Accuracy of developing tooth length as an estimate of age in human skeletal remains: the deciduous dentition

Dental age assessments are widely used to estimate age of immature skeletal remains. Most methods have relied on fractional stages of tooth emergence and formation, particularly of the permanent dentition, for predicting the age of infants and very young children. In this study, the accuracy of regression equations of developing deciduous tooth length for age estimation (Liversidge et al.) is tested on a sample of 30 Portuguese subadult skeletons of known age at death. Overall the method shows high accuracy and the average difference between estimated and chronological age is between 0.20 and -0.14 years when using single teeth, and 0.06 years, when using all available teeth. However, there is a tendency for the deciduous molars to provide overestimates of chronological age. Results show that age estimates can be obtained within +/-0.10 years with a 95% confidence interval when several teeth are used. Overall between-tooth agreement in age estimates decreases with increasing age but there is less variability of estimates with more teeth contributing to overall mean age. One seemingly limitation of this method may be the fact that it was developed by combining the maxillary and mandibular teeth. The other is related to the accuracy with which radiographic tooth length can be used as a valid surrogate for actual tooth length. Nevertheless, the advantages of this metric method surpass the limitations of chronologies based on stages of dental development.     

A Reappraisal of Developing Deciduous Tooth Length as an Estimate of Age in Human Immature Skeletal Remains

This study provides an update on a quantitative method for immature age estimation based on postnatal deciduous mandibular tooth length. Two known sex and age skeletal collections from Western Europe were sampled (n = 97). Linear regression models for age estimated were calculated for each individual tooth, each sex, and sex combined sample using classical calibration. Prediction errors, residuals, and percentage of individuals whose real age fell within the 95% prediction interval were calculated. The teeth which develop earlier in life, the incisors and the first molar, showed the greatest precision, while the canine showed the least. This method has greater applicability to archeological skeletons or to children in developing countries than for use in North American or European forensic contexts. The method can be applied to incomplete or poorly preserved remains of unknown sex, particularly when dental radiographs are not an option or when teeth have been removed from the alveolus or crypt.     

The Frontal Sinus Cavity Exhibits Sexual Dimorphism in 3D Cone‐beam CT Images and can be Used for Sex Determination

Few studies have assessed the use of the frontal sinus cavities for sex differentiation. In this study, a new methodology was used to assess the reliability of CBCT images of the frontal sinus cavity for determining sex based on the sexual dimorphism found in this anatomical structure. The survey sample consisted of 130 scans that were reconstructed three‐dimensionally. 3D images of the cavity volume in the frontal, lateral, and basal views were exported in TIFF. The following variables were measured in a second program: area, perimeter, bounding rectangle, ellipse fit, circularity, aspect ratio, roundness, solidity, and Feret's diameter. The methodology demonstrated the existence of sexual dimorphism with an accuracy of 80.0% in the logistic regression model. The basal view had the greatest explanatory power in the final model. This methodology may be used as an alternative way of determining a reliable biological profile during the analysis of skeletal remains.     

Police Legitimacy and the Norm to Cooperate: Using a Mixed Effects Location-Scale Model to Estimate the Strength of Social Norms at a Small Spatial Scale

Journal of Quantitative Criminology - Test whether cooperation with the police can be modelled as a place-based norm that varies in strength from one neighborhood to the next. Estimate whether...     

Diurnal and Nocturnal Flight Activity of Blow Flies (Diptera: Calliphoridae) in a Rainforest Fragment in Brazil: Implications for the Colonization of Homicide Victims

Nocturnal flight of blow flies (Diptera: Calliphoridae) is a controversial issue in forensic entomology. We performed two field experiments to investigate the diurnal and nocturnal activity of six blow fly species in a rainforest fragment in Brazil. Initially, nocturnal (17:30–05:30) versus diurnal (05:30–17:30) flight activity was investigated. Only 3.9% of adults were collected at night, mostly the native species Mesembrinella bicolor, and nocturnal oviposition did not occur. In the second experiment, collection of adults took place at the following intervals: 05:30–08:30, 08:30–11:30, 11:30–14:30, and 14:30–17:30. The proportions of adults did not differ significantly among the four diurnal intervals, except for Hemilucilia segmentaria, which was captured more frequently in the early morning. Calliphoridae has predominantly diurnal behavior, not laying eggs in darkness. The association of the native species M. bicolor, Hemilucilia semidiaphana, and H. segmentaria to forested areas reinforces the forensic relevance of data on their flight pattern.     

Amazonian peasant livelihood differentiation as mutuality-market dialectics

ABSTRACT

Economistic approaches to the study of peasant livelihoods have considerable academic and policy influence, yet, we argue, perpetuate a partial misunderstanding – often reducing peasant livelihood to the management of capital assets by rational actors. In this paper, we propose to revitalize the original heterodox spirit of the sustainable livelihoods framework by drawing on Stephen Gudeman’s work on the dialectic between use values and mutuality on the one hand, and exchange values and the market on the other. We use this approach to examine how historically divergent mutuality-market dialectics in different Amazonian regions have shaped greater prominence of either extractivism or agriculture in current livelihoods. We conclude that an approach centered on the mutuality-market dialectic is of considerable utility in revealing the role of economic histories in shaping differential peasant livelihoods in tropical forests. More generally, it has considerable potential to contribute to a much-needed re-pluralization of approaches to livelihood in academia and policy.     

Is the length of the sternum reliable for estimating adult stature? A pilot study using fresh sterna and a test of two methods using dry sterna

Stature estimation is one of the four attributes of the biological profile obtained from human skeletal remains. The length of the long bones has been consistently used to estimate stature from regression equations, but these may be useless when dealing with fresh or decomposed mutilated remains. Until recently, there was no consistent assessment of the reliability of measurements of the sternum for stature estimation. The purpose of this paper is to test previously developed regression formulae for stature based on measurements of the dry sternum and to assess the reliability of measurements of the fresh sternum in estimating stature. The formulae developed by Menezes et al. and Singh et al. were applied to a sample of 5 known stature skeletons from the identified human skeletal collection curated at the National Museum of Natural History, in Lisbon, Portugal. Testing of these formulae showed that estimated stature confidence intervals do not allow discrimination between individuals with similar stature. The length of the fresh sternum was measured on a sample of 45 male individuals autopsied at the National Institute of Legal Medicine - North Delegation (Porto, Portugal). Cadaver length was regressed on sternum length and a simple linear regression formula was obtained. The regression model provided a 95% confidence interval of 13.32 cm and a correlation coefficient of only 0.329. Compared to other studies, regression formulae based on the length of the sternum provided considerably larger standard errors than that based on long bone lengths. These results suggest that the length of the sternum has limited forensic value and relatively low reliability in estimating stature from mutilated human skeletal remains, either skeletonized or fresh.     

Identification of a tooth-like foreign body in Swine sausage

A tooth-like foreign body (FB) was found inside a sausage bread. Analysis aimed to investigate whether the FB was a tooth and its origin. The FB was measured, weighed, photographed, and radiographed. Macroscopic findings were suggestive of an anterior tooth. Histological slides of undecalcified cross-sections of the FB and samples of human and swine teeth were prepared. Histological features of the FB (in light microscopy, 125× magnification) were discrepant from human tissues. Compared histological analysis displayed majority of features consistent with a hypsodont swine tooth, probably a canine. Cellularized cementum in crown region, adjacent to the enamel, and shape of the cementocytes were the main criteria excluding the possibility of human origin of the FB. Scanning electronic microscopy and energy-dispersive spectroscopy were not performed because of fewer features to be analyzed and FB size. It was concluded that the FB may have been incorporated during meat grinding of the sausage.