ABSTRACT
Abstract Introduction: According to the literature, the amount of osteons has been suggested as a good proxy to determine the age of death in adults. However in subadults research has not been carried out yet. Objective: To determine the accuracy of the histomorphometric technique predicting the age at death in subadults using bone remains. Methodology: The information of static histomorphometric parameters from about 120 iliac bones retrieved from the exhumed remains of subadults whose age at death was known was taken from the Granada collection. In order to predict the age at death we performed a step by step linear regression to estimate the fittest model. Results: The most closely and significantly associated biopsy findings with age were: the osteon count, the internal cortical width, and the trabecular bone volume. Pearson's correlation index indicated a weak linear association among these variables. To assess the accuracy of the model we used a coefficient of determination with a 0.32 value. 32% of the age variation in the subadults was explained by the three variables. Conclusion: This regression model explains a percentage of the total age variation in the subadult population. However this model is not enough to determine the age at death.
Resumen Introducción: La capacidad de predicción de las osteonas para determinar la edad de muerte de los individuos ha sido descrito en la literatura científica. No obstante, no se ha determinado dicha capacidad en individuos subadultos. Objetivo: Determinar la eficacia de lo parámetros histomorfometricos en población subadulta. Metodología: Se realizaron biopsias de hueso ilíaco en los restos de 120 subadultos, de la Colección Osteológica de Granada, con edad conocida en el momento de la muerte. Para establecer la capacidad de predicción se utilizó el R2 obtenido a partir de regresión lineal múltiple. Resultados: Las variables con mayor nivel predictivo y significativo para la estimación de la edad fueron: recuento de osteonas tipo 2 de la cortical interna y externa, y el volumen óseo trabecular; En la evaluación del modelo, se obtuvo un coeficiente de determinación de 0.32, es decir, el 32% de la variación en la edad de los subadultos se explica por el modelo. Sin embargo, se evidenció diferencias en la capacidad de predicción por sexo. Conclusión: Este modelo de regresión explica un porcentaje sustancial de la varianza de la edad de los individuos en la muestra. No obstante, no es suficiente para garantizar una adecuada predicción de la edad al momento de muerte de los individuos subdultos.
Subject(s)
Humans , Age Determination by Skeleton , Ilium , Least-Squares Analysis , Linear Models , Haversian System , HistologyABSTRACT
Objective To investigate the conduction behavior of fluid flow induced by physiological loads at different scales of bone. Method sThe multiscale bone models were established by using the COMSOL Multiphysics software, and the fluid behaviors were investigated at macro-, meso- and micro-scale. Results At macro-meso scale，the distribution of pore pressure and fluid velocity of osteon near the periosteum and endoosteum were different from that in other parts. Due to the different structure and material parameters at different layers, the loading and fluid pressure caused different biomechanical responses in the process of transferring from macro-scale to micro-scale. Conclusions The multi-scale layered modeling of bone structure-osteon-lacunae-bone canaliculi was established, which provided the theoretical reference for deeper understanding of fluid stimulation and mechanotransduction.
ABSTRACT
Objective To investigate the relationship between microstructure characteristics and its mechanical behavior. Methods The compression experiments on longitudinal and transverse specimens of the cortical bone from bovine femoral bone were conducted. The fracture routes of longitudinal and transverse specimens and microstructural features of fractured surfaces were observed. The effects of osteon orientation on elastic modulus and ultimate fracture strength of the bone were analyzed based on the theory of composite micromechanics. Results The compressive elastic modulus and ultimate fracture strength of longitudinal specimens were significantly greater than those of transverse specimens. The fracture routes of longitudinal specimens were along their loading direction (0°) and relatively flat, while the fracture routes of transverse specimens were relatively zigzagging, being approximately 45° with their loading direction. There were many striped structures on fractured surfaces of longitudinal specimens and the fractured surfaces were relatively smooth, while there were many annular concave and convex structures on fractured surfaces of transverse specimens and the fractured surfaces were relatively rough. Conclusions The bovine femoral bone had anisotropic mechanical properties, and its anisotropic mechanical properties were closely related to the orientation of osteons.
ABSTRACT
In situations where the skeletal remains found are too fragmented, it is necessary to assess the human origin of such remains; for this purpose, various parameters are used, both anatomical and histological. The objective of the present study is to evaluate the various histomorphometric parameters to differentiate human from non-human bones, to further construct discriminatory functions that allow interspecies classification. Tibia bones sections from human, bovine, pig, hen, cat, and dog species were used, processed through conventional histological techniques and observed under the microscope with a 40x magnification, analyzing the Haversian Canal Density parameters by mm2, Diameter of the Haversian Canal and the Diameter of the Haversian System which were compared through one way ANOVA with Scheffé post test, p<0.05. Subsequently, the discriminatory functions were constructed for each species and the percentage of well-diagnosed cases was determined. Meaningful differences were found in the parameters analyzed; the discriminatory functions allowed to correctly classify 88.5 percent of the cases. Our results suggest that it is possible to differentiate human skeletal remains from non-human through the observation of their histological characteristics and histomorphometric parameters, but interspecies differentiation requires a more complex analysis...
En situaciones donde los restos óseos que se encuentran están muy fragmentados, es necesario evaluar el origen humano de dichos restos, para ello se utilizan diversos parámetros morfológicos tanto anatómicos como histológicos. El propósito de este estudio fue evaluar los distintos parámetros histomorfométricos para diferenciar hueso humano de no humano, para posteriormente construir las funciones discriminantes que permitan la clasificación interespecies. Se utilizaron secciones de hueso de tibia de individuos de especies: humano, bovino, cerdo, gallina, gato y perro, procesadas mediante técnica histológica convencional y observadas al microscópio con aumento 40x, analizándose los parámetros Densidad del canal de Havers por mm2, Diámetro del canal de Havers y diámetro del sistema Haversiano, los cuales fueron comparados mediante one way ANOVA con Scheffé post test con p<0,05. Posteriormente se construyeron las funciones discriminantes para cada especie y se determinó el porcentaje de casos bien diagnosticados. Se encontraron diferencias significativas en los parámetros analizados, las funciones discriminantes permitieron la correcta clasificación del 88,5 por ciento de los casos. Nuestros resultados sugieren que es posible diferenciar restos óseos humanos de no humanos mediante la observación de sus características histológicas y parámetros histomorfométricos, pero la diferenciación interespecie requiere de análisis más complejo...
Subject(s)
Humans , Animals , Forensic Anthropology/methods , Histological Techniques , Bone and Bones/anatomy & histology , Cross-Sectional Studies , Discriminant Analysis , Species SpecificityABSTRACT
Microscopic analysis of bone is very useful method for estimating age at death of individual identification, diagnosing metabolic disorder or dietary deficiency in bone tissue, and differentiating human bone or not when applied to fragmentary skeletal remains. The purpose of this study was to establish a systematic method for preparing bone tissues by manual grinding method and offer help in application of related histomorphometric field such as estimating age at death. For this, human bone tissues of rib and femur from cadavers were prepared and considered histomorphological variations of osteon with light microscope. As results of this study, Type II osteons, smaller versions of Intact osteons (Type I) that form by radial remodeling of a preexisting Haversian canal, were distinguished from double-zonal osteons, one of the osteons that exhibit hypercalcified ring within their concentric lamellae, by the lack of an internal reversal line and the parallel contours of lamellae, and it is possible to suggest metric basis for drifting osteons as counting one osteon with the exception of size measurement. By applying this method of present study, one could easily make a bone tissue all oneself that would be helpful for establishing basic data in physical and forensic anthropology.
Subject(s)
Humans , Bone and Bones , Cadaver , Femur , Forensic Anthropology , Haversian System , RibsABSTRACT
Objective To explore the applicability of the histological features of plexiform bone and osteon banding to species identification. Methods 35 ground cross sections of the tibial midshaft collected from 10 human cadavers, 10 pigs, 5 cattle, 5 dogs, and 5 sheep, were observed under light microscope at 100-fold magnification. Results Plexiform bone and osteon banding were mostly observed in nonhuman bones, whereas rarely in human bones. Additionally, histological structures also varied with different individuals within a species. Conclusion The plexiform bone and osteon banding are the two important characteristics for certifying nonhuman bone in species identification.