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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Beyond thick versus thin: mapping cranial vault thickness patterns in recent Homo sapiens

Marsh, Hannah Eyre 01 May 2013 (has links)
Cranial vault thickness (CVT) has been reported at many different osteometric landmarks and features on the vault. Historically, only a few landmarks are used, often bregma, lambda, vertex, and right and left euryon, and frequently comparisons are based only on “thick” versus “thin” to describe the vault overall. What is inherent in this strategy is the use of a few locations to characterize the entire vault. The problem remains that there is little information concerning CVT variation throughout an individual's vault, and the causes of variation within recent Homo sapiens important to investigating thickness variation between species in Homo. This work describes thickness variation over the entire superior vault and compares the sexes, age groups and populations in recent H. sapiens. A proportional grid is applied to the superior vault to measure thickness at 219 sampling points in a geographically diverse sample of recent H. sapiens. Thickness values are analyzed in their two-dimensional spatial relationships to determine patterns of vault thickness. Males were identified to be thicker than females at more lateral locations and along the midsagittal plane, although this finding is not statistically significant. Individuals over the age of 45 years are found to be statistically significantly thicker than individuals younger than 31 years at more lateral locations of the vault. Aboriginal Australians are statistically significantly thicker at more lateral locations of the vault than any other populations, whereas Northern Canada/Greenland individuals were thinner than other populations at these locations. The trend of thicker vaults in the older age group and the Australians is identified across the vault, although is not statistically significant at more locations. Several thickness patterns are identified. The boss thickening pattern is the most common pattern, followed by a midsagittal pattern, a posterior pattern, and an anterior pattern. Some specimens do not demonstrate thickness variation and are coded as undifferentiated. Each pattern is observed alone and in combination with others, signifying that pattern causes are not mutually exclusive. Boss thickening is interpreted as the result of passive bone thickening during normal bone and brain growth during fetal and adolescent development. The midsagittal thickness pattern coincides with inferred strain along the sagittal suture from nuchal muscle engagement during mastication. Previous researchers have proposed adaptive explanations for thickness variation, such as protection from interpersonal violence; the patterns of cranial vault thickness reported here point to normal growth and development of the brain as a driving force, a relationship that could drive thickness variation in other Homo species. Comparing thickness at bregma, and the frontal and parietal eminences for recent H. sapiens and H. erectus, there is no statistical difference between African and Asian H. erectus, and between the on average thicker H. sapiens populations and H. erectus, based on published data. Future work will investigate the presence or absence of thickness patterns in these fossil species.
2

Investigating Patterns of Interpersonal Violence Using Frequency Distributions of Cranial Vault Trauma

Anzellini, Armando 01 January 2013 (has links)
Violence has been found ubiquitously across human societies and throughout time. An act of violence can be defined as purposeful harm brought upon one individual as a direct or indirect result of the actions of another. The purpose of this research is to develop a quantitative approach to examining lethality using frequency distributions for location of trauma on the cranium in order to model patterns of interpersonal violence. This is accomplished through the study of a skeletal sample, from the prehispanic Chachapoya (existing around A.D. 800 – 1535), discovered at the site of Kuelap in the northern Peruvian Andes. Metric data were gathered from 81 individuals including males, females, and subadults. The data consisted of precise location of traumatic injury measured from anatomical landmarks in each of five two-dimensional views of the cranium as well as estimated diameter of impact for all lesions. The lesions were separated between perimortem (lethal) and antemortem (non-lethal) in order to explore patterns of lethality that correlate with location of injury. A statistical difference (p > 0.05) in location could not be determined when the distributions were compared in five standard two-dimensional views or between the sexes. Statistical significance (p > 0.05), however, was encountered when the entire cranium was used for the distribution. This distribution showed that perimortem injuries tend to occur more frequently on the posterior aspect of the cranium while antemortem injuries tend to occur more frequently on the anterior for this sample. These results show that a quantitative approach to location of injuries to the cranial vault can reveal new patterns of violent interactions and aid in the study of violent behavior.
3

The investigation of craniofacial variation between archaic and intermediate-late periods of Chile using morphometric analysis

Getler, Anna Elizabeth 20 February 2021 (has links)
In skeletal studies of prehistoric populations of Chile’s semiarid north, it is common practice for physical anthropologists to visually categorize crania as dolichophallic and brachycephalic which are then attributed to cultures or time periods based on the observed shape. The validity of this classification is still debated and poses several questions regarding the prehistory of Chile. The goal of this study is to investigate the craniofacial variation in populations representing the Archaic period and Intermediate-Late periods of Chile’s semiarid north using morphometric analysis. The samples comprise two collections from the Museo Arqueologico de La Serena in La Serena, Chile. The Archaic period dates from 10,000 BC to 300 AC. The Intermediate-Late period dates from 900 AC to 1500 AC. The Archaic period included 87 crania, while the Intermediate-Late period included 78 crania. Cranial vault modification was practiced in all prehistoric populations, and modified individuals comprise ~4.6% of the Archaic period sample and ~74.4% of the Intermediate-Late period sample. Individuals observed to be dolichocephalic are associated with the Archaic period, while brachycephalic individuals are associated with the Intermediate-Late period. Previous studies have shown that individuals with intentional cranial modification, annular and tabular, exhibit predictable changes in the craniofacial complex due to compensatory growth and shape changes related to peripheral structures of the cranial vault. A form of tabular modification is seen in both periods included in this sample, with the Intermediate-Late period sample being dominated by this modification. All craniometric landmarks were recorded using a Microscribe™ 3D digitizer, with exclusion of mandibular landmarks. MorphoJ was utilized to analyze the geometric morphometric data. Coordinates using the Microscribe were recorded in order to investigate the differences in shape of the craniofacial complex between the two samples. Two separate analyses were performed, one with all landmarks recorded and one excluding landmarks prosthion, alveolon, ectomolare and zygion. The results of both Canonical Variate analyses and associated Mahalanobis Distance values (2.699 and 2.9316) indicates statistically significant differences (p<0.001) between the two samples. It is also evident that shape changes along CV1, increases in minimum frontal breadth, upper facial breadth, and nasal height, correspond with characteristics associated with brachycephalism and tabular cranial vault modification. The large range of variation of the Intermediate-Late period sample is speculated to be a result of multiple small populations moving toward the coast possibly due to a change in climate. These small populations exhibited various morphologies which were influenced by nonrandom environmental factors. The Mahalanobis distances of the different cultural groups also indicate statistically significant differences. This method has the potential to be used in conjunction with others to identify cultural context and significance of remains in archaeological contexts in Chile. In the event of repatriation acts this method could also be used to attribute individuals to corresponding cultures and be donated to the appropriate community or facility.
4

A Biomechanical Study of Critical Size Cranial Defect Reconstruction Techniques Using Two Bone Substitutes

Porzel, Alec P. 20 May 2008 (has links)
No description available.
5

Fracturation sur os frais ou sur os sec de la voûte crânienne : approche méthodologique et application archéologique / Skull vault fracturing on fresh bone or dry bone : methodological approach and archaeological application

Jordana, Fabienne 13 January 2010 (has links)
Etablir le diagnostic différentiel entre des fractures réalisées sur os frais de celles produites sur os sec permet, quelle que soit la période chronologique considérée, une approche interprétative relative à l’attitude comportementale humaine qu’ils s’agissent des relations au sein d’un groupe ou face à une autre population, ainsi que les gestes réservés aux morts. Ainsi peuvent être envisagés le cannibalisme, des comportements de violence, ou des pratiques funéraires originales. Si certaines méthodes analytiques existaient pour le squelette infracrânien, aucun référentiel permettant de différentier les fractures sur os frais (intentionnelles ou non) des cassures sur os secs n’est actuellement disponible pour le squelette crânien. Notre objectif de recherche s’est donc concentré sur un essai de détermination des critères statistiquement valides de distinction du moment de fracturation sur os fossiles. Une partie importante de ce travail est consacrée aux études expérimentales menées pour tenter de distinguer une différence de comportement mécanique entre une fracture réalisée sur os frais de celle réalisée sur os sec (essais mécaniques, rugosimétrie confocale, microtomographie ou numérisation des pièces osseuses). Puis, les critères de la médecine légale sont discutés à partir d’échantillons osseux provenant de séries archéologiques différentes d’un point de vue chronologique et géographique et relevant de problématiques différentes. Il ressort de ce travail que très peu de critères pris individuellement sont suffisamment pertinents pour différencier fracturation sur os frais et fracturation sur os sec (décollement de la lame corticale). Ils doivent toujours être discutés à l’échelle d’une série archéologique et non sur un échantillon isolé, seul ou sorti de son contexte. Dans le meilleur des cas, ils nous permettent de proposer des hypothèses (cannibalisme, pression des sédiments…) qui devront être corroborées en fonction du contexte archéologique et anthropologique par une analyse interdisciplinaire. / Establishing a differential diagnosis between fresh bone fractures and dry bone fractures allows, whatever the chronological period considered, an interpretative approach relating to the human behaviours within a group or another population, as well as the deaths gestures. Thus, cannibalism, violent behaviours, or original funerary practices can be considered. If some analytical methods existed for the infracranial skeleton, no references allowing for the differentiation between fresh bone fractures (intentional or not) and dry bone breaks were available for the cranial skeleton. Thus, our research objective concentrated on a determination trial of statistically valid criteria that distinguished the fracturing moment on fossil bones. An important part of our work concerned experimental studies undertaken to distinguish a mechanical behavioural difference between fresh bone fractures and dry bone fractures (mechanical tests, rugosimetry, microtomography, or bone pieces digitalization). Forensic medicine criteria was also discussed with osseous samples coming from different archeological series that were taken from chronological and geographical points of view and used to represent each different problem. It appears that there exist very few criteria taken individually that are sufficiently relevant to differentiate fracturing on fresh bone and fracturing on dry bone (delamination). They must always be discussed on an archeological series scale and not on an isolated sample, either alone or taken out of context. In the best of the cases, they enable us to propose assumptions (cannibalism, pressure of the sediments…) that will have to be corroborated according to the archaeological and anthropological context by an interdisciplinary analysis.
6

Contribution à l’approche anthropologique et médico-légale des sutures viscérocrâniennes utiles dans l’estimation de l’âge au décès (Sutures palatines, fronto-naso-maxillaires et zygomatiques). / Contribution to a useful anthropological and medico-legal approach of the viscerocranial sutures in the age at death estimation (palatine, fronto-naso-maxillary and zygomatic sutures).

Beauthier, Jean-Pol J.-P. R.A.G. 30 November 2009 (has links)
Les sutures crâniennes ont été régulièrement étudiées au fil des siècles puisque déjà Vésale établissait une relation entre l’âge et la synostose suturale. Leur imprécision a quelque peu confiné l’observation de ces sutures dans un certain oubli, justifié en partie. Il est clair que leur fiabilité quant à l’estimation de l’âge au décès reste discutable et ce, pour diverses raisons. Leur observation est difficile et dès lors sujette à subjectivité dans l’appréciation de leurs stades de fusion. De plus, leur apparence sur le crâne sec peut être altérée par divers artéfacts de conservation (cire, vernis…). Outre l’observation des classiques sutures ectocrâniennes de voûte et l’utilisation des méthodes habituelles en la matière (méthode de Acsádi et Nemeskéri, méthode de Masset), nous avons orienté notre étude vers des sutures peu voire pas exploitées, à savoir les sutures palatines, les sutures fronto-naso-maxillaires et les sutures de l’os zygomatique. Ces trois groupes suturaux ont la particularité d’évoluer de manière très lente vers la fusion, à tel point que peu d’individus en présentent une oblitération complète. Face au vieillissement de la population et de par notre expérience médico-légale et anthropologique d’étude de pièces osseuses de personnes âgées, nous avons estimé qu’il était utile de se pencher sur des collections particulières de sujets d’âge avancé, afin d’apprécier l’évolution morphologique de ces sutures faciales. Si certaines personnes fort âgées gardent malgré tout des caractéristiques suturales peu évoluées, il existe dans l’ensemble, une progression suturale quasiment constante en fonction de l’âge. Nous avons tenté de la cerner, en attribuant à ces sutures, des degrés bien définis de cette progressive fusion et par là, l’aboutissement à un coefficient moyen d’oblitération suturale, se traduisant aisément en pourcentage d’oblitération ou pouvant être introduit dans des équations de régression. Tout en connaissant les limites de cette approche, nous pouvons estimer qu’elle peut rendre des services lors de l’étude de restes humains squelettisés, notamment s’ils appartiennent à des personnes fort âgées, dès lors qu’à ces stades de vieillissement, peu de méthodes restent encore applicables. D’autre part, l’approche en pourcentage d’oblitération suturale rend également des services lorsque les crânes étudiés sont fragmentés. C’est la situation que nous rencontrons actuellement lors de l’étude d’une très importante collection anthropologique à l’Institut royal des Sciences naturelles de Belgique. Cette observation suturale pourra également – à l’avenir – trouver un terrain d’approche fort utile par l’étude des sutures en CT-Scan ou en micro-CT. Enfin, grâce à ces techniques modernes d’imagerie médicale, les sutures trouvent un regain d’intérêt dans une application toute particulière, qui est celle de l’identification comparative, puisqu’il apparaît que le « dessin sutural » s’avère tout à fait propre à chaque individu.
7

Contribution à l'approche anthropologique et médico-légale des sutures viscérocrâniennes utiles dans l'estimation de l'âge au décès (Sutures palatines, fronto-naso-maxillaires et zygomatiques) / Contribution to a useful anthropological and medicolegal approach of the viscerocranial sutures for the age at death estimation (palatine, fronto-naso-maxillary and zygomatic sutures)

Beauthier, Jean-Pol 30 November 2009 (has links)
Les sutures crâniennes ont été régulièrement étudiées au fil des siècles puisque déjà Vésale établissait une relation entre l’âge et la synostose suturale.<p><p>Leur imprécision a quelque peu confiné l’observation de ces sutures dans un certain oubli, justifié en partie.<p><p>Il est clair que leur fiabilité quant à l’estimation de l’âge au décès reste discutable et ce, pour diverses raisons.<p><p>Leur observation est difficile et dès lors sujette à subjectivité dans l’appréciation de leurs stades de fusion.<p><p>De plus, leur apparence sur le crâne sec peut être altérée par divers artéfacts de conservation (cire, vernis…).<p><p>Outre l’observation des classiques sutures ectocrâniennes de voûte et l’utilisation des méthodes habituelles en la matière (méthode de Acsádi et Nemeskéri, méthode de Masset), nous avons orienté notre étude vers des sutures peu voire pas exploitées, à savoir les sutures palatines, les sutures fronto-naso-maxillaires et les sutures de l’os zygomatique.<p><p>Ces trois groupes suturaux ont la particularité d’évoluer de manière très lente vers la fusion, à tel point que peu d’individus en présentent une oblitération complète.<p><p>Face au vieillissement de la population et de par notre expérience médico-légale et anthropologique d’étude de pièces osseuses de personnes âgées, nous avons estimé qu’il était utile de se pencher sur des collections particulières de sujets d’âge avancé, afin d’apprécier l’évolution morphologique de ces sutures faciales.<p><p>Si certaines personnes fort âgées gardent malgré tout des caractéristiques suturales peu évoluées, il existe dans l’ensemble, une progression suturale quasiment constante en fonction de l’âge.<p><p>Nous avons tenté de la cerner, en attribuant à ces sutures, des degrés bien définis de cette progressive fusion et par là, l’aboutissement à un coefficient moyen d’oblitération suturale, se traduisant aisément en pourcentage d’oblitération ou pouvant être introduit dans des équations de régression.<p><p>Tout en connaissant les limites de cette approche, nous pouvons estimer qu’elle peut rendre des services lors de l’étude de restes humains squelettisés, notamment s’ils appartiennent à des personnes fort âgées, dès lors qu’à ces stades de vieillissement, peu de méthodes restent encore applicables. D’autre part, l’approche en pourcentage d’oblitération suturale rend également des services lorsque les crânes étudiés sont fragmentés. C’est la situation que nous rencontrons actuellement lors de l’étude d’une très importante collection anthropologique à l’Institut royal des Sciences naturelles de Belgique.<p><p>Cette observation suturale pourra également – à l’avenir – trouver un terrain d’approche fort utile par l’étude des sutures en CT-Scan ou en micro-CT.<p><p>Enfin, grâce à ces techniques modernes d’imagerie médicale, les sutures trouvent un regain d’intérêt dans une application toute particulière, qui est celle de l’identification comparative, puisqu’il apparaît que le « dessin sutural » s’avère tout à fait propre à chaque individu.<p><p>/<p><p>Cranial sutures were regularly studied during centuries since Vésale already established a relationship between age at death and sutural fusion. <p><p>Their inaccuracy somewhat confined the observation of these joints in a certain lapse of memory, partly justified. <p><p>Various reasons clearly indicate that their reliability for age at death estimation remains debatable. <p><p>Their observation is difficult and consequently prone to subjectivity in the appreciation of their stages of fusion. <p><p>Moreover, their appearance on dry cranium can be modified by various artefacts from preserving methods (wax, varnished…). <p><p>In addition to the traditional observation of ectocranial sutures (with the usual methods such as Acsádi and Nemeskéri method and Masset method), we have directed our study towards not much exploited sutures, namely the palatine sutures, the fronto-naso-zygomatic sutures and the sutures of the zygomatic bone. <p><p>These three sutural groups are characteristic by evolving very slowly to fusion, and than, only few individuals present a complete obliteration of the latter. <p><p>Because of general population ageing and our medicolegal and anthropological experience of skeletal remains in elderly, we estimated the usefulness in studying particular collections of old people, in order to appreciate the morphological evolution of these facial joints. <p><p>Despite some very old people who present little evolved sutural characteristics, we consider as a whole, an almost constant sutural progression according to age. <p><p>We tried to define degrees of this progressive fusion and by the way, the result with a sutural obliteration average coefficient, can be easily translate as a percentage obliteration or able to be introduced into regression equations. <p><p>The limits of this approach are well known but we estimate that it is possible to help the examination of human skeletal remains in elderly, although at these stages of ageing, some methods remain still applicable. In addition, the approach expressed as a percentage of sutural obliteration is also very helpful when craniums are fragmented. This situation is currently observed on the anthropological collections at the Royal Belgian Institute of Natural Sciences. <p><p>Furthemore in the future, the sutural observation will find an interesting and useful approach by the study of the joints in CT-Scan or micro-CT. <p><p>At least, thanks to these modern techniques of medical imagery, the sutures find a renewed interest in a very particular application, such as comparative identification. It appears that the "sutural drawing" proves completely specific to each individual. <p><p> / Doctorat en sciences médicales / info:eu-repo/semantics/nonPublished

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