Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.802
Filtrar
2.
Homo ; 70(2): 147-154, 2019 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-31486824

RESUMO

The aim of this study was to compare the prevalence of anatomical variants of maxillary lateral incisors in archaeological and modern populations from the Maya region. Both populations were derived from the state of Yucatan, Mexico. The archaeological sample consisted of human remains representing 122 individuals from the ancient Maya archaeological site of Xcambo (AD 250-700). The modern sample consisted of 475 dental models from the municipality of Tahdziú, Yucatan. The anatomical variants evaluated included microdontia, barrel-shaped incisors, and talon cusp. The prevalence of each anatomical variant for each population was calculated and compared (Fisher p < 0.05). The prevalence of anatomical variants was 15.57% (n = 19) in the archaeological sample and 14.11% (n = 67) in the modern one; the difference was not significant (p = 0.666). When compared by specific anatomical variants, a significant (p = 0.013) association was observed for microdontia: 2.45% (n = 3) in the archaeological population and 9.05% (n = 43) in the modern population. Barrel-shaped incisors (p = 0.522) and talon cusp (p = 0.466) did not exhibit significant associations. The overall prevalence of anatomical variants in the maxillary lateral incisors in this region has not changed. The prevalence of microdontia has increased over the last 1500 years, and different microevolutionary processes may be called into question for such change.


Assuntos
Incisivo/anatomia & histologia , Incisivo/patologia , Maxila/anatomia & histologia , Anormalidades Dentárias/patologia , Arqueologia , História Antiga , História Medieval , Humanos , México , Paleodontologia , Anormalidades Dentárias/história
3.
Homo ; 70(1): 3-14, 2019 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-31475293

RESUMO

Deciduous teeth are occasionally well represented in archaeological skeletal samples, yet their potential value in reconstructing biological adaptations of prehistoric populations is often overlooked. Independent investigations of the metric dimensions of deciduous dental remains from the Chalcolithic site of Nevasa (Deccan Plateau, western India) yield a unique opportunity to compare odontometric methods and gain insight regarding dental variation in prehistoric India. Mesiodistal (MD) and buccolingual (BL) dimensions of deciduous teeth were measured by two researchers. Intra- and inter-observer precision in dental measurements are evaluated statistically using multiple methods of comparison. Mean MD and BL dental dimensions (mm) and crown areas (MD × BL; mm2) are reported for Nevasa and compared with mean crown dimensions for Inamgaon. Tooth crown size for Nevasa is evaluated using maxillary, mandibular and total crown areas. The apportionment of tooth mass to incisor and molar tooth classes permits assessment of inter-group variation. No significant differences in mean crown dimensions (MD, BL) or mean crown areas were found between Nevasa (493.6 mm2) and Inamgaon (504.6 mm2). While the apportionment of crown area to incisor and molar tooth classes differed, in overall size (total crown area) both sites are intermediate when compared with prehistoric and living groups from South, Southeast and East Asia. The well documented trend in reduction of permanent tooth size is paralleled by reduction in deciduous tooth size in South Asian prehistory.


Assuntos
Grupo com Ancestrais do Continente Europeu/estatística & dados numéricos , Coroa do Dente/anatomia & histologia , Dente Decíduo/anatomia & histologia , Humanos , Índia , Odontometria , Paleodontologia
4.
Am J Phys Anthropol ; 170(2): 319-323, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31265762

RESUMO

OBJECTIVES: Dental caries is often perceived as a modern human disease. However, their presence is documented in many early human groups, various nonhuman primates and, increasingly, our hominin ancestors and relatives. In this study, we describe an antemortem lesion on the root of a Paranthropus robustus third molar from Drimolen, South Africa, which likely represents another example of caries in fossil hominins. MATERIALS AND METHODS: The molar, DNH 40, is dated to 2.0-1.5 Ma and displays a lesion on the mesial root surface, extending from the cementoenamel junction 3 mm down toward the apex. The position and severity of the lesion was macroscopically recorded and micro-CT scanned to determine the extent of dentine involvement. RESULTS: A differential diagnosis indicates root caries, as the lesion is indistinguishable from clinical examples. Although necrotic in appearance, external tertiary dentine is evident on a micro CT scan. Gingival recession and/or continuous eruption of the tooth as a result of extensive occlusal wear would have occurred to facilitate caries formation. Therefore, the lesion is likely linked to relative old age of this individual. DISCUSSION: This new example increases the total number of carious lesions described in P. robustus teeth to 10, on occlusal, interproximal, and now, root surfaces. Beyond the consumption of caries-causing food, caries formation would have also required the presence of requisite intraoral cariogenic bacteria in this individual and the species. Of interest, the presence of tertiary dentine on the outward surface suggests the DNH 40 lesion may have been arrested, that is, no longer active, perhaps relating to a change in diet or oral microbiome just prior to the individual's death.


Assuntos
Cárie Dentária , Hominidae , Dente Serotino , Raiz Dentária , Animais , Cárie Dentária/diagnóstico por imagem , Cárie Dentária/história , Cárie Dentária/patologia , História Antiga , Dente Serotino/diagnóstico por imagem , Dente Serotino/patologia , Paleodontologia , África do Sul , Raiz Dentária/diagnóstico por imagem , Raiz Dentária/patologia , Microtomografia por Raio-X
5.
Isotopes Environ Health Stud ; 55(4): 344-365, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31272217

RESUMO

Carbon and oxygen isotopes ratios from herbivore teeth have previously been used as paleo-environmental proxies in temperate zones. However, their utility in tropical zones remains uncertain. In this study, sequential sub-samples from white-tailed deer (Odocoileus virginianus) teeth (second and third molars) from the Maya archaeological site of La Joyanca, located in northwestern Petén, Guatemala, show that δ18O of enamel carbonate corresponds broadly to modern observed precipitation δ18O over the 10-month period of tooth formation, capturing rainfall seasonality. The analyses also detect significant diachronic differences in the δ18O between the periods 1100-1000 BP (850-950 A.D.) and 1000-900 BP (950-1050 A.D.) at La Joyanca. The δ13C in both periods are indicative of a C3-plant based diet, which suggests cultivation of maize did not differentially affect deer diet during this period.


Assuntos
Isótopos de Carbono/análise , Cervos , Esmalte Dentário/química , Fósseis , Isótopos de Oxigênio/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Carbonatos/análise , Ecossistema , Guatemala , Paleodontologia/métodos , Estações do Ano
6.
Am J Phys Anthropol ; 170(2): 246-259, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31222724

RESUMO

OBJECTIVES: To increase understanding of the subsistence practices of the first Americans through analysis of the near-complete dentition of a young woman dating to the terminal Pleistocene of the Yucatan Peninsula, Mexico. MATERIALS AND METHODS: The skeleton is that of "Naia" a 15 to 17-year-old female from the submerged natural trap of Hoyo Negro found in association with remains of numerous extinct species of megafauna. Superbly preserved remains included the skull with 28 teeth, which are analyzed for evidence of caries, periodontal disease, wear patterns, and malocclusion. RESULTS: Naia exhibits a high frequency of dental caries, along with aggressive periodontal disease that threatened all her teeth, particularly her incisors. Dental attrition was extremely light for a hunter-gatherer, reaching to four on the Molnar scale on only one tooth. Lack of wear is associated with severe mandibular retrognathia, and low masticatory forces. DISCUSSION: Naia's dental condition is compared with that of other northern Paleoamericans, mostly females, dating before 11,000 cal BP. These exhibit a high degree of variability in both caries and tooth wear. All, however, exhibit rapid anterior wear owing to technological use of the front teeth. Naia exhibits the highest rate of caries, similar to that of the earliest South Americans, and one of the lowest rates of attrition. This demonstrates that she had a nonabrasive diet that was at least seasonally rich in carbohydrates. This does not mean her diet was low in meat, however, because similarly light dental attrition is seen in the Arch Lake female, a Paleoamerican from a big-game hunting society.


Assuntos
Dieta/história , Índios Norte-Americanos/história , Saúde Bucal/história , Adolescente , Cárie Dentária/patologia , Feminino , História Antiga , Humanos , México/etnologia , Paleodontologia
7.
Mem Inst Oswaldo Cruz ; 114: e180595, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31116227

RESUMO

The genetic information of ancient Paragonimus westermani, the oriental lung fluke infecting over 20 million people worldwide, has not been thoroughly investigated thus far. We analysed genetic markers (COI and ITS2) of P. westermani from coprolite specimens (n = 6) obtained from 15th to 18th century Korean mummies. Our results indicated that all P. westermani sequences were generally distinct from the other species of the genus Paragonimus. The sequences were clustered into three groups: Group I for East Asia; Group II for South and Southeast Asia; and Group III for India and Sri Lanka. In this study, we found that ancient P. westermani sequences in Korea belong to Group I, adding invaluable information to the existing knowledge of Paragonimus paleogenetics.


Assuntos
DNA de Helmintos/genética , DNA Espaçador Ribossômico/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Fezes/parasitologia , Múmias/parasitologia , Paragonimus westermani/isolamento & purificação , Animais , Ásia , Humanos , Paleodontologia , Paragonimus westermani/genética , Contagem de Ovos de Parasitas , Filogenia
8.
An Acad Bras Cienc ; 91Suppl. 2(Suppl. 2): e20170848, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31090797

RESUMO

This study presents the oldest record of Acanthocephala parasite eggs in coprolites preliminary assigned to Crocodyliformes, recovered in the region of Santo Anastácio Municipality, Southwestern São Paulo State. For this, a paleoparasitological investigation was carried out on 53 mineralized coprolites (complete or fragmented), with round shape or cylindrical shape of rounded or pointed ends, 0.2 - 3.9 cm in length x 0.1 - 2.4 cm in diameter, 3.7 grams in weight, and absence of food remains. Individual samples of the surface and internal portions of each coprolite were extracted by electric drill, dissociated with Cloridic Acid 10% solution, washed with Distilled Water, and filtered in granulometric screen Mesh / Tyler 325. After laboratory processing, the sediments retained on the granulometric screen was studied with Glycerin under optical microscopy, and the presence of four Acanthocephala eggs could be observed in sample of only one of these ichnofossils. All specimens were well preserved and showed 72.5 - 85 µm in length x 27.5 - 50 µm in width, elliptical shape, three concentric and thick shells, and embryos in their interior. This study inaugurates investigations and knowledge about Paleoparasitology in Crocodyliformes coprolites from the Bauru Group, Upper Cretaceous from the Paraná Basin.


Assuntos
Acantocéfalos/isolamento & purificação , Fósseis/parasitologia , Contagem de Ovos de Parasitas , Parasitos/isolamento & purificação , Animais , Brasil , Fezes/parasitologia , Paleodontologia , Répteis
9.
Proc Natl Acad Sci U S A ; 116(20): 9931-9940, 2019 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-31036651

RESUMO

The long-standing view that Mesozoic mammaliaforms living in dinosaur-dominated ecosystems were ecologically constrained to small size and insectivory has been challenged by astonishing fossil discoveries over the last three decades. By studying these well-preserved early mammaliaform specimens, paleontologists now agree that mammaliaforms underwent ecomorphological diversification during the Mesozoic Era. This implies that Mesozoic mammaliaform communities had ecological structure and breadth that were comparable to today's small-bodied mammalian communities. However, this hypothesis remains untested in part because the primary focus of most studies is on individual taxa. Here, we present a study quantifying the ecological structure of Mesozoic mammaliaform communities with the aim of identifying evolutionary and ecological drivers that influenced the deep-time assembly of small-bodied mammaliaform communities. We used body size, dietary preference, and locomotor mode to establish the ecospace occupation of 98 extant, small-bodied mammalian communities from diverse biomes around the world. We calculated ecological disparity and ecological richness to measure the magnitude of ecological differences among species in a community and the number of different eco-cells occupied by species of a community, respectively. This modern dataset served as a reference for analyzing five exceptionally preserved, extinct mammaliaform communities (two Jurassic, two Cretaceous, one Eocene) from Konservat-Lagerstätten. Our results indicate that the interplay of at least three factors, namely the evolution of the tribosphenic molar, the ecological rise of angiosperms, and potential competition with other vertebrates, may have been critical in shaping the ecological structure of small-bodied mammaliaform communities through time.


Assuntos
Evolução Biológica , Ecossistema , Fósseis , Magnoliopsida , Mamíferos , Animais , Tamanho Corporal , Dieta , Locomoção , Dente Molar , Paleodontologia
10.
Am J Phys Anthropol ; 169(2): 253-269, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30924143

RESUMO

OBJECTIVES: Bioarchaeological investigations of sex-based differences in the prevalence of dental pathological lesions, particularly caries, have drawn considerable attention, and out of this work, two dominant models have emerged. Traditionally, the first model interprets sex-related patterns in caries as a product of gendered differences in diet. A more recent model interprets a generally higher propensity for caries prevalence in females in light of reproductive ecology. To test the hypothesis that females have higher risk of caries in accordance with reproductive ecology, we examined and analyzed caries prevalence and other potentially synergistic oral pathological lesions in a late medieval (A.D. 1300-1500) Italian archaeological sample. MATERIALS AND METHODS: We examined sex- and age-related prevalence in caries and other oral pathological lesions in a late medieval Italian skeletal assemblage excavated from Villamagna consisting of 38 females and 37 males (n = 1,534 teeth). We examined age- and sex-related patterns in six dental traits: antemortem tooth loss, caries, calculus, periapical inflammation, tooth wear, and periodontitis. RESULTS: Significant age-related increases in antemortem tooth loss, caries, calculus, and tooth wear were observed in both males and females. However, there was a lack of expected sex differences in oral pathological lesions, with instead older males exhibiting significantly more antemortem tooth loss and corrected caries than females. DISCUSSION: Results are discussed in relation to the ethnohistoric context of medieval rural dietary practices as well as biomedical salivary literature, which suggest that dietary changes throughout the life course may have facilitated trade-offs that buffered females from higher rates of dental pathological lesions.


Assuntos
Doenças Dentárias , Adolescente , Adulto , Arqueologia , Feminino , História Medieval , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Paleodontologia , Fatores Sexuais , Doenças Dentárias/epidemiologia , Doenças Dentárias/história , Doenças Dentárias/patologia , Adulto Jovem
11.
Am J Phys Anthropol ; 168(4): 750-763, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30784057

RESUMO

OBJECTIVE: Previous researchers have assumed that the Late Prehistoric Oneota were less reliant on maize agriculture than their Middle Mississippian neighbors to the south. This assumption is based on the idea that intensive maize agriculture is related to sociopolitical complexity, and that the climate of the Great Lakes region was less conducive to full-scale agriculture than that of the American Bottom. Here, we assess the diet of the Oneota using dental pathology to test the hypothesis that the Oneota in Eastern Wisconsin were highly reliant on maize agriculture. MATERIALS AND METHODS: To test our hypothesis, skeletal remains representing 187 individuals and 1,102 teeth were examined from nine Oneota sites from the Middle Fox and Koshkonong Localities, as well as the Late Woodland/Middle Mississippian site of Aztalan. Dental caries, antemortem tooth loss (AMTL), and dental abscesses were assessed for each individual in the sample. Dental pathologies in the Oneota groups were compared to each other based on Locality and to the Aztalan population using chi-squared tests. RESULTS: Dental caries rates for the Oneota, based on the tooth count approach, were observed at 16.8% for the Middle Fox Locality, and 49% for the Koshkonong Locality. Comparatively, the Late Woodland/Middle Mississippian population from Aztalan had a tooth count rate of 19.5%. AMTL rates were similar across samples. Dental abscessing was universally low. DISCUSSION: The relatively high rate of dental caries among the Oneota is comparable to Middle Mississippian populations from throughout the Midwest, suggesting similar reliance on maize between the groups.


Assuntos
Cárie Dentária , Índios Norte-Americanos , Saúde Bucal/história , Adolescente , Adulto , Agricultura/história , Criança , Cárie Dentária/epidemiologia , Cárie Dentária/história , Cárie Dentária/patologia , Dieta/história , Feminino , História Antiga , Humanos , Índios Norte-Americanos/etnologia , Índios Norte-Americanos/história , Índios Norte-Americanos/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Paleodontologia , Dente/patologia , Wisconsin , Adulto Jovem
12.
Am J Phys Anthropol ; 168(3): 552-565, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30613949

RESUMO

OBJECTIVES: Dental plaque is associated with a variety of systemic diseases and mortality risks in living populations. However, bioarchaeologists have not fully investigated the mortality risks associated with plaque (or its mineralized form, calculus) in the past. This study examines the relationship between survivorship and calculus in a medieval skeletal sample. MATERIALS AND METHODS: Our sample (n = 1,098) from four medieval London cemeteries, c. 1000-1540 CE, includes people who died under attritional (normal) and catastrophic (famine and plague) conditions. The associations between age and the presence of dental calculus on the permanent left first mandibular molar are assessed using binary logistic regression and Kaplan-Meier survival analysis. RESULTS: The regression results indicate a significant negative relationship between age and calculus presence for individuals of all ages who died under normal mortality conditions and for adults who died under both normal and catastrophic conditions. Survival analysis reveals decreased survivorship for people of all ages with calculus under normal mortality conditions. Similarly, during conditions of catastrophic mortality, adult males with calculus suffered reduced survivorship compared to males without it, though there was no difference in survivorship between adult females with and without calculus. CONCLUSIONS: These results suggest that, as in modern populations, calculus accumulation in the inhabitants of medieval London reflects a greater risk of premature death. The evaluation of calculus, a potential measure of underlying frailty, in the context of a demographic measure of general health suggests that it might provide insights into health in past populations.


Assuntos
Cálculos Dentários/história , Cálculos Dentários/mortalidade , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Cemitérios , Criança , Pré-Escolar , Cálculos Dentários/epidemiologia , Feminino , História Medieval , Humanos , Lactente , Recém-Nascido , Modelos Logísticos , Londres/epidemiologia , Masculino , Pessoa de Meia-Idade , Paleodontologia , Adulto Jovem
13.
Arch Oral Biol ; 98: 176-181, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30500667

RESUMO

OBJECTIVE: Increased prevalence of dental caries evidently is correlated with increasing intake of sugar and carbohydrate-rich foods. Preceding and accompanying this dietary alteration might have been a shift from a hunting-and-gathering subsistence strategy to one based on agriculture. We corroborated this conjecture by means of a study on the prevalence of caries, antemortem tooth loss (AMTL) and tooth wear among 16th to 19th century hunter-gatherers and agriculturalists who co-existed in West Siberia. DESIGN: Indigenous skeletons (n = 75) exhumed from Tatar, Selkup, Khant, and Nenet graves along with Russian settler skeletons (n = 79) from Izyuk were examined. The prevalence of caries, AMTL and tooth wear among the indigenous peoples were compared with those among the Russian settlers. The resulting statistical inferences were tested using package R. RESULTS: The agriculturalist Russian settlers showed a significantly higher prevalence of dental caries (11.88%) than did the non-agriculturalist indigenous Siberian people (3.85%). Among the latter, the prevalence was the lowest in the Khanty and the highest in the Tatars, suggesting that caries differently affected each sub-group of indigenous Siberian people. Correspondingly to the case of dental caries, the Russian settlers' AMTL prevalence also was higher than that of the indigenous Siberians, regardless of age. On the other hand, the native Siberians and the Russian settlers did not show statistical differences in tooth wear. CONCLUSION: In the study on 16th to 19th century West Siberian populations, we were able to corroborate our presumption that agriculturalists ingesting a carbohydrate-rich diet would have higher rates of dental caries and AMTL than would hunter-gatherers.


Assuntos
Cárie Dentária/epidemiologia , Cárie Dentária/história , Perda de Dente/epidemiologia , Perda de Dente/história , Desgaste dos Dentes/epidemiologia , Agricultura , Dieta , Feminino , Mapeamento Geográfico , História do Século XVI , História do Século XVII , História do Século XVIII , História do Século XIX , Humanos , Masculino , Paleodontologia , Prevalência , Federação Russa/epidemiologia , Sibéria/epidemiologia , Esqueleto
14.
Arch Oral Biol ; 97: 97-101, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30368203

RESUMO

OBJECTIVE: To determine the cause of a large dental lesion, tentatively identified as a case of pre-eruptive intra-coronal resorption (PEIR), in the permanent second mandibular molar of a young individual from an Iron Age cemetery at Tel Erani (Israel), dated to ca. 3000 years B.P. The provisional diagnosis was based on the massive size of the lesion in a young individual in whom the adjacent teeth were caries-free and showed no visible enamel defects. DESIGN: The lower molars of Tel Erani on the affected side were radiographed and compared to radiographs of a modern clinical case of PEIR treated by one of us (U.Z) and the internal structure and mineral content of the lesion examined in detail using energy-dispersive X-ray spectroscopy (EDS). RESULTS: The Tel Erani specimen closely resembled the modern clinical case of PEIR. Moreover, both cases occurred in young individuals in whom the adjacent teeth were caries-free. Examination with SEM revealed absence of dentine in the affected tooth from Tel Erani, together with changes in structure and mineral content characteristic of resorption. CONCLUSIONS: Our study shows that the changes found in the lower second molar of the 3000 year old mandible from Tel Erani are characteristic of PEIR and demonstrate the antiquity of this condition.


Assuntos
Reabsorção de Dente/diagnóstico por imagem , Dente não Erupcionado/diagnóstico por imagem , História Antiga , Humanos , Israel , Mandíbula , Dente Molar , Paleodontologia , Espectrometria por Raios X
15.
PLoS One ; 13(11): e0204737, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30383758

RESUMO

Scholars have debated the taxonomic identity of isolated primate teeth from the Asian Pleistocene for over a century, which is complicated by morphological and metric convergence between orangutan (Pongo) and hominin (Homo) molariform teeth. Like Homo erectus, Pongo once showed considerable dental variation and a wide distribution throughout mainland and insular Asia. In order to clarify the utility of isolated dental remains to document the presence of hominins during Asian prehistory, we examined enamel thickness, enamel-dentine junction shape, and crown development in 33 molars from G. H. R. von Koenigswald's Chinese Apothecary collection (11 Sinanthropus officinalis [= Homo erectus], 21 "Hemanthropus peii," and 1 "Hemanthropus peii" or Pongo) and 7 molars from Sangiran dome (either Homo erectus or Pongo). All fossil teeth were imaged with non-destructive conventional and/or synchrotron micro-computed tomography. These were compared to H. erectus teeth from Zhoukoudian, Sangiran and Trinil, and a large comparative sample of fossil Pongo, recent Pongo, and recent human teeth. We find that Homo and Pongo molars overlap substantially in relative enamel thickness; molar enamel-dentine junction shape is more distinctive, with Pongo showing relatively shorter dentine horns and wider crowns than Homo. Long-period line periodicity values are significantly greater in Pongo than in H. erectus, leading to longer crown formation times in the former. Most of the sample originally assigned to S. officinalis and H. erectus shows greater affinity to Pongo than to the hominin comparative sample. Moreover, enamel thickness, enamel-dentine junction shape, and a long-period line periodicity value in the "Hemanthropus peii" sample are indistinguishable from fossil Pongo. These results underscore the need for additional recovery and study of associated dentitions prior to erecting new taxa from isolated teeth.


Assuntos
Esmalte Dentário/anatomia & histologia , Dentina/anatomia & histologia , Fósseis/anatomia & histologia , Hominidae/anatomia & histologia , Dente Molar/anatomia & histologia , Animais , Ásia , Fósseis/história , História Antiga , Humanos , Paleodontologia , Pongo/anatomia & histologia , Coroa do Dente/anatomia & histologia , Microtomografia por Raio-X
16.
PLoS One ; 13(10): e0203334, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30281589

RESUMO

Tooth crown tissue proportions and enamel thickness distribution are considered reliable characters for inferring taxonomic identity, phylogenetic relationships, dietary and behavioural adaptations in fossil and extant hominids. While most Pleistocene hominins display variations from thick to hyper-thick enamel, Neanderthals exhibit relatively thinner. However, the chronological and geographical origin for the appearance of this typical Neanderthal condition is still unknown. The European late Early Pleistocene species Homo antecessor (Gran Dolina-TD6 site, Sierra de Atapuerca) represents an opportunity to investigate the appearance of the thin condition in the fossil record. In this study, we aim to test the hypothesis if H. antecessor molars approximates the Neanderthal condition for tissue proportions and enamel thickness. To do so, for the first time we characterised the molar inner structural organization in this Early Pleistocene hominin taxon (n = 17) and compared it to extinct and extant populations of the genus Homo from African, Asian and European origin (n = 355). The comparative sample includes maxillary and mandibular molars belonging to H. erectus, East and North African Homo, European Middle Pleistocene Homo, Neanderthals, and fossil and extant H. sapiens. We used high-resolution images to investigate the endostructural configuration of TD6 molars (tissue proportions, enamel thickness and distribution). TD6 permanent molars tend to exhibit on average thick absolute and relative enamel in 2D and 3D estimates, both in the complete crown and the lateral enamel. This condition is shared with the majority of extinct and extant hominin sample, except for Neanderthals and some isolated specimens. However, while the total crown percentage of dentine in TD6 globally resembles the low modern values, the lateral crown percentage of dentine tends to be much higher, closer to the Neanderthal signal. Similarly, the H. antecessor molar enamel distribution maps reveal a relative distribution pattern that is more similar to the Neanderthal condition (with the thickest enamel more spread at the periphery of the occlusal basin) rather than that of other fossil specimens and modern humans (with thicker cuspal enamel). Future studies on European Middle Pleistocene populations will provide more insights into the evolutionary trajectory of the typical Neanderthal dental structural organization.


Assuntos
Evolução Biológica , Fósseis/anatomia & histologia , Dente Molar/anatomia & histologia , Coroa do Dente/anatomia & histologia , Animais , Coroas , Esmalte Dentário/anatomia & histologia , Esmalte Dentário/química , Humanos , Homem de Neandertal , Paleodontologia , Filogenia , Espanha
17.
PLoS One ; 13(8): e0203307, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30161214

RESUMO

The formation of dental caries is mainly caused by dietary habits and therefore, may contain information for dietary reconstructions of fossil hominids. This study investigates the caries lesion in the 12.5 Ma old type specimen of Dryopithecus carinthiacus Mottl 1957 (Primates, Hominidae) from St. Stefan (Austria). Potential food sources are identified on associated palynological data, which allow conclusions about food quality, sugar availability and the hominid metabolism during the Middle Miocene. Using micro computed tomography (µCT) and scanning electron microscopy (SEM) we provide a detailed analysis and characterization of the individuals' caries type. Its lesion is compared with a dataset of 311 wild chimpanzees, indicating morphological and etiological differences in caries formation between both species. The affected molar of D. carinthiacus reveals features known from severe dental caries in humans: (1) Cavitation with steep walls and smooth surface; (2) Reparative dentine at the roof of the pulp chamber; (3) Sclerotic dentine below the cavitation; (4) Association with dental calculus and (5) Unilateral usage of the healthy right tooth row. Its advanced primary caries, initiating on the intact enamel surface, indicates a frequent intake of highly cariogenic sugar-rich fruits, which likely exceeds the frugivory of extant chimpanzees. This finding corresponds with the associated palynological record, which infers a habitat with nearly year-round supply (9-10 months/year) of high quality foods (>carbohydrates; < fibers). Our conclusions challenge the model of a step-wise increase in dietary quality during hominid evolution and support the uricase hypothesis, which discusses the hominid autapomorphy of a fructose-based fat accumulation for periods of starvation. This model receives further validation by the identification of soft-tissue preservation, interpreted as fossilized white adipose cells, in the articulated hominid skeleton of Oreopithecus bamboli from Italy.


Assuntos
Cárie Dentária/história , Sacarose na Dieta , Comportamento Alimentar , Fósseis , Hominidae , Dente/patologia , Animais , Áustria , Cárie Dentária/etiologia , Cárie Dentária/patologia , Fósseis/ultraestrutura , História Antiga , Paleodontologia , Dente/ultraestrutura
18.
Am J Phys Anthropol ; 167(3): 507-523, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30159869

RESUMO

OBJECTIVES: In this study, we evaluate the role of plants in the diet of fisher-hunter gatherers adapted to highly productive coastal environments. Oral health markers were used to track spatiotemporal variations (regional and diachronic) in the composition of carbohydrate in the diets of prehistoric shell mound builders (sambaqui) from the Southeast of Brazil. Our main objective is to test the supposed stability in the dietary habits of sambaqui populations and identify modulating effects of chronological, cultural, and/or ecological factors. METHODS: Eighteen oral health markers (divided into three categories: caries, periodontal disease, and dental wear) were applied in 233 individuals from 7 sambaquis (dated between 4800 and 1100 BP) from 5 geographic regions. RESULTS: Our results reveal variable oral health patterns among sites. Despite that, we found a number of common features, such as dental wear and associated pulp lesions. Some oral health patterns are compatible with cariogenic diets and high carbohydrate consumption. CONCLUSIONS: Our analyses suggest that plant resource management is plausible at some sites and support the emerging evidence that plant consumption among sambaqui populations was driven more by ecologic factors than chronological or cultural ones. A comprehensive record of oral health markers shows promise as a methodology to differentiate between otherwise extremely similar diets.


Assuntos
Dieta/estatística & dados numéricos , Carboidratos da Dieta , Saúde Bucal/estatística & dados numéricos , Adulto , Exoesqueleto , Animais , Brasil , Cárie Dentária/epidemiologia , Cárie Dentária/patologia , Comportamento Alimentar , Feminino , Humanos , Masculino , Paleodontologia , Desgaste dos Dentes/epidemiologia , Desgaste dos Dentes/patologia
19.
Am J Phys Anthropol ; 167(2): 400-406, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30129183

RESUMO

OBJECTIVES: Rapid prototyping (RP) technology is becoming more affordable, faster, and is now capable of building models with a high resolution and accuracy. Due to technological limitations, 3D printing in biological anthropology has been mostly limited to museum displays and forensic reconstructions. In this study, we compared the accuracy of different 3D printers to establish whether RP can be used effectively to reproduce anthropological dental collections, potentially replacing access to oftentimes fragile and irreplaceable original material. METHODS: We digitized specimens from the Yuendumu collection of Australian Aboriginal dental casts using a high-resolution white-light scanning system and reproduced them using four different 3D printing technologies: stereolithography (SLA); fused deposition modeling (FDM); binder-jetting; and material-jetting. We compared the deviations between the original 3D surface models with 3D print scans using color maps generated from a 3D metric deviation analysis. RESULTS: The 3D printed models reproduced both the detail and discrete morphology of the scanned dental casts. The results of the metric deviation analysis demonstrate that all 3D print models were accurate, with only a few small areas of high deviations. The material-jetting and SLA printers were found to perform better than the other two printing machines. CONCLUSIONS: The quality of current commercial 3D printers has reached a good level of accuracy and detail reproduction. However, the costs and printing times limit its application to produce large sample numbers for use in most anthropological studies. Nonetheless, RP offers a viable option to preserve numerically constraint fragile skeletal and dental material in paleoanthropological collections.


Assuntos
Modelos Dentários , Paleodontologia/métodos , Impressão Tridimensional , Humanos , Estereolitografia
20.
J Hum Evol ; 123: 96-108, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30025871

RESUMO

Dental fractures can be produced during life or post-mortem. Ante-mortem chipping may be indicative of different uses of the dentition in masticatory and non-masticatory activities related to variable diets and behaviors. The Krapina collection (Croatia, 130,000 years BP), thanks to the large number of teeth (293 teeth and tooth fragments) within it, offers an excellent sample to investigate dental fractures systematically. Recorded were the distribution, position and severity of the ante-mortem fractures according to standardized methods. High frequencies of teeth with chipping in both Krapina adults and subadults suggest that the permanent and deciduous dentition were heavily subjected to mechanical stress. This is particularly evident when the frequencies of chipping are compared with those in modern humans (Upper Paleolithic and historic samples) that we analysed using the same methods. The distribution of chipping in the Krapina sample (anterior teeth are more affected) and its position (labial) suggest a systematic use of the anterior teeth for non-masticatory tasks.


Assuntos
Fósseis/patologia , Homem de Neandertal , Fraturas dos Dentes/epidemiologia , Animais , Antropologia Física , Croácia/epidemiologia , Paleodontologia , Fraturas dos Dentes/etiologia , Fraturas dos Dentes/patologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA