Palate Shape and Depth: A Shape-Matching and Machine Learning Method for Estimating Ancestry from Human Skeletal Remains.

In the past, assessing ancestry relied on the naked eye and observer experience; however, replicability has become an important aspect of such analysis through the application of metric techniques. This study examines palate shape and assesses ancestry quantitatively using a 3D digitizer and shape-matching and machine learning methods. Palate curves and depths were recorded, processed, and tested for 376 individuals. Palate shape was an accurate indicator of ancestry in 58% of cases. Cluster analysis revealed that the parabolic, hyperbolic, and elliptical shapes are discrete from one another. Preliminary results indicate that palate depth in Hispanic individuals is greatest. Palate shape appears to be a useful indicator of ancestry, particularly when assessed by a computer. However, these data suggest that palate shape is not useful for assessing ancestry in Hispanic individuals. Although ancestry may be determined from palate shape, the use of multiple features is recommended and more reliable.

In vivo facial tissue depth for Canadian aboriginal children: a case study from Nova Scotia, Canada.

This study examines facial tissue depth in Canadian Aboriginal children. Using ultrasound, measurements were taken at 19 points on the faces of 392 individuals aged 3-18 years old. The relationships between tissue thickness, age, and sex were investigated. A positive linear trend may exist between tissue thickness and age for Aboriginal females and males at multiple points. No points show significant differences in facial tissue depth between males and females aged 3-8 years old; seven points show significant differences in facial tissue depth between males and females aged 9-13 years old; and five points show significant differences in facial tissue depth between males and females aged 14-18 years old. Comparisons were made with White Americans and African Nova Scotians. These data can assist in 3-D facial reconstructions and aid in establishing an individual's identity. Previously, no data existed for facial tissue thickness in Canadian Aboriginal populations.

Shark-inflicted trauma: a case study of unidentified remains recovered from the Gulf of Mexico.

Here, we present a case of an unidentified male whose remains, except for the right arm, were recovered from the Gulf of Mexico 10 years prior to osteological analysis by forensic anthropologists. After the poorly preserved soft tissue was removed and the bones cleaned, forensic analysis revealed an unusual series of hard tissue trauma later attributed by a shark expert as shark scavenging and/or predation. Identified were five unique hard tissue trauma patterns that are bite mark artifacts produced by sharks: punctures without fractures, punctures with associated fractures, striations with bone shaving, overlapping striations, and incised bone gouges. The cooperation among experts provided a comprehensive death case analysis and a better understanding of shark-inflicted trauma on human skeletal remains.

The use of vertebral osteoarthritis and osteophytosis in age estimation.

Previous research on age and vertebral degenerative change has focused on osteophytosis. The present study expands this research by examining the association between osteoarthritis and osteophytosis and by assessing their relationship to age. Researchers scored the bodies and facets in 104 individuals. Statistical analyses assessed relationships between age and degenerative change for the bodies and facets, both separately and combined, for all vertebrae collectively, and for subcategories of vertebral types. Separate analyses were conducted which included only regions that experience heavier stress loads. Results indicate that osteophytosis and osteoarthritis are not associated with each other for all subcategories of vertebrae. Also, the inclusion of osteoarthritis does not enhance the relationship between age and degenerative change, nor does limiting analyses to areas of heaver stress. Finally, although both conditions are significantly correlated with age, the relationship is not strong enough to yield predictive power for establishing age beyond a general estimate.

In vivo facial tissue depth study of Chinese-American adults in New York City.

This study examines facial tissue depth in adult Chinese-Americans. Using ultrasound, measurements were taken at 19 landmarks across the faces of 101 individuals aged from 18 to 87 years. Summary statistics are reported for a sample of 67 individuals of normal weight (as determined by a body mass index [BMI] of 19-25). Statistical analyses were used to assess relationships between tissue thickness, age, and BMI. Results indicate that no significant relationship exists between tissue thickness and age for males, and for only 3/19 points in females. Also, only four points showed significant relationships between tissue thickness and sex. However, significant relationships exist between BMI and tissue thickness at multiple points for both males and females. Compared to other American and Asian populations in the literature, Chinese-Americans generally had thinner facial tissue; though, this difference was not assessed statistically. Finally, data generated in this study will add to the body of knowledge concerning facial tissue depth variation in modern humans.

Suicide by blasting caps: a case study of rare cranial trauma.

Suicide is a deliberate act of ending one's life. Suicide by use of any explosive device, when not involved in a terrorist act, is quite rare in occurrence when compared with other methods routinely utilized. In this paper, we present to the medicolegal community a case of an adult male who committed suicide with blasting caps and the subsequent extensive damage to the cranial hard tissue. Although the cause and manner of death were relatively straightforward, consultation with forensic anthropologists was requested for an anthropological trauma assessment of the highly fragmented skull. After the skull was cleaned and reconstructed, the analysis revealed similarities between blasting cap trauma to the head and high velocity gunshot trauma to the head. Therefore, in a case where some evidence may have been removed or destroyed, forensic analysis involving trauma of this magnitude could result in a misinterpretation of the true mechanism responsible for the osseous damage. In this case, cooperation among the law enforcement agency, coroner's investigators, the forensic pathologist, and forensic anthropologists provided a comprehensive death case analysis.

Use of the global positioning system in the field recovery of scattered human remains.

This study examines the Global Positioning System (GPS) as a tool for field mapping of scattered human remains or other materials in forensic investigations. Two aspects of the GPS are considered: (1) the level of accuracy that can be obtained using a mid-priced GPS unit, and (2) the effectiveness of using the GPS to map scattered materials. The positional accuracy of the GPS receiver was tested using a National Geodetic Survey (NGS) point located in Baton Rouge, LA. The utility of the GPS for mapping was investigated by setting up a mock field recovery and mapping the remains using both the GPS and traditional archeological methods. The results indicate that the positional error for a single location using GPS was less than one-half meter. However, when multiple positions were considered, the data produced on different days were not consistent. Further, the GPS receiver used in this study could not distinguish items in close association. Factors such as tree cover density, the proximity of the materials to structures or trees, and satellite positioning contributed to the erratic data. These results indicate that traditional techniques and photographs are still indispensable for mapping scattered remains or artifacts.

The application of geographic information systems and spatial analysis to assess dumped and subsequently scattered human remains.

This study utilizes geographic information systems (GIS) and spatial analysis (SA) technology to address the problems associated with prediction of location and effective recovery of dumped and scattered human remains in Louisiana. The goals are to determine if a selective bias exists in Louisiana as to where and when human remains are dumped and to assess whether or not geographically specific patterns exist in the dispersal of human remains. We hypothesized that a positive relationship exists between postmortem interval (PMI) and dispersal distance, and that there are negative relationships between PMI and dispersal direction and between dispersal direction and distance. Our results indicate that, in Louisiana, remains are more often dumped in rural areas away from a structure, and are found within (1/4) mile of the nearest road. For Louisiana, no seasonal bias was found in the analysis of when remains are dumped. Furthermore, with the exception of the relationship between PMI and the shortest distance remains were dispersed, no geographically specific patterns were detected in the analyses of dispersal distance, dispersal direction, and PMI.

Fluvial transport of human remains in the lower Mississippi River.

The Mississippi River has claimed many lives over the last several decades. A better understanding of the universal dynamics of its fluvial system can help direct the production of a predictive model regarding the transportation of human remains in the river. The model may then be applied to situations where the location and the identification of water victims are necessarily part of the recovery process. Results from the preliminary phase of a longitudinal project involving the transport of human remains in the Mississippi River are presented and represent the analyses of 233 case files of river victims. A provisional model for fluvial transport of human remains in the Mississippi River is proposed and examined. This model indicates that time in the river and distance a body travels are related. Such a model may assist in pinpointing entry location for unidentified human remains found in the river or on its banks. Further, it has the potential to provide local and regional law enforcement agencies, the United States Coast Guard, and other search and rescue organizations with primary search areas when someone is missing in the river. Other results from this study indicate that a relationship exists between the side of the river where victims enter the water and the side of the river where the remains are recovered. Finally, relationships are established between the length of time before recovery of the remains and state of preservation exhibited by those remains. A secondary benefit from this study is a database of river victims that can be used by a variety of different agencies.