Radiocarbon dating as tool to assist in triaging cases of unidentified human remains in Victoria, Australia: A case series.

In cases where human remains are unidentified because there is no initial identification hypothesis, limited contextual information, and/or poor preservation, radiocarbon (14 C) dating may be a useful tool to further assist with identification. Through measuring the amount of 14 C remaining in organic material, such as bone, teeth, nail, or hair, radiocarbon dating may provide an estimated year of birth and year of death for a deceased person. This information, may assist in, establishing whether a case of unidentified human remains (UHR) is actually of medicolegal significance and therefore, requires forensic investigation and identification. This case series highlights the application of 14 C dating to seven of the 132 UHR cases in Victoria, Australia. Cortical bone was sampled from each case and the level of 14 C was measured to provide an estimated year of death. Four of the seven cases analyzed contained the levels of 14 C consistent with an archeological timeframe, one contained a level of 14 C consistent with a modern (i.e., of medicolegal significance) timeframe, and the results for the remaining two samples were inconclusive. Applying this technique not only reduced the number of UHR cases in Victoria but also has investigative, cultural, and practical implications for medicolegal casework in general.

Average thickness of the bones of the human neurocranium: development of reference measurements to assist with blunt force trauma interpretations.

The accurate interpretation of a blunt force head injury relies on an understanding of the case circumstances (extrinsic variables) and anatomical details of the individual (intrinsic variables). Whilst it is often possible to account for many of these variables, the intrinsic variable of neurocranial thickness is difficult to account for as data for what constitutes 'normal' thickness is limited. The aim of this study was to investigate the effects of age, sex and ancestry on neurocranial thickness, and develop reference ranges for average neurocranial thickness in the context of those biological variables. Thickness (mm) was measured at 20 points across the frontal, left and right parietals, left and right temporals and occipital bones. Measurements were taken from post-mortem computed tomography scans of 604 individuals. Inferential statistics assessed how age, sex and ancestry affected thickness and descriptive statistics established thickness means. Mean thickness ranged from 2.11 mm (temporal squama) to 19.19 mm (petrous portion). Significant differences were noted in thickness of the frontal and temporal bones when age was considered, all bones when sex was considered and the, right parietal, left and right temporal and occipital bones when ancestry was considered. Furthermore, significant interactions in thickness were seen between age and sex in the frontal bone, ancestry and age in the temporal bone, ancestry and sex in the temporal bone, and age, sex and ancestry in the occipital bone. Given the assorted influence of the biological variables, reference measurement ranges for average thickness incorporated these variables. Such reference measurements allow forensic practitioners to identify when a neurocranial bone is of normal, or abnormal, thickness.

An evaluation of the differences in paediatric skeletal trauma between fatal simple short falls and physical abuse blunt impact loads: An international multicentre pilot study.

In cases where a deceased child exhibits trauma as a result of a physical abuse blunt impact load, a parent/caregiver may provide a simple short fall (SSF) as the justification for that trauma. The skeletal fractures remain difficult to differentiate between a SSF and physical abuse however, as both are the result of a blunt impact load, and are therefore biomechanically alike, and the rare nature of these fatalities means only anecdotal research has been available to validate such claims. The aim of this pilot study was to investigate if there may be differences in the skeletal fracture patterns and types resulting from SSFs compared with those resulting from physical abuse blunt impacts. Paediatric (<10 years) cases of fatal SSFs (≤1.5 m) and physical abuse were collected from the Victorian Institute of Forensic Medicine (Australia), Institut Médico-Légal de Paris (France), University of Pretoria (South Africa) and Great Ormond Street Hospital (England). For each case the intrinsic and extrinsic variables were recorded from medico-legal reports and skeletal trauma was documented using post-mortem computed tomography scans and/or skeletal surveys. Three SSFs and 18 physical abuse cases were identified. Of the SSF cases, two exhibited fractures; both of which were simple linear neurocranial fractures. Comparatively, 12 of the physical abuse cases exhibited fractures and these were distributed across the skeleton; 58% located only in the skull, 17% only in the post-cranial and 25% located in both. Skull fracture types were single linear, multiple linear and comminuted. This pilot study suggests, anecdotally, there may be differences in the fracture patterns and types between blunt impact loads resulting from a SSF and physical abuse. This data will form the foundation of the Registry of Paediatric Fatal Fractures (RPFF) which, with further multicentre contributions, would allow this finding to be validated.

An Assessment of the Skeletal Fracture Patterns Resulting from Fatal High (˃3 m) Free Falls.

The injury patterns resulting from fatal high (˃3 m) free falls have previously been documented in clinical and medico-legal contexts; however, details relating specifically to the skeletal blunt force trauma (BFT) have been limited. This study aimed to augment what is known of the skeletal fracture patterns resulting from fatal high free falls. Skeletal trauma was analyzed from full-body postmortem computed tomography scans of 95 individuals who died following a high free fall. Fracture patterns were documented using the five general anatomical regions, axial and appendicular regions, and postcranial unilateral and bilateral regions. Patterns were analyzed in the context of the extrinsic and intrinsic variables that may influence fractures using multiple logistic regression. Fracture patterns involved all aspects of the skeleton, with 98.9% exhibiting polytrauma, and were influenced primarily by the height fallen, manner of death, and landing surface. This improved understanding of fracture patterns will augment anthropological interpretations of the mechanism of BFT in cases of suspected high falls.

An Anthropological Examination of the Types of Skeletal Fractures Resulting from Fatal High (˃3 m) Free Falls.

Fatal falls from heights (˃3 m) often result in blunt force trauma (BFT) to the skeleton. The fracture patterns that result from this BFT mechanism are well understood in forensic anthropology and forensic pathology; however, details of the specific types of fractures that result remain poorly documented. The aim of this study was to provide a detailed examination of the types of fractures that may result from fatal high falls. Fractures were recorded from 95 full-body postmortem computed tomography scans of individuals known to have died from a high fall. Trauma was then analyzed taking into account the extrinsic and intrinsic variables known to influence a fall using multiple logistic regression. A total of 339 types of fractures were classified, of which 16 were significantly associated with this BFT mechanism. Classified fracture types will augment anthropological interpretations of the circumstances of death from BFT in cases of suspected high falls.

The skeletal trauma resulting from a fatal B.A.S.E jump: A case study showing the impact of landing feet-first under extreme vertical deceleration.

The term 'B.A.S.E jump' refers to jumping from a building, antenna, span (i.e., bridge) or earth (i.e., cliff) structure, and parachuting to the ground. There are numerous hazards associated with B.A.S.E jumps which often result in injury and, occasionally, fatality. This case report details the skeletal trauma resulting from a fatal B.A.S.E jump in Australia. In this case, the jumper impacted the ground from a fall of 439m in a feet-first landing position, as a result of a partially deployed parachute, under extreme vertical deceleration. Skeletal trauma was analyzed using full-body post mortem computed tomography (PMCT) and contextual information related to the circumstances of the jump as reported by the Coroner. Trauma to 61 skeletal elements indicates the primary impact was to the feet (i.e., feet-first landing), followed by an anterior impact to the body (i.e., fall forwards). Details of the individual fracture morphologies indicate the various forces and biomechanics involved in this fall event. This case presents the types of fractures that result from a B.A.S.E jump, and highlights the value of using PMCT and coronial data as tools to augment skeletal trauma interpretations.

Fatal falls involving stairs: an anthropological analysis of skeletal trauma.

The skeletal blunt force trauma resulting from fatal falls involving stairs is complex. There are countless ways an individual may fall when stairs are involved, and thus a variety of ways the skeleton may fracture. Therefore anecdotally, it may be said that there is no specific skeletal trauma characteristic of this fall type. In order to scientifically investigate this anecdotal understanding, this study provides a detailed investigation of the skeletal fracture patterns and morphologies resulting from fatal falls involving stairs. Skeletal trauma was analyzed using the full-body postmortem computed tomography scans of 57 individuals who died from a fall involving stairs. Trauma was examined in the context of the variables that potentially influence how an individual falls (i.e. sex, age, body mass index, number of stairs involved, psychoactive drugs, pre-existing conditions, landing surface and manner of the fall) using logistic regression. Skeletal trauma primarily occurred in the axial skeleton. An analysis of fracture patterns showed the cranial base was less likely to fracture in younger individuals and the cervical vertebrae were more likely to fracture in falls that involved more than half a flight of stairs. A total of 56 fracture morphologies were identified. Of these, diastatic fractures were less likely to occur in older individuals. Findings indicate that there are skeletal fracture patterns and morphologies characteristic of a fatal fall involving stairs.

Skeletal Trauma Resulting From Fatal Low (≤3 m) Free Falls: An Analysis of Fracture Patterns and Morphologies.

The skeletal trauma resulting from fatal low (≤3 m) free falls is poorly researched and understood by forensic practitioners. The aim of this study was to identify the types of skeletal trauma resulting from low falls through investigating fracture patterns and morphologies. Skeletal trauma was analyzed using full-body postmortem computed tomography scans of 145 individuals who died from a low free fall. Trauma was then contextualized to the variables that influence how a person falls using multiple logistic regression. Results showed fracture patterning primarily involved the axial skeleton and that there were a number of patterns significantly associated with the height fallen, pre-existing health conditions, and age. Analysis of fracture morphologies showed 108 possible fracture types, six of which were significantly associated with the height fallen. Understanding the skeletal trauma characteristic of low free falls will further inform anthropological interpretations of trauma in cases where a fall may be considered the possible mechanism.

Recording skeletal completeness: A standardised approach.

Recording the preservation of human skeletal remains is the foundation of osteological analyses for forensic and archaeological skeletal material. Methods for recording the skeletal completeness, one of the components of skeletal preservation documentation, are however currently non-standardised and subjective. To provide practitioners with a scientific means to accurately quantify skeletal completeness in an adult skeleton, percentage values for each skeletal element have been established. Using computed tomography (CT) volume rendering applications and post-mortem CT skeletal data for one adult individual, the percentage value for each bone relative to the complete skeleton was calculated based on volume. Percentage values for skeletal elements ranged from 0.01% (select hand and foot bones) to 8.43% (femur). Visual and written mediums detailing individual skeletal percentages have been provided as user-friendly reference sources. Calculating the percentage of skeletal remains available for analysis provides practitioners with a means to scientifically and objectively record skeletal completeness.

Skeletal fractures resulting from fatal falls: A review of the literature.

To investigate what is currently known about skeletal blunt force trauma (BFT) resulting from falls, and how valuable that research is in contributing to forensic anthropology investigations and interpretations of circumstances of death, a comprehensive review of forensic anthropology, forensic pathology and clinical medicine literature was performed. Forensic anthropology literature identified that establishing the type of fall from the analysis of BFT is difficult given the uniqueness of each fall event, the complexities involved with identify BFT and, in particular, the limited available research documenting fracture patterning and morphologies. Comparatively, skeletal BFT resulting from fatal falls is well documented in the forensic pathology and clinical medicine literature. These disciplines cover a wide range of fall types (free falls, falls in juveniles, specific fractures produced from falls, falls down staircases, falls resulting in impalements, and 'other' fall types), provide details on how the nature of the fall influences the skeletal fracturing, and documents the anatomical regions susceptible to fracturing. Whilst these contributions may assist forensic anthropologists, they provide limited details of fracture patterns and morphologies and thus further research investigating the details of skeletal BFT resulting from fatal falls is required.