Though applied in bioarchaeology, dental wear is an underexplored age indicator in the biological anthropology of contemporary populations, although research has been conducted on dental attrition in forensic contexts (Kim et al. 2000, Prince et al. 2008, Yun et al. 2007). The purpose of this study is to apply and adapt existing techniques for age estimation based on dental wear to a modern American population, with the aim of producing accurate age range estimates for individuals from an industrialized context. Methodologies following Yun and Prince were applied to a random sample from the University of New Mexico (n=583) and Universidade de Coimbra (n=50) cast and skeletal collections. Analysis of variance (ANOVA) and linear regression analyses were conducted to examine the relationship between tooth wear scores and age. Application of both Yun et al. (2007) and Prince et al. (2008) methodologies resulted in inaccurate age estimates. Recalibrated sectioning points correctly classified individuals as over or under 50 years for 88% of the sample. Linear regression demonstrated 60% of age estimates fell within ±10 years of the actual age, and accuracy improved for individuals under 45 years, with 74% of predictions within ±10 years. This study demonstrates that age estimation from dental wear is possible for modern populations, with comparable age intervals to other established methods. It provides a quantifiable method of seriation into “older” and “younger” adult categories, and is a more reliable method than cranial sutures in instances where only the skull is available. / 2019-07-11T00:00:00Z

Rib fractures are present in 25 percent of all trauma-related deaths, making the mechanism and pattern of rib fractures an important area of trauma research (Lien et al. 2009). Rib fractures are important to consider when researching trauma because they can cause serious complications contributing to an individual's mortality. This retrospective research study focuses on rib fracture patterns in fatal motor vehicle accidents (MVAs). The sample consists of 105 MVA victims--68 males and 37 females. Data was collected at the Hillsborough County Medical Examiner's Office in Tampa, Florida. The study investigates motor-vehicle-related deaths from 2011 to 2013 to establish rib fracture patterns in association with several variables. Fractures of the manubrium and sternum are included in the analyses since the ribs articulate in several places with the manubrium and sternum and they are frequently injured in MVAs. First, this research study investigates the rib fracture patterns that exist in correlation to soft tissue organ injury. Injuries to the heart, lungs, liver, diaphragm, and spleen were analyzed based on their direct contact with the ribcage. The results show that several significant relationships exist, including that lung injury is about 12 times more likely to occur when a fracture is present in the left middle ribs and 4 times more likely to occur when there is a fracture on the manubrium. Heart injury is found to be 9 times more likely to occur when the sternum is fractured and the liver is found to be 4 times more likely when the right middle ribs are fractured and 0.3 times more likely when the right high ribs are fractured. Second, this study examines rib fracture patterns controlling for seatbelt use, airbag deployment, and cardiopulmonary resuscitation (CPR) administration. Each of these variables is tested to determine their influence in causing injury and the fracture patterns resulting from accidents. For drivers, specifically, it is also tested if fracture patterns can predict seatbelt use. The results show a significant relationship between fracture of the left low ribs and seatbelt use. In drivers, it is 5 times more likely that the individual was wearing a seatbelt if the left low ribs are fractured. Lastly, a significant relationship was found for fractures of the manubrium and CPR administration. Finally, this research study aims to predict the number of ribs fractured by an individuals' age. Progressive mineralization of the skeleton and other age-related changes increase the risk of fracture in elderly individuals. The results of this study indicate a significant, positive correlation between age and the total number of rib fractures sustained in MVAs, supporting the presumption that elderly are at a higher risk for rib fractures.

Forensic taphonomy is concerned with investigation of graves and grave sites. The primary aim of forensic taphonomy is development of accurate estimations of postmortem interval (PMI) and/or postburial interval (PBI). Soil has previously been largely ignored, therefore this thesis is designed to investigate changes in decomposition as imparted by the soil. Furthermore the impact of cadaver interment on the surrounding soil may offer prospects for identification of clandestine graves. A series of laboratory controlled decomposition experiments using cadavers (Mus musculus) and cadaver analogues (skeletal muscle tissue (SMT); Sus scrofa, Homo sapiens, Ovis aries and Bos Taurus) were designed to investigate decomposition in burial environments. Sequential destructive harvests were carried out to monitor temporal changes during decomposition. Analyses conducted included; mass loss, microbial activity (CO2 respiration) and soil chemistry (pH, EC and extractable NH4 +, NO3 -, PO4 3- and K+). Several experimental variables were tested; frozen-thawed versus refrigerated SMT, different mammalian sources of SMT, different soil type and contribution of soil versus enteric microbial communities. Mass loss measurements for SMT experiments demonstrated a sigmoidal pattern of mass loss, however, larger cadavers (Mus musculus, 5 weeks) did not. The inhumation of SMT (frozen, unfrozen, different mammalian sources) or cadavers leads to an increase in microbial activity (CO2 respiration) within 24 hours of burial. A peak of microbial activity is attained within a week, followed by a decrease and eventual plateau. The rapid influx in microbial activity is matched by corresponding increases in pH and NH4 + concentration. pH and NH4 + are strongly correlated in soils with acidic basal pH, by comparison highly alkaline soil demonstrated no relationship. NH4 + concentration also appeared to be related directly to NO3 - concentration and cadaver or SMT mass. A decrease in NH4 + corresponds with an increase in NO3 -, however, nitrification was unpredictable. Rapid nitrification was observed in sand systems when SMT was interred, but was not noted when cadavers were interred. By comparison both sandy clay loam and loamy sand soils demonstrated rapid nitrification after inhumation of a cadaver. When cadaver or cadaver analogue mass was larger, so were NH4 + and NO3 - concentrations in systems that experienced nitrification.

Forensic anthropologists and archaeologists have been increasingly engaged, at police request, in investigations to locate and recover buried human remains ( Rodriguez and Bass, 1985 ; France et al., 1992 ; Owsley, 1995 ; Hunter et al., 1996 ). Current search methods are derived from archaeology, geology, botany, geography and taphonomy. However, there is limited testing of search techniques, particularly over graves containing human bodies, and few studies that have examined the appearance of gravesites over several years. In the absence of such studies in Australia, eight shallow burials ( six animal graves, two human graves ) and one calibration pit were established in South Australia to provide information about the physical properties of graves and the effectiveness of burial site location techniques. The findings provide descriptive information about the surface appearance of graves over six years, the chemical elements remaining in the upper levels of grave soil and the practical implications of using geophysical instruments to search for buried human remains in typical forensic cases in South Australian landscapes. Key surface indicators identified included ongoing faunal scavenging, soil surface differences, absence of moss, absence of vegetation in dry periods, the slow return of ground debris, and the formation of depressions. These were not all associated with the presence of a body but could be related to disturbance of the ground surface. There was a relationship between surface indicators and seasonal conditions and the position of the gravesites in relation to surrounding landscape features, in particular, trees. Higher levels of certain soil elements at the upper surface layer at the gravesites were identifiable after several years of burial ; in particular, calcium and magnesium were identifiable at the human body and kangaroo gravesites. Ground penetrating radar, electrical resistivity and electromagnetic induction were used to survey the gravesites. Ground penetrating radar provided the most significant results in terms of anomalies compared to the surrounds. However, use of these instruments highlighted the potential of overlooking gravesites due to lack of definitive survey data, the impact of seasonal conditions and the problems associated with using the instruments in some burial areas. Comparison of these findings is made with other international studies. Electrical resistivity surveying was successfully used to locate a 150 year old burial. A national survey on body location techniques used by police investigators in a seven year period was conducted, demonstrating a limited reported success in and use of search techniques other than ground search, implying a need to develop more reliable techniques for clandestine grave location. The results provide previously unavailable information about the surface appearance of gravesites, detectable elements in grave soil and the use of geophysical survey instruments for this purpose in South Australia. / Thesis (Ph.D.)--University of Adelaide, School of Medical Sciences, Discipline of Anatomical Sciences, 2006.

Dans nos sociétés culturelles, trois régions anatomiques sont habituellement apparentes et visibles donc identifiables : ce sont le visage et les mains. La main est donc un élément d’identification spécifique à chaque individu et reconnaissable. En mesurant le volume de la main démembrée d’une personne, peut-on déterminer la typologie de cette personne associant, entre autres mesures de la main, le volume au poids? La mesure du volume de moulage des mains de 109 adultes (dont 14 gauchers) est réalisée à l’aide d’un volumètre à aiguille et plusieurs équations de régression mettent en évidence les relations entre des composantes anthropométriques du corps et de ses segments avec le volume des mains. Ensuite, le volume et des variables spécifiques des mains d’un nouvel échantillon de 88 sujets vivants sont mesurés et leur typologie est également déterminée. Les équations de régression caractérisant les relations entre les variables des mains et la typologie estiment la stature par les longueur et largeur des mains (Main Droite : r² = .66 ; SEE = 4 cm ; Main Gauche : r² = .62 ; SEE = 4,2cm) et le poids par le volume et le périmètre de PII du 5ème doigt (MD : r² = .69 ; SEE = 6.64kg ; MG : r² = .64 ; SEE = 7,13kg) La validation de la méthode est réalisée sur un échantillon analogue mais indépendant de 21 sujets adultes. Le poids de 90.5 % des sujets est estimé avec un écart maximum de 5.98kg et la stature de 76% de l’échantillon avec un écart maximum de 3cm. De nombreuses techniques ont été élaborées afin de reconstruire le visage à partir du crâne d’une personne disparue ; dans le même ordre d’idée peut-on reconstruire l’aspect virtuel de la peau d’une main en disposant de son squelette ? Des modèles informatisés, par CT Scan, des os et de la peau sont obtenus des mains d’un cadavre et d’un volontaire. Le logiciel Lhp Builder permet la localisation des coordonnées spatiales de points de repères anatomiques osseux des modèles. A partir de 3 repères, les relations spatiales entre les modèles sont établies et employées afin d’interpoler la peau manquante de la main. Le volume de la « peau interpolée » et le volume de la « peau réelle » obtenus par imagerie médicale sont comparés afin de valider la méthode. Une différence de volume de 3.5 % entre les volumes respectifs de la main du cadavre et de la main reconstruite situe le niveau de précision de la méthode. D’autres manipulations de reconstruction sont exécutées dans des situations analogues au cadre médico-légal (enfouissement en terre de pièces animales, mise en digestion dans des produits caustiques) Cette première approche méthodologique de reconstruction de la main semble prometteuse et la main reconstruite deviendrait un élément important pour l’identification de personnes disparues./ In our cultural society, three anatomical body parts are usually apparent so visible and thus identifiable: the face and the hands. The hand may be an element of identification specific to each individual and recognizable. By measuring the dismembered hand volume of a person, the typology of this person associating, inter alia measurements of the hand, volume with weight could be determined ? The volume measurement of casts hands of 109 adults (of which 14 left-handed persons) is realized using a needle volumeter and several regression equations highlight the relations between anthropometrical components of the body and its segments with the hands volume. Then, the hands volume and specific hands variables of a new sample of 88 living subjects are measured and their typology is also determined. The regression equations characterizing the relations between the hands variables and typology estimate the stature by hands length and width (Right hand: r² = 66; SEE = 4 cm; Left hand: r² = 62; SEE = 4,2cm) and the weight by volume and perimeter of PII of the 5 th finger (Right hand: r² = 69; SEE = 6.64kg; Left hand: r² = 64; SEE = 7,13kg). The validation of the method is carried out on a sample similar but independent of 21 adult subjects. The weight of 90.5 % of the subjects is estimated with a maximum difference of 5.98kg and the stature of 76% of the sample with 3cm maximum. Many techniques were elaborated in order to rebuild the face starting from cranium of a missing person; in the same order can one rebuild the virtual aspect of the hand skin while having its skeleton? From computerized models, by CT Scan, bones and skin are obtained of hands of a corpse and a living volunteer. The software Lhp Builder allows the localization of the 3D co-ordinates of anatomical bones landmarks of the models. From 3 landmarks, the 3D relations between the models are established and used in order to interpolate the missing skin of the hand. The volume of the " interpolated skin " and the volume of the " real skin " obtained by medical imaging are compared in order to validate the method. A volume difference of 3.5 % between respective volumes of the hand corpse and the rebuilt hand estimates the level of precision of the method. Other experiments of rebuilding are carried out in situations similar to the medico-legal framework (ground hiding of animal parts, digestion in caustic products) This first methodological approach of hand rebuilding seems promising and the rebuilt hand would become a significant element for the identification of missing people.

In this dissertation I evaluate the potential of the morphology of the petrous portion of the human temporal bone as seen on axial CT scans of the head as a means to generate identifications of fragmentary human skeletal remains. The specific goals are threefold: (1) To investigate variability in the shape of the petrous portion of the human temporal bone using two-dimensional morphometric analysis; (2) to evaluate the reliability of the resultant method in forensic identification; and (3) to consider the results within the framework of Bayesian theory in light of recent rulings regarding the admissibility of forensic testimony. The data used in this research were collected from axial CT images of the cranium. Two sets of images were collected for each of the 115 individuals in the sample so that Euclidean distance comparisons could be made between images of the same individual and images from different individuals. I collected two-dimensional coordinate data from 36 landmarks on each of the CT images and calculated the distances between each of the coordinate points to generate the data used in the statistical analyses. I pared down this set of measurements using two different models (referred to as the biological and PCFA models). The measurement sets of both models were then compared to one another using nearest neighbor analysis, to test their relative efficiency in matching replicate images to one another. The results of both models were highly accurate. Three incorrect nearest neighbor matches resulted from the biological model and 5 from the PCFA model. The errors appear to have been the result of variation in the axial plane between the first and second scans. The results of the nearest neighbor comparisons were then considered within the context of Bayes' Theorem by calculating likelihood ratios and posterior probabilities. The likelihood ratios and posterior probabilities were very high for both models, indicating that: 1) there is significant individual variability in the measurements of the petrous portion used in this research, and 2) this variation represents a high level of potential accuracy in the application of this method in the identification of forensic remains.

Due to the strong genetic component of dental development, research has shown that mineralization patterns of the human dentition are relatively buffered against environmental influences that normally affect bone growth and development. It is because of this resistance to environmental factors and the continuous growth of the permanent dentition throughout childhood and adolescence that the evaluation of dental development patterns has become the preferred method of age estimation in living and deceased children. Researchers (Harris and Mckee 1990; Tompkins 1996; Blankenship et al. 2007; Kasper et al. 2009) have suggested that the timing of dental development varies by ancestral descent and geographic populations. However, further evaluations of these perceived differences in the timing of dental development among populations are necessary as classical statistical methods result in age estimations that are biased toward the age structure of the reference population. However, the Bayesian approach is beneficial since it incorporates relevant prior knowledge into the analysis and formalizes the relationship between assumptions and conclusions (Buck et al. 1996). Therefore, the purpose of this research is to incorporate methods in Bayesian analysis to compare the timing of dental development between two contemporary populations of the Southeastern United States, as well as test the accuracy of dental development age parameters devised by Moorrees et al. (1963) on a contemporary Florida Population. For this study, 51 panoramic radiographs of individuals from a contemporary Florida population ranging in age from 7.7-20.4 years were reviewed. Statistical analyses incorporated a Bayesian approach to compare the timing of dental development for individuals comprising the contemporary Florida sample with the timing of dental development for a contemporary Middle Tennessee population by utilizing the age structure of the Middle Tennessee population as informed prior knowledge, otherwise referred to as an informed prior. Transition distributions for age, given stage of dental development, were also modeled for individuals comprising the contemporary Florida sample. The accurate observation and comparison of probability density distributions for age can serve as a noninvasive method for evaluating the probability of whether or not an unknown individual is a particular age, given the stage of dental development. Results of this research indicate that there is a consistent underestimation of age for individuals comprising the contemporary Florida population when the age structure of the Middle Tennessee population is utilized as an informed prior. Additionally, the results of this thesis indicate that there is a consistent underestimation of age when utilizing age parameters of Moorrees et al. (1963) for the estimation of age for individuals from a contemporary Florida population. By incorporating a Bayesian approach to compare two contemporary populations of the Southeastern United States, a comprehensive analysis of the relationship between age and stage of dental development can be achieved. Therefore, the results of this thesis support Bayesian analysis as an appropriate method of evaluating perceived differences in the timing of dental development between contemporary populations. Furthermore, the results of this research are beneficial to the field of forensic anthropology as the observation of advanced stages of molar development utilizing panoramic radiographs serves as a noninvasive method in estimating age for unknown juveniles and young adults, and can also assist courts within the United States in determining whether or not an individual is legally considered a minor or an adult.

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The investigation of mass graves involves aspects of high political, judicial, and emotional impact. Understanding how bodies held within mass graves change between the time they are deposited and the time they are discovered (the realm of forensic taphonomy) is vital for competent collection of evidence and accurate evaluation of the scene. This thesis explores these issues by detailing experimental research undertaken to better understand the affects of environmental factors on low-density, orderly placement mass graves. Issues pertaining to how decomposition of bodies in contact differs from that of single bodies, intentional disturbance, and temperature change were examined experimentally using pigs as human analogues over a period of almost one year outside of Edmonton, Canada. There are three primary avenues in which the information obtained can be applied to the real world: estimation of elapsed time since death, planning mass grave investigations and reducing evidence loss, and evaluating post-burial disturbance or intentional vandalism.