Dental wash: a problematic method for extracting microfossils from teeth

A variety of microfossils, originating from plant foods, become trapped in the dental calculus matrix. Processing of dental calculus allows extraction of these microfossils. The resulting data can be used to reconstruct diet at the individual and population levels as the identification of microfossils like starch grains and phytoliths to the generic level, and sometimes to the species level, is possible. However, in some archaeological sites, dental calculus deposits do not preserve well enough to be processed. To prevent the loss of information in such cases, we present a technique, called “dental wash”. It permits extracting microfossils from cryptic dental calculus deposits. In the two experimental archaeological cases presented herein we identified phytoliths, starch grains as well as a diatom fragment with this method, whereas in a control sample no microfossils were found. Moderate damage to the teeth was detected when they were already friable due to poor preservation. Minor damage to the surface of well-preserved teeth was observed. This indicates that the proposed method is efficient in recovering microfossils, but unacceptable because of damage to teeth. If the method can be refined, it will expand the potential of dental calculus analysis to a greater range of archeological sites.     

基于人牙结石的淀粉粒证据探讨裴李岗遗址先民植物性食物来源

人牙结石淀粉粒分析是开展古代居民食物来源研究的有效途径之一。用此方法对河南新郑裴李岗遗址仅存的两具裴李岗文化人骨牙齿上的结石开展了淀粉粒分析,成功提取出38颗淀粉粒,其中可鉴定种属的淀粉粒主要来自于栎属、豆科和块茎类等非农作物,少量有可能来自于粟黍类作物。虽然分析样品较少,提取出的淀粉粒数量不多,但这一结果或许表明采集植物有可能构成了裴李岗遗址居民植物性食物的主体。结合贾湖、莪沟、石固和寨根等裴李岗文化遗址的植物考古学研究,裴李岗文化居民的食物结构具有广谱性特征。本研究为全面认识中原地区裴李岗文化居民食物构成和聚落生业经济,深入探讨中原地区早期农业形成过程等提供了新思路和新证据。     

Dirty teeth and ancient trade: Evidence of cotton fibres in human dental calculus from Late Woodland,Ohio

Analysis of ancient human dental calculus for the presence of inclusions related to diet and dental health has been overlooked in anthropological literature. Small particles of archaeobotanical debris, which would otherwise not be preserved in the archaeological record, can become incorporated into unmineralised plaque on teeth during mastication and oral manipulation. When plaque mineralises into calculus, debris is preserved in situ. Samples of dental calculus (n = 18) were collected from the Danbury site (33OT16) in Ottawa County, Ohio and viewed under a scanning electron microscope for inclusions. Analysis yielded a variety of noticeable inclusions, including mineralised bacteria, calcium‐phosphate crystalline structures and numerous phytoliths. Here we report the first evidence of fibres consistent with cotton (Gossypium spp.) embedded in the dental calculus from the Late Woodland component (900–1100 AD ) of the Danbury site. Prehistoric cotton has not been previously documented in Ohio. The distinct morphology of the Danbury cotton and its presence in the Late Woodland component at Danbury suggests long‐distance interaction at a time in Ohio when movement of exotic goods appeared to have diminished. These microscopic remains provide insight into paleoethnobotanical history of ancient Ohioans and attest to how analysis of dental calculus could be used to supplement other paleodietary and archaeological analyses. Copyright © 2010 John Wiley & Sons, Ltd.     

Evaluating microfossil content of dental calculus from Brazilian sambaquis

To date, limited numbers of dental calculus samples have been analyzed by researchers in diverse parts of the world. The combined analyses of these have provided some general guidelines for the analysis of calculus that is non-destructive to archaeological teeth. There is still a need for a quantitative study of large numbers of calculus samples to establish protocols, assess the level of contamination, evaluate the quantity of microfossils in dental calculus, and to compare analysis results with the literature concerning the biology of calculus formation. We analyzed dental calculus from 53 teeth from four Brazilian sambaquis. Sambaquis are the shell-mounds that were established prehistorically along the Brazilian coast. The analysis of sambaqui dental calculi shows that there are relatively high concentrations of microfossils (phytoliths and starch), mineral fragments, and charcoal in dental calculus. Mineral fragments and charcoal are possibly contaminants. The largest dental calculi have the lowest concentrations of microfossils. Biologically, this is explained by individual variation in calculus formation between people. Importantly, starch is ubiquitous in dental calculus. The starch and phytoliths show that certainly Dioscorea (yam) and Araucaria angustifolia (Paraná pine) were eaten by sambaqui people. Araceae (arum family), Ipomoea batatas (sweet potato) and Zea mays (maize) were probably in their diet.     

The Diet of Three Medieval Individuals from Caravate (Varese,Italy). Combined Results of ICP‐MS Analysis of Trace Elements and Phytolith Analysis Conducted on Their Dental Calculus

Teeth are in close contact with foodstuffs: phenomena such as caries and wear of the crowns are precious keys to gather information on diet and cooking techniques. Phytoliths are granules of hydrated amorphous silica, which are deposited in the oral cavity while chewing fruit and vegetables and incorporated into dental calculus during its formation. In diet investigation, different plants may therefore be related to specific phytolith shapes. Analysis of chemical trace elements, incorporated in dental calculus from ingested food and replacing small percentages of calcium in normal processes of resorption and redeposition, can further enrich the research on ancient diet. The aim of our work was to set up an analytical protocol, focalised on phytoliths and the inorganic elemental composition of dental calculus, on samples coming from medieval skeletons excavated in Caravate (Varese, Italy). The inductively coupled plasma mass spectrometry analytical technique proved to be particularly suitable for such studies. The results suggested a diet based both on the consumption of carbohydrates (dicotyledons and monocotyledons such as the Poaceae, also known as Gramineae; and Coniferae) and on proteins, mostly derived from fish. Copyright © 2015 John Wiley & Sons, Ltd.     

Sugar Consumption,Dental Health and Foodways in Late Medieval Iin Hamina and Early Modern Oulu,Northern Finland

This article examines the modernization of northern Finnish food culture, especially in 17th- and 18th-century urban Oulu, by applying the methods of archaeology and history research. During the 17th century, the food culture was still quite conservative. Coffee, sugar, wheat flour, and fruit began entering the diet of affluent northern Finnish people from the 18th century onwards. The food culture of Oulu inhabitants is studied by comparing dental material retrieved from Oulu Cathedral graveyard to data obtained from historical document sources. A comparison point to the early modern bone material of Oulu is provided by late Middle Ages material from Ii, which lies north of Oulu on the coast of the Gulf of Bothnia. Carbohydrate consumption is related to many dental conditions, such as caries and calculus, which can be traced in archaeological human skeletal remains. The diets of males and females, as well as the diets of adults and children, are compared, in order to retrieve information on the emerging consumption of sugar in different groups, such as gender and age groups. The relationship between carbohydrate consumption and class identity in northern Finland is discussed.     

DNA FROM HUMAN ANCIENT BACTERIA: A NOVEL SOURCE OF GENETIC EVIDENCE FROM ARCHAEOLOGICAL DENTAL CALCULUS

We report a molecular methodology to obtain and analyse ancient bacterial DNA from archaeological dental calculus. Recent and archaeological DNA samples, as old as 4000 bp , were successfully extracted and amplified with species‐specific PCR primers. We propose this approach in order to: detect the presence of specific bacterial species infecting past human populations; compare the composition of ancient oral microbiomes among human populations; and analyse the genetic variability and covariation of bacteria and human host populations. Genomic analysis of bacteria from dental calculus is a promising source of evidence for palaeopathological and micro‐evolutionary studies, focused either on micro‐organisms or their human hosts.     

Using plant microfossils from dental calculus to recover human diet: a case study from Tell al-Raqā'i,Syria

Dietary reconstructions based on plant microfossils, such as starch grains and phytoliths, have been useful in increasing our understanding of past human populations. Microfossils have been recovered from sediments, stone tools, and, more recently, dental calculus. Methods for recovering microfossils from dental calculus have yet to be firmly established and there is some question about potential damage to the teeth. Using a sample of teeth from the middle Holocene site of Tell al-Raqā'i, Syria, we tested using a dental pick to sample the calculus. ESEM images taken before and after sampling show no damage to the enamel surface, and examination of the recovered microfossils show that this method provides ample material for study, even when not all of the calculus is removed from the tooth. Preliminary identification of the plant microfossils suggests that these individuals were consuming a variety of plant foods, but that domesticated cereals such as wheat and barley made up a surprisingly small portion of their diet.     

Automated classification of starch granules using supervised pattern recognition of morphological properties

Image analysis techniques have been used to investigate the likelihood of being able to classify and assign a probability regarding the plant origin of individual starch granules in a collection of granules. Quantifiable variables were used to characterize the granules, and the assignments and probabilities were calculated objectively. We consider the classification of images containing granules of a single species and of mixed species and the possibility of assigning a class to granules of unknown species in an image of a slide obtained from the dental calculus of chimpanzees.     

Ancient bacterial DNA (aDNA) in dental calculus from archaeological human remains

The purpose of this study was to identify reactive bacterial aDNA in archaeological human dental calculus. Dental calculus was collected from a middle/late Neolithic human skull from Hulbjerg passage grave, Langeland, Denmark and prepared for transmission electron microscopy (TEM) or gold-labeled antibody TEM. TEM showed calcified, as well as non-calcified bacteria. Immunogold labeling occurred over the cytoplasmic portions of the sectioned bacteria. The result demonstrated that it is possible to identify aDNA sequences from bacteria in archaeological material of considerable age by this technique.     

The differential survival of native starch during cooking and implications for archaeological analyses: a review

Cooking makes foods more palatable and digestible, less toxic and suitable for longer-term storage. Starch granules usually undergo gelatinisation during cooking, resulting in the loss of native structure and morphology. Once fully gelatinised, starch is very difficult to recognise microscopically and to classify taxonomically, impeding identification of cooked starch in archaeological food residues. Gelatinisation involves a complex interplay between temperature, moisture content and the presence of solutes, lipids and proteins, as well as species-specific starch physicochemical properties. Understanding the influence of these factors, particularly moisture, on the degree and extent of starch conversion during heat treatment enables predictive models of native starch survival in archaeological samples based on cooking method and food type. The findings of this review indicate that differential native starch survival may significantly influence archaeobotanical reconstructions and interpretations of artefact function.     

Starch residues on museum artefacts: implications for determining tool use

A sample of 11 museum artefacts was examined to assess the preservation of any adhering organic residues, particularly starch granules, and to assess the potential for the identification of cooked starchy foods. The primary aim was to examine starchy deposits, extract starch granules and examine their physical condition to increase our understanding of the taphonomy of starch granules and associated organic residues in archived material and archaeological deposits. The study shows that organic plant residues could be recovered from archived artefacts and makes a significant contribution to understanding the function of this material. Recovered starch granules showed an interesting pattern of varying organic preservation on the surface of stone and wooden artefacts. Some starch granules were found to be well preserved while others in the same sample appeared to have been affected by enzyme degrading micro-organisms. Recovered residues included fully gelatinised starch.     

Dental pathology and diet at Apollonia,a Greek colony on the Black Sea

Dental pathology has the potential to provide insight into the composition of the diet and to reveal dietary differences based on age, sex and social status. Human skeletal remains from the Greek colonial site of Apollonia (5^th to 2^nd centuries BC) on the Black Sea coast of Bulgaria were analysed for various forms of dental pathology in order to: assess the prevalence of dental disease in the population; compare the dental pathology data from Apollonia with dietary data derived from ancient literary texts and from previous stable isotopic analysis of the colonists' remains; explore variations in dental disease with respect to age and sex; and compare the prevalence of dental pathology in the Apollonians with that of other Greek populations. The composition of the diet, as indicated by the dental pathology data, is consistent with the stable isotopic evidence from Apollonia and with the ancient literary texts, both of which indicate the consumption of a relatively soft, high carbohydrate diet. The higher frequency of dental caries, abscesses, calculus, and antemortem tooth loss in older adults compared with younger ones reflects the age‐progressive nature of these conditions. The lack of significant sex differences in caries, abscesses, calculus and tooth loss corresponds with the stable carbon and nitrogen isotopic data derived from bone collagen, which indicate no significant sex differences in the consumption of dietary protein. In contrast, these findings conflict with the ancient literary texts, which refer to distinct dietary differences between males and females, and with the stable carbon isotopic values derived from bone carbonate, which indicate sex differences with respect to the overall diet. Despite the lack of marked sex differences in dental pathology, overall trends point to subtle dietary differences between males and females. A greater degree of tooth wear in males also hints at possible sex differences in the use of the teeth as tools. Copyright © 2007 John Wiley & Sons, Ltd.     

Reliability of the Assessment of Periodontal Disease in Historical Populations

Periodontal disease is the destruction of all portions of periodontium. However, only periodontitis, based on whether attachment loss has occurred, can be detected in archaeological material. Therefore, several methods have been used to assess the frequency of periodontitis in past populations. The main scope of this study is to determine whether diagnoses of periodontitis through various methods are consistent with diagnoses obtained using the radiographic method. The samples (35 individuals, 576 teeth) were selected from Radom Cemetery's collection (in use between 1790 and 1811). For each individual, a periodontal status assessment was made using the following parameters: (i) measuring the distance between the cement–enamel junction (CEJ) and the crest of the alveolar bone (AC); (ii) the degree of root exposure; (iii) presence of the inter‐dental septum; (iv) dental calculus; (v) scoring system on the texture of the alveolar bone (Kerr's method) and (vi) radiography. In the studies, a correlation was found between the radiographic images and Kerr's method (r = 0.92) and root furcation (r = 0.96). Increasing degree of change on the alveolar bone is connected with increases in the CEJ–AC distance. A relationship between the frequency of the prevalence of dental calculus and changes on the alveolar bone was found. It means that the radiographic method, which is not always possible to use in archaeological collections, can be replaced by the presented macroscopic methods. Copyright © 2016 John Wiley & Sons, Ltd.     

Stable carbon and nitrogen isotopes of human dental calculus: a potentially new non-destructive proxy for paleodietary analysis

Fifty-eight dental calculus samples from medieval and post-medieval skeletons from Vitoria, Spain, and a single sample from an Alaskan Inuit were tested for stable carbon and nitrogen isotope compositions. There was sufficient carbon and nitrogen concentrations to obtain δ¹³C and δ¹⁵N values, and the samples from Spain produced results that were replicable and comparable to European isotope values based on bone collagen collected from literature sources. The Alaskan Inuit calculus sample yielded a δ¹⁵N value of +17.5‰, well beyond the range of the Spanish samples, but consistent with literature data for modern Greenlandic Inuit consuming a diet rich in marine food. There are several potential sources for carbon and nitrogen in calculus. The results of this study yield stable isotope values consistent with those obtained from other biomaterials used as isotope proxies for paleodietary research, including bone collagen, hair, and fingernails, although further work is necessary to verify the fidelity of calculus as an isotope proxy. Many studies in bioarchaeology are precluded by curatorial concerns regarding the destructive analysis of primary biomaterials. However, calculus is an “add-on”, or secondary biomaterial, that is not an integral part of the dental or skeletal system. Hence, its consumption during analysis is technically not destructive. Therefore, isotope analysis of dental calculus may provide a potential new avenue for paleodietary analysis where the use of other primary biomaterials is precluded.     

Diet and the aetiology of dental calculus

The aetiology of dental calculus formation is not fully understood, but it is known that a number of factors play a role. Generally, anthropologists have overlooked the role of other causative factors in the formation of dental calculus, attributing it almost exclusively to diet, particularly protein consumption. Anthropologists have also oversimplified the role of diet in the formation of dental calculus. This may be due to a general paucity on research on dietary effects on calculus formation, as well as a lack of integration between anthropological and non‐anthropological data. Copyright © 1999 John Wiley & Sons, Ltd.     

Synchrotron radiation microprobe analysis of human dental calculi from an archaeological site: A new possible perspective in palaeonutrition studies

The X-ray microprobe at beamline X-26 of the National Synchrotron Light Source (Brookhaven National Laboratory) has been used to determine minor and trace elements in small fragments of dental calculus. This material was removed from 11 individuals found in the Norman necropolis discovered recently under the church of San Lorenzo di Aversa (Caserta, southern Italy, ca. AD 900–1200). The aim of these experiments is to develop new methods for non-destructive analysis of organic archaeological materials in studies of palaeonutrition and palaeopathology. These preliminary analyses show little variability in the main trace elements of dietary significance, such as Sr and Zn.     

Chemical Analysis of Starch‐Like Mineral Crystals to Eliminate Misidentification in Ancient Residue Research

To clarify issues involved in problematic identification of ancient starch granules, we investigated suspected granules found in residues from a Neolithic grinding stone in north‐east China. The chemical compositions of suspected granules and modern starch granules were tested via SEM–EDS. The results show that the elemental composition of the suspected granules mainly comprises O, S and Ca, which is similar to the composition of calcium sulphate, but quite different from that of real starch granules, which show high levels of C and O, with very low level of other elements. The findings in this study act as a warning that tiny mineral granules may be misidentified as starch, and also indicate that the method of SEM–EDS can be useful to confirm the nature of suspected granules in ancient starch analysis.     

Plant microfossils in human dental calculus from Nemrik 9, a Pre-Pottery Neolithic site in Northern Iraq

Samples of dental calculus were taken from 11 human individuals buried at Nemrik 9, a Pre-Pottery Neolithic site in Northern Iraq. All of them represented the time span of ca. 9100–8600 bp. In total, 95 microfossils were retrieved from these samples, including 70 phytoliths, 9 starch granules or clusters of starch, 3 pollens, and 1 xylem fragment. Most microfossils could be attributed to C₃ cool season cereals, most likely wheat and barley, which is consistent with previous knowledge about the composition of crops in early farming communities living in the Fertile Crescent. In addition, three phytoliths and one starch granule typical of C₄ warm season grasses were recovered including one subangular and faceted starch granule, which might derive from a native grass, but is not diagnostic of any genus. Prior to assigning diagnostic status to this starch, exhaustive reference work on native grass seeds is necessary. The presence of one Phragmites phytolith suggests non-alimentary processing of reeds using teeth or perhaps using the stem of this grass as a toothbrush or toothpick.     

Tooth wear in two ancient populations of the Khazar Kaganat region in the Ukraine

Tooth wear is a common phenomenon in archaeological material. It has been related to the abrasiveness of diet and to the tribological attrition of teeth of individuals. Numerous investigations have been carried out in north and middle American samples as well as African anthropological material. Not much is known about tooth wear in European cultures. Eleven skulls from Chervona Gusarovka, and 14 skulls from the Upper Saltov sites of the Khazar Kaganat region (8th–10th centuries AD) in eastern Ukraine, with different diets were examined. A total of 208 teeth were studied for tooth wear, caries prevalence and periodontal status. Abrasion grades were determined according to a standardised classification and statistically evaluated. Periodontal status was measured using the distance between the enamel‐cementum junction and alveolar crest and the gingival attachment level respectively. Tooth wear was significantly different (P < 0.01) between the two populations. A low caries prevalence of 4.2% in the Chervona Gusarovka population and 1.7% in the Upper Saltov population was found. Significantly more alveolar crest bone resorption on the lingual side was found in the premolars and anterior teeth of the Chervona Gusarovka population. No significant differences were found regarding gingival attachment levels and gingival recession. It is concluded that the content and mode of food preparation influenced tooth wear, as reflected by the prevalence of dental caries and periodontal diseases in these ancient populations. Copyright © 2006 John Wiley & Sons, Ltd.