Biological and Physical Anthropology Commons^™

The Effects Of Diet, Size, And Phylogeny On Primate Dental Proportions, Rudolph J. Wilkins

Graduate Theses and Dissertations

It is generally appreciated that there is a relationship between the relative size of the incisors, mandible length, and diet in primates. More specifically, the differences in relative incisor size among primate species are believed to be evolutionary adaptations to their use during food processing and acquisition. While this satisfactorily explains relatively large incisors, it fails to address the relatively small incisor size seen in many taxa. One hypothesis is that there is a trade-off between molar size and incisor size in species with relatively short mandibles. The following study uses two-way ANOVA to evaluate the possibility that spatial constraint …

Tooth Crown Morphology And Testosterone Transfer In Female Members Of Opposite-Sex Dizygotic Twin Pairs, Randall Feezell

Graduate Theses and Dissertations

The twin testosterone transfer (TTT) hypothesis posits that females gestated with male co-twins develop more masculine phenotypes due to in-utero androgen exposure. Research has shown co-gestational effects to be associated with increased deciduous and permanent tooth size in females belonging to opposite-sex dizygotic twin pairs (OSF) as compared with females belonging to same-sex monozygotic (MZF) and dizygotic (SSF) twin pairs and female siblings. This study evaluates whether the TTT hypothesis explains patterns of dental morphological variation, namely differences between OSF and other females (SSF, MZF, female siblings) in a contemporary sample that includes both deciduous and permanent data. This work …

Dental Microwear Textures Of Paranthropus Robustus From Kromdraai, Drimolen, And An Enlarged Sample From Swartkrans: Ecological And Intraspecific Variation, Alexandria Sachiko Peterson

Graduate Theses and Dissertations

The original microwear texture baseline for South African hominins was done by Scott et al. (2005) and concluded that Paranthropus robustus exhibited higher complexity values (Asfc) that are seen in occasional hard object feeders. Australopithecus africanus has higher anisotropy values (epLsar) consistent with consuming tough objects. This study expands upon this baseline by increasing the sample size from n = 9 for P. robustus and n = 10 for Au. africanus to n = 66 and n = 44, respectively. Additionally, this study incorporates multiple different sites and deposits. The P. robustus sample includes Drimolen, Kromdraai, and an expanded sample …

Limiting The Impact Of Destructive Analytical Techniques Through Sequential Microspatial Sampling Of The Enamel From Single Teeth, Alexis E. Dolphin, Mathew A. Teeter, Christine D. White, Fred J. Longstaffe

Earth Sciences Publications

A fundamental research concern within contemporary bioarchaeology is the sensitive balance between the preservation of human remains and the use of destructive techniques to collect information. Here we describe one example of how multiple microspatial destructive/semi-destructive techniques may be carried out in sequence using only the enamel of a single tooth. With careful planning of both sample preparation strategies and sequencing of sampling methods, it is possible to produce multiple datasets, and yet to retain material for future analyses.

In this case, enamel from the teeth of 27 individuals who lived during the early medieval period (AD 1170-1198) in Bergen, …

The Political Ecology Of Early Childhood Lead Exposure At The New York African Burial Ground, Joseph Jones

Doctoral Dissertations

Nearly 25 years ago federal officials unearthed over 400 skeletal remains in Lower Manhattan. The site of the excavation was the New York African Burial Ground (NYABG), a 17th- and 18th-century cemetery for the city’s mostly enslaved African population. Today, the burial ground serves as a reminder of New York’s 200-year experiment with slavery. It is the first National Monument to honor enslaved African New Yorkers. This recognition is a testament to the resolve of African American descendants and their allies who, through political activism, would see these ancestors afforded in death some of the respect denied them in life. …

Adult Scurvy In New France: Samuel De Champlain's "Mal De La Terre" At Saint Croix Island, 1604-1605, Thomas A. Crist, Marcella H. Sorg

Anthropology Faculty Scholarship

No abstract provided.

A Stable Isotope Investigation Of Palaeodiet And Residential Mobility During The Integration Period, Quito Basin, Ecuador, Carlie Pennycook

Electronic Thesis and Dissertation Repository

The Integration Period (500/600-1532 C.E.) saw pre-Columbian society in the Quito Basin of Ecuador develop more politically and socially complex chiefdoms focused around agricultural production and trade. In this study, carbon, nitrogen and oxygen isotopic analyses of bone and teeth from 115 individuals from the sites of Tajamar (n=73) and Nuevo Aeropuerto Internacional de Quito (NAIQ) (n=42) were performed in order to reconstruct short- and long-term dietary patterns, and residential mobility in the Quito Basin. Emphasis was placed on how/if these large-scale societal changes in the region affected group dietary patterns and individual choices and actions.

The isotopic analysis of …

Predicting Failure In Mammalian Enamel, Brian Lawn, James Lee, Paul Constantino, Peter Lucas

Paul J. Constantino

Dentition is a vital element of human and animal function, yet there is little fundamental knowledge about how tooth enamel endures under stringent oral conditions. This paper describes a novel approach to the issue. Model glass dome specimens fabricated from glass and back­filled with polymer resin are used as representative of the basic enamel/dentine shell structure. Contact loading is used to deform the dome structures to failure, in simulation of occlusal loading with opposing dentition or food bolus. To investigate the role of enamel microstructure, additional contact tests are conducted on two­phase materials that capture the essence of the mineralized­rod/organic­sheath …

Fracture Susceptibility Of Worn Teeth, Amanda Keown, Mark Bush, James Lee, Chris Ford, Paul Constantino, Brian Lawn

Paul J. Constantino

An experimental simulation study is made to determine the effects of occlusal wear on the capacity of teeth to resist fracture. Tests are carried out on model dome structures, using glass shells to represent enamel and epoxy filler to represent dentin. The top of the domes are ground and polished to produce flat surfaces of prescribed depths relative to shell thickness. The worn surfaces are then loaded axially with a hard sphere, or a hard or soft flat indenter, to represent extremes of food contacts. The loads required to drive longitudinal cracks around the side walls of the enamel to …

Remarkable Resilience Of Teeth (How Are Teeth So Brittle Yet So Resilient), Paul J. Constantino

Biological Sciences Faculty Research

Tooth enamel is inherently weak, with fracture toughness comparable with glass, yet it is remarkably resilient, surviving millions of functional contacts over a lifetime. We propose a microstructural mechanism of damage resistance, based on observations from ex situ loading of human and sea otter molars (teeth with strikingly similar structural features). Section views of the enamel implicate tufts, hypomineralized crack-like defects at the enamel–dentin junction, as primary fracture sources. We report a stabilization in the evolution of these defects, by ‘‘stress shielding’’ from neighbors, by inhibition of ensuing crack extension from prism interweaving (decussation), and by self-healing. These factors, coupled …

Fracture In Teeth—A Diagnostic For Inferring Bite Force And Tooth Function, Paul J. Constantino, Brian R. Lawn, James J.-W. Lee, Peter W. Lucas

Biological Sciences Faculty Research

Teeth are brittle and highly susceptible to cracking. We propose that observations of such cracking can be used as a diagnostic tool for predicting bite force and inferring tooth function in living and fossil mammals. Laboratory tests on model tooth structures and extracted human teeth in simulated biting identify the principal fracture modes in enamel. Examination of museum specimens reveals the presence of similar fractures in a wide range of vertebrates, suggesting that cracks extended during ingestion or mastication. The use of ‘fracture mechanics’ from materials engineering provides elegant relations for quantifying critical bite forces in terms of characteristic tooth …