Pascal Adalian

New forensic approach to age determination in children based on tooth eruption

The present study proposes equations for age determination both in living and dead children, obtained with the help of stepwise ascending multiple linear regression. The equations should be applied, based on the number of erupted teeth and tooth germs, which were detected on radiographs, during clinical examination and in infant skeletal remains. The proposed equations proved to be efficient just like Demirjians method used as a reference today, and permit age estimation till 20 years of age.

Limits of the Lamendin method in age determination

This study shows that epithelial attachment level, used as age determination criterion in Lamendins method, is not reliable for adults of either sex above the age of 49 years with periodontal diseases in any quadrant. The underestimation of calculated age increases from 7 to 19 years with chronological age. On the other hand, the present paper confirms the pertinence of dentin translucency as an age indicator in Lamendins method.

Three-dimensional Modeling of the Various Volumes of Canines to Determine Age and Sex: A Preliminary Study

Abstract:  Canines are usually used in anthropological and forensic sciences for sex and age determination. The best methods to estimate age are based on secondary dentine apposition, evaluated from periapical X‐rays. The aim of this study was to propose a new method of sex and age estimation using 3D models to obtain more precise predictions using tooth volumes. Fifty‐eight dental CT scans of patients aged 14–74 with a well‐balanced sex ratio composed the sample. One hundred and thirty‐three healthy canines were modeled (Mimics 12.0). The sample was divided into a training sample and a validation sample. An age formula was determined using the “pulp volume/tooth volume” ratio. Sex prediction was adjusted with total volumes. Applying the equations to the validation sample, no significant difference was found between the real and predicted ages, and 100% of the sex predictions were correct. This preliminary study gives interesting results, and this method is worth being tested on a larger data sample.

Hyperostosis frontalis interna: Forensic issues

The use of pathological conditions in age and sex determination, important factors in personal identification, is not widespread in anthropology and legal medicine. Hyperostosis frontalis interna (HFI) is a bone condition that mainly affects the inner table of the frontal bone. Although there are numerous publications on the subject, at the present time its etiology remains obscure. Several associations of symptoms, whose incidence varies according to the population studied, have been described. Age and gender appear to be linked with the preponderance of this condition, as does the presence of behavioral disturbances. The aim of our study, based on a series of 1532 autopsies, was to define the incidence and the associations observed with other pathological conditions. Thirteen cases of HFI were identified (0.8% of autopsies), 12 women and one man whose mean age was 59.15 years (range: 42-79 years). All had behavioral disturbances and most were under psychiatric care. This study emphasizes the value of this condition in medico-legal identification.

Effects of fall conditions and biological variability on the mechanism of skull fractures caused by falls

In a forensic investigation, there is considerable difficulty in distinguishing between different mechanisms that could explain the head injury sustained. The key question is often whether the injury was the consequence of a fall, a blow, or a fall caused by a blow. Better understanding of the parameters influencing the mechanism of skull fracture could be of use when attempting to distinguish between different causes of injury. Numerous parameters concerning fall conditions and biological variability are reported in the literature to influence the mechanism of skull fracture. At the current time, there are no studies that investigate both the effect of a fall and biological parameters. The aim of this paper is to study the influence of these parameters on the mechanism of skull fracture using a numerical approach. We focused on accidental falls from a standing height. A multibody model was used to estimate head impact velocities and a finite element model was used to investigate the effect of the fall conditions and of biological variability on skull fracture. The results show that the mechanism of skull fractures is influenced by a combination of at least four parameters: impact velocity, impact surface, cortical thickness and cortical density.

Nouvelle formule de détermination de l’âge d’un fœtus

Abstract The methods utilised in anthropology for foetal age assessment are generally rather old, based on small samples and have never been tested on other samples than the one they were established on. In this study, we establish a formula on 344 foetuses of known age, and compare it with other age determination methods found in the scientific literature. Except our formula, the tested other methods do not give the limits of the prediction’s confidence interval, and therefore do not take into account the total variability. Therefore, we demonstrate the necessity to establish formulas based on large samples and on a validated methodology.

An anatomical and biometrical study of the femoral trochlear groove in the human fetus

We performed a biometric analysis of the femoral trochlear groove in the fetus and compared our findings with those observed in adults. We studied 44 formalin‐preserved fetuses (13–38 weeks) and used digitized images to obtain measurements (α angle of the groove, trochlear slopes θL and θM). A comparison of means between our series and adults was achieved. For each angle of the distal epiphysis (α, θL, θM) there was no significant difference between our fetal series and adults. This is the first biometric study of fetal trochlea. The morphology of the lower femur appears to be the same in the fetus and the adult.

Determination of sex: interest of frontal sinus 3D reconstructions.

Frontal sinuses (FSs) have been studied in radiology, anthropology, and forensic anthropology. This study aimed to determine whether it was possible to predict the age and sex of an individual using FS volume. Sixty‐nine anonymized CT scans were imported to MIMICS 10.01® software (Materialise N.V.), and each FS volume was calculated in mm3. There was an absence of significant difference between right and left FS volume (p = 0.173) and an absence of correlation between age and FS volume (Pearsons test; p = 0.705). Sexual dimorphism was significantly different (p = 0.001). However, the most discriminant datum for determining sex was found to be the total FS volume (sum of an individuals right and left FS volumes) with linear discriminant Fishers function coefficients of −2.759 for the male group and −1.275 for the female group. With this model, 72.5% of our sample was correctly classified according to sex.

Mechanisms of hyoid bone fracture after modelling: Evaluation of anthropological criteria defining two relevant models

Several studies have attempted to describe the morphology of the hyoid bone, while other authors have focused on discovering the role of this bone in the occurrence of fractures. Hyoid fractures are known to be dependent on the force applied against the bone, or on the location at which the force is applied. We wished to assess the value of defining one or more models of the hyoid bone by analyzing variations in the size and angle of the various component parts of the bone relative to the sex and morphology of an individual (height and weight) in a sample of 72 bones obtained during forensic autopsy at our institution. Statistical analyses were developed using SAS software (Statistical Analysis System, version 9.2). We observed that the length of the hyoid bone and the angle between the greater horns differed significantly between men and women. Length was significantly greater in men (38.20 ± 4.67 mm) than in women (30.49 ± 7.90 mm) and the angle between the greater horns of the hyoid bone was larger in women (36.46 ± 13.77°) than in men (27.56 ± 13.02°). There was also a statistically significant correlation between the body mass index of an individual and the length of the hyoid bone. As weight increased, the hyoid bone was found to be longer. The weight of an individual was also significantly correlated with the angle of the hyoid bone, with lower weight resulting in larger angles of the bone. Furthermore, hierarchical classification enabled the hyoid bone to be differentiated into two groups or clusters according to anthropometric measurements. ROC curves were used to determine threshold values of length, width and angle to classify the hyoid bones in these two clusters: the first was composed of individuals with longer hyoid bones, and the second of individuals with greater hyoid bone widths and wider angles. Logistic regression showed male gender was more frequently associated with the first group. The morphology of the hyoid bone can be differentiated according to the gender and corpulence of an individual because these parameters are correlated. These findings are crucial in establishing a protocol for modelling the mechanism of fracture of the hyoid bone in strangulation. Two models of the hyoid bone appear to be needed to meet the practical requirements that are the purpose of these biomechanical studies.

Fetal age estimation using orbital measurements: 3D CT-scan study including the effects of trisomy 21.

Abstract:  This study evaluates a new method of fetal age estimation based on orbital measurement and including the potential trisomy 21 of the fetus. Six orbital and one facial CT‐scan measurements were taken on 71 fetuses ranging from 14 to 41 weeks of gestational age. Forty‐eight fetuses were “normal” and 23 fetuses presented the Down syndrome (trisomy 21). The anatomy/imagery correspondence was evaluated comparing our results to those obtained by direct bone measurements on the same fetuses and revealed no significant differences between the two kinds of measurements. Moreover, a multiple linear stepwise regression was realized to estimate fetal age and showed that the “trisomy 21 parameter” is not conserved in the final determination model. Therefore, we conclude that the good radio‐anatomical correspondence offers an interesting alternative to direct bone measurement (necessitating dissections) and allows a reliable fetal age determination, whatever is the trisomy 21 condition of the fetus.