Preliminary Validation of Handheld X‐Ray Fluorescence Spectrometry: Distinguishing Osseous and Dental Tissue from Nonbone Material of Similar Chemical Composition

One of the tasks of a forensic anthropologist is to sort human bone fragments from other materials, which can be difficult when dealing with highly fragmented and taphonomically modified material. The purpose of this research is to develop a method using handheld X‐ray fluorescence (HHXRF) spectrometry to distinguish human and nonhuman bone/teeth from nonbone materials of similar chemical composition using multivariate statistical analyses. The sample materials were derived primarily from previous studies: human bone and teeth, nonhuman bone, nonbiological materials, nonbone biological materials, and taphonomically modified materials. The testing included two phases, testing both the reliability of the instrument and the accuracy of the technique. The results indicate that osseous and dental tissue can be distinguished from nonbone material of similar chemical composition with a high degree of accuracy (94%). While it was not possible to discriminate rock apatite and synthetic hydroxyapatite from bone/teeth, this technique successfully discriminated ivory and octocoral.     

Skeletal Indicators of Shark Feeding on Human Remains: Evidence from Florida Forensic Anthropology Cases

This research examines a series of six Florida forensic anthropology cases that exhibit taphonomic evidence of marine deposition and shark‐feeding activities. In each case, we analyzed patterns of trauma/damage on the skeletal remains (e.g., sharp‐force bone gouges and punctures) and possible mechanisms by which they were inflicted during shark predation/scavenging. In some cases, shark teeth were embedded in the remains; in the absence of this evidence, we measured interdental distance from defects in the bone to estimate shark body length, as well as to draw inferences about the potential species responsible. We discuss similarities and differences among the cases and make comparisons to literature documenting diagnostic shark‐inflicted damage to human remains from nearby regions. We find that the majority of cases potentially involve bull or tiger sharks scavenging the remains of previously deceased, adult male individuals. This scavenging results in a distinctive taphonomic signature including incised gouges in cortical bone.     

The Use of an Alternate Light Source for Detecting Bones Underwater

When searching underwater crime scenes or disaster scenes for fragmentary human remains, it may be advantageous for forensic divers to be able to detect the presence of bones and teeth among other marine materials (such as shells and rocks). In terrestrial environments, this can typically be accomplished by visual and instrumental methods, but underwater conditions make it difficult to employ detection and sorting techniques in these environments. This study investigates fluorescence of bones and teeth and other marine materials using a submersible alternate light source (ALS) and concludes that an ALS can be a useful tool for detecting bones and teeth in underwater searches as well in terrestrial searches and laboratory environments. The results could impact the methods and equipment used by forensic divers and forensic anthropologists when searching for skeletal remains, potentially increasing the quantity and efficiency of forensic evidence recovered.     

法医骨组织学研究

在实际检案中 ,当现场发现的骨骼残片体积较小时 ,用解剖学观察无法进行骨骼残片的法医鉴定 ,需使用骨组织学的方法进行骨骼残片的个体识别。目前 ,这是法医人类学中一门较活跃的领域 ,即法医骨组织学。法医骨组织学的内容主要包括两个方面 :(1)骨骼残片是否属于人类骨骼 ,或属于何种动物骨骼。这方面的研究包括人类骨骼的组织学特征研究及不同动物的组织学特征研究。 (2 )人类骨骼个体识别的组织学研究。这方面的研究主要包括 ,人类骨骼的组织学特征的年龄判断 ,例如股骨、胫骨、肱骨、锁骨等 ,以及使用骨组织学方法 ,进行人类骨骼的年龄评价的准确性研究。本文对上述内容进行了综述。     

Postmortem changes of human bodies on the bathyal sea floor--two cases of aircraft accidents above the open sea

Forensic taphonomy in the marine context recently received growing attention. However, only limited information is available about the fate of human bodies at greater sea depth. Following two fatal aircraft accidents (west of Namibia, south of Sicily) human remains were recovered from a depth of 540-580 m (both cases) after 3 months (Namibia)/34 days (Sicily). In the Namibia case fully skeletonized bones were lifted. In the Sicily case a complete, dressed body was found exhibiting a partially skeletonized skull, starting adipocere formation and pink teeth. The rate and mode of decomposition of human bodies in the deep sea varies considerably and is mainly influenced by the local faunal composition. Of special relevance for the understanding of both cases was the oceanographic observation that the highly efficient necrophageous lyssianassids are abundant off Namibia but are rare in the Mediterranean, emphasizing the importance of collaboration of forensic and marine scientists in such case work.     

The Importance of Blind Forensic Odontology Analyses

Forensic odontology cases examined from 2012 to 2019 at the Defense POW/MIA Accounting Agency (DPAA) laboratory were reviewed. Five cases from World War II and the Korea War were selected. Three of the cases presented involve dental assemblages, which were built by previous analysts. Postmortem radiographic analyses at the DPAA laboratory of these cases were complicated by the use of an older version of a digital x-ray program and the assumption that teeth placed in the parent bone (maxilla and mandible) did not fully articulate due to the presence of debris at their root apices. Conflicting mitochondrial DNA test results for the submitted teeth and previously believed to be parent bone indicated these elements were not from the same individual. The remaining two cases are examples of how knowledge of findings from other disciplines may sway an opinion and could possibly lead to the rendering of erroneous opinions by the forensic odontologist. Having knowledge of previous examinations or results from other scientists, disciplines, and lines of evidence may lead to a bias in findings or opinions. If not careful, even the best-intended scientist may fall victim to a bias in their opinion/analysis. The forensic odontologist should perform all analysis in the blind, not knowing any information which may bias their opinion, and utilize current versions of digital x-ray software available and their tools when performing their examinations.     

利用AutoMate Express~(TM)自动化法医DNA提取系统提取骨骼及牙齿DNA

目的探讨建立骨骼及牙齿DNA自动化提取的新方法。方法将33份骨骼及15份牙齿样本分别用冷冻研磨和手工处理两种方法研磨成粉,采用AutoMate ExpressTM自动化法医DNA提取系统提取DNA并定量。结果 AutoMate ExpressTM自动化法医DNA提取系统能够在3h左右完成骨骼、牙齿DNA的提取,两种方法处理的骨骼样本所得DNA质量浓度差异无统计学意义。冷冻研磨处理的骨骼和牙齿样本均获得了较好的STR分型结果,且牙齿样本所得DNA质量浓度高于手工提取所得。结论应用AutoMate ExpressTM自动化法医DNA提取系统是自动化提取骨骼、牙齿DNA的一种新方法,可应用于法医实际案件检验。     

The Use of Tooth Crown Measurements in the Assessment of Ancestry

As the hardest tissue in the body, teeth have the potential to offer a wealth of biological information to the forensic anthropologist, which can include the assessment of ancestry. Using a large data set of dental measurements, the efficacy of mesiodistal and buccolingual tooth dimensions to discriminate between broad, geographically based groups is explored. A general pattern is identified: African populations have the largest teeth, Asians possess teeth of intermediate size, and Europeans have the smallest teeth. In a discriminant function analysis using crown measurements of all teeth (mandibular and maxillary and excluding the third molar), individuals were correctly classified in 71.3% of cases. When the sex of the individual is known, classification is improved up to 88.1% in females and 71.9% of males (cross‐validated). Based on these results, we argue that dental metrics can be regularly employed as part of the development of the biological profile.     

Implant Bone Integration Importance in Forensic Identification

Odontological identification consists of the comparison of antemortem dental information regarding a missing person with postmortem data from an unidentified corpse or human remains. Usually, the comparison concerns morphologic features that the operator chooses among all the visible characteristics because of inter‐individual uniqueness; for this reason, implants can be of enormous assistance. A case concerning the recovery of a burnt oral implant, connected to a bone fragment, among 2780 charred bone fragments, suspected to have belonged to a victim of homicide, is presented to demonstrate that dental implants and their site of bone integration represent a very precious element for personal forensic identification. Because of their morphological invariability in time and because of their morphologic uniqueness, they were used as evidence to associate unidentified human charred remains to a missing person where DNA analysis failed to do so. The case illustrates the fundamental contribution, not yet described in literature, given by the clinical aspects of tooth replacement with dental implants to a forensic discipline. Clinical practitioners should therefore be aware of the great importance of their work and of dental records in a forensic identification scenario.     

CT在法医人类学中的应用与展望

计算机X线断层摄影术具有分辨率高、成像清晰、可进行三维重建等优点,对骨骼和牙齿的成像效果较好。近十年来,国外有学者将其用于推断年龄和身高,判定种族和性别,在相关文献中介绍了有关的研究方法和数据,并对这些方法和数据在法医人类学个体识别中的应用价值进行了客观的评估。笔者对近几年发表的部分文献进行综述,希望能够为法医人类学科研和办案提供新的方法和思路。     

利用牙齿影像进行同一认定的研究进展

牙齿是人体最坚固的组织,利用牙齿进行个体识别是最基础也是最具价值的方法之一。本文通过对国内外牙齿形态影像在个体识别中的特异性、稳定性及其技术的综述,提出了建立我国法齿学的设想。     

An Update on the Hazards and Risks of Forensic Anthropology,Part I: Human Remains

This work reviews the hazards and risks of practicing forensic anthropology in North America, with a focus on pathogens encountered through contact with unpreserved human remains. Since the publication of Galloway and Snodgrass' seminal paper concerning the hazards of forensic anthropology, research has provided new information about known pathogen hazards, and regulating authorities have updated recommendations for the recognition and treatment of several infections. Additionally, forensic anthropology has gained popularity, exposing an increased number of students and practitioners to these hazards. Current data suggest many occupational exposures to blood or body fluids go unreported, especially among students, highlighting the need for this discussion. For each pathogen and associated disease, this work addresses important history, reviews routes of exposure, provides an overview of symptoms and treatments, lists decontamination procedures, and presents data on postmortem viability. Personal protection and laboratory guidelines should be established and enforced in conjunction with the consideration of these data.     

Histological Determination of the Human Origin of Bone Fragments

Abstract:  A frequently encountered task in the forensic scenario is verification of the human origin of severely degraded fragments of bone. In these cases histological methods which consider osteon size and morphology can prove to be useful. The authors in the present study verify the applicability of published algorithms to flat and subadult bones from human, dog, cat, cow, rabbit, sheep, pig, chicken, quail, and turkey samples. Metric analysis was performed on 2031 Haversian canals. Analyses carried out on human samples confirmed a success rate of around 70% on long adult bones; however the percentage of wrong answers was particularly high in the case of newborns and older subadults as well as on flat bones in general. Results therefore suggest that such regression equations should be limited only to bone fragments from long adult bones.     

Effect of Temperature on Bone Tissue: Histological Changes

The analysis of burned human remains has been of great interest among forensic anthropologists largely due to the difficulty that their recovery, classification, reconstruction, and identification present. The main purpose of this analysis is to present histological methodology for the interpretation of bones altered by thermal processes. We include analyses of the microscopic changes among bones exposed to different temperatures, with the goal of establishing categories of histological morphology in relation to fire temperature. Samples of bone (ilium) were exposed systematically to controlled temperatures. Analysis of the resulting histological changes has allowed the formation of a clear four‐stage classification of the alterations observed. This classification should prove useful in assessing bone changes in relation to temperature of exposure, particularly in cases where this temperature was previously not known.     

Structural analysis of human rib fracture and implications for forensic interpretation

Patterns of rib fractures are of significant clinical and forensic interest. Linking patterns of rib fracture with specific physical events provides a foundation for understanding the nature of traumatic events that are associated with rib fracture in forensic contexts. In this study, isolated human ribs (n = 8) were end-loaded to failure to investigate: (i) local deformations (bone strain) prior to and during structural failure, (ii) location of ultimate failure, and (iii) fracture mode. Structural properties of ribs were used to calculate theoretical stresses to determine whether such calculations could be used to predict site of fracture. Ribs fractured on the sternal side of midshaft in all experiments, but mode of failure varied with transverse, buckle, spiral, and "butterfly" fractures observed. Comparison of calculated stress with observed strain values suggest that experimental, rather than theoretical, approaches will be most productive in furthering understanding rib fracture in forensic contexts.     

Using Carbon,Oxygen, Strontium,and Lead Isotopes in Modern Human Teeth for Forensic Investigations: A Critical Overview Based on Data from Bulgaria

Isotopic data obtained from human remains can provide information about an individual's origin, migration, and diet. We evaluate the usefulness of carbon, oxygen, strontium, and lead isotopes for forensic investigations by comparing data from Bulgarian teeth with data from other regions. Geo‐referencing based on oxygen or strontium isotopes can be misleading due to overlap with other countries in Europe and other continents. Carbon and lead isotopes, in combination with oxygen and strontium isotopes, provide the most useful information for identification of local vs foreigner status. In particular, high‐precision Pb isotopes show a distinct “Bulgarian” range; however, it is possible that individuals from other countries in Eastern Europe and/or central to western Asia could have overlapping isotopic values. Additional high‐precision multi‐isotope data from modern humans from different regions in the world are required to transition from speculative to more quantitative estimation of a geographical place of origin for unidentified human remains.     

A method for defleshing human remains using household bleach

Medical examiners and forensic anthropologists are often faced with the difficult task of removing soft tissue from the human skeleton without damaging the bones, teeth and, in some cases, cartilage. While there are a number of acceptable methods that can be used to remove soft tissue including macerating in water, simmering or boiling, soaking in ammonia, removing with scissors, knife, scalpel or stiff brush, and dermestid beetles, each has its drawback in time, safety, or potential to damage bone. This technical report using the chest plate of a stabbing victim presents a safe and effective alternative method for removing soft tissue from human remains, in particular the chest plate, following autopsy, without damaging or separating the ribs, sternum, and costal cartilage. This method can be used to reveal subtle blunt force trauma to bone, slicing and stabbing injuries, and other forms of trauma obscured by overlying soft tissue. Despite the published cautionary notes, when done properly household bleach (3-6% sodium hypochlorite) is a quick, safe, and effective method for examining cartilage and exposing skeletal trauma by removing soft tissue from human skeletal remains.     

The Effect of Soft Tissue on Temperature Estimation from Burnt Bone Using Fourier Transform Infrared Spectroscopy

This study investigated the effect of soft tissue and different exposure times on the prediction of burning temperatures of bone when using Fourier transform infrared spectroscopy (FTIR). Ovis aries rib bones were burnt at different temperatures and for varying time intervals. Results of a linear regression analysis indicated that burn temperatures can be predicted with a standard error of ±70°C from defleshed bone spectra. Exposure time does not have a significant impact on prediction accuracy. The presence of soft tissue has a significant impact on heat‐induced changes of the bone matrix in low (<300°C) as well as high temperatures (>800°C), slowing down combustion in the former and accelerating it in the latter (p < 0.05). At medium temperatures, no significant difference was noted. These results provide forensic investigators a new perspective with which to interpret the results of crystallinity measures derived from burnt bone.     

Estimating the Temperature of Heat‐exposed Bone via Machine Learning Analysis of SCI Color Values: A Pilot Study

Determining maximum heating temperatures of burnt bones is a long‐standing problem in forensic science and archaeology. In this pilot study, controlled experiments were used to heat 14 fleshed and defleshed pig vertebrae (wet bones) and archaeological human vertebrae (dry bones) to temperatures of 400, 600, 800, and 1000°C. Specular component included (SCI) color values were recorded from the bone surfaces with a Konica‐Minolta cm‐2600d spectrophotometer. These color values were regressed onto heating temperature, using both a traditional linear model and the k‐nearest neighbor (k‐NN) machine‐learning algorithm. Mean absolute errors (MAE) were computed for 1000 rounds of temperature prediction. With the k‐NN approach, the median MAE prediction errors were 41.6°C for the entire sample, and 20.9°C for the subsample of wet bones. These results indicate that spectrophotometric color measurements combined with machine learning methods can be a viable tool for estimating bone heating temperature.     

Stature estimation based on dimensions of the bony pelvis and proximal femur

Pelin et al. recently showed that sacral height measured on lateral magnetic resonance images can be used with moderate accuracy to reconstruct stature in males. In most forensic anthropological cases, however, sacral dimensions must be obtained from dry bones. In this study, the relationship between stature and sacral height, hip height, and femur head diameter measured on dry bone was evaluated for American Blacks and Whites of both sexes (n = 247). There are significant correlation between stature and these three dimensions, but the results suggest that none of the dimensions predict stature with the accuracy needed to be useful in forensic anthropological investigations.