Sex estimation in the cranium and mandible: a multislice computed tomography (MSCT) study using anthropometric and geometric morphometry methods.

INTRODUCTION: The purpose of this study was to analyze the respective contribution of the skull and mandible to sex estimation in an entire cranium using metric and geometric morphometric methods and multislice computed tomography (MSCT) analysis. MATERIALS: The study sample comprised 120 individuals aged 23 to 84 years and divided into three groups (whole sample and over or under 40 years of age). METHODS: Forty-eight osteometric landmarks were positioned using Osirix®, 34 for the cranium and 14 for the mandible. The data were analyzed using univariate analyses and logistic regression using backward stepwise selection with cross-validation of the classification results. Generalized procrustes analysis (GPA) was used, and Goodall's F test and Mahalanobis D2 matrices allowed an assessment of statistical significance. RESULTS: The classification accuracy of cranium models ranged from 87% to 88.3%, and from 68% to 81.4% for the mandibular models. With geometric morphometry, accuracy was of 94-100% for the cranium and 84.2% for the mandible. DISCUSSION: We conclude that the mandible had a higher accuracy rate for individuals over 40 years than individuals under 40 years of age, although the accuracy of geometric morphometry did not differ significantly between the age groups. The cranium, however, presented greater predictability for all the parameters assessed.

Cameriere's third molar maturity index in assessing age of majority: a study of a French sample.

Forensic age estimation is a challenging field in forensic sciences because of the increase of migratory flows. Medicolegal age assessment is a key point because it has many implications for authorities. Dental age estimation is an essential part of the global age assessment. The aim of this study was to evaluate and test the accuracy of Cameriere's cutoff values of the third molar maturity index (I3M) in assessing legal adult age of 18 years in a French population. The sample was constituted of 431 orthopantomograms performed between January 2014 and August 2017 on patients aged between 14 and 22 years. The reproducibility and repeatability of the method were high. Age distribution gradually decreases as I3M increases in both sexes. 0.08 seemed to be the best I3M cutoff. For females, the sensitivity and specificity of the test were 74.51% and 88.23%, respectively. The sensitivity and specificity for males were 92.19% and 88.35%, respectively. The accuracies were 80.74% for female, 90.57% for male. Estimated post-test probabilities were 0.879 for female and 0.899 for male. To conclude, the specific cutoff value of I3M ˂ 0.08 may be a useful additional tool in discriminating adults and minors in French population.

[Thanatobiochemistry: its contribution to the diagnosis of hypothermia fatalities]. / Biochimie thanatologique : ses apports au diagnostic de décès par hypothermie.

Hypothermia is a potentially lethal pathology whose in vivo diagnosis is relatively easy, based on the observation of a body temperature below 35̊C. However, its post mortem diagnosis is much more complex because of a thermal decrease occurring systematically after the death, which renders most often uninterpretable the body temperature as a diagnostic argument for hypothermia. Moreover, none of the macroscopic or microscopic autopsy elements described as suspicious of hypothermia are pathognomonic of a hypothermic death. Currently, this diagnosis arises in the light of an association of concordant arguments including these autopsic and histological elements but also some biomarkers. The aim of this article is to illustrate by a practical case the diagnostic complexity of a death by hypothermia through the evocative elements currently described, by emphasizing the reflection on some biomarkers confirmed or under study.

Contribution of third molar eruption to the estimation of the forensic age of living individuals.

Forensic age estimation of a living individual is frequently performed in clinical forensic medicine. Medicolegal physicians are usually called upon by the authorities to estimate the age of a living person requesting asylum or to determine whether a suspected offender is subject to juvenile or adult criminal law. Dental age is one of the parameters studied to estimate biological age. Several methods are used, and among these, analysis of the eruption of the third molar (M3) on an orthopantomogram (OPG) is one of the common methods. The objective of the study was to analyse the contribution of M3 eruption to age estimation, in particular with regard to the threshold of 18 years of age, in a sample of individuals examined in a French university hospital. The stage of wisdom tooth eruption of all individuals aged between 15 and 24 years, who had an OPG performed between 1 January 2013 and 31 December 2015, was interpreted using a three-stage scoring system. In total, 557 OPGs (340 males and 217 females) were included. None of the stage scores allowed a distinction between minors and majors, for either sex. Overall, 85% of females and 98% of males with four M3s in stage 3 (complete emergence in the occlusal plane) were majors.

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

Medicolegal physicians are increasingly called upon to aid in determining the administrative age group affiliation of refugees with questionable unaccompanied minor claims. According to guidelines for forensic age assessment, age differentiation along the 18-year-old cut-off relies on clavicular ossification. The thin-slice computed tomography scan (TSCTs) of the medial clavicular epiphysis (MCE) is one of the methods contributing to this assessment, though it is not yet universally accepted. The aim of this systematic review was to identify scientific papers where age was assessed using TSCTs of the MCE and to observe whether this examination was reproducible and reliable in estimating a person's age relative to the 18-year-old threshold. A search algorithm was applied to several databases to identify articles in accordance with the PRISMA (Preferred Reporting Items for Systematic-Reviews and Meta-Analyses) statement. One boxplot per article was constructed, separating by stage of maturation and sex. The 13 articles selected represented a sample of 5605 individuals (3396 males, 2209 females) aged 10 to 35 years. All individuals classified as stages 4 and 5 were aged 18 years or older. The same result was obtained concerning stage 3c, except in one article. The results thus appear reliable and reproducible, in particular, with respect to the 18-year-old threshold; medicolegal physicians should be able to estimate that all individuals in stages 4 and 5 are at least 18 years old. Additional studies applied to several other populations in the world should complement the selected studies.

Twenty-five years of French jurisprudence in criminal medical liability.

We report on a comprehensive 25-year study on criminal medical liability in France, undertaken to establish trends in the number of cases being brought before the criminal courts. We did this by interrogating the database on the Légifrance website using a Boolean equation (' pénal' (criminal) AND ' médecin' (physician) OR ' docteur' (doctor)). In total 539 cases were selected, in which the status of the physician either influenced the punishment imposed, or was a prerequisite for the commission of the offence. The results of the search produced two outcomes: offences and the dates of the most recent criminal judgements (which had been left blank). Further data were also collected: references to court cases, hearing dates, offence dates, procedural time limits, numbers of accused parties, types of punishments and physician characteristics. The number of court hearings increased from the 1980s until the late 1990s. Since then, it has remained stable at around 25 cases per year. Of the defendants appearing before the courts, 39.2% have been found guilty. On average, 10 to 13 physicians every year - that is, one per month - are punished. Those most often punished are obstetrician-gynaecologists (13%), followed by intensive care anaesthetists (11%) and then by general practitioners (6.7%). The offences most frequently occurring are manslaughter (36.5%), illegal profits (12%), unintentional injuries (11.5%) and sexual offences (10.1%). The results are most reassuring in terms of the risks posed by the practice of medicine in France. Such a risk does indeed exist; however, it is at a low level and stable.

Reliability of the Suchey-Brooks method for a French contemporary population.

The Suchey-Brooks method is commonly used for pubic symphyseal aging in forensic cases. However, inter-population variability is a problem affected by several factors such as geographical location and secular trends. The aim of our study was to test the reliability of the Suchey-Brooks method on a virtual sample of contemporary French males. We carried out a retrospective study of 680 pubic symphysis from adult males undergoing clinical Multislice Computed Tomography in two hospitals between January 2013 and July 2014 (Toulouse and Tours, France). The reliability of the Suchey-Brooks method was tested by the calculation of inaccuracy and bias between real and estimated ages, and the mean age for each stage and the mean stage for each 10-years age interval were compared. The degree of inaccuracy and bias increased with age and inaccuracy exceeded 20 years for individuals over 65 years of age. The results are consistent with an overestimation of the real age for stages I and II and an underestimation of the real age for stages IV, V and VI. Furthermore, the mean stages of the reference sample were significantly lower for the 14-25 age group and significantly higher for individuals over 35 years old. Age estimation is potentially limited by differential inter-population error rates between geographical locations. Furthermore, the effects of secular trends are also supported by research in European countries showing a reduction in the age of attainment of indicators of biological maturity during the past few decades. The results suggest that the Suchey-Brooks method should be used with caution in France. Our study supports previous findings and in the future, the Suchey-Brooks method could benefit from re-evaluation of the aging standards by the establishment of new virtual reference samples.

Sudden Death Due to Undiagnosed Rheumatic Heart Disease in a Child.

We report the case of a 5-year-old boy who died from complications of rheumatic heart disease with atypical presentation. He was hospitalized for recent inflammatory and neurological symptoms. He was diagnosed with viral encephalitis. He died the day after he was discharged. The macroscopic autopsy findings were unremarkable. Histology revealed typical rheumatic heart disease. Neuropathology showed cerebral infarction due to an embolic event linked with the rheumatic valvulitis. The cause of death was determined as heart failure due to rheumatic heart disease secondary to an undiagnosed acute rheumatic fever. It is related to an autoimmune response to infection with group A streptococcus. It mainly affects children in developing countries. In our case, viral encephalitis was consistent with the medical history and the proper diagnosis was made on histological analysis. Forensic pathologists should consider this diagnosis facing a sudden unexpected death in childhood, even in industrialized countries.

Contribution of magnetic resonance imaging of the wrist and hand to forensic age assessment.

Forensic age estimation of living individuals is a controversial subject because of the imprecision of the available methods which leads to errors. Moreover, young persons are exposed to radiation, without diagnostic or therapeutic advantage. Recently, non-invasive imaging techniques such as magnetic resonance imaging (MRI) have been studied in this context. The aim of this work was to study if the analysis of wrist/hand MRI enabled determination of whether a subject was 18 years old. Two observers retrospectively analyzed metaphyseal-epiphyseal fusion of the distal epiphysis of the radius and the ulna and the base of the first metacarpus in wrist/hand MRI of living people between 9 and 25 years of age. A three-stage scoring system was applied to all epiphyses. Intra- and inter-observer variability was excellent. Staging of the distal radial epiphysis allowed the subjects to be correctly evaluated with regard to the 18-year-old threshold in more than 85 % of cases. Analysis of the radius alone was as good as the analysis of the three epiphyses together. Evaluation of the metaphyseal-epiphyseal fusion of the distal radius in wrist MRI gave good results in forensic age estimation. Wrist MRI could meet ethical expectations with regard to the link between the benefit and risk of practicing radiologic examination on individuals in this context.

Is a CT-scan of the medial clavicle epiphysis a good exam to attest to the 18-year threshold in forensic age estimation?

Computed tomography (CT) scan of the medial clavicular epiphysis is one of the methods recommended by the Study Group on Forensic Age Diagnostics to estimate the age of living individuals. The aim of our study was to assess the relationship between the skeletal maturation of the sternal end of the clavicle and the chronological age in a sample of French individuals, using a nine-stage classification. We retrospectively reviewed 319 chest CT-scans of individuals aged 15-30 years old (252 males, 67 females). Among males and females, all individuals with a complete fusion, or an ongoing fusion of more than one third of the total surface of the metaphysis were at least 18 years old. Our results were consistent with data in the literature indicating that individuals with a complete fused clavicle were at least 18 years old. Similar studies with the same methods allow for creating a database of samples from different countries to confirm the validity of this method and its excellent results in forensic age estimation of living individuals.

Contribution of Antemortem Computed Tomography Findings to Cause of Death Determination: An Unusual Fatal Stroke.

In the case reported here, the antemortem computed tomography scan (CT scan) was essential in the forensic investigation. A 32-year-old man was found fully awake with a facial abrasion, after what seemed to be a car accident. He lost consciousness suddenly one hour after initial management. Successive CT scan showed a facial fracture and a metallic foreign body in the carotid canal associated with an occlusion/dissection of the left internal carotid, a pseudoaneurysm, and a carotid-cavernous fistula. The victim died from a stroke. Autopsy confirmed that the facial abrasion was a gunshot entrance wound, the metallic foreign body being a projectile. Intracranial vascular injuries linked with gunshot wounds are most of the time isolated and due to pelet embolism. The observed vascular injury association has never been described in the existing literature. The CT scan provided a better understanding of the chronology of events that led to death.

Exogenous lipoid pneumonia as a contributory factor in a drug-related death.

Postmortem investigation often reveals various conditions, which may or may not have played a part in the death of the individual. The case of a 32-year-old woman is reported, with a long history of drug addiction. She was found dead in her bed. The autopsy revealed diffuse pulmonary edema with congestion of the lungs, brain, liver, and spleen. Microscopic examination of the lungs showed multiple intra-alveolar and interstitial foamy macrophages and extracellular fat droplets surrounded by polynuclear giant cells. Death was attributed to acute polydrug intoxication. As microscopic examination had revealed severe pulmonary lesions, lipoid pneumonia was considered as a contributing factor to death. Lipoid pneumonia is an uncommon entity with the characteristic radiograph features and histologic findings of alveoli filled with vacuolated, lipid-laden histiocytes. It can be either exogenous or endogenous in cause, based on the source of the lipid. Exogenous lipoid pneumonia usually results from aspiration or inhalation of fat-like material, such as mineral oil or petroleum-based lubricants and decongestants, resulting in pulmonary inflammatory reactions.

Is the persistence of an epiphyseal scar of the knee a reliable marker of biological age?

Age estimation of living individuals is a regular activity in medico-legal practice. Among the available tools for determining skeletal age, some authors have stated that the disappearance of epiphyseal scars could be a useful marker. The aim of the present study was to assess whether the presence of an epiphyseal scar on the knee, as seen on a plain X-ray, was linked to biological age. A total of 988 frontal X-rays of individuals (509 females and 479 males) aged between 15 and 40 years were analyzed to see whether a scar was visible or not on each of the three epiphyses of the knee. A scar was visible for 96% of the females and 98% of the males. For each sex, scars were visible at each year of age, from 15 to 40 years. In younger females, there were 15 individuals with no scar visible on the fibula, 16 on the tibia, and 20 on the femur. For males, the ages were respectively 16, 17, and 18 years. On a frontal X-ray, the persistence of epiphyseal scars was not a marker of a recent fusion. All individuals with fully ossified knee that had no scar on the femur were older than 18 years. Further studies focusing on epiphyseal scars on MR and CT scans could be useful, as these techniques allow the more precise analysis of the epiphysis.

Can the Greulich and Pyle method be used on French contemporary individuals?

Forensic age estimation of living individuals has become increasingly important in forensic practice with the constant increase of migration movements to developed countries. The method of Greulich and Pyle is one of the most frequently used methods for age determination. The aim of our study was to verify the reliability of this method on a French contemporary population. We retrospectively analyzed 190 frontal hand and wrist radiographs of living subjects aged between 10 and 19 years (100 males and 90 females) performed in the Radiology Department of the University Hospital of Tours. These radiographs were compared with the Greulich and Pyle atlas to determine the skeletal age (SA) and to compare it to the chronological age (CA). We calculated the coefficient of correlation and the coefficient of determination for each sex group. The SA of our subjects was also inserted in the graphs provided by Greulich and Pyle in their atlas. Intra- and inter-observer variabilities were good, demonstrating the reproducibility and repeatability of the method. The correlation coefficients were high (0.98 for males and 0.93 for females) and comparable with published data. The mean difference between CA and SA was -2.29 months for males and -6.44 months for females, showing an overestimation of CA for both sexes. No statistical difference was found between CA and SA for both male and female samples. We concluded that the method of Greulich and Pyle can be used on a contemporary French population but not without caution because of a tendency for this method to overestimate age. A fully developed hand and wrist does not allow to state that the 18th year of life is completed beyond a reasonable doubt. We recommend using it in association with other methods.

Evaluation of an automatic method for forensic age estimation by magnetic resonance imaging of the distal tibial epiphysis--a preliminary study focusing on the 18-year threshold.

The contribution of magnetic resonance imaging to forensic age estimation of living individuals is a subject of ongoing research. Several studies have focused on the wrist, clavicle, knee, and foot, and shown interesting results regarding the 18-year threshold. Authors have developed various staging systems for epiphyseal growth plate maturation. However, the procedure is observer-dependent and requires experience and a certain time-learning process. To reduce these pitfalls, we have developed an automatic method based on the analysis of variations of gray levels within the epiphyseal-metaphyseal junction. This method was tested on 160 MRI scans of the distal tibial epiphysis in a sample of individuals aged from 8 to 25 years old, after intensity non-uniformity correction of all images. Results showed that in our sample, 97.4 % of males and 93.9 % of females aged 18 years or more would be correctly classified using this method. To our knowledge, automatic methods for MRI analysis have not been used in the field of age estimation yet. Further studies should be performed to assess the validity of this procedure.

Is the corticomedullary index valid to distinguish human from nonhuman bones: a multislice computed tomography study.

The first step in the identification process of bone remains is to determine whether they are of human or nonhuman origin. This issue may arise when only a fragment of bone is available, as the species of origin is usually easily determined on a complete bone. The present study aims to assess the validity of a morphometric method used by French forensic anthropologists to determine the species of origin: the corticomedullary index (CMI), defined by the ratio of the diameter of the medullary cavity to the total diameter of the bone. We studied the constancy of the CMI from measurements made on computed tomography images (CT scans) of different human bones, and compared our measurements with reference values selected in the literature. The measurements obtained on CT scans at three different sites of 30 human femurs, 24 tibias, and 24 fibulas were compared between themselves and with the CMI reference values for humans, pigs, dogs and sheep. Our results differed significantly from these reference values, with three exceptions: the proximal quarter of the femur and mid-fibular measurements for the human CMI, and the proximal quarter of the tibia for the sheep CMI. Mid-tibial, mid-femoral, and mid-fibular measurements also differed significantly between themselves. Only 22.6% of CT scans of human bones were correctly identified as human. We concluded that the CMI is not an effective method for determining the human origin of bone remains.

Age estimation by magnetic resonance imaging of the distal tibial epiphysis and the calcaneum.

Age estimation of living individuals is of critical importance in forensic practice, especially because of the increased migration in developed countries. Recently, the contribution of magnetic resonance imaging (MRI) to age evaluation has been studied, as it seems to be an efficient technique to analyze growth plate maturation and epiphyseal fusion. We developed an MRI staging system for the distal tibial epiphysis and the calcaneal epiphysis and evaluated its reliability on 180 MRI scans of the ankle and foot in a sample of individuals aged from 8 to 25 years old. For both bones, the degree of union between the metaphysis and epiphysis was classified in three stages. Intra- and inter-observer variabilities were good, showing the validity and reproducibility of the method. Our results were consistent with data in the literature indicating that both epiphyses mature earlier in females than in males. Bayesian predictive probabilities were used to assess the validity of our method in estimating the age of an individual in relation to the 18-year threshold. MRI of the ankle and foot can be used in association with other methods to estimate age in living individuals.