Dental microwear variability on buccal tooth enamel surfaces of extant Catarrhini and the Miocene fossil Dryopithecus laietanus (Hominoidea)

Analyses of buccal tooth microwear have been used to trace dietary habits of modern hunter-gatherer populations. In these populations, the average density and length of striations on the buccal surfaces of teeth are significantly cor-related with the abrasive potential of food items consumed. In non-human pri-mates, tooth microwear patterns on both occlusal and buccal wear facets have been thoroughly studied and the results applied to the characterization of dietary habits of fossil species. In this paper, we present inter- and intra-specific buccal microwear variability analyses in extant Cercopithecoidea (Cercopithecus mitis, C. neglectus, Chlorocebus aethiops, Colobus spp., Papio anubis) and Hominoidea (Gorilla gorilla, Pan troglodytes, Pongo pygmaeus). The results are tentatively compared to buccal microwear patterns of the Miocene fossils Dryopithecus and Oreopithecus. Significant differences in striation density and length are found among the fossil taxa studied and the extant primates, suggesting that buccal microwear can be used to identify dietary differences among taxa. The Dryopithecus buccal microwear pattern most closely resembles that of abrasive, tough plant foods consumers, such as the gorilla, in contrast to stud-ies of dental morphology that suggest a softer, frugivorous diet. Results for Oreopithecus were equivocal, but suggest a more abrasive diet than that previously thought.     

Seasonal Mortality Patterns in Primates: Implications for the Interpretation of Dental Microwear

The microscopic traces of use wear on teeth have been extensively studied to provide information that will assist in elucidating the dietary habits of extinct hominin species. 1 - 13 It has been amply documented that dental microwear provides information pertaining to diet for living animals, where there is a strong and consistent association between dental microwear patterns and different types of foods that are chewed. The details of occlusal surface wear patterns are capable of distinguishing among diets when the constituent food items differ in their fracture properties. 14 - 20 For example, the microwear traces left on the teeth of mammals that crush hard, brittle foods such as nuts are generally dominated by pits, whereas traces left on the teeth of mammals that shear tough items such as leaves tend to be characterized by scratches. These microwear features result from and thus record actual chewing events. As such, microwear patterns are expected to be variably ephemeral, as individual features are worn away and replaced or overprinted by others as the tooth wears down in subsequent bouts of mastication. Indeed, it has been demonstrated, both in the laboratory and the wild, that short‐term dietary variation can result in the turnover of microwear. 17 , 21 - 23 Because occlusal microwear potentially reflects an individual's diet for a short time (days, weeks, or months, depending on the nature of the foods being masticated), tooth surfaces sampled at different times will display differences that relate to temporal (for example, seasonal) differences in diet. 24     

A Comparative Test of Adaptive Explanations for Hypsodonty in Ungulates and Rodents

Hypsodonty has long been recognized as an adaptation for grazing: grazing is suggested to increase tooth wear due to endogenous (e.g., fiber, silica) and/or exogenous (e.g., dust, grit) properties of ingested food. However, it is unknown whether tooth crown height is correlated with the mastication of high fiber or silica in grasses, the ingestion of external abrasives, or both. Furthermore, comparative studies of hypsodonty have not explicitly taken into account phylogenetic biases due to shared ancestry in tooth morphology and/or feeding behavior. This study highlights the relationship between molar crown height and feeding habits in African ungulates and South American rodents when phylogenetic effects are controlled. Among ungulates, high hypsodonty indices are significantly associated with specific plant and foraging height preferences, while habitat and climate show no correlation with tooth crown height. For rodents, grass-eating species are significantly more hypsodont than frugivorous or folivorous species, and arboreal rodents are less hypsodont than terrestrial species. These results as well as those of a posteriori analyses controlling for aspects of the behavioral ecology (e.g., grass-eating, substrate preference) of the sample species confirm the role of both diet and grit in shaping the evolution of cheek tooth crown height in herbivorous mammals.     

Exploring sex differences in diets and activity patterns through dental and skeletal studies in populations from ancient Corinth,Greece

Sex and temporal differences are assessed in relation to dietary habits and activity patterns in three ancient populations from Corinth, Greece. The skeletal sample spans time from the Geometric to the Early Byzantine Period (9th c. BCE-5th c. CE). Dental caries and tooth wear have been proven to be reliable dietary indicators. Similarly, spinal osteoarthritis, spinal facet remodeling and Schmorl’s nodes, have been used to infer activity patterns.     

The oral apparatus of tadpoles of Rana dalmatina, Bombina variegata, Bufo bufo, and Bufo viridis (Anura)

The morphology and development of the larval oral apparatus of Rana dalmatina, Bombina variegata, Bufo bufo, and Bufo viridis are described and compared using scanning electron microscopy. The species show different arrangements of the mouthparts. The small oral apparatus of R. dalmatina larvae has three labial tooth rows on the upper labium, while there are four tooth rows on the lower labium with a medial gap in row proximal to the mouth. The margins of the oral apparatus are defined by papillae that encircle the lower labium. B. variegata tadpoles have two upper labial tooth rows and three lower labial tooth rows that are uninterrupted, unlike the ones of R. dalmatina. The mouth is encircled by papillae that are larger than those of R. dalmatina. The oral discs of tadpoles of both B. bufo and B. viridis are similar. They are defined by two upper labial tooth rows (the second of which is interrupted by a medial gap) and by three lower tooth rows that differ in lengths in the two Bufo species. Both species develop papillae on the mouth angles and in two rows on the upper labium. Some morphological differences among the oral discs of R. dalmatina, B. variegata, B. bufo, and B. viridis tadpoles can be attributed to phylogenetic differences, but most can be related to their varying feeding habits and/or to their dietary specializations.     

'Inadequate' dietary habits and mastication in elderly men

Objective: The aim of this study was to re‐evaluate data about oral status, mastication and nutrition in elderly men in Malmö, Sweden, recorded in 1985–1987, to assess associations between inadequate dietary habits, oral conditions and masticatory function. Materials and methods: Four hundred and eighty‐one men, aged 67–68, participated in a comprehensive health examination, including tooth and denture status and masticatory tests. A separate study of dietary habits and nutritional status was made. Ninety‐five men had inadequate dietary habits. The databases of dental/denture status, mastication, nutritional status and social network factors were re‐evaluated for assessment of associations. Results: No significant differences between those with adequate or inadequate nutrition were found with regard to the number of teeth, occlusal contacts or removable dentures. Also self‐assessed chewing did not show any differences. Conclusion: Inadequate dietary habits were independent of teeth and denture status. Some correlations to social network conditions could be identified. Overweight, obesity, low physical activity and high alcohol intake were more common among those with inadequate nutritional intake.     

Dental chipping in Aleuts, Eskimos and Indians

Analysis of dentitions belonging to 324 prehistoric and protohistoric Aleuts, Eskimos and northern Indians, all of whom were regularly meat-eaters, reveals a significant difference between Eskimos and Aleut-Indians for a little known type of tooth wear. This wear is characterized by severe crushing and/or flaking of the crown surface of one or more teeth (termed “pressure-chipping”). It occurs chiefly in dentitions of high arctic Eskimos of Alaska, Canada, and Greenland, and significantly less often in the teeth of Kodiak Island Eskimos, Aleuts and northern Indians. Sex differences do not exist but pressure-chipping occurs significantly more often in adult (21–x years) than in non-adult (0–20 years) Eskimos. The exact mechanism(s) responsible for pressure-chipping is unknown, although ethnographic accounts of Eskimo eating habits suggest that crushing of hard substances such as bone was involved. The severity of this wear could have contributed to the selection for, or preservation of, large and complex crowns in high arctic Eskimos. Pressure-chipping is offered as evidence favoring the view that tooth size (longevity) may have had in the past some adaptive value.     

Buccal dental microwear variability in extant African Hominoidea: taxonomy versus ecology

Buccal microwear patterns on teeth are good indicators of the abrasiveness of foodstuffs and have been used to trace the dietary habits of fossil species, including primates and hominids. However, few studies have addressed the variability of this microwear. The abrasiveness of dietary components depends not only on the hardness of the particles ingested, but also on the presence of dust and other exogenous elements introduced during food processing. These elements are responsible for the microwear typology observed on the enamel surfaces of primate teeth. Here we analyzed the variability of buccal microwear patterns in African Great Apes (Gorilla gorilla and Pan troglodytes), using tooth molds obtained from the original specimens held in several osteological collections. Our results suggest that ecological adaptations at subspecies or population level account for differences in microwear patterns, which are attributed to habitat and ecological conditions within populations rather than differences between species. The findings from studies on the variability of buccal dental microwear in extant species will contribute to a better understanding of extinct hominids’ diet and ecology.     

Evolution of feeding specialization in Tanganyikan scale-eating cichlids: a molecular phylogenetic approach

Background  

Cichlid fishes in Lake Tanganyika exhibit remarkable diversity in their feeding habits. Among them, seven species in the genus Perissodus are known for their unique feeding habit of scale eating with specialized feeding morphology and behaviour. Although the origin of the scale-eating habit has long been questioned, its evolutionary process is still unknown. In the present study, we conducted interspecific phylogenetic analyses for all nine known species in the tribe Perissodini (seven Perissodus and two Haplotaxodon species) using amplified fragment length polymorphism (AFLP) analyses of the nuclear DNA. On the basis of the resultant phylogenetic frameworks, the evolution of their feeding habits was traced using data from analyses of stomach contents, habitat depths, and observations of oral jaw tooth morphology.     

Non-occlusal dental microwear variability in a sample of Middle and Late Pleistocene human populations from Europe and the Near East

Non-occlusal, buccal tooth microwear variability has been studied in 68 fossil humans from Europe and the Near East. The microwear patterns observed suggest that a major shift in human dietary habits and food processing techniques might have taken place in the transition from the Middle to the Late Pleistocene populations. Differences in microwear density, average length, and orientation of striations indicate that Middle Pleistocene humans had more abrasive dietary habits than Late Pleistocene populations. Both dietary and cultural factors might be responsible for the differences observed. In addition, the Middle Paleolithic Neanderthal specimens studied show a highly heterogeneous pattern of microwear when compared to the other samples considered, which is inconsistent with a hypothesis of all Neanderthals having a strictly carnivorous diet. The high density of striations observed in the buccal surfaces of several Neanderthal teeth might be indicative of the inclusion of plant foods in their diet. The buccal microwear variability observed in the Neanderthals is compatible with an overall exploitation of both plant and meat foods on the basis of food availability. A preliminary analysis of the relationship between buccal microwear density and climatic conditions prevailing in Europe during the Late Pleistocene has been attempted. Cold climatic conditions, as indicated by oxygen isotope stage data, seem to be responsible for higher densities of microwear features, whereas warmer periods could correspond to a reduced pattern of scratch density. Such a relationship would be indicative of less abrasive dietary habits, perhaps more meat dependent, during warmer periods.     

Ontogenetic and sexual characterization of the feeding habits of franciscanas,Pontoporia blainvillei,based on tooth dentin carbon and nitrogen stable isotopes

We assessed the feeding habits of franciscanas (Pontoporia blainvillei) from southern Brazil through carbon and nitrogen stable isotopes measured in the tooth dentin of dolphins from different age classes. Generalized additive models were fitted to assess whether sex, age, and total body length explained changes in franciscanas isotope ratios. Bayesian isotope mixing models were applied to estimate the contributions of prey items, selected based on stomach content analysis (SCA), to franciscanas' diet. Different trophic enrichment factors (TEF) were applied and the results were compared using Bhattachayya's coefficient index to test for differences in model outputs and to define the best TEF for franciscanas. We found different relative importance of the main prey between the methods, and the contribution by squids could be lower than suggested by SCA. Because the dentin deposited during nursing seems to influence the isotopic ratios of juveniles, caution is recommended when interpreting dietary estimates based on whole tooth samples. This study is the first to characterize ontogenetic shifts in franciscanas' feeding habits using stable isotope analysis (SIA) and testing different TEF values. SIA and SCA complement each other in dietary studies, mitigating potential biases resulting from the use of each method separately.     

The carbon isotope ecology and diet of Australopithecus africanus at Sterkfontein,South Africa

The stable carbon isotope ratio of fossil tooth enamel carbonate is determined by the photosynthetic systems of plants at the base of the animal's foodweb. In subtropical Africa, grasses and many sedges have C(4)photosynthesis and transmit their characteristically enriched 13C/(12)C ratios (more positive delta13C values) along the foodchain to consumers. We report here a carbon isotope study of ten specimens of Australopithecus africanus from Member 4, Sterkfontein (ca. 2.5 to 2.0Ma), compared with other fossil mammals from the same deposit. This is the most extensive isotopic study of an early hominin species that has been achieved so far. The results show that this hominin was intensively engaged with the savanna foodweb and that the dietary variation between individuals was more pronounced than for any other early hominin or non-human primate species on record. Suggestions that more than one species have been incuded in this taxon are not supported by the isotopic evidence. We conclude that Australopithecus africanus was highly opportunistic and adaptable in its feeding habits.     

Epidemiological study on improving the QOL and oral conditions of the aged--Part 2: Relationship between tooth loss and lifestyle factors for adults men

Oral health in early- and mid-adulthood is essential for the improvement of one's QOL, this study was investigated to include an epidemiological analysis of the relationship between tooth loss and life style, such as smoking, regular exercise, and the food habits of approximately 2,000 employees. Compared with the group with mild or no periodontal disease (CPI of 0, 1, or 2), the frequency of tooth loss in the group with advanced periodontal disease (CPI of 4) was 2.00 times (odds ratio, 2.00; 95% confidence limit, 1.37 to 2.93). The probability of tooth loss showed statistical significance in relation to smoking, alcohol drinking, and frequency of meals. Compared with non-smokers, the probability that current smokers will lose teeth is 1.53 times greater (odds ratio, 1.53; 95% confidence limit, 1.20 to 1.96). It was concluded that periodontal disease and smoking must be averted for preventing tooth loss.     

Jaw biomechanics in the South American aetosaur <Emphasis Type="Italic">Neoaetosauroides engaeus</Emphasis>

The function of the jaw apparatus and the possible dietary habits of the aetosaur Neoaetosauroides engaeus from the Triassic of South America were analyzed in comparison with Northern Hemisphere aetosaurs Desmatosuchus haplocerus and Stagonolepis robertsoni and the living short-snouted crocodile Alligator mississippiensis. The adductor and depressor jaw musculature of these was reconstructed on the basis of dental and skeletal comparisons with living closest relatives’ extant phylogenetic bracket (EPB), followed by the analysis of the moment arms of these muscles to infer feeding habits. The aetosaurian skull design indicates that the total leverage of the inferred jaw musculature provides force rather than speed. However, within aetosaurs, the high ratios of muscle moment arms to bite moments indicate stronger bites in the northern Hemisphere forms, and faster ones in Neoaetosauroides. These differences indicate more developed crushing, chopping, and slicing capacities, especially at the back of the tooth series for D. haplocerus and S. robertsoni; whereas it opens a window to consider different abilities in which speed is involved for N. engaeus. There are differences among aetosaurs in dental characteristics, position of the supratemporal fenestra, location of the jaw joint relative to the tooth row, and shape of the lower jaw. Neoaetosauroides does not show evidence of dental serrations and wear facets, probably consistent with a relatively soft and non-abrasive diet, for example soft leaves and/or larvae and insects without hard structures. It might be possible that Neoaetosauroides represents a tendency towards insectivorous feeding habits, exploiting a food source that was widespread in continental environments throughout the Triassic.     

全冠牙体预备后局部龈沟菌群的变化

目的 :定量观察临床全冠修复患者牙体预备完成 1w内 ,其龈沟菌丛的变化。方法 :选择 14颗需进行全冠修复的第一磨牙作为研究对象 ,以同颌同名牙作为研究对照 ,分别采集牙体预备前、预备后 72h及 1w时 ,预备牙和同颌同名牙龈沟菌丛的标本。经细菌接种、厌氧培养、生化鉴定 ,进行可培养菌计量。比较同一时期预备牙龈沟菌丛与同颌同名牙龈沟菌丛间 ,以及不同时期预备牙龈沟菌丛间可培养菌量的变化。结果 :(1)牙体预备后 1w内 ,预备牙龈沟菌丛中多数细菌菌量接近或超过预备前水平 ,差异无显著性 (P>0 .0 5 ) ,但以放线菌为主的 G+性杆菌增多明显。(2 )同一时期以放线菌为主要的 G+杆菌和奈瑟菌的菌量在预备牙龈沟菌丛和同颌同名牙龈沟菌丛间差异有显著性 (P<0 .0 5 )。结论 :(1)牙体预备后 ,预备牙龈沟菌丛的自然变化过程 ,与天然牙菌斑形成过程相似 ,其龈沟菌丛菌量和菌种随时间的延长而增多。 (2 )预备牙龈沟菌丛和同颌同名牙龈沟菌丛间以放线菌为主的 G+杆菌和奈瑟菌差异有显著性 (P<0 .0 5 )。     

TV viewing, computer game playing and nightmares in school children.

Often the question arises whether TV viewing or playing computer games, especially those of violent and aggressive content, has negative effects on children's sleep patterns and dreaming. Empirical data on this topic, however, are scarce. Two hundred fifty-two schoolchildren (range: 9 to 13 years) completed a questionnaire about media use and nightmares. The findings indicates that interindividual differences in nightmare frequency were not explained by interindividual differences in TV viewing or computer game playing habits. In addition, no effect of the TV films the evening before completing the questionnaire on the dreams the subsequent night could be demonstrated. Since the approach could not rule out an effect of media use habits on nightmares, the next step will be a longitudinal study eliciting the media use habits and the occurrence of nightmares by applying self-rated scales as well as information obtained by parents. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dental Health Diet and Social Status among Central African Foragers and Farmers

An oral health survey of African pygmies and Bantu revealed significant contrasts that can be explained by differences in diet, social status, and oral hygiene. Pygmy men have fewer carious lesions and less tooth loss than pygmy women. Ethnographic data suggest that this results from sex differences in eating habits and access to cariogenic foods. Pygmy "leaders" have much better dental health than "nonleaders." This status difference appears to be explained by social and dietary variables.     

Variation in radular teeth and acuspid side of the radula in Lacuna pallidula, L. parva and L. vincta (Gastropoda: Littorinidae) from the Isle of Wight, United Kingdom

The variation in the radula of three species of Lacuna has been investigated and the back of the rachidian tooth is proposed as providing a new character set of potentially high taxonomic value. The term basal plate is introduced for the back of the rachidian tooth. Cusp and tooth morphology are closely related to diet and wear, and are subject to considerable homoplasy, whereas the structure of the basal plate of the rachidian tooth provides a more neutral character set. The difference in this character set between the lacunids has been quantified using seven measurements and the exploratory multivariate statistical procedure principal component analysis. The basal plate of the rachidian tooth showed interspecific differences. The taxonomic value of this new character set should be evaluated in further studies of other prosobranchs. Received in revised form: 25 October 2000 Electronic Publication     

Bigger teeth for longer life? Longevity and molar height in two roe deer populations

The role of tooth wear as a proximate cause of senescence in ruminants has recently been highlighted. There are two competing hypotheses to explain variation in tooth height and wear; the diet-quality hypothesis predicting increased wear in low-quality habitats, and the life-history hypothesis predicting molar height to be related to expected longevity. We compared tooth height and wear from roe deer of known age from two contrasting populations of roe deer (Capreolus capreolus) in France: Trois Fontaines (TF) with good habitat and shorter animal life expectancy and Chizé (CH) with poor habitat and longer animal life expectancy. There was no population difference in tooth wear, leading to rejection of the diet-quality hypothesis. However, despite their smaller body size, initial molar height for animals from CH was larger than for animals from TF. This provides the first evidence that variation in longevity between populations can lead to differences in molar height within a species.