Tooth Wear Analysis Research Articles

Dental eruption sequence and hypsodonty index of a Pleistocene macraucheniid from the Brazilian Intertropical Region

AbstractLitopterna is represented in the Pleistocene of the Brazilian Intertropical Region by a monospecific genus of Macraucheniidae, Xenorhinotherium. Although most of the knowledge about this family is derived from the dentition, some dental features still remain unknown. This study describes the eruption sequence of permanent dentition and classifies the hypsodonty status of X. bahiense. The specimens studied are from Toca dos Ossos, a limestone cave located in Bahia State. We perform qualitative macroscopic analysis to describe the eruption dental sequence. Additionally, we perform quantitative analysis to determine the hypsodonty index. The dental eruption sequence of the juvenile specimen is M1, M2, I1, I2, M3, I3, P1, P2, P3, and P4. In addition, the analysis of tooth wear in adult specimens provides similar results. The hypsodonty index assigns a mesodont tooth crown for X. bahiense. The dental eruption sequence is most similar to a rapid-growth extant mammal. Moreover, our results do not support afrotherian-like delayed dental eruption to Litopterna. The hypsodonty index can be related to data on vegetation of the Brazilian Intertropical Region and the shape of the premaxilla of X. bahiense, both of which suggest a browsing diet for this macraucheniid.

The evolution of dual meat and milk cattle husbandry in Linearbandkeramik societies.

Cattle dominate archaeozoological assemblages from the north-central Europe between the sixth and fifth millennium BC and are frequently considered as exclusively used for their meat. Dairy products may have played a greater role than previously believed. Selective pressure on the lactase persistence mutation has been modelled to have begun between 6000 and 4000 years ago in central Europe. The discovery of milk lipids in late sixth millennium ceramic sieves in Poland may reflect an isolated regional peculiarity for cheese making or may signify more generalized milk exploitation in north-central Europe during the Early Neolithic. To investigate these issues, we analysed the mortality profiles based on age-at-death analysis of cattle tooth eruption, wear and replacement from 19 archaeological sites of the Linearbandkeramik (LBK) culture (sixth to fifth millennium BC). The results indicate that cattle husbandry was similar across time and space in the LBK culture with a degree of specialization for meat exploitation in some areas. Statistical comparison with reference age-at-death profiles indicate that mixed husbandry (milk and meat) was practised, with mature animals being kept. The analysis provides a unique insight into LBK cattle husbandry and how it evolved in later cultures in central and western Europe. It also opens a new perspective on how and why the Neolithic way of life developed through continental Europe and how dairy products became a part of the human diet.

On the prediction of friction coefficient and wear in spiral bevel gears with mixed TEHL

A prediction model of the friction coefficient and wear of the spiral bevel gears in the mixed lubrication condition is proposed. Effect of a coupling thermo-elasto-hydrodynamic phenomenon on tooth surface should be considered comprehensively prior to the execution of tooth wear analysis. An effort is devoted to application of TEHL with rough surface contact to analyze the performance of spiral bevel gears in terms of the pressure, flash temperature, friction coefficient, and particularly wear rate. Wear mechanism and rules under a condition of the mixed lubrication are revealed to provide evidence for gear design and engineering application. And comparison of the prediction wear depth with the experimental measurements shows good agreement.

A new Galeopid (Anomodontia, Galeopidae) from the Permian of Eastern Europe

A new anomodont genus and species, Parasuminia ivakhnenkoi sp. nov. (Galeopidae), from the Sundyr-1 locality (Upper Severodvinian Substage, Upper Permian) is described. Based on morphological analysis of tooth wear, the type of work of the jaw apparatus similar to that of Suminia Ivachnenko, 1994 is revealed.

Morphometry, Microstructure, and Wear Pattern of Neornithischian Dinosaur Teeth From the Upper Cretaceous Iharkút Locality (Hungary).

Teeth of iguanodontian ornithopods and ceratopsians could be remarkably similar, thus the referral of isolated dental material to particular neornithischian clades can be highly problematic. These groups are represented by the rhabdodontid Mochlodon vorosi and the basal coronosaurian Ajkaceratops kozmai in the Upper Cretaceous Csehbánya Formation at Iharkút (western Hungary). Whereas teeth of Mochlodon are common elements at the locality, no dental material belonging to Ajkaceratops was identified until now. Here we used mathematical statistical approaches, as well as tooth wear and dental microstructure analysis in order to decide whether the teeth previously referred to Mochlodon can be treated as a homogenous sample, or some remains belong rather to Ajkaceratops. According to our results, there was a striking morphological and structural convergence between the teeth of both taxa. However, the wear study revealed the existence of two different patterns within the sample. One is characterized by straight and parallel microstriations that suggest orthal movements during the jaw closure. This pattern was associated with Mochlodon. The other pattern appeared only on a few teeth, and it can be differentiated by its distinctive curved microstriations that indicate circumpalinal chewing. Because curved striations have never been described in ornithopods, but are found in several neoceratopsians, this pattern was associated here with Ajkaceratops. Here we present the first teeth that can provisionally be referred to the latter genus. We believe that the methodology discussed in this article will facilitate distinguishing ceratopsian and ornithopod teeth in other localities as well. Anat Rec, 300:1439-1463, 2017. © 2017 Wiley Periodicals, Inc.

Dietary flexibility and niche partitioning of large herbivores through the Pleistocene of Britain

Abstract Tooth wear analysis techniques (mesowear and microwear) are employed to analyze dietary traits in proboscideans, perissodactyls and artiodactyls from 33 Pleistocene localities in Britain. The objectives of this study are to examine the variability in each taxon, to track dietary shifts through time, and to investigate resource partitioning among species. The integration of mesowear and microwear results first allowed us to examine dietary variability. We identified differences in variability among species, from more stenotopic species such as Capreolus capreolus to more eurytopic species such as Megaloceros giganteus and Cervus elaphus . Broad dietary shifts at the community level are seen between climatic phases, and are the result of species turnover as well as dietary shifts in the more flexible species. The species present at each locality are generally spread over a large part of the dietary spectrum, and resource partitioning was identified at most of these localities. Mixed feeders always coexist with at least one of the two strict dietary groups, grazers or browsers. Finally, for some species, a discrepancy is observed between meso- and microwear signals and may imply that individuals tended to die at a time of year when their normal food was in short supply.

Unraveling a Neanderthal palimpsest from a zooarcheological and taphonomic perspective

Practically all archeological assemblages are palimpsests. In spite of the high temporal resolution of Abric Romani site, level O, dated to around 55 ka, is not an exception. This paper focuses on a zooarcheological and taphonomic analysis of this level, paying special attention to spatial and temporal approaches. The main goal is to unravel the palimpsest at the finest possible level by using different methods and techniques, such as archeostratigraphy, anatomical and taxonomical identification, taphonomic analysis, faunal refits and tooth wear analysis. The results obtained are compared to ethnoarcheological data so as to interpret site structure. In addition, activities carried out over different time spans (from individual episodes to long-term behaviors) are detected, and their spatial extent is explored, allowing to do inferences on settlement dynamics. This leads us to discuss the temporal and spatial scales over which Neanderthals carried out different activities within the site, and how they can be studied through the archeological record.

Decades of habitat use reveal food limitation of Newfoundland caribou

Abstract Identifying limiting factors is fundamental to understanding and conserving mammals, yet it often requires long-term data for long-lived species. Numerical changes of migratory caribou ( Rangifer tarandus ), for example, may unfold over decades, but few studies have examined habitat use at similar timeframes. We analyzed multiple decades of habitat use by caribou in Newfoundland, Canada, coincident with their numeric growth ( r = 0.064 in 1980s, 1990s) and decline ( r = −0.099 in 2000s). We examined 2 scales: selection of land cover, based on radiotracking of 520 adult females, and diet, based on microhistological analysis of feces and age-specific tooth wear from jawbones of harvested animals. Caribou responded at both scales. In contrast to previous decades, females during the population decline used proportionally less open coniferous and closed coniferous forests, they used more shrublands (in fall and winter) and barrens, open habitats with greater vascular plant resources. Patterns of selection also changed from nonselection to avoidance of open coniferous forest and from avoidance to nonselection or preference of barrens. The proportion of dietary moss increased at the expense of deciduous shrubs, especially during spring and summer and of ericaceous shrubs, graminoids, and lichens during winter. Teeth of both sexes exhibited premature wear, likely indicative of abrasion from low-quality forages and cropping of foods near the ground. These patterns mirror other responses, including declines in calf weight, female body size, number of male antler points, herd affinities, and time spent on the summer grounds. We surmise that they reflect density-dependent forage limitation of this island population.

Characterizing evulsion in the Later Stone Age Maghreb: Age, sex and effects on mastication

This paper assesses the earliest evidence for widespread dental modification in Northwest Africa. The intentional modification of teeth has implications for an individual's appearance, sense of identity and perceived status. The range of modifications reported varies from alterations of shape or color to the complete removal of healthy teeth (evulsion or ablation). The availability of well-dated collections reveals that Northwest Africa was the first region where the custom of tooth evulsion was widely practiced. Analysis of Iberomaurusian (Late Stone Age, n = 77) and Capsian dental material (n = 12) shows that evulsion was present in most male and female individuals (>94%). The most common Iberomaurusian practice involved removal of both upper central incisors (around 65%) although removal of fewer, none and more teeth was also recorded. Observations of the extent of alveolar remodeling of different sockets revealed that teeth were frequently removed at different ages, suggesting that the cultural significance was age transgressive and may have related to an event that individuals experienced more than once. During the Capsian period the prevalence of evulsion was lower in males than in females, but when present more teeth were removed with evulsion frequently involving both mandible and maxilla. Tooth wear analysis shows that evulsion affected not only the appearance of the individual but also the functioning of the masticatory complex.

Evaluation of the effectiveness of the new tooth wear measurement parameters

Nowadays, there has been an increasing interest in the preservation of natural dentition and the proper occlusion related to tooth wear for quality of life. To overcome the problems of the existing qualitative tooth wear analysis method, virtual three-dimensional models have been used. This study was designed to develop and validate a new quantitative method using tooth wear measurement parameters with angles obtained from virtual vectors and planes of the three-dimensional models. Sixteen parameters were evaluated in the virtual models of 20 students (7.57±1.55 years old) and 20 adults (56.85±6.34 years old). There were 12 angle and 4 height parameters, and the number of parameters measured from the virtual planes and vectors were 10 and 6, respectively. For each parameter, means and standard deviations were calculated, and an unpaired sample t test was performed to compare the young and the adult groups. Also, differences between the means were determined and expressed as percentages. The results were statistically significant between the two groups (P<0.001). In general, parameters using virtual vectors showed greater change than virtual plane. Although there were statistically significant differences among all parameters using virtual planes (P<0.001), the changes of the three angles were similar, except distolingual cusp angle. It was found that the parameters using virtual vectors were effective and tooth wear took place in both buccal and lingual cusps. Likewise, the validation of the new measurement parameters suggests that they can also be applied in the assessment of tooth wear related to dental biomaterials.

Middle Pleistocene ecology and Neanderthal subsistence: Insights from stable isotope analyses in Payre (Ardèche, southeastern France)

The Middle Palaeolithic site of Payre in southeastern France yields abundant archaeological material associated with fossil hominid remains. With its long sequence of Middle Pleistocene deposits, Payre is a key site to study the Middle Palaeolithic chronology of this region. This study is the first to investigate carbon and oxygen isotope contents of Neanderthal tooth enamel bioapatite, together with a wide range of herbivorous and carnivorous species. The aim is to contribute to the understanding of hunting behaviour, resource partitioning, diet and habitat use of animals and Neanderthals through a palaeoecological reconstruction.Local topography had a visible influence on carbon and oxygen stable isotope values recorded in herbivore tooth enamel. This was used to investigate possible habitats of herbivores. The different herbivorous species do not show large variations of their carbon and oxygen isotope values through time, indicating niche conservatism from OIS 8–7 to OIS 6–5, i.e., independently of palaeoclimatic and palaeoenvironmental variations. Based on these new observations, we conclude that Neanderthals employed a stable subsistence strategy over time, using a variety of local resources, with resource partitioning visible between humans and carnivores, especially wolves.A comparison of the results of stable isotopic investigation with the results of tooth wear analyses previously conducted on the same teeth allowed us to demonstrate that grazing and browsing do not bind animals to a specific habitat in a C3 environment as reflected in the isotopic values.

Caracterização Metodológica dos Estudos In Situ sobre Erosão Dentária: Uma Abordagem Atual

Objective: To characterize the methodology of studies on dental erosion. Material and Methods: Literature searches were carried out the databases Scopus and PubMed, using the descriptor erosion, the term in situ and the Boolean operator AND. The survey instrument consisted of a form containing the following variables: author, country where the research was performed, publication year, type of sterilization of the specimens; prior preparation of the tooth surface; analysis of tooth wear; origin, tissue and type of tooth; dentition; substance, pH and quantity of the demineralization/chelating solution; duration of the erosive challenge; number of volunteers and study length. Results: A total of 26 manuscripts were selected. The biological material mostly used was of human origin (69.23%), of which 100% corresponded to enamel. Teeth sterilization was carried out preferably with ethylene oxide (26.9%). The immersion 150ml, soft drink, 4 times/day and 5min were the most frequent choices for the erosive challenging. The pH values ranged from 1.0 to 3.8. Preventive measures by the use of fluorides or presence of acquired pellicle on the specimens’ surface were observed 80.76% of the articles. Profilometry and microhardness were the most commonly used tests to assess dental erosion. Conclusion: The most applied methodology consisted of human teeth sterilized with ethylene oxide exposed to soft drinks, evaluated by means of profilometry and microhardness tests. DESCRIPTORES: Tooth erosion. Methods. Clinical trial.

Paleoindian subsistence strategies and late Pleistocene paleoenvironments in the northeastern and southwestern United States: a tooth wear analysis

Paleoindians of North America entered a continent undergoing rapid climatic and environmental changes. This paper is a preliminary contribution toward obtaining a better picture regarding how climate and environmental change might have impacted the first settlers of North America. The Paleoindian sites we analyzed are, from the oldest to the youngest, Ingleside (Texas), Blackwater Draw Locality No. 1 (New Mexico), Hiscock Site (New York), and Plainview Quarry (Texas). Paleoenvironmental reconstruction involves identifying the dietary traits of ungulate species that might reflect the environmental conditions where they were living, and also where they might have been hunted by Paleoindians. Such an approach is realized through tooth microwear and mesowear analyses. Results indicate that a variety of food resources were available for the ungulates at these sites as well as the likely presence of mosaic environments around these sites which allowed Paleoindians to exploit resources in a large variety of habitats. The application of a method that allows for the estimation of the duration of occupation at archaeological sites reveals that results for Blackwater Draw and Hiscock Site indicate a long-term occupation of probably several months. However, during short events, Paleoindians were most likely hunting herds of horse and bison when these prey were available near the site. Results indicate that Plainview Quarry was likely used only for short-term occupations, with large game hunting focusing on bison. These patterns identified at the archeological sites studied are related to the fact that Paleoindians follow a high-technology forager model and frequently shifted their territory depending on the composition and distribution of the large mammal fauna.

Quantitative analysis of conodont tooth wear and damage as a test of ecological and functional hypotheses

Analysis of dental wear and damage is becoming an increasingly important tool in unraveling the trophic ecology of a wide range of vertebrates, and when applied to fossils it can provide evidence of both diet and feeding kinematics that is independent of morphological analysis. Conodonts have the best fossil record among vertebrates and their skeletal elements are known to exhibit surface wear and damage generated in vivo as a consequence of their function as teeth. We report the results of the first systematic survey and analysis of the frequency and extent of this wear and damage in conodonts (based on P1elements from a range of Carboniferous genera). This has revealed that wear and damage are remarkably common, present in all conodont elements sampled. Multivariate analysis reveals that patterns of wear and damage differ significantly among different conodont taxa, and exploratory ANOVA and linear discriminant analyses show that wear and damage differ according to the position of taxa in an onshore-offshore gradient, and whether they are likely to have had a benthic or pelagic mode of life. The incidence of denticle tip spalling in particular is higher in more-offshore environments and in taxa likely to have had a pelagic mode of life. Aspects of the data also reflect the occlusal kinematics of the elements, providing a means of testing hypotheses of element function. Our results have wide-ranging implications for unlocking the fossil record of conodonts, by, for example, furnishing direct evidence of the diet-mediated processes that may have driven observed patterns of evolutionary change, and reducing the confounding effects of depth segregation when using conodonts in isotope-based paleotemperature studies.

Ungulate feeding ecology and middle Pleistocene paleoenvironments at Hundsheim and Deutsch-Altenburg 1 (eastern Austria)

The purpose of this study is to analyze the dietary traits in the ungulate communities from two middle Pleistocene localities in eastern Austria, Deutsch-Altenburg 1 and Hundsheim, and to revise the paleoecological reconstructions at each site using tooth wear analyses (mesowear and microwear). The data will also be used to test for intra- and inter-site differences and analyze resource partitioning among ungulates. Intra-site comparisons show significant differences at the two localities and reveal the use of different resources for the various ungulates studied. This suggests the existence of dietary partitioning and niche segregation that would not be detected using traditional morphological proxies. The local environment at the two sites is characterized by the availability of both open and forested habitats. This study indicates the presence of mixed environmental conditions which is a different conclusion from previous paleoenvironmental reconstructions.

Invasive species and bushmeat hunting contributing to wildlife conservation: the case of feral pigs in a Neotropical wetland

AbstractAn unusual combination of two major conservation threats, invasive species and bushmeat hunting, has had a positive outcome for wildlife conservation in the Brazilian Pantanal. The Pantanal is a wetland and one of the few non-protected areas in the Neotropics where people live but rarely hunt native wildlife. To understand why wildlife hunting is not a major conservation issue in the Pantanal an exploratory survey, semi-structured interviews, skull collection and tooth wear analysis of feral pig Sus scrofa, white-lipped peccary Tayassu pecari and collared peccary Pecari tajacu were conducted, and hunting registers distributed, in the central region of the Pantanal. The results showed that feral pigs are the main hunting target. Feral pigs are effectively acting as a replacement species for hunting of native wildlife because the pigs provide a constant, culturally acceptable, readily available and free source of meat and oil to remote ranches. We cannot evaluate, however, if the buffer from hunting that feral pigs provide to native wildlife outweigh this species’ potential negative ecological impacts.

The first four million years of human evolution

In one of the last paragraphs of The origin of species (1859), Darwin famously suggested that ‘Much light will be thrown on the origin of man and his history’. When he published The descent of man 12 years later, there was still no fossil evidence of our earliest evolutionary history, and

Dietary plasticity in ungulates: Insight from tooth microwear analysis

In recent years, tooth microwear has been used as a powerful tool for investigating mammalian diets in paleontological or archaeological contexts. Tooth microwear techniques were applied to a number of late Pleistocene assemblages of bison ( Bison antiquus) from North America to analyze bison dietary traits, but more particularly, to test for dietary plasticity of the fossil species compared to their modern relatives. Modern bison species are known to be grazers from their ecology. However, the results from tooth wear analysis indicate that dietary traits were more diverse in the fossil bison than in their modern relatives. Bison paleodiets range from pure grazing to mixed feeding. The results illustrate not only the dietary plasticity for that species, but also the potential implications involved when using modern species as analogues for reconstructing the ecology of fossil species. Tooth microwear is a good proxy in archaeological contexts because it gives an insight on the diet of the last days of an animal’s life. The intra-population variability in diet is discussed in relation to the duration of formation of the assemblages (natural assemblages versus archaeological Paleo-Indian sites).

Prey selection by barn owls in relation to small-mammal community and population structure in a Sahelian agro-ecosystem

Barn owl pellet content was studied on seven occasions over a 2-y period during which terrestrial small-mammal populations were assessed via a capture-mark-recapture (CMR) programme in a Sahelian agro-ecosystem of the Inner Delta of Niger River in Mali. Rodents (especially Mastomys huberti representing 78.5% of the total number of prey) were the major prey of the barn owl on all but one occasion, when bats were dominant. This exception coincided with the period of lowest abundance of M. huberti at the study site. Distribution of M. huberti prey into four age classes was assessed through analysis of tooth wear in remains from the seasonal pellet samples. Comparisons with age structure of the CMR population indicate that the barn owl tended to prey on smaller-than-average (thus younger) individuals, especially when these are rare in the population (non-reproductive period between June and October). The spectrum of prey consumed is compared with data previously reported in Sahelian Africa, showing for the first time in this region a major shift in prey choice by the barn owl when its preferred prey becomes rare. At the rodent population level, the apparent choice of younger M. huberti prey at some periods is interpreted in the light of our knowledge on population dynamics of the species in this habitat.

Tooth wear and dental pathology at the advent of agriculture: New evidence from the Levant

Differences in patterns of diet and subsistence through the analysis of dental pathology and tooth wear were studied in skeletal populations of Natufian hunter-gatherers (10,500-8300 BC) and Neolithic populations (8300-5500 BC, noncalibrated) from the southern Levant. 1,160 Natufians and 804 Neolithic teeth were examined for rate of attrition, caries, antemortem tooth loss, calculus, periapical lesions, and periodontal processes. While the Natufian people manifest a higher rate of dental attrition and periodontal disease (36.4% vs. 19%), Neolithic people show a higher rate of calculus. Both populations manifested low and similar rates of caries (6.4% in the Natufian vs. 6.7% in the Neolithic), periapical lesions (not over 1.5%), and antemortem tooth loss (3.7% vs. 4.5%, respectively). Molar wear pattern in the Neolithic is different than in the Natufian. The current study shows that the dental picture obtained from the two populations is multifactorial in nature, and not exclusively of dietary origin, i.e., the higher rate and unique pattern of attrition seen in the Natufian could result from a greater consumption of fibrous plants, the use of pestles and mortars (which introduce large quantities of stone-dust to the food), and/or the use of teeth as a "third hand." The two major conclusions of this study are: 1) The transition from hunting and gathering to a food-producing economy in the Levant did not promote changes in dental health, as previously believed. This generally indicates that the Natufians and Neolithic people of the Levant may have differed in their ecosystem management (i.e., gathering vs. growing grains), but not in the type of food consumed. 2) Changes in food-preparation techniques and nondietary usage of the teeth explain much of the variation in tooth condition in populations before and after the agricultural revolution.