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.

Forensic age assessment of living adolescents and young adults at the Institute of Legal Medicine, Münster, from 2009 to 2018.

Due to high migration inflows to Europe, forensic age assessment of living persons has clearly gained importance. If there is a legal justification for X-ray examinations without a medical indication, the Study Group on Forensic Age Diagnostics (AGFAD) recommends the combination of a physical examination with anamnesis, an X-ray examination of the hand and a dental examination with evaluation of an orthopantomogram for age assessments of adolescents and young adults. If the development of the hand skeleton has been completed, an additional CT examination of the clavicles is to be performed. To demonstrate the outcome of forensic age assessments according to AGFAD recommendations with regard to migrants of doubtful minority declaration, this study analyzes the expert reports carried out at the Institute of Legal Medicine, Münster, from 2009 to 2018. A total of 597 age assessments were performed during the study period. A total of 227 age assessments were issued on behalf of youth welfare offices in the legal area of social law, 282 in family law proceedings, 76 in criminal proceedings, and 12 age assessments in immigration law proceedings. In 211 out of 597 cases, the stated age was compatible with the findings of the age assessment. In the remaining 386 cases, the average difference between the stated age and the minimum age was 1.9 years. The average difference between stated age and most probable age was 5.1 years. Of the 521 age assessments carried out outside criminal proceedings, 197 unaccompanied minors with questionable age minority (37.8%) have reached the age of majority beyond doubt. A total of 388 unaccompanied minors (74.5%) have most probably reached the age of majority. Forensic age assessments with the AGFAD methodology make an important contribution to legal certainty, the welfare of the child, and the fair distribution of resources.

Examination of regressive features of third molars for the purpose of age assessment in the living by means of rescaled regression analyses.

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

Magnetic resonance imaging-based evaluation of ossification of the medial clavicular epiphysis in forensic age assessment.

Evaluation of the degree of ossification of the medial clavicular epiphysis plays a crucial role in determining with an adequate degree of probability whether legally relevant age boundaries after the age of 17 have been crossed. In view of the need to avoid unnecessary radiation exposure, establishing non-X-ray methods for investigating the clavicle has long been a key objective in forensic age assessment research. Based on magnetic resonance imaging examinations in a large sample of healthy subjects, the current study for the first time presents statistical measures which allow inferences to be drawn for forensic age assessment in both sexes. We undertook a prospective study of a reference sample of 334 female and 335 male German volunteers aged from 12 to 24 using a 3-T MRI scanner. A 3D FFE (fast field echo) T1-weighted sequence with fat saturation was acquired. To stage ossification of the medial clavicular epiphysis, we used the clavicular ossification staging systems described by Schmeling et al. and Kellinghaus et al. Ossification stage IIIc offers a means in both sexes of demonstrating that the age of 18 has been attained prior to complete ossification of the epiphyseal plate. In both sexes, if a subject has reached ossification stage IV, it can be stated that he or she has attained the age of 21. Magnetic resonance imaging is a valid diagnostic procedure for determining the ossification stage of the medial clavicular epiphysis.

Magnetic resonance imaging of the distal radial epiphysis: a new criterion of maturity for determining whether the age of 18 has been completed?

To improve the accuracy of forensic age estimation where there is no legal basis for carrying out x-ray examinations, it would be useful to establish non-x-ray imaging techniques. The objective of this study was to provide reference data for the magnetic resonance imaging-based evaluation of the ossification stage of the distal radius. Furthermore, we tested a new criterion of the maturity of the distal radial epiphysis for determining whether an individual has completed the age of 18. We investigated 668 MRI scans of the distal radial epiphysis from 333 female and 335 male subjects ranging in age from 12 to 24. To determine the ossification stage, we used the clavicular ossification staging systems described by Schmeling et al. and Kellinghaus et al. Ossification stage IV as described by Schmeling et al. was divided into two sub-stages, IVa and IVb, depending on whether or not it was possible to identify a triple-banded meta-epiphyseal zone of calcification. All study subjects were able to be assigned to an ossification stage without ambiguity. We present statistics relating to the distribution of ossification stages divided by sex. The age of the youngest female subject assessed as ossification stage IVb was 16.8, the age of the youngest male subject 18.6. The youngest age at which female subjects were assessed as ossification stage V was 22.3; for male subjects it was 23.1. Further independent studies should be carried out to determine whether ossification stage IVb can indeed be used to reliably determine whether a male subject has completed the age of 18.

Dental age estimation in the living after completion of third molar mineralization: new data for Gustafson's criteria.

There is a need for dental age estimation methods after completion of the third molar mineralization. Degenerative dental characteristics appear to be suitable for forensic age diagnostics beyond the 18th year of life. In 2012, Olze et al. investigated the criteria studied by Gustafson using orthopantomograms. The objective of this study was to prove the applicability and reliability of this method with a large cohort and a wide age range, including older individuals. For this purpose, 2346 orthopantomograms of 1167 female and 1179 male Germans aged 15 to 70 years were reviewed. The characteristics of secondary dentin formation, cementum apposition, periodontal recession and attrition were evaluated in all the mandibular premolars. The correlation of the individual characteristics with the chronological age was examined by means of a stepwise multiple regression analysis, in which the chronological age formed the dependent variable. Following those results, R 2 values amounted to 0.73 to 0.8; the standard error of estimate was 6.8 to 8.2 years. Fundamentally, the recommendation for conducting age estimations in the living by these methods can be shared. The values for the quality of the regression are, however, not precise enough for a reliable age estimation around regular retirement date ages. More precise regression formulae for the age group of 15 to 40 years of life are separately presented in this study. Further research should investigate the influence of ethnicity, dietary habits and modern health care on the degenerative characteristics in question.

The chronology of the radiographic visibility of the periodontal ligament and the root pulp in the lower third molars.

Eruption and mineralization of third molars are the main criteria for dental age estimation in living adolescents. As the validation of completion of the 18th year of life appears not to be possible with the forensically necessary probability even if all the third molars of a person are completely mineralized, degenerative dental characteristics might be used for this purpose. In previous publications by Olze et al. (2010a,b) the radiographic visibility of the periodontal ligament and the root pulp in lower third molars were suggested as methods for this purpose. The aim of this study was to validate these characteristics in a large study population with a wide age range. In a material of 2346 orthopantomograms of 1167 female and 1179 male Germans aged from 15 to 70years the radiographic visibility of the root pulp in the lower third molars with completed mineralization were studied according to stage classifications proposed by Olze et al. (2010a,b). 1541 orthopantomograms of 705 females and 836 males with a sufficient quality of the radiograph showed at least one third molar. The suitability of the studied characteristics for age estimation in living individuals could be confirmed. Males and females presenting stage 1 of both characteristics were older than 18years of life. Males and females presenting stage 2 of both characteristics were older than 21years of life. The high number of missing third molars in the studied age group (46-60%) must be considered as a limitation of the methods. In further studies the influence of ethnicity, dietary habits and modern dental health care on the characteristics in question should be investigated.