Forensic age estimation using computed tomography of the medial clavicular epiphysis: a systematic review

Age assessment in unaccompanied minors: assessing uniformity of protocols across Europe

Age assessment of migrants is crucial, particularly for unaccompanied foreign minors, a population facing legal, social, and humanitarian challenges. Despite existing guidelines, there is no unified protocol in Europe for age assessment.The Forensic Anthropology Society of Europe (FASE) conducted a comprehensive questionnaire to understand age estimation practices in Europe. The questionnaire had sections focusing on the professional background of respondents, annual assessment numbers, requesting parties and reasons, types of examinations conducted (e.g., physical, radiological), followed protocols, age estimation methods, and questions on how age estimates are reported.The questionnaire's findings reveal extensive engagement of the forensic community in age assessment in the living, emphasizing multidisciplinary approaches. However, there seems to be an incomplete appreciation of AGFAD guidelines. Commonalities exist in examination methodologies and imaging tests. However, discrepancies emerged among respondents regarding sexual maturity assessment and reporting assessment results. Given the increasing importance of age assessment, especially for migrant child protection, the study stresses the need for a unified protocol across European countries. This can only be achieved if EU Member States wholeheartedly embrace the fundamental principles outlined in EU Directives and conduct medical age assessments aligned with recognized standards such as the AGFAD guidelines.

Collaborative exercise: analysis of age estimation using a QIAGEN protocol and the PyroMark Q48 platform

Human age estimation from trace samples may give important leads early in a police investigation by contributing to the description of the perpetrator. Several molecular biomarkers are available for the estimation of chronological age, and currently, DNA methylation patterns are the most promising. In this study, a QIAGEN age protocol for age estimation was tested by five forensic genetic laboratories. The assay comprised bisulfite treatment of the extracted DNA, amplification of five CpG loci (in the genes of ELOVL2, C1orf132, TRIM59, KLF14, and FHL2), and sequencing of the amplicons using the PyroMark Q48 platform. Blood samples from 49 individuals with ages ranging from 18 to 64 years as well as negative and methylation controls were analyzed. An existing age estimation model was applied to display a mean absolute deviation of 3.62 years within the reference data set.

Key points

Age determination as an intelligence tool during investigations can be a powerful tool in forensic genetics.In this study, five laboratories ran 49 samples and obtained a mean absolute deviation of 3.62 years.Five markers were analyzed on a PyroMark Q48 platform.

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.

Age estimation based on the metamorphosis of the clavicle end: A test of Falys and Prangle method in two contemporary samples

Upon finding skeletal unidentified remains, four are the questions that must be answered: age, sex, ancestry, and stature. Regarding age estimation, clavicle has received special attention because medial epiphysis is the last epiphysis, among long bones that ossifies. Falys and Prangle proposed a method of age estimation based on three degenerative characteristics-surface topography (TOP), Porosity (POR) and Osteophyte formation (OST)-evaluated on the sternal end of the clavicle according to the descriptions and the illustrations provided in the original article producing satisfactory results. The current study aims to test the applicability of the Falys' and Prangle's method on 174 individuals from two contemporary samples, one from Greece (Cretan osteological Collection and Athens Forensic Anthropology Lab collection) and one from Thailand (Osteological collection in Chiang Mai). Composite scores were calculated, inter and intra- observer error were estimated by kappa statistics and regression equations of the original study were tested in our sample and in subsamples divided by sex and population. The Greek sample gave more accurate estimates compared to the Thai sample. Regressions of known sex gave slightly better results in most cases. When individuals <40 years old were excluded, classification increased for both Thai and Greeks. The results of this pilot study indicate that there are morphological features on the clavicle that are highly correlated with age. Thus, there is a scope of expanding research on the morphological features of the collar bone.

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.

Standards of practice in forensic age estimation with CT of the medial clavicular epiphysis-a systematic review

The AGFAD (Arbeitsgemeinschaft für Forensische Alterdiagnostik, Study Group on Forensic Age Diagnostics) has published several recommendations regarding both technical aspects of computed tomography (CT) of the medial clavicular epiphysis (MCE) and the process of reading and interpreting the CT images for forensic age estimations (FAE). There are, however, no published recommendations regarding CT scan protocols and no dose reference values for CT of the MCE. The objective of this analysis was to assess adherence to AGFAD recommendations among practitioners of FAE and analyse reported dose-relevant CT scan parameters with the objective of helping to establish evidence-based dose reference values for FAE. A systematic literature search was conducted in PubMed and in Google Scholar with specific MeSH terms to identify original research articles on FAE with CT of the MCE from 1997 to 2022. A total of 48 studies were included. Adherence to AGFAD recommendations among practitioners of FAE is high regarding the use of Schmeling main stages (93%), bone window (79%), ≤ 1 mm CT slices (67%), axial/coronal CT images (65%), and Kellinghaus sub-stages (59%). The reporting of CT technique and CT dose-relevant scan parameters is heterogeneous and often incomplete in the current literature. Considering the success achieved by the AGFAD in creating standards of practice of FAE in living subjects, there is potential for the AGFAD to establish standards for radiation protection in FAE as well.

Forensic Age Estimation: A Multifactorial Approach in a Retrospective Population Study

Objectives: The objective of this study was to evaluate the accuracy of forensic age estimation in a German population by combining clavicle and wisdom teeth assessments based on cone beam computed tomography (CT) data. The study aimed to determine the reliability of this approach in predicting biological age. Material and Methods: A total of 161 CT data sets from 120 males and 41 females with known exact ages were evaluated by three raters. The clavicle was assessed according to stages 1-5 (including substages 2a-c and 3a-c), and the Demirjian stage's classification method was used for the wisdom teeth. Inter-class correlation (ICC) was calculated to assess the agreement among the three raters. Additionally, ordinary least square regressions were performed to predict chronological age using the clavicle or one of the four teeth. Finally, age prediction models using multiple indicators were developed. Results: The ICCs ranged from 0.82 for the clavicle to 0.86 and 0.88 for the wisdom teeth. Linear estimation tended to overestimate chronological age, especially in subjects over 18 years old. The clavicle showed the strongest overestimation. Combining age estimation from the clavicle with the upper and lower wisdom teeth improved the predictive power, resulting in a 14% and 15% increase in R² for the upper and lower wisdom teeth, respectively. Adding more than one tooth to the prediction did not improve the predictive power (all ΔR² < 1%). Conclusions: Age estimation using CT can be significantly improved by combining information from the analysis of wisdom teeth with age estimation based on the clavicle.

Convolutional neural network of age-related trends digital radiographs of medial clavicle in a Thai population: a preliminary study

Age at death estimation has always been a crucial yet challenging part of identification process in forensic field. The use of human skeletons have long been explored using the principle of macro and micro-architecture change in correlation with increasing age. The clavicle is recommended as the best candidate for accurate age estimation because of its accessibility, time to maturation and minimal effect from weight. Our study applies pre-trained convolutional neural network in order to achieve the most accurate and cost effective age estimation model using clavicular bone. The total of 988 clavicles of Thai population with known age and sex were radiographed using Kodak 9000 Extra-oral Imaging System. The radiographs then went through preprocessing protocol which include region of interest selection and quality assessment. Additional samples were generated using generative adversarial network. The total clavicular images used in this study were 3,999 which were then separated into training and test set, and the test set were subsequently categorized into 7 age groups. GoogLeNet was modified at two layers and fine tuned the parameters. The highest validation accuracy was 89.02% but the test set achieved only 30% accuracy. Our results show that the use of medial clavicular radiographs has a potential in the field of age at death estimation, thus, further study is recommended.

McKern-Stewart method as a technique for analysing age related pubic symphyseal changes: A systematic review and meta-analysis

Age estimation is one of the essential criteria in the identification process. The method of age estimation employed depends on the availability of skeletal material brought for forensic examination. McKern and Stewart's method constitutes one of the principal approaches towards pubic symphyseal age estimation. The method entails evaluating morphological changes within the pubic symphysis and subsequently allotting a specific score corresponding to the observed changes. Based on the obtained scores, an age range is then assigned to the remains presenting for examination. The present systematic review was undertaken to ascertain the applicability of the McKern-Stewart method for age estimation. Studies pertaining to the use of the McKern-Stewart method for age estimation in skeletal remains were retrieved by keying in a combination of MeSH terms and other free terms from four databases. The retrieved articles were subjected to a stringent inclusion and exclusion criteria, following which the risk of bias was assessed and the overall quality of evidence was established. Once the final tally of relevant articles was obtained, data specific to the mean age corresponding to each score was extracted. Non-parametric tests and boxplots were employed to compare the mean ages reported across multiple studies. The present systematic review concludes that the McKern-Stewart method can be applied for the purpose of age estimation in skeletal remains. Broader age cohorts for higher scores, as well as, overlapping values for age ranges in relation to the cumulative scores, however, can be considered a limitation for its applicability in forensic case work.

Magnetic resonance and diffusion tensor imaging of the adolescent rabbit growth plate of the knee

PURPOSE

To assess the ability of MRI-DTI to evaluate growth plate morphology and activity compared with that of histomorphometry and micro-CT in rabbits.

METHODS

The hind limbs of female rabbits aged 16, 20, and 24 wk (n = 4 per age group) were studied using a 9.4T MRI scanner with a multi-gradient echo 3D sequence and DTI in 14 directions (b-value = 984 s/mm² ). After MRI, the right and left hind limb were processed for histological analysis and micro-CT, respectively. The Wilcoxon signed-rank test was used to evaluate the height and volume of the growth plate. Intraclass correlation and Pearson correlation coefficient were used to evaluate the association between DTI metrics and age.

RESULTS

The growth plate height and volume were similar for all modalities at each time point and age. Age was correlated with all tractography and DTI metrics in both the femur and tibia. A correlation was also observed between all the metrics at both sites. Tract number and volume declined with age; however, tract length did not show any changes. The fractional anisotropy color map showed lateral diffusion centrally in the growth plate and perpendicular diffusion in the hypertrophic zone, as verified by histology and micro-CT.

CONCLUSION

MRI-DTI may be useful for evaluating the growth plates.

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.

Assessment of renal glomerulosclerosis and thickness of the carotid intima-media complex as a means of age estimation in Western European bodies

INTRODUCTION

The estimation of age-at-death of unidentified cadavers is a central aspect of the identification process. With increasing age, the incidence of glomerulosclerosis and the thickness of the carotid wall have been observed to also increase. This correlation has been demonstrated in various international histological studies. The aim of our study was to assess whether these correlations also apply to a Western European population.

METHODOLOGY

In this retrospective observational study, kidney and common carotid artery samples from 216 cases autopsied at the Institute of Legal Medicine at the Justus-Liebig University in Giessen, Germany, were examined. Only cases with available tissue samples from both body sides were included. Exclusion criteria were poor sample quality and an age younger than 21 years. After histological processing, the tissue samples were assessed and digitally evaluated. Regression and classification analyses were used to investigate the correlation between age-at-death and intima-media thickness and age-at-death and the incidence of renal glomerular sclerosis.

RESULTS

Of the 216 autopsy cases, 183 were included for evaluation. Analysis of the carotid artery segments showed a strong correlation (Pearson correlation coefficient r = 0.887) between the intima-media-complex thickness and chronological age. Classification of the glomerulosclerotic incidence showed a correlation of 37.7-43.1% with the predicted age group.

DISCUSSION

Both the intima-media thickness and the proportion of sclerotic glomeruli can be used to estimate age in Western European cadavers. On the basis of these results, both methods are suited to supplement other already established methods for age-at-death estimation in the identification of an unknown cadaver.

Creation and Validation of a Shorthand Magnetic Resonance Imaging Bone Age Assessment Tool of the Knee as an Alternative Skeletal Maturity Assessment

BACKGROUND

In managing pediatric knee conditions, an accurate bone age assessment is often critical for diagnostic, prognostic, and treatment purposes. Historically, the Greulich and Pyle atlas (hand atlas) has been the gold standard bone age assessment tool. In 2013, a shorthand bone age assessment tool based on this atlas (hand shorthand) was devised as a simpler and more efficient alternative. Recently, a knee magnetic resonance imaging (MRI) bone age atlas (MRI atlas) was created to circumvent the need for a left-hand radiograph.

PURPOSE

To create a shorthand version of the knee MRI atlas.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 2.

METHODS

A shorthand bone age assessment method was created utilizing the previously published MRI atlas, which utilizes several criteria that are visualized across a series of images. The MRI shorthand draws on characteristic criteria for each age that are best observed on a single MRI scan. For validation, we performed a retrospective assessment of skeletally immature patients. One reader performed the bone age assessment using the MRI atlas and the MRI shorthand on 200 patients. Then, 4 readers performed the bone age assessment with the hand atlas, hand shorthand, MRI atlas, and MRI shorthand on a subset of 22 patients in a blinded fashion. All 22 patients had a knee MRI scan and a left-hand radiograph within 4 weeks of each other. Interobserver and intraobserver reliability, as well as variability among observers, were evaluated.

RESULTS

A total of 200 patients with a mean age of 13.5 years (range, 9.08-17.98 years) were included in this study. Also, 22 patients with a mean age of 13.3 years (range, 9.0-15.6 years) had a knee MRI scan and a left-hand radiograph within 4 weeks. The intraobserver and interobserver reliability of all 4 assessment tools were acceptable (intraclass correlation coefficient [ICC] ≥ 0.8; P < .001). When comparing the MRI shorthand with the MRI atlas, there was excellent agreement (ICC = 0.989), whereas the hand shorthand compared with the hand atlas had good agreement (ICC = 0.765). The MRI shorthand also had perfect agreement in 50% of readings among all 4 readers, and 95% of readings had agreement within 1 year, whereas the hand shorthand had perfect agreement in 32% of readings and 77% agreement within 1 year.

CONCLUSION

The MRI shorthand is a simple and efficient means of assessing the skeletal maturity of adolescent patients with a knee MRI scan. This bone age assessment technique had interobserver and intraobserver reliability equivalent to or better than the standard method of utilizing a left-hand radiograph.

Forensic age estimation using conventional radiography of the medial clavicular epiphysis: A systematic review

Of the many roles that forensic anthropologists and medico-legal professionals need to perform, forensic age estimation is one of the most frequent and important. Scoring medial clavicular epiphyseal (MCE) fusion is a method used to estimate age in young adults. The aim of this systematic review is to assess the reliability and reproducibility of MCE fusion visualised by conventional radiography and scored by Schmeling's grading system to determine whether an individual has attained the age of 18 years. Four articles were acquired after screening 4589 articles across four databases, and these were subjected to qualitative and quantitative synthesis. The risk of bias was calculated in the qualitative synthesis using the QUADAS-2 tool. Horizontal box plots were constructed to see whether MCE fusion as visualised by conventional radiography can be used to ascertain whether an individual has attained the age of maturity (18 years). It was observed that stages 4 and 5 of the Schmeling's method of age estimation from MCE fusion are observed only in individuals aged ≥18 years. This indicates that MCE fusion, when visualised using x-rays, which are associated with less ionisation radiation compared to computed tomography, can be used to verify the attainment of the age majority in individuals.

CT of the medial clavicular epiphysis for forensic age estimation: hands up?

Purpose

The aim of this study was to assess the impact of arm position in computed tomography (CT) of the clavicle performed for forensic age estimation on clavicular position, image noise, and radiation dose.

Methods and materials

Forty-seven CT scans of the medial clavicular epiphysis performed for forensic age estimation were conducted with either hands and arms held upwards (CT_HU, 28 persons) or positioned at the body (CT_HD, 19 persons). Presets were identical for both positions (70 mAs/140 kVp; Brilliance iCT, Philips). Each CT scan was reconstructed with an iterative algorithm (i-Dose 4) and evaluated at the middle of the sternoclavicular joint. Clavicular angle was measured on a.p. topograms in relation to a horizontal line. Quantitative image noise was measured in air at the level of medial clavicular epiphysis. Effective dose and scan length were recorded.

Results

Hands-up position compared with hands-down position resulted in a lower lateral body diameter (CT_HU 41.1 ± 3.6 cm vs. CT_HD 44.6 ± 3.1 cm; P = 0.03), a reduced quantitative image noise (CT_HU: 39.5 ± 9.2; CT_HD: 46.2 ± 8.3; P = 0.02), and lower CTDI_vol (5.1 ± 1.4 mGy vs. 6.7 ± 1.8 mGy; P = 0.001). Scan length was longer in patients examined with hands up (HU: 8.5 ± 3.4 cm; HD: 6.2 ± 2.1 cm; P = 0.006). Mean effective dose for CT_HU was 0.79 ± 0.32 mSv compared with 0.95 ± 0.38 mSv in CT_HD (P = 0.12). Clavicular angle was 17° ± 6° in patients with hands down and 32° ± 7° in patients with hands up (P < 0.001).

Conclusion

By elevated arm positioning, the image quality of clavicular CT scans can be improved while maintaining radiation dose compared with hands down. Clavicular position differs according to the hand position. Thus, positioning patients with elevated hands is advisable for forensic clavicular CT examinations, but multiplanar CT reconstructions should be adjusted to clavicular position and scan length should be reduced to a minimum.

The influence of motion artefacts on magnetic resonance imaging of the clavicles for age estimation

PURPOSE

To determine how motion affects stage allocation to the clavicle's sternal end on MRI.

MATERIALS AND METHODS

Eighteen volunteers (9 females, 9 males) between 14 and 30 years old were prospectively scanned with 3-T MRI. One resting-state scan was followed by five intentional motion scans. Additionally, a control group of 72 resting-state scans were selected from previous research. Firstly, six observers allocated developmental stages to the clavicles independently. Secondly, they re-assessed the images, allocating developmental statuses (immature, mature). Finally, the resting-state scans of the 18 volunteers were assessed in consensus to decide on the "correct" stage/status. Results were compared between groups (control, prospective resting state, prospective motion), and between staging techniques (stages/statuses).

RESULTS

Inter-observer agreement was low (Krippendorff α 0.23-0.67). The proportion of correctly allocated stages (64%) was lower than correctly allocated statuses (83%). Overall, intentional motion resulted in fewer assessable images and less images of sufficient evidential value. The proportion of correctly allocated stages did not differ between resting-state (64%) and motion scans (65%), while correctly allocated statuses were more prevalent in resting-state scans (83% versus 77%). Remarkably, motion scans did not render a systematically higher or lower stage/status, compared to the consensus.

CONCLUSION

Intentional motion impedes clavicle MRI for age estimation. Still, in case of obvious disturbances, the forensic expert will consider the MRI unsuitable as evidence. Thus, the development of the clavicle as such and the staging technique seem to play a more important role in allocating a faulty stage for age estimation.

Dental and Skeletal Imaging in Forensic Age Estimation: Disparities in Current Approaches and the Continuing Search for Optimization

Medical imaging for forensic age estimation in living adolescents and young adults continues to be controversial and a subject of discussion. Because age estimation based on medical imaging is well studied, it is the current gold standard. However, large disparities exist between the centers conducting age estimation, both between and within countries. This review provides an overview of the most common approaches applied in Europe, with case examples illustrating the differences in imaging modalities, in staging of development, and in statistical processing of the age data. Additionally, the review looks toward the future because several European research groups have intensified studies on age estimation, exploring four strategies for optimization: (1) increasing sample sizes of the reference populations, (2) combining single-site information into multifactorial information, (3) avoiding ionizing radiation, and (4) conducting a fully automated analysis.

Juristische Aspekte der forensischen Altersdiagnostik auf der Grundlage des § 42f SGB VIII

Seit Inkrafttreten des § 42f SGB VIII am 01.11.2015 ist das Verfahren zur Altersfeststellung von unbegleiteten und fraglich minderjährigen Ausländern durch Jugendämter in Deutschland gesetzlich geregelt. Hiernach hat das Jugendamt die Minderjährigkeit zunächst durch Einsichtnahme in die Ausweispapiere des jungen Menschen zu prüfen. Fehlen gültige Ausweispapiere, oder sind die in ihnen enthaltenen Geburtsdaten zweifelhaft, haben Jugendamtsmitarbeiter die Minderjährigkeit mittels einer qualifizierten Inaugenscheinnahme zu beurteilen. Lässt sich auch dadurch eine Minderjährigkeit nicht zweifelsfrei ausschließen, hat das Jugendamt eine ärztliche Untersuchung zur Altersfeststellung zu veranlassen. Eine Analyse der einschlägigen Rechtsprechung sowie der juristischen Fachliteratur ergab, dass Röntgenuntersuchungen zur forensischen Altersdiagnostik auf der Grundlage des § 42f SGB VIII nicht nur zulässig sind, sondern diese auch ausdrücklich eingefordert werden. Die Rechtsprechung erkennt zudem die medizinischen Untersuchungen nach den Empfehlungen der Arbeitsgemeinschaft für Forensische Altersdiagnostik (AGFAD) zur Altersdiagnostik unbegleiteter minderjähriger Ausländer als rechtlich zulässige, valide und zumutbare Methode an. Der von der Zentralen Ethikkommission (ZEKO) bei der Bundesärztekammer vertretenen Auffassung, dass die von der AGFAD empfohlenen Methoden nicht geeignet seien, Volljährigkeit hinreichend zuverlässig nachzuweisen, wird von der Rechtsprechung nicht gefolgt. Vielmehr wird darauf verwiesen, dass durch die Anwendung des Mindestalterkonzepts die von der ZEKO geäußerten Bedenken hinsichtlich der Schwankungsbreiten medizinischer Untersuchungen ausgeräumt werden.

Estimation of the age of majority through radiographic evaluation of the third molar maturation degree

Background

Although the third molar is the tooth with the greatest anatomical and developmental variability, some authors consider it important to estimate whether a subject is of legal age or not. The Demirjian’s technique is the most widely used tool to estimate dental age and was therefore used in our study to assess possible correlation between the age of majority and the maturational degree of the lower third molars, evaluated through radiographic images.

Material and Methods

This observational transversal study was conducted on 180 panoramic radiographs from consecutive patients. The degree of maturation of the lower third molar was independently classified by two observers, according to the Demirjian´s maturational stage method.

Results

A total of 180 patients – 65 men (36.12%) and 115 women (63.88%) – were included (mean age 21.6 years; standard deviation 5.2). The age range of our subjects corresponded to maturational stages D to H in the Demirjian’s classification. A logistic regression analysis showed that subjects classified into the highest maturational stage H had a significantly higher probability of being considered of legal age by both observers, as compared with subjects in the lowest stage D. Inter-observer agreement was very high. Gender predictive capacity was not observed.

Conclusions

Our results showed that subjects with the lower third molars in the highest maturational stage could be estimated to be older than 18 years and therefore considered of legal age, a finding also reported by other authorsThe Demirjian´s tooth maturational stage method, applied to the lower third molars, can be reliably used to estimate whether an individual is of legal age (18 years or older). High concordance between different observers using this method can be expected.

Key words:Age estimation, third molar development, panoramic radiographs, Demirjian’s method, dental age estimation, forensic odontology.

Can canines alone be used for age estimation in Chinese individuals when applying the Kvaal method?

Due to the secondary dentin formation, the dental pulp undergoes changes in shape throughout life. Based on this phenomenon, the Kvaal method has been applied to various populations for age estimation, and its usefulness has been verified. When applying the Kvaal method to Chinese subjects, we observed a relatively strong correlation between mandibular canines and age. This study notes the correlation between canines and chronological age and is the first to identify which canine is most closely related to chronological age. In addition, a new, simpler formula is determined based on canines according to Kvaal's methodology. The radiographs of 360 individuals from northern China were selected, from which the widths and lengths of the pulp from four canines were measured according to the Kvaal method. Next, inter- and intra-observer reliabilities were analyzed in order to assess the repeatability of these measurements. The correlation between measurements and age was examined, and Chinese-specific age estimation formulae were derived. The results revealed that the ratios from the left maxillary canine exhibited the strongest correlation with age compared to the other canines, whereas the left mandibular canine showed the weakest correlation, which may contribute to the overall poor correlation of mandibular canines with age. What's more, the formula derived from the left maxillary canine in this study displayed the highest coefficients of determination, and the formula derived from all canines showed the lowest residuals. Both of these formulae performed better than the Chinese-specific formula derived from six different types of teeth in our previous study, which had formerly possessed the highest coefficients of determination and the lowest residuals. Thus, we concluded that canines do play an important role in age estimation in the Chinese population, and the correlation between maxillary canines and chronological age is stronger than that of mandibular canines, although no distinct trend as to which side is better correlated with age was established. Going forward, we recommend the analysis of additional samples from different geographical regions and populations to further verify the importance of canines in age estimation.

Comparison of different iterative CT reconstruction techniques and filtered back projection for assessment of the medial clavicular epiphysis in forensic age estimation

PURPOSE

To assess the impact of iterative reconstruction and filtered back projection (FBP) on image quality in computed tomography (CT)-based forensic age estimation of the medial clavicular epiphysis.

METHODS AND MATERIALS

CT of the clavicle was performed in 19 patients due to forensic reasons (70 mAs/140 kVp). Raw data were reconstructed with FBP and with an iterative algorithm at level 4 and 6. Clavicular ossification stage was determined by two radiologists in consensus, firstly on FBP reconstructed images and secondly after reviewing all reconstructions including iDose 4 and 6. In addition, the 3 reconstructions were compared regarding artefacts and delineation of the meta-/epiphyseal interface. Quantitative image noise was measured.

RESULTS

Quantitative noise was lower in iDose 6 reconstructed images than in FBP (P < 0.042), but not significantly lower between iDose 4 and FBP (P = 0.127). Side by side comparison revealed lesser qualitative image noise on both iDose reconstructed images than for FBP. The meta-/epiphyseal interface delineation was rated better on both iDose levels than with FBP. In 3 of 19 patients, the clavicular ossification stage was reclassified after iterative reconstructions had been additionally reviewed.

CONCLUSION

Using iterative CT reconstruction algorithms, a reduction of image noise and an enhancement of image quality regarding the meta-/epiphyseal clavicular interface can be achieved. The study highlights the importance of image standardization as variation of reconstruction technique has impact on forensic age estimation.

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Estimating forensic age via magnetic resonance imaging of the distal radial epiphysis

Magnetic resonance imaging is currently being studied extensively, but it is still far from being the frequently recommended radiological method for age estimation. In this study, we used magnetic resonance imaging (MRI) of distal radius ossification to obtain data for age estimation. Wrist MRI scans from 338 individuals, aged 10-29 years, were examined retrospectively using the staging system of Schmidt et al. and the extension of the stages as described by Timme et al. The results revealed that the minimum ages for stage 4a ossification were 16.0 years in women and 17.7 years in men, whereas those for stage 4b ossification were 16.6 and 18.2 years in women and men, respectively. Stage 5 was not detected in any patient. These results were comparable with those of a previous study using the same methodology with distal radial epiphysis ossification. Our finding regarding stage 4b ossification may provide valuable information on legally important age thresholds relevant to the use of MRI in evaluating the distal radial epiphysis in males. Further research needs to be conducted with large series in different populations to evaluate the triple banding at the distal radial epiphysis.

Dental age estimation based on the radiographic visibility of the periodontal ligament in the lower third molars: application of a new stage classification

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

Age assessment in the living using modified Gustafson's criteria in a northern Chinese population

Regressive dental changes appear to be suitable for age assessment in living adults. In 2012, Olze et al. showed that several criteria presented by Gustafson for extracted teeth can also be applied to orthopantomograms. The objective of this study was to test the applicability and reliability of this method in a Chinese population. For this purpose, 1300 orthopantomograms of 650 female and 650 male Chinese aged between 15 and 40 years were evaluated. The characteristics of secondary dentin formation, periodontal recession, attrition, and cementum apposition were reviewed in all the mandibular premolars. The sample was split into a training and test dataset. Based on the training set, the correlation of the individual characteristics with chronological age was studied with a stepwise multiple regression analysis, in which individual characteristics formed the independent variable. According to the results, the R values amounted to 0.80 to 0.83; the standard error of estimate was 4.29 to 4.75 years. By analyzing the test dataset, the accuracy of the present study, Olze's and Timme's formulas were determined by the difference between the estimated dental age (DA) and chronological age (CA). Taking both mean differences and mean absolute differences into account, the Chinese age estimation formula did not always perform better compared with Olze's and Timme's formulas for both males and females. It was concluded that this method can be used in Chinese individuals for age assessment. However, the applicability of the method is limited by the quality of the X-ray images, and the method should only be applied by experienced forensic odontologists.