, a lower sensitivity value was observed for the age of 12 (73.91%) and a higher for 18 years (91.03%), increasing with age. The accuracy was higher at 12 years (89.62%) and lowest at 18 years (83.02%). Specificity values were higher for ages 12 and 14 (93.98% and 95.24%, respectively). The lowest AUC value was recorded for 18 years (0.889), while for ages 12, 14, and 16, the values were similar, indicating lower reliability for the legal age of 18.

CONCLUSION

For individuals under 12, 14, 16, and 18 years old, the bone method is the most effective. However, combining both methods allows greater accuracy and consistency in age estimation for medico-legal applications.

Bone Age Assessment Using Various Medical Imaging Techniques Enhanced by Artificial Intelligence

Bone age (BA) reflects skeletal maturity and is crucial in clinical and forensic contexts, particularly for growth assessment, adult height prediction, and managing conditions like short stature and precocious puberty, often using X-ray, MRI, CT, or ultrasound imaging. Traditional BA assessment methods, including the Greulich-Pyle and Tanner-Whitehouse techniques, compare morphological changes to reference atlases. Despite their effectiveness, factors like genetics and environment complicate evaluations, emphasizing the need for new methods that account for comprehensive variations in skeletal maturity. The limitations of classical BA assessment methods increase the demand for automated solutions. The first automated tool, HANDX, was introduced in 1989. Researchers now focus on developing reliable artificial intelligence (AI)-driven tools, utilizing machine learning and deep learning techniques to improve accuracy and efficiency in BA evaluations, addressing traditional methods' shortcomings. Recent reviews on BA assessment methods rarely compare AI-based approaches across imaging technologies. This article explores advancements in BA estimation, focusing on machine learning methods and their clinical implications while providing a historical context and highlighting each approach's benefits and limitations.

A probability model for estimating age in young individuals relative to key legal thresholds: 15, 18 or 21-year

Age estimations are relevant for pre-trial detention, sentencing in criminal cases and as part of the evaluation in asylum processes to protect the rights and privileges of minors. No current method can determine an exact chronological age due to individual variations in biological development. This study seeks to develop a validated statistical model for estimating an age relative to key legal thresholds (15, 18, and 21 years) based on a skeletal (CT-clavicle, radiography-hand/wrist or MR-knee) and tooth (radiography-third molar) developmental stages. The whole model is based on 34 scientific studies, divided into examinations of the hand/wrist (15 studies), clavicle (5 studies), distal femur (4 studies), and third molars (10 studies). In total, data from approximately 27,000 individuals have been incorporated and the model has subsequently been validated with data from 5,000 individuals. The core framework of the model is built upon transition analysis and is further developed by a combination of a type of parametric bootstrapping and Bayesian theory. Validation of the model includes testing the models on independent datasets of individuals with known ages and shows a high precision with separate populations aligning closely with the model's predictions. The practical use of the complex statistical model requires a user-friendly tool to provide probabilities together with the margin of error. The assessment based on the model forms the medical component for the overall evaluation of an individual's age.

Application of Vieth staging in forensic age estimation in the living using MRI of the distal radial epiphysis

Forensic age estimation is crucial in various legal and civil contexts, particularly in regions experiencing significant migration and inadequate birth registration systems. This study evaluates the applicability of the Vieth staging system for forensic age estimation in the living using MRI of the distal radial epiphysis. A retrospective analysis was conducted on 620 left wrist MRI scans from individuals aged 9.92 to 29.58 years. The study demonstrated high intra- and inter-observer agreement values (κ = 0.974 and κ = 0.961), confirming the method's reliability. Spearman's rank correlation analysis showed significant positive correlations between age and ossification stage for both sexes. The minimum ages observed for males were 9.92 years at stage 2, 15.00 years at stage 3, 15.00 years at stage 4, 17.00 years at stage 5, and 20.00 years at stage 6. For females, the minimum ages were 10.08 years at stage 2, 12.33 years at stage 3, 14.25 years at stage 4, 16.33 years at stage 5, and 18.42 years at stage 6. The study supports the applicability of the Vieth methodology for forensic age estimation in the living and suggests that MRI could be a non-invasive and potentially effective tool for determining critical age thresholds in forensic contexts. Further research is recommended to refine these methods and explore their applicability across different populations.

T2-weighted spoiled gradient echo MRI for forensic age estimation: a study on knee growth plates

The timing of growth plate fusion is a key indicator for age estimation and is primarily used in forensic investigations. On the other hand, non-ionizing techniques such as MRI are being developed to provide safer and more ethical evaluations in forensic casework. This study aims to evaluate the closure process of growth plates in the distal femoral and proximal tibial epiphyses using Multiple Echo Recombined Gradient Echo (MERGE) MRI sequences and provide age estimation data based on staging methods for forensic purposes. We retrospectively analyzed 559 patients (294 males, 265 females, aged 8-25 years) diagnosed with trauma and knee pain at Tepecik Training and Research Hospital from 2016 to 2019. MRI scans were performed using a 1.5-T system with MERGE sequences and evaluated by two observers using a new staging system. Observer agreement was assessed using Cohen's κ test, yielding high agreement values (κ > 0.8). Positive correlations were found between age and ossification stages (p < 0.001). Minimum age thresholds for stages 5a and 5b of the distal femoral epiphysis were 16 and 18 years for females and 17 and 19 years for males, respectively. For the proximal tibial epiphysis, the minimum ages for stages 5a and 5b were 15 years for females and 17 years for males. The MERGE sequence provides a viable method for assessing skeletal maturity in living individuals with significant ethical advantages due to non-ionizing radiation. This study supports the potential application of the MERGE sequence in forensic age estimation, demonstrating high observer agreement and consistency. Future research should focus on comparing different sequences and populations to enhance the methodology's applicability.

Paediatric Prosthetic Knee Design: The Technical Requirements of a Swing Phase Control Mechanism Are Correlated With Parameters of Childhood Growth

OBJECTIVE

There is a lack of innovation in affordable prosthetic knee joints for children. One significant reason is the absence of technical requirements which consider the foundation of childhood: growth. This study aims to develop and use a modelling tool to determine the technical requirements throughout childhood growth for one prosthetic knee design feature, a swing phase control mechanism (SPCM).

METHODS

3D gait data of 31 non-disabled children across a range of physical maturities were analyzed. For each participant 2 models were created from a validated paediatric non-disabled musculoskeletal model. The model was first linearly scaled, then a corresponding unilateral right knee-disarticulation amputation model produced by removing segments below the knee and replacing with prosthetic componentry. Long established low-cost prosthetic componentry and a novel polycentric knee were implemented. For each participant, inverse dynamics were conducted and the SPCM torque requirements defined.

RESULTS

Prosthetic knee SPCM torque requirements were significantly less than the non-disabled knee to emulate non-disabled gait at free speed: 17.9% (± 10.2) and 66.3% (± 17.0) reduction in maximum extension and flexion torque, respectively. Maximum knee extension torque showed the strongest negative correlation with intact body mass (ρ = -0.6251) whereas flexion torque showed the strongest correlation with height (ρ = 0.6611). Corresponding linear regression fits produced RMSE of 1.91and 1.73 Nm, respectively. Results were also determined for slow and fast speeds.

CONCLUSION

The torque requirements of an affordable paediatric prosthetic knee SPCM are defined and found to strongly correlate with parameters of childhood growth (body mass, height, and age).

SIGNIFICANCE

Current results recommend low-cost paediatric prosthetic SPCM designs can be tailored to accommodate growth. The creation of musculoskeletal models facilitate multiple future studies.

Forensic age estimation of adolescents using computed tomography of the clavicles

In forensic age estimation, CT imaging of the clavicles is used to determine an age over completed 21 years. If ossification of the medial clavicular epiphysis is complete, young men are assumed to be over 21 years of age. The aim of this study is to check the statistical parameters (specificity, predictive probability) for the characteristic "completed ossification of the medial clavicles". 285 male patients who, for various reasons, received a chest CT at the Medical Center of the University of Freiburg between 1st December 2019 and 6th December 2022 were screened for the study, of whom 203 patients were included in the study. The stage of clavicular ossification was classified as stage 1 - 5 according to Schmeling. While 70 out of 71 patients under 21 years of age were correctly estimated to be under 21 years of age, there was one patient whose ossification on one side was classified as stage 4 and who would therefore have been estimated to be over 21 years of age. If only subjects whose ossification stage was the same on both sides are included, the specificity of the test method is 100% and the positive predictive probability is 100%. If patients for whom only one side is stage 4 are also included, the specificity is 98.6%. Thus, only the complete and symmetrical ossification of both clavicles (stage 4 according to the Schmeling classification) in a standardised thin-layer CT can be classified as a reliable indicator of an age over 21 years in young men. In the case of asymmetric ossification of the medial clavicles (stage 4 is not reached on one side), false positive evaluations and the incorrect assumption of an age over 21 years can occur.

Forensic age estimation by MRI of the knee - comparison of two classifications for ossification stages in a German population

AIM AND OBJECTIVES

In forensic age estimation e.g. for judicial proceedings surpassed age thresholds can be legally relevant. To examine age related differences in skeletal development the recommendations by the Study Group on Forensic Age Diagnostics (AGFAD) are based on ionizing radiation (among others orthopantomograms, plain x-rays of the hand). Vieth et al. and Ottow et al. proposed MRI-classifications for the epiphyseal-diaphyseal fusion of the knee joint to define different age groups in healthy volunteers. The aim of the present study was to directly compare these two classifications in a large German patient population.

MATERIALS AND METHODS

MRI of the knee joint of 900 patients (405 female, 495 male) from 10 to 28 years of age were retrospectively analyzed. Acquired T1-weighted turbo spin-echo sequence (TSE) and T2-weighted sequence with fat suppression by turbo inversion recovery magnitude (TIRM) were analyzed for the two classifications. The different bony fusion stages of the two classifications were determined and the corresponding chronological ages assigned. Differences between the sexes were analyzed. Intra- and inter-observer agreements were determined using Cohen's kappa.

RESULTS

With the classification of Ottow et al. it was possible to determine completion of the 18th and 21st year of life in both sexes. With the classification of Vieth et al. completion of the 18th year of life for female patients and the 14th and 21st year of life in both sexes could be determined. The intra- and inter-observer agreement levels were very good (κ > 0.82).

CONCLUSION

In the large German patient cohort of this study it was possible to determine the 18th year of life with for both sexes with the classification of Ottow et al. and for female patients with the classification of Vieth et al. It was also possible to determine the 21st year of life for all bones with the classification of Ottow et al. and for the distal femur with the classification of Vieth et al.

Forensic age estimation at the University Center of Legal Medicine Lausanne-Geneva: a retrospective study over 12 years

With the undeniable increase in asylum requests from unaccompanied alleged minors, age estimation of living individuals has become an essential part of the routine work in European forensic centers. This study aims to review the forensic age estimations performed in our center since 2010, to evaluate the state-of-the-art of this practice in Switzerland with the evolution of the methodology according to upcoming recommendations. Our institute's expert reports performed between 2010 and 2022 were retrospectively analyzed. We gathered the following parameters: demographic data, morphological characteristics, alleged age compared with the assessed minimum age, sexual maturation, dental and bone age. When available, we collected personal and family history, medical history, records of torture-related/self-inflicted injuries, and information about eating habits that might affect skeletal development. Data collection amounted to 656 cases. Forensic age estimations ordered by the Swiss Secretariat for Migration (SEM) represented 76.4% of cases, with 23.6% of them ordered by the Court/Public Prosecutor. Most alleged minors were male (94.5%) and came from Afghanistan (53.4%). Adjunction of CT scans of the sternoclavicular joints was necessary in 86.4% of cases. Only 25.2% of our reports concluded on most probable minority, with 55.6% of definite majors; in 19.2% of our cases, minority could not be excluded. This study aspires to further broaden our expertise regarding forensic age estimations. Given the increasing migratory flows, we can expect a notable increase in the frequency of these requests. Consequently, this study aims to promote a multidisciplinary approach and the international standardization of the methodology of these estimations.

Radiological age assessment based on clavicle ossification in CT: enhanced accuracy through deep learning

BACKGROUND

Radiological age assessment using reference studies is inherently limited in accuracy due to a finite number of assignable skeletal maturation stages. To overcome this limitation, we present a deep learning approach for continuous age assessment based on clavicle ossification in computed tomography (CT).

METHODS

Thoracic CT scans were retrospectively collected from the picture archiving and communication system. Individuals aged 15.0 to 30.0 years examined in routine clinical practice were included. All scans were automatically cropped around the medial clavicular epiphyseal cartilages. A deep learning model was trained to predict a person's chronological age based on these scans. Performance was evaluated using mean absolute error (MAE). Model performance was compared to an optimistic human reader performance estimate for an established reference study method.

RESULTS

The deep learning model was trained on 4,400 scans of 1,935 patients (training set: mean age = 24.2 years ± 4.0, 1132 female) and evaluated on 300 scans of 300 patients with a balanced age and sex distribution (test set: mean age = 22.5 years ± 4.4, 150 female). Model MAE was 1.65 years, and the highest absolute error was 6.40 years for females and 7.32 years for males. However, performance could be attributed to norm-variants or pathologic disorders. Human reader estimate MAE was 1.84 years and the highest absolute error was 3.40 years for females and 3.78 years for males.

CONCLUSIONS

We present a deep learning approach for continuous age predictions using CT volumes highlighting the medial clavicular epiphyseal cartilage with performance comparable to the human reader estimate.

Demystifying the Radiography of Age Estimation in Criminal Jurisprudence: A Pictorial Review

Skeletal radiographs along with dental examination are frequently used for age estimation in medicolegal cases where documentary evidence pertaining to age is not available. Wrist and hand radiographs are the most common skeletal radiograph considered for age estimation. Other parts imaged are elbow, shoulder, knee, and hip according to suspected age categories. Age estimation by wrist radiographs is usually done by the Tanner-Whitehouse method where the maturity level of each bone is categorized into stages and a final total score is calculated that is then transformed into the bone age. Careful assessment and interpretation at multiple joints are needed to minimize the error and categorize into age-group. In this article, we aimed to summarize a suitable radiographic examination and interpretation for bone age estimation in living children, adolescents, young adults, and adults for medicolegal purposes.

MRI segmentation of tooth tissue in age prediction of sub-adults - a new method for combining data from the 1st, 2nd, and 3rd molars

PURPOSE

We aimed to establish a model combining MRI volume measurements from the 1st, 2nd and 3rd molars for age prediction in sub-adults and compare the age prediction performance of different combinations of all three molars, internally in the study cohort.

MATERIAL AND METHOD

We examined 99 volunteers using a 1.5 T MR scanner with a customized high-resolution single T2 sequence. Segmentation was performed using SliceOmatic (Tomovision©). Age prediction was based on the tooth tissue ratio (high signal soft tissue + low signal soft tissue)/total. The model included three correlation parameters to account for statistical dependence between the molars. Age prediction performance of different combinations of teeth for the three molars was assessed using interquartile range (IQR).

RESULTS

We included data from the 1st molars from 87 participants (F/M 59/28), 2nd molars from 93 (F/M 60/33) and 3rd molars from 67 (F/M 45/22). The age range was 14-24 years with a median age of 18 years. The model with the best age prediction performance (smallest IQR) was 46-47-18 (lower right 1st and 2nd and upper right 3rd molar) in males. The estimated correlation between the different molars was 0.620 (46 vs. 47), 0.430 (46 vs. 18), and 0.598 (47 vs. 18). IQR was the smallest in tooth combinations including a 3rd molar.

CONCLUSION

We have established a model for combining tissue volume measurements from the 1st, 2nd and 3rd molars for age prediction in sub-adults. The prediction performance was mostly driven by the 3rd molars. All combinations involving the 3rd molar performed well.

Age Estimation Based on Computed Tomography Analysis of the Scapula

Background and Objectives: Age estimation from skeletal remains and in living individuals is an important issue for human identification, and also plays a critical role in judicial proceedings for migrants. Forensic analysis of ossification centers is the main evaluation method for age estimation, and ossification degree can be determined using computed tomography analysis. The purpose of this study is to investigate the applicability of CT (computed tomography) in the analysis of left scapula ossification centers, for forensic age estimation in Turkish society. Materials and Methods: We analyzed six ossification centers of the left scapula and these ossification centers are the coracoid, subcoracoid, coracoid apex, acromial, glenoid, and inferior angle ossification centers. A pediatric radiologist analyzed these six ossification centers of the scapula by using a staging method defined by Schmeling et al. in 2004. Two months after the first assessment, 20 randomly selected cases was reanalyzed by the first observer and by another pediatric radiologist. Correlation between the age and ossification stage was assessed using Spearman's nonparametric correlation test. Linear regression analysis was performed using a backwards model. Cohen's kappa coefficient was used for evaluating interobserver and intraobserver variability. Results: In this retrospective study, 397 (248 male and 149 female) cases were evaluated. Ages ranged between 7.1 and 30.9. The mean age was 19.83 ± 6.49. We determined a positive significant correlation between the age and the ossification stages of ossification centers analyzed in both sexes. In each ossification center, except inferior angle, all of the stage 1 and 2 cases in both sexes were under 18 years old. Intraobserver and interobserver evaluations showed that reproducibility and consistency of the method was relatively good. Conclusions: The present study indicated that CT analysis of scapula ossification centers might be helpful in forensic age assessment of living individuals and dry bones.

Forensic Diagnostics of the Skeletal Age in the Living - Backgrounds and Methodology

BACKGROUND

The expert opinions on forensic age diagnostics requested by state institutions are used to show the exceeding of legally relevant age thresholds, especially the completed 18th year of life. According to the recommendations of the Study Group on Forensic Age Diagnostics (AGFAD), this requires - among other things - a determination of skeletal age.

METHOD

Considering recent scientific knowledge, the current conditions and established skeletal age diagnostics methods are presented. Additionally, this review article sheds light on the influence of ethnicity and socioeconomic status, questions regarding indication, as well as alternative and future developments.

RESULTS AND CONCLUSION

In forensic age diagnostics, particularly hand radiography and thin-slice CT of the medial clavicular epiphysis are relevant for determining skeletal age. The Atlas method of Greulich and Pyle (1959) and the clavicular stages by Schmeling et al. (2004) and Kellinghaus et al. (2010) are primarily used for this. This spectrum of methods, which is based on a very solid database, might be supplemented by MRI studies of the knee joint in the near future.

KEY POINTS

· Determining skeletal age is an essential part of forensic age diagnostics commissioned by state authorities and courts.. · Hand radiography and CT of the medial clavicular epiphysis form the core of the spectrum of methods recommended by the Study Group of Forensic Age Diagnostics (AGFAD).. · Since the radiological studies required for forensic age diagnostics are not medically indicated, it must be ensured that the legal basis is specifically named in each case when commissioning expert opinions.. · MRI studies of the knee joint might increase the spectrum of methods in the near future..

CITATION FORMAT

· Wittschieber D, Hahnemann ML, Mentzel H. Forensic Diagnostics of the Skeletal Age in the Living - Backgrounds and Methodology. Fortschr Röntgenstr 2024; 196: 254 - 261.

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

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

Should we consider the sex when estimating bone age from hand bone biometrics?

BACKGROUND

Recently, it was proposed to estimate age from the biometric information of hand bones. We observed that these estimations became less precise as children get older, especially from the age of 13-15 years.

OBJECTIVE

This study aimed to evaluate the influence of considering sex for age estimation based on hand bones biometrics.

MATERIALS AND METHODS

The study sample consisted of metacarpals and proximal phalanges measurements collected on 1003 medical images performed at Nancy and Marseille Hospitals of individuals aged under 21 years. This sample was divided into two subgroups delineated by the age of 13, as it is a relevant legal threshold for most European countries. First, the influence of sex on the hand bones biometrics and on the estimated age was evaluated. Then, based on these results, new sex-specific age estimation formulas were constructed from linear models and their precision was assessed using residual analysis, in comparison with previous global formulas.

RESULTS

An influence of sex was only highlighted from the age of 13 and for the total study sample. Thus, new sex-specific age estimation formulas were built for the [1-21] global sample and the [13-21] subsample. Even though the differences with the previous formulas were minor, age was more accurately estimated when sex was considered.

CONCLUSION

Considering sex in age estimation is relevant when relying on hand bone biometrics. A new tool was proposed to select the most appropriate age estimation formula, based on the discriminant analysis result and the a priori knowledge of the sex.

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

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

Skeletal age estimation of living adolescents and young adults: A pilot study on conventional radiography versus magnetic resonance imaging and staging technique versus atlas method

OBJECTIVE

To compare conventional radiography (CR) and magnetic resonance imaging (MRI) of the left hand/wrist and both clavicles for forensic age estimation of adolescents and young adults.

MATERIALS AND METHODS

CR and MRI were prospectively conducted in 108 healthy Caucasian volunteers (52 males, 56 females) aged 16 to 21 years. Skeletal development was assessed by allocating stages (wrist, clavicles) and atlas standards (hand/wrist). Inter- and intra-observer agreements were quantified using linear weighted Cohen's kappa, and descriptive statistics regarding within-stage/standard age distributions were reported.

RESULTS

Inter- and intra-observer agreements for hand/wrist CR (staging technique: 0.840-0.871 and 0.877-0.897, respectively; atlas method: 0.636-0.947 and 0.853-0.987, respectively) and MRI (staging technique: 0.890-0.932 and 0.897-0.952, respectively; atlas method: 0.854-0.941 and 0.775-0.978, respectively) were rather similar. The CR atlas method was less reproducible than the staging technique. Inter- and intra-observer agreements for clavicle CR (0.590-0.643 and 0.656-0.770, respectively) were lower than those for MRI (0.844-0.852 and 0.866-0.931, respectively). Furthermore, although shifted, wrist CR and MRI within-stage age distribution spread were similar, as were those between staging techniques and atlas methods. The possibility to apply (profound) substages to clavicle MRI rendered a more gradual increase of age distributions with increasing stages, compared to CR.

CONCLUSIONS

For age estimation based on the left hand/wrist and both clavicles, reference data should be considered anatomical structure- and imaging modality-specific. Moreover, CR is adequate for hand/wrist evaluation and a wrist staging technique seems to be more useful than an atlas method. By contrast, MRI is of added value for clavicle evaluation.

Prediction of Age Older than 18 Years in Sub-adults by MRI Segmentation of 1st and 2nd Molars

PURPOSE

To investigate prediction of age older than 18 years in sub-adults using tooth tissue volumes from MRI segmentation of the entire 1st and 2nd molars, and to establish a model for combining information from two different molars.

MATERIALS AND METHODS

We acquired T2 weighted MRIs of 99 volunteers with a 1.5-T scanner. Segmentation was performed using SliceOmatic (Tomovision©). Linear regression was used to analyse the association between mathematical transformation outcomes of tissue volumes, age, and sex. Performance of different outcomes and tooth combinations were assessed based on the p-value of the age variable, common, or separate for each sex, depending on the selected model. The predictive probability of being older than 18 years was obtained by a Bayesian approach using information from the 1st and 2nd molars both separately and combined.

RESULTS

1st molars from 87 participants, and 2nd molars from 93 participants were included. The age range was 14-24 years with a median age of 18 years. The transformation outcome (high signal soft tissue + low signal soft tissue)/total had the strongest statistical association with age for the lower right 1st (p= 7.1*10-4 for males) and 2nd molar (p=9.44×10-7 for males and p=7.4×10-10 for females). Combining the lower right 1st and 2nd molar in males did not increase the prediction performance compared to using the best tooth alone.

CONCLUSION

MRI segmentation of the lower right 1st and 2nd molar might prove useful in the prediction of age older than 18 years in sub-adults. We provided a statistical framework to combine the information from two molars.

Evaluation of distal tibial epiphysis and calcaneal epiphysis according to the Vieth method in 3.0 T magnetic resonance images: a pilot study

In forensic medicine practice, age estimation-both in living and deceased individuals-can be requested due to legal requirements. Radiologic methods, such as X-rays, for the estimation of bone age have been discussed, and ethical concerns have been raised. Given these factors, radiologic methods that reduce radiation exposure have gained importance and have become one of the research topics in forensic medicine. In this study, the MR images of the ankles of patients aged between 8 and 25 years, obtained with a 3.0 T MR scanner, were evaluated retrospectively according to the staging method defined by Vieth et al. In the study, the ankle MR images of 201 cases (83 females and 118 males) with sagittal T1-weighted turbo spin echo and T2-weighted short tau inversion recovery sequences were evaluated independently by two observers. According to the results of our study, the intra- and inter-observer agreements are at a very good level for both the distal tibial and calcaneal epiphyses. All the cases detected as stages 2, 3, and 4 in both sexes for both the distal tibial and the calcaneal epiphyses have been determined to be under the age of 18 years. According to the data obtained from our study, we consider that stage 5 for males and stage 6 for both sexes in the distal tibial epiphysis and stage 6 for males in the calcaneal epiphysis can be used to estimate the age of 15 years. As far as we know, our study is the first to evaluate ankle MR images with the method defined by Vieth et al. Further studies should be conducted to evaluate the validity of the procedure.

Evaluation of two methods of bone age assessment in peripubertal children in Zimbabwe

OBJECTIVES

Bone age (BA) measurement in children is used to evaluate skeletal maturity and helps in the diagnosis of growth disorders in children. The two most used methods are Greulich and Pyle (GP), and Tanner and Whitehouse 3 (TW3), both based upon assessment of a hand-wrist radiograph. To our knowledge no study has compared and validated the two methods in sub-Saharan Africa (SSA), and only a few have determined BA despite it being a region where skeletal maturity is often impaired for example by HIV and malnutrition. This study aimed to compare BA as measured by two methods (GP and TW3) against chronological age (CA) and determine which method is most applicable in peripubertal children in Zimbabwe.

METHODS

We conducted a cross-sectional study of boys and girls who tested negative for HIV. Children and adolescents were recruited by stratified random sampling from six schools in Harare, Zimbabwe. Non-dominant hand-wrist radiographs were taken, and BA assessed manually using both GP and TW3. Paired sample Student t-tests were used to calculate the mean differences between BA and chronological age (CA) in boys and girls. Bland-Altman plots compared CA to BA as determined by both methods, and agreement between GP and TW3 BA. All radiographs were graded by a second radiographer and 20 % of participants of each sex were randomly selected and re-graded by the first observer. Intraclass correlation coefficient assessed intra- and inter-rater reliability and coefficient of variation assessed precision.

RESULTS

We recruited 252 children (111 [44 %] girls) aged 8.0-16.5 years. The boys and girls were of similar mean ± SD CA (12.2 ± 2.4 and 11.7 ± 1.9 years) and BA whether assessed by GP (11.5 ± 2.8 and 11.5 ± 2.1 years) or TW3 (11.8 ± 2.5 and 11.8 ± 2.1 years). In boys BA was lower than CA by 0.76 years (95 % CI: -0.95, -0.57) when using GP, and by 0.43 years (95 % CI: -0.61, -0.24) when using TW3. Among the girls there was no difference between BA and CA by either GP [-0.19 years (95 % CI: -0.40, 0.03)] or TW3 [0.07 years (95 % CI: -0.16, 0.29)]. In both boys and girls, there were no systematic differences between CA and TW3 BA across age groups whereas agreement improved between CA and GP BA as children got older. Inter-operator precision was 1.5 % for TW3 and 3.7 % for GP (n = 252) and intra-operator precision was 1.5 % for TW3 and 2.4 % for GP (n = 52).

CONCLUSION

The TW3 BA method had better precision than GP and did not systematically differ from CA, meaning that TW3 is the preferred method of assessment of skeletal maturity in Zimbabwean children and adolescents. TW3 and GP methods do not agree for estimates of BA and therefore cannot be used interchangeably. The systematic differences in GP BA assessments over age means it is not appropriate for use in all age groups or stages of maturity in this population.

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

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

A machine-learning approach using pubic CT based on radiomics to estimate adult ages

PURPOSE

Adult skeletal age estimation is an active research field. To evaluate the performance of a pubic CT radiomics-based machine learning model for estimating age, we established a multiple linear regression model based on radiomics and machine learning methods.

METHODS

A total of 355 subjects were enrolled in this retrospective study from August 2016 to August 2021, and divided into a training cohort (N = 325) and a testing cohort (N = 30). Computerized texture analysis of the semi-automatically segmentation was performed and 107 texture features were extracted from the regions. Then we used univariate linear regression and multivariate stepwise regression to assess correlations of texture parameters with age. The most vital features were used to make the best predictive model. Eventually, the established radiomics model was tested with an additional 30 patients.

RESULTS

Clinical characteristics include age, sex, height, weight and BMI were not statistically significant different between training and testing cohort (p = 0.098-0.888). Through a multivariate regression analysis using stepwise regression, six texture parameters were found to have significant correlations with age. The regression formula estimating the age was constructed.

CONCLUSIONS

The radiomics model using machine learning is considered as a new approach forage estimation frompubic symphysis CT features.Digital osteology is obtained in a non-invasive way so that it can be an ideal collection for anthropological studies.

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.

Forensische Altersdiagnostik mittels Niederfeld-Magnetresonanztomographie

Hintergrund

Ein rechtlich zulässiges medizinisches Altersfeststellungsverfahren mit möglichst schonenden und zuverlässigen Methoden bei unbegleiteten und fraglich minderjährigen Ausländern ist erforderlich, um den tatsächlich Minderjährigen den für sie gesetzlich vorgesehenen besonderen Schutz zukommen zu lassen.

Ziel der Arbeit

Studiendesign und erste Ergebnisse einer Studie zur forensischen Altersdiagnostik mittels Niederfeld-Magnetresonanztomographie werden vorgestellt.

Material und Methoden

Geplant ist die prospektive Untersuchung von 650 Studienteilnehmenden, gleichmäßig verteilt innerhalb der Altersgruppe 12 bis 24 Jahre zu je 25 Personen je Geschlecht. Es sollen Entwicklungsstadien von distalem Radius, distaler Ulna, distalem Femur und proximaler Tibia mithilfe eines 0,31-Tesla(T)-Niederfeld-MRT-Scanners erfasst und mittels Anwendung der Vieth-Klassifikation ausgewertet werden.

Ergebnisse

Nach Auswertung der Untersuchungen der bisher 487 untersuchten Studienteilnehmenden ist ersichtlich, dass die gewählten Sequenzen die für die Vieth-Klassifikation relevanten Charakteristika der Ossifikation der untersuchten Epiphysen erfassen. Die Untersuchungen erweisen sich überdies als einfach in der Durchführung.

Schlussfolgerung

Untersuchungen zur forensischen Altersschätzung am Lebenden unter Anwendung der Vieth-Klassifikation sind mit Niederfeld-MRT-Scannern bei einer Feldstärke von 0,31 T durchführbar. Es bleibt zu klären, ob die mit einem 0,31-T-Niederfeld-MRT-Scanner nachweisbaren Ossifikationsmerkmale am Handgelenk und am Knie einen zweifelsfreien Volljährigkeitsnachweis erlauben.

Multiple Regression Modeling for Age Estimation by Assessment and Comparison of Spheno-Occipital Synchondrosis Fusion and Cervical Vertebral Maturation Stages

Objectives The aim of this study was (1) to evaluate the relationship between spheno-occipital synchondrosis (SOS) fusion stages, cervical vertebral maturation (CVM) stages, and clivus sizes with chronological age on cone-beam computed tomography (CBCT) images, and (2) to compare these methods for accurate age estimation using regression analysis.

Methods The CBCT images of 200 individuals (102 females and 98 males) were included in the study. The SOS fusion stages and CVM stages were evaluated. The width and length of the clivus were measured. The effects of SOS fusion stages, CVM stages, clivus width, and clivus length on age estimation were evaluated by univariate tests and the effects of coexistence with ANCOVA and regression model. Spearman rank correlation analysis was also used to investigate the relationship between the SOS fusion stage, CVM stage, clivus width, and clivus length.

Results The SOS stages, CVM stages, and clivus width were not shown statistically significant differences between the sexes (p-values = 0.205, 0.162, and 0.277, respectively), whereas clivus length was significantly longer in males (42.9 ± 4.26 mm) than in females (41.04 ± 3.74 mm). Multiple regression analysis showed 80% success when all parameters (SOS fusion stages, CVM stages, clivus width, and clivus length) were taken into consideration.

Conclusion In conclusion, with the use of CVM stages and SOS fusion stages together, an accurate and reliable age estimation can be obtained in forensic medicine.

Dental age estimation with fewer than mandibular seven teeth: An accuracy study of Bedek models in Turkish children

OBJECTIVES

One or more missing teeth, such as hypodontia, make it difficult to obtain accurate results in age estimation methods. This paper aims to test the accuracy of the models developed by Bedek et al. that can estimate age with fewer than seven teeth for Turkish children.

MATERIALS AND METHODS

Panoramic radiographs of 1118 children (540 girls and 578 boys) aged between 6 and 16 years were evaluated using the Willems method and Bedek models for the entire sample and for different ages and sexes. Differences between dental age (DA) and chronological age (CA) calculated for all methods for each sex and all age groups were analyzed the paired sample t-test and Wilcoxon signed rank test. The accuracy of the DA estimation methods was determined by the proximity of DA to CA by calculating mean absolute error (MAE).

RESULTS

While all Bedek models underestimated CA by 0.2 to 0.1 years, the Willems method overestimated CA by 0.3 years. DA-CA difference in the total sample and girls was statistically significant in all methods. In the total sample, the seven- and four-teeth models had the lowest MAE, while the one-tooth model had the highest MAE.

CONCLUSIONS

Seven- and four-teeth models were the most suitable for age estimation, and all models except the one-tooth model were found to be more accurate than the Willems method in northwestern Turkish children.

CLINICAL RELEVANCE

Especially in children with hypodontia, it may be possible to estimate DA with the use of Bedek models.

Alternative methods for skeletal maturity estimation with the EOS scanner—Experience from 934 patients

Background

Hand-wrist bone age assessment methods are not possible on typical EOS 2D/3D images without body position modifications that may affect spinal position. We aimed to identify and assess lesser known bone age assessment alternatives that may be applied retrospectively and without the need for extra imaging.

Materials and methods

After review of 2857 articles, nine bone age methods were selected and applied retrospectively in pilot study (thirteen individuals), followed by evaluation of EOS images of 934 4-24-year-olds. Difficulty of assessment and time taken were recorded, and reliability calculated.

Results

Five methods proved promising after pilot study. Risser ‘plus’ could be applied with no difficulty in 89.5% of scans (836/934) followed by the Oxford hip method (78.6%, 734/934), cervical (79.0%, 738/934), calcaneus (70.8%, 669/934) and the knee (68.2%, 667/934). Calcaneus and cervical methods proved to be fastest at 17.7s (95% confidence interval, 16.0s to 19.38s & 26.5s (95% CI, 22.16s to 30.75s), respectively, with Oxford hip the slowest at 82.0 s (95% CI, 76.12 to 87.88s). Difficulties included: regions lying outside of the image—assessment was difficult or impossible in upper cervical vertebrae (46/934 images 4.9%) and calcaneus methods (144/934 images, 15.4%); position: lower step length was associated with difficult lateral knee assessment & head/hand position with cervical evaluation; and resolution: in the higher stages of the hip, calcaneal and knee methods.

Conclusions

Hip, iliac crest and cervical regions can be assessed on the majority of EOS scans and may be useful for retrospective application. Calcaneus evaluation is a simple and rapidly applicable method that may be appropriate if consideration is given to include full imaging of the foot.

Exploring the problem of determining human age from fingermarks using MALDI MS-machine learning combined approaches

For over a century fingerprints have been predominantly used as a means of biometric identification. Notwithstanding, the unique pattern of lines that can contribute to identifying a suspect is made up of molecules originating from touch chemistry (contaminants) as well as from within the body. It is the latter class of molecules that could provide additional information about a suspect, such as lifestyle, as well as physiological, pharmacological and pathological states. An example of the physiological state (and semi-biometric information) is the sex of an individual; recent investigations have demonstrated the opportunity to determine the sex of an individual with an 86% accuracy of prediction based on the peptidic/protein profile of their fingerprints. In the study presented here, the first of its kind, a range of supervised learning predictive methods have been evaluated to explore the depth of the issue connected to human age determination from fingermarks exploiting again the differential presence of peptides and small proteins. A number of observations could be made providing (i) an understanding of the more appropriate study design for this kind of investigation, (ii) the most promising prediction model to test within future work and (iii) the deeper issues relating to this type of determination and concerning a mismatch between chronological and biological ages. Particularly resolving point (iii) is crucial to the success in determining the age of an individual from the molecular composition of their fingermark.

Age Estimation in Children by the Measurement of Open Apices in Teeth: A Study in the Western Indian Population

In forensic sphere and clinical dentistry, age estimation is a topic of utmost importance. Various techniques are employed in children to determine age; however, dental development has proven to be an appropriate method because of its low variability. Cameriere's method is a widely accepted method of age estimation in children, which is carried out by measuring the projections of open apices and also the heights of developing permanent teeth seen on panoramic radiographs. The aim of this study is to establish a new formula for age estimation in the Western Indian population by measuring the open apices of mandibular teeth using Cameriere's European formula. For this study, we included 311 panoramic radiographs of healthy children living in Western India (Maharashtra, Gujarat, and Goa) aged 4–15 years which were analysed by two independent researchers. Seven left permanent mandibular teeth were assessed for length and width of open apices. Dental maturity was evaluated using measurements of the left seven permanent mandibular teeth (x_i = A_i/L_i, i = 1,…, 7), the sum of the normalized open apices (s), and the number (N0) of teeth with complete root formation. A linear relationship between open apices, N0, age, and other factors was evaluated with the aid of a stepwise multiple regression model. A stepwise linear regression showed that all parameters, gender, s, N0, and x₅, were significantly associated with age (R = 85%). No statistically significant difference was found between the predicted and actual chronological age of children in the age group of 4–13 years using the regression equation for the Western Indian population. The present research suggests that the new regression formula developed will be more accurate for age assessment in the Western Indian population.

Forensic age assessment by 3.0 T MRI of the wrist: adaption of the Vieth classification

OBJECTIVES

In order to find a reliable method to correctly assess majority in both sexes by MRI, a study was conducted to evaluate the applicability of the recently presented Vieth classification in wrist MRI, after it had originally been proposed for knee MRI.

METHODS

After receiving a positive vote by the ethics committee, the left-hand wrists of 347 male and 348 female volunteers of German nationality in the age bracket 12-24 years were scanned. Before conducting the prospective, cross-sectional examinations, an informed consent was obtained from each volunteer. A 3.0 T MRI scanner was used, acquiring a T1 turbo spin-echo sequence (TSE) and a T2 TSE sequence with fat suppression by spectral presaturation with inversion recovery (SPIR). The images were assessed by applying the Vieth classification. Minimum, maximum, mean ± standard deviation, and median with lower and upper quartiles were defined. Intra- and interobserver agreements were determined by calculating the kappa coefficients. Differences between the sexes were analyzed using the Mann-Whitney U test.

RESULTS

By applying the unmodified Vieth classification with corresponding schematics, it was possible to assess majority in both sexes via the epiphyseal-diaphyseal fusion of the distal radius and in males also via the epiphyseal-diaphyseal fusion of the distal ulna. The Mann-Whitney U test implied significant sex-related differences for all stages. For both epiphyses, the intra- and interobserver agreement levels were very good (κ > 0.8).

CONCLUSION

If confirmed by further studies, it would be possible to determine the completion of the 18th year of life in both sexes by 3.0 T MRI of the wrist and using the Vieth classification.

KEY POINTS

• The Vieth classification allows determining majority in males and females alike based on the distal radius' epiphysis by 3.0 T MRI of the wrist. • The Vieth classification also allows determining majority in males based on the distal ulna's epiphysis by 3.0 T MRI of the wrist, but not in females. • The presented data can be deemed referential within certain discussed boundaries.

Magnetic resonance imaging of the proximal tibial epiphysis is suitable for statements as to the question of majority: a validation study in forensic age diagnostics

Determining majority plays a key role for forensic age diagnostics in living individuals. Recent data suggest that magnetic resonance imaging (MRI) of the proximal tibial epiphysis (PTE) may be a suitable alternative or at least an additional tool to clarify whether an individual has reached majority. However, the reference data situation is still sparse. Hence, the present dual center study retrospectively analyzed routine MRI of the knee in 413 cases (214 males and 199 females) of a Western Caucasian population aged between 12 and 25 years. MRI was performed at 1.5 and 3.0 T clinical scanners using T1- and T2-weighted sequences. The classification system by Vieth et al. (Eur Radiol 2018; 28:3255-3262) was applied for determining the ossification stages of the PTE. Intra-observer agreement was "very good" (κ = 0.931), and inter-observer agreement was "good" (κ = 0.798). Minimum ages above the age of 18 years were observed with the final stage (stage 6) in either sex (20.27 years in males and 18.55 years in females). The results are not in contradiction with the previous data and can be considered a strong and valuable support of the so far existing database. Therefore, the investigation of the PTE using routine MRI (either at 1.5 or 3.0 T) could be taken into consideration for application in forensic age estimation practice in near future.

A probability model for assessing age relative to the 18-year old threshold based on magnetic resonance imaging of the knee combined with radiography of third molars in the lower jaw

OBJECTIVE

This study aims to generate a statistical model based on magnetic resonance imaging of the knee and radiography of third molars in the lower jaw, for assessing age relative to the 18-year old threshold.

METHODS

In total, 58 studies correlating knee or tooth development to age were assessed, 5 studies for knee and 7 studies for tooth were included in the statistical model. The relation between the development of the anatomical site, based on a binary system, and age were estimated using logistic regression. Separate meta-populations for knee and tooth were generated from the individual based data for men and women. A weighted estimate of probabilities was made by combining the probability densities for knee and tooth. Margin of errors for males and females in different age groups and knee and tooth maturity were calculated within the larger framework of transition analysis using a logit model as a base. Evidentiary values for combinations of knee and tooth maturity were evaluated with likelihood ratios.

RESULTS

For males, the sensitivity for the method was calculated to 0.78 (probability of correctly classifying adults), the specificity 0.90 (probability of correctly classifying minors), the negative predictive value 0.80 (proportion identified minors are minors) and the positive predictive value 0.89 (proportion identified adults are adults) indicating a model better at identifying minors than adults. The point at which half the female population has reached closed knee lies before the 18-year threshold, adding the knee as an indicator lowers specificity and increases sensitivity. The sensitivity when using tooth as an indicator for females is 0.24 and specificity 0.97, signifying few minors misclassified as adults but also a low probability of identifying adults. The negative predictive value for women when using tooth as the sole indicator is 0.56 and positive predictive value 0.88. Probabilities were calculated for males and females assuming a uniform age distribution between 15 and 21years. The calculated margin of error of minors classified as adults in a population between 15 and 21 years with the model was 11% for males and 12% for females. Further, the evidentiary value as well as margin of error vary for different combinations of knee and tooth maturity.

CONCLUSION

The statistical model based on the combination of MRI knee and radiography of mandibular third molars is a valid method to assess age relative to the 18-year old threshold when applied on males and of limited value in females.

Analysis of interrater reliability in age assessment of minors: how does expertise influence the evaluation?

Nowadays, the clinical forensic medical management of migration flows comprises the age assessment of unaccompanied minors. The process of age estimation is a fundamental pillar for legally ensuring the minors' rights and their protection needs. The procedure is complex and involves different phases and actors, from medical doctors to law enforcement officers. The present study aimed to investigate the performance of Greulich and Pyle, Demirjian, and Mincer methods when performed by raters both trained and without training. Also, the interrater reliability within groups of raters from different areas of expertise was evaluated. A total of 36 participants were enrolled for this study, divided in two groups according to their level of experience with age estimation methods. Each rater was asked to allocate stages and standards for age assessment, evaluating ten orthopantomograms and ten hand-wrist roentgenograms. The interrater reliability expressed through the Fleiss Kappa coefficient and the agreement with the reference standard were calculated. The results showed that none of the categories analyzed could reach a good interrater reliability (ĸ > 0.8) for both methods. The study results highlighted variation and disagreement in the interpretation of the sample among raters and in the subsequent stages and standards allocation. In conclusion, the results of this study highlight that expertise does influence the reliability of the most utilized methods of age estimation of living individuals and stress the importance of proper training and practice, which could greatly increase the accuracy of age assessments.

Age estimation from the biometric information of hand bones: Development of new formulas

INTRODUCTION

In the judicial context of the age estimation of living individuals, a new method was recently proposed, based on the collection of biometric information on hand bones radiographs. The aim of this study was to apply this method to a large French sample to provide new tools for age estimation MATERIALS AND METHODS: The study sample consisted of metacarpals and proximal phalanges measurements of 1003 individuals aged less than 21 years. This sample was divided into two subgroups 1-12 and 13-21 years as the age of 13 is a relevant legal threshold for most European countries. A quadratic discriminant analysis was performed to identify the group to which an individual was most likely to belong. Age estimation formulas were also constructed from linear models: for each subgroup and the total sample.

RESULTS

The belonging of an individual to the 1-12 or 13-21 subgroup was determined with a correct classification rate of 89.8%. Age estimation formulas became less precise with age, with a mean absolute error ranging between 11 and 21 months.

CONCLUSION

We proposed a two-step procedure for age estimation: firstly, the identification of the age group to which the individual is most likely to belong, and secondly, the age estimation of this individual by applying the appropriate formula.

Age estimation in the living: A scoping review of population data for skeletal and dental methods

Age estimation of living individuals has become a crucial part of the forensic practice, especially due to the global increase in cross-border migration. The low rate of birth registration in many countries, hence of identification documents of migrants, especially in Africa and Asia, highlights the importance of reliable methods for age estimation of living individuals. Despite the fact that a number of skeletal and dental methods for age estimation have been developed, their main limitation is that they are based on specific reference samples and there is still no consensus among researchers on whether these methods can be applied to all populations. Though this issue remains still unsolved, population information at a glance could be useful for forensic practitioners dealing with such issues. This study aims at presenting a scoping review and mapping of the current situation concerning population data for skeletal (hand-wrist and clavicle) and dental methods (teeth eruption and third molar formation) for age estimation in the living. Two hundred studies on the rate of skeletal maturation and four hundred thirty-nine on the rate of dental maturation were found, covering the period from 1952 and 2020 for a total of ninety-eight countries. For most of the western and central African countries there are currently no data on the rate of skeletal and dental maturation. The same applies to the countries of the Middle East, as well as the eastern European countries, especially as regard the skeletal development.

Ultrasonographic assessment of ossification of the distal radial epiphysis for estimating forensic age

Since forensic age estimation is not a valid medical indication, research on the use of nonionizing methods is increasing. Ultrasonography is a radiological approach that protects patients from radiation exposure and offers special convenience to them. In this study, ultrasonography was used for age estimation by investigating the degree of ossification of the distal radial epiphysis. Its applicability on the Turkish population was investigated. The left wrist of 688 (322 males, 366 females) patients between the ages of 9 and 25 years was prospectively evaluated by ultrasonography. The intra- and interobserver reliabilities in evaluating the distal radial epiphysis and Cohen’s kappa statistics show that the interobserver error was very low, and the kappa value was found to be 0.919. Stage 3 and 4 ossification of the distal radial epiphysis was first detected at age 14.3 and 15.3 years in males and 12.7 and 14.8 years in females, respectively. The data obtained may help determine legally critical age limits of 14 and 15. Although it does not seem useful for the age of 18, ultrasonography may be recommended in selected cases as a fast, inexpensive, frequently reproducible radiological method without concern about radiation and without a predictable health risk.

Forensic age estimation based on fast spin-echo proton density (FSE PD)-weighted MRI of the distal radial epiphysis

Radiation exposure is a crucial factor to consider in forensic age estimation. The various magnetic resonance imaging (MRI) modalities used in forensic age estimation avoid radiation exposure. This study examined the reliability of distal radius ossification using fast spin-echo proton density (FSE PD)–weighted MRI to estimate age. Left wrist MRI findings of 532 patients aged 10–29 years were evaluated retrospectively using the five-stage system of Dedouit et al. The intra- and interobserver reliability values were κ = 0.906 and 0.869, respectively. Based on the results, the respective minimum ages estimated for stages 4 and 5 were 13.4 and 16.1 years for females, and 15.1 and 17.3 years for males; the method could not estimate an age of 18 years in any case. FSE PD MRI analysis of the distal radius epiphysis provides supportive data and can be used when evaluating the distal radius for forensic age estimation.

Zur Altersdiagnostik lebender Personen: der Einfluss des sozioökonomischen Status auf die Skelett- und Zahnentwicklung in einer deutschen Studienkohorte

Die forensische Altersdiagnostik kann ein entscheidendes Instrument zur Durchführung rechtstaatlicher Verfahren sein. Bei der Altersdiagnostik wird die Entwicklung von Skelett- und Zahnmerkmalen einer zu begutachtenden Person mit Daten von Referenzpopulationen verglichen. Als möglicher Einflussfaktor auf die Altersdiagnose ist der sozioökonomische Status (SES) der zu begutachtenden Person zu berücksichtigen. Allerdings ist die Studienlage zu diesem Einflussfaktor bislang spärlich. Prospektiv wurde der Zusammenhang zwischen der Skelett- bzw. Zahnentwicklung und dem SES innerhalb einer deutschen Studienpopulation aus freiwilligen Teilnehmern ermittelt. Dazu wurde die Entwicklung der medialen Epiphyse des Schlüsselbeins, der distalen Epiphyse des Radius, der distalen Epiphyse des Femurs, der proximalen Epiphyse der Tibia und des linken unteren dritten Molaren bei 294 Frauen und 287 Männern im Alter von 12 bis 24 Jahren mittels 3‑Tesla-Magnetresonanztomographie (MRT) untersucht. Zusätzlich wurde der SES der Teilnehmer erfasst. Hierzu wurde das Bildungsniveau der Eltern erfragt. Der Einfluss des SES auf die Einzelmerkmale sowie die Gesamtheit der untersuchten Skelettmerkmale wurde mittels linearer Regression ermittelt. Für alle untersuchten Merkmale und Kombinationen konnte keine Evidenz für einen Zusammenhang festgestellt werden. Es wurde geschlussfolgert, dass sich die Lebensumstände der Studienteilnehmer offenbar nicht ausreichend stark unterschieden, um einen Einfluss des SES auf das Skelettalter darzustellen.