The burning maze: The potential value of the human bony labyrinth in estimating sex of calcined remains.

Estimating sex from burnt human remains is a challenging task in bioanthropology, mainly due to their high level of alteration and fragmentation. Protected within the petrous part of the temporal bone, the bony labyrinth may be particularly valuable for assessing the sex of burnt remains. This prospective study aims at testing predictive models, already found reliable on unburnt bony labyrinths, to burnt specimens. Six discriminant functions were applied on six bony labyrinths of donated adult cadavers of known sex, before and after outdoor burning experiments. Comparisons between unburnt and burnt measurements were executed using Mann-Whitney U tests while shape and size differences induced by fire exposure were examined through a geometric morphometrics (GM) analysis. Predicted sex on unburnt bony labyrinths was consistent with known sex in five cases while a systematic misclassification for males was highlighted on burnt specimens. Higher values of shrinkage were found in males for two measurements included in the equations. GM analysis revealed significant differences in centroid size among males after calcination. Visualization of mean consensus of both female and male bony labyrinths evidenced a reduction in cochlear size and variations in the width and length of semicircular canals of burnt specimens. This exploratory study seems to confirm that designing sex estimation standards specifically for burnt bony labyrinth may be advisable. Understanding how the burning process could impact its morphology is highly recommended through further experiments on larger samples and in controlled environments.

Sexing the bony labyrinth: A morphometric investigation in a subadult and adult Belgian identified sample.

In forensic anthropology, sex estimation is a fundamental step in assessing individual biological profiles when analyzing human skeletons. Yet, current methods are not reliable enough to allow an accurate sex identification of highly fragmented, burnt, or subadult remains. This paper aims to investigate sexual dimorphism of the bony labyrinth on both identified subadult and adult individuals. The bony labyrinth is of particular interest for sex estimation since it is alleged to complete size and maturation pre-pubertally and is located inside the petrous part of the temporal bone which protects it from taphonomic processes. The study was performed on 93 CT scans of identified individuals from two Belgian osteological collections (19-20th century) and from current pediatric images (Erasme hospital, Brussels). Linear and angular measurements were taken on 2D slices of right bony labyrinths. Intra- and interobservers error measurements were calculated. Statistical tests were used to unravel any morphological variations between subadult and adult bony labyrinths and to highlight differences between females and males, separately in subadults and adults. Linear discriminant functions were established by cross-validation and tested on an independent sample from Belgium. Some measurements were significantly different between subadults and adults, and between females and males within both subadult and adult samples. Univariate functions achieved 72.7% in subadults and 68.4% in adults whereas multivariate equations increased accuracy respectively up to 84.9% and 78.4%. This study entails promising results to design a sex estimation method suitable for fragmented and/or subadult remains. Further metric approaches are needed to explore bony labyrinth sexual dimorphism.

Wounded to the bone: Digital microscopic analysis of traumas in a medieval mass grave assemblage (Sandbjerget, Denmark, AD 1300-1350).

Battle-related mass burials are considered the most unequivocal evidence of past violence. However, most published studies involve only macroscopic analysis of skeletal remains, commonly arriving only at broad conclusions regarding trauma interpretation. The current study considers a possible avenue for achieving both greater detail and accuracy through digital microscopy. Patterns of injury were investigated among 45 individuals from a Medieval Danish mass grave (Sandbjerget, AD 1300-1350). Injuries were recorded on every anatomical element, except hand and foot bones. Each was photographed and cast, facilitating remote evaluations. Macroscopic analysis was compared with digital microscopy in order to test the relative utility of the latter in characterizing skeletal injuries (mechanism, weapon class, direction, timing of injury). The location of 201 observed injuries, mainly sharp force defects, suggested that many lesions were probably not inflicted by face-to-face opponents. Some microscopic features were indicative of a specific lesion type and weapon class. Digital microscopy was therefore demonstrated to be a complementary tool to macroscopic assessment, enhancing feature observation and quantification and serving to compensate for many of the limitations of macroscopic assessment.

Normal growth, altered growth? Study of the relationship between harris lines and bone form within a post-medieval plague cemetery (Dendermonde, Belgium, 16th Century).

OBJECTIVES: Harris lines (HLs) are defined as transverse, mineralized lines associated with temporary growth arrest. In paleopathology, HLs are used to reconstruct health status of past populations. However, their etiology is still obscure. The aim of this article is to test the reliability of HLs as an arrested growth marker by investigating their incidence on human metrical parameters. METHODS: The study was performed on 69 individuals (28 adults, 41 subadults) from the Dendermonde plague cemetery (Belgium, 16th century). HLs were rated on distal femora and both ends of tibiae. Overall prevalence and age-at-formation of each detected lines were calculated. ANOVA analyses were conducted within subadult and adult samples to test if the presence of HLs did impact size and shape parameters of the individuals. RESULTS: At Dendermonde, 52% of the individuals had at least one HL. The age-at-formation was estimated between 5 and 9 years old for the subadults and between 10 and 14 years old for the adults. ANOVA analyses showed that the presence of HLs did not affect the size of the individuals. However, significant differences in shape parameters were highlighted by HL presence. Subadults with HLs displayed slighter shape parameters than the subadults without, whereas the adults with HLs had larger measurements than the adults without. CONCLUSIONS: The results suggest that HLs can have a certain impact on shape parameters. The underlying causes can be various, especially for the early formed HLs. However, HLs deposited around puberty are more likely to be physiological lines reflecting hormonal secretions. Am. J. Hum. Biol. 29:e22885, 2017. © 2016 Wiley Periodicals, Inc.