Protocol for Recording Enamel Hypoplasia in Modern and Archaeological Caprine Populations

This paper outlines the first methodology for recording dental enamel hypoplasia in the high‐crowned dentition of modern and archaeological caprine teeth. The method has been developed and trialed on five caprine populations from Orkney (UK); two modern populations (Shetland and North Ronaldsay breeds) and three Neolithic assemblages from the archaeological sites of Knap of Howar, Skara Brae and Holm of Papa Westray. Problems associated with differential tooth wear, as well as the presence of coronal cementum, are discussed, and recommendations are given on the identification and recording of hypoplastic dental defects in caprines. Copyright © 2012 John Wiley & Sons, Ltd.     

Turner Teeth and childhood caries in a protohistoric California Indian population

Three instances of unusual enamel defects are reported from a late prehistoric and protohistoric non-agricultural California Indian population. The defects, consisting of irregular absence of enamel over much of the crown of single premolars, with no corresponding hypoplastic defects in the remainder of the dentition, are typical of Turner teeth. Such defects are a consequence of pulp exposure from severe caries infections in the primary dentition. Their presence is suggestive of unusually high levels of childhood caries experience for a non-agricultural population, a suggestion borne out by examination of the deciduous dentitions.     

A protocol for recording linear enamel hypoplasia on archaeological pig teeth

A method is proposed for recording linear enamel hypoplasia (LEH) present on archaeological pig teeth. The methods described have been developed and tested on material from five archaeological sites of a wide range of periods; Durrington Walls (UK), Wellin, Ename, Sugny and Londerzeel (Belgium). Recommendations are made on what teeth, surface, cusp, and side to record, as well as on details of the visibility, the identification and the measurement of LEH lines. Problems encountered with the application of the recording protocol to the five case studies are detailed, and possible interpretative drawbacks are discussed. © 1998 John Wiley & Sons, Ltd.     

Comparing the Chronological Distribution of Enamel Hypoplasia in Rogowo,Poland (2nd century ad) Using Two Methods of Defect Timing Estimation

The frequency and chronological distribution of enamel hypoplasias were assessed in a Roman Period population of the Wielbark culture from Rogowo, northern Poland, dated to the 2nd century ad . Hypoplasias were recorded on permanent incisors, canines, and premolars of 52 skeletons. The position of linear defects on the crown surface was measured and then converted to the age of occurrence using two methods: a conventional method that employs the chart of enamel development for the permanent teeth, constructed by Massler et al. (1941) in Swärdstedt's (1966) modification, and the method by Goodman & Song (1999), which corrects for hidden cuspal enamel. Hypoplastic defects were found in 48.1% of examined cases. Linear defects [linear enamel hypoplasias (LEH)] were observed in 38.5% of individuals and in 22% of investigated teeth. The chronological distribution of LEH according to the conventional method revealed two peaks of defects: one at 2.6–3.0 years of age and the other at 4.1–4.5 years of age. The method that accounts for hidden cuspal enamel also provided two peaks, but they occurred at later ages: 3.0–4.0 and 4.6–5.0 years of age. The prevalence of hypoplasia in the Rogowo population in comparison with other European populations of the Roman Period seems to be rather low for both individuals and teeth affected. This may indicate advantageous living conditions, which are supported by archaeological data that suggest general well‐being of the Wielbark people. Copyright © 2011 John Wiley & Sons, Ltd.     

Identification of metal residues associated with bit-use on prehistoric horse teeth by scanning electron microscopy with energy dispersive X-ray microanalysis

Our ability to identify evidence of the use of horses for transportation from archaeozoological remains is important for improving our understanding of the role of horses in socioeconomic changes throughout prehistory. When a horse is used with a bit, the bit can come into contact with the anterior (‘front’) surface of the lower second premolar (P₂). Here, results of X-ray microanalysis, undertaken in a variable pressure scanning electron microscope, of chemical elements on the anterior surface of four archaeological horse P₂ are presented. Analysis of dental materials (enamel and cementum) returned expected results, with calcium, phosphorous and oxygen dominating. Iron-rich residues are also identified on the front of two of the teeth, which are interpreted here as deriving from contact with iron bits. It is proposed that such analyses may provide a useful additional method for identifying bitting damage in archaeological horses or corroborating interpretations made from macroscopic examinations.     

The Use of Small‐Angle X‐Ray Diffraction Studies for the Analysis of Structural Features in Archaeological Samples

X‐ray diffraction or scattering analysis provides a powerful non‐destructive technique capable of providing important information about the state of archaeological samples in the nanometer length scale. Small‐angle diffraction facilities are usually found at synchrotron sources, although the potential of a laboratory source is also described. Specific examples of analysis using X‐ray diffraction of historic parchment, archaeological bone, a Central Mexico style pictograph and microdiffraction of calcified tissues are used to show the scope and versatility of the technique. Diffraction data is capable of giving fundamental structural information as well as quantifying the remodelling of structures influenced by environmental factors.     

Problems and pitfalls in the diagnosis of linear enamel hypoplasia in cheek teeth of cattle

Prevalence and intensity of enamel hypoplasia have been used as markers of generalized physiological stress during dental development in a wide range of mammalian taxa. We studied cattle (Bos taurus) cheek teeth exhibiting morphological characteristics that are of relevance to the diagnosis of enamel hypoplasia in this and other bovid species. These characteristics were multiple, more or less horizontally arranged (waveform) lines or grooves in the cementum of the tooth crown and the adjacent root area, leading to an imbricated appearance of the cementum. On macroscopic examination of tooth surfaces, these lines resembled linear enamel hypoplasia (LEH). Microscopic analysis of tooth sections, however, revealed that the lines occurred in the cementum only, and that the underlying enamel did not exhibit morphological irregularities. In cheek teeth of older cattle, a thick cementum layer is regularly found in the cervical crown portion and the adjacent root area. Apposition of this cementum is related to the uplifting of the teeth from their alveoli, a process that compensates for the shortening of the tooth crowns due to occlusal wear. In the studied specimens, a pronounced periodic nature of tooth uplifting and the related deposition of cementum is the likely cause for the observed imbricated appearance of the cementum. While this phenomenon may be misinterpreted as representing a case of LEH, presence of enamel hypoplasia in bovid teeth may be overlooked when the defects become filled with coronal cementum and are therefore not apparent on external inspection. This was the case in one of the cattle teeth analyzed by us, in which the hypoplastic enamel defects were, however, clearly discernible in ground sections. Microscopic analysis of tooth sections is recommended for recording of LEH in bovid teeth in cases where macroscopic examination of tooth surfaces alone does not produce unequivocal results.     

X射线显微CT成像技术在金属文物制作工艺研究与腐蚀状态评估中的应用

金属腐蚀过程不仅受环境等外部因素的影响,制作工艺、合金组成及缺陷等内部因素同样起着重要作用。为实现金属文物制作工艺和内部腐蚀状态的可视化研究,运用X射线显微CT对铜镜文物碎片以及出土、海洋出水铁质文物样品进行扫描探测,并结合X射线荧光、X射线衍射等检测手段,开展金属文物材质、工艺及矿化程度的综合分析。结果表明,在显微CT影像重建基础上,通过设定不同的阈值,可实现文物内部缺陷、腐蚀矿化程度等内部信息的测量统计。该方法可为金属文物材质、制作工艺研究和腐蚀状态评估提供无损的研究手段。     

Micro‐CT Imaging and Analysis of Enamel Defects on the Early Late Pleistocene Xujiayao Juvenile

Dental pathologies and enamel defects in East Asian hominins have rarely been reported. Here, we systematically document and describe a suite of enamel defects in the Xujiayao juvenile maxilla, an East Asian hominin from the early Late Pleistocene that may represent an unknown hominin lineage. In addition, we determine the chronology of growth disruptions represented by matched linear enamel hypoplasias, evaluate the long‐held hypothesis that the large brownish pit on the I¹ is evidence of dental fluorosis and assess the utility of micro‐computed tomography (micro‐CT) techniques in analyzing enamel defects. With the use of binocular microscopy, scanning electron microscopy (SEM) and micro‐CT imaging techniques, the Xujiayao teeth were found to exhibit a high number of pit‐form defects seldom seen in the fossil record. By matching the timing of linear enamel hyperplasia across multiple teeth, a minimum of five developmental disruptions were identified, indicating that the Xujiayao juvenile experienced several growth disturbances during its short lifespan. Our SEM and micro‐CT analyses suggest that the large pit on the I¹ is an enamel hypoplasia due to its morphology and pre‐eruptive enamel thinning. It is not a post‐eruptive fluorotic pit, and there is no evidence of chalkiness or opacity associated with dental fluorosis. The micro‐CT technique made it possible to verify the presence of enamel hypoplasia and to more precisely quantify defect dimensions, especially in unerupted teeth and shallow hypoplasias that are difficult to detect by binocular microscopy or SEM. Copyright © 2015 John Wiley & Sons, Ltd.     

SYNCHROTRON FTIR MICRO‐SPECTROSCOPY APPLIED TO THE STUDY OF POLISHED SERPENTINITE ARTEFACTS: A NON‐DESTRUCTIVE ANALYTICAL APPROACH

In prehistory, serpentinite was one of the most frequently used raw materials to produce polished stone artefacts. Several conventional analytical techniques can be applied to identify the serpentine minerals, but their application generally requires a powdered sample. This implies that the artefacts to be analysed must be damaged, and the possibility of analysing a mixture of different serpentine polytypes is high. The use of spatially resolved techniques is therefore a necessity to overcome this problem. Several thin sections of serpentinitic rocks and prehistoric axes have been analysed by synchrotron radiation Fourier transform infrared micro‐spectroscopy. The spectra were acquired directly on specific points of polished stone artefacts and this allowed the recognition of the different polytypes of serpentine minerals without causing any damage to the objects. The results show the infrared micro‐spectroscopy technique to be a useful tool for the characterization of archaeological lithic material.     

Burnt bones and teeth: an experimental study of color,morphology, crystal structure and shrinkage

Burnt osteological materials are one focus of interest in forensic, archaeological, and palaeontological studies. We document the effects of experimental, controlled heating on a sample of modern bones and teeth from sheep and goats. Four aspects of heating specimens to between 20 and 940°C were considered: color, microscopic morphology, crystalline structure and shrinkage. Our results show that changes in both color and microscopic morphology of burnt bones and teeth can be divided into five stages each of which is typical of a particular temperature range, although the stages based on color do not correlate exactly with those based on micromorphology. These stages can be used to determine (1) if specimens of unknown taphonomic history were burnt, and (2) the maximum temperature reached by those specimens. In addition, powder X-ray diffraction studies show that heating causes an increase in the crystal size of hydroxyapatite, the major inorganic component of bones and teeth. This fact in conjunction with the microscopic morphology can be used to confirm deduced heating to 645°C or more. The data on shrinkage are analyzed to yield a polynomial expression that summarizes percentage shrinkage as a function of the maximum temperature reached by bones. Thus, the original size of specimens can be reconstructed within limits since the maximum temperature reached by the bones can be deduced on the basis of color, microscopic morphology and/or powder X-ray diffraction patterns. Finally, because there is a discrepancy between the maximum heating device temperature and the maximum specimen temperature, caution must be exercised in distinguishing between the effects of man made and natural fires.     

Element localization in archaeological bone using synchrotron radiation X-ray fluorescence: identification of biogenic uptake

Trace element analysis related to archaeological bone is viewed as one way to determine levels of element exposure in past populations. This area of research is complex because there is the potential for the incorporation of trace elements from the burial environment into archaeological bone. We tested the hypothesis that matching the spatial distribution of trace elements within cortical bone with the biological structures would provide evidence of biogenic uptake. We examined samples from a non-segregated Royal British Naval cemetery (1793–1822) in Antigua, West Indies. A key historical question related to this population was the extent of exposure to lead and the resulting health effects. Images from conventional light microscopy (histological) analysis of the bone samples were matched with elemental maps of calcium, strontium, and lead that were created through the use of synchrotron radiation X-ray fluorescence (SR-XRF). Biogenic uptake of both strontium and lead was indicated based on the localization of these trace elements within discreet microstructural elements. The successful integration of histological information with XRF data is a powerful technique for the interpretation of past biological events through trace elements.     

Dental evidence of biological affinity and environmental conditions in prehistoric Trentino (Italy) samples from the Neolithic to the Early Bronze Age

The use of teeth in anthropological analyses has always provided valuable information on the subsistence patterns of human communities, as well as the biological relationships among them. The present study analyses the permanent dentition of several diachronically continuing samples from the Trentino alpine region of Italy from the Neolithic to the Early Bronze Age. The study of both metric and non‐metric dental traits show a strong level of homogeneity from the earlier to the later samples, indicating little external biological influence from surrounding areas. However, the evidence of oral pathology and linear enamel hypoplasia highlights a trend of increase in defects, particularly between the Neolithic and the Copper Age. This has been ascribed to a shift towards more intense agricultural activities and pastoralism, that led to a change in diet and to an increased sedentism. Copyright © 1999 John Wiley & Sons, Ltd.     

Dental Modifications in a Skeletal Sample of Enslaved Africans Found at Lagos (Portugal)

An archaeological intervention in Valle da Gafaria (Lagos, Portugal) allowed the excavation of a deposit of waste dating from the 15^th to 17^th centuries. Among discarded objects, an important amount of human skeletal remains was exhumed (N = 158 individuals). The archaeological and historical context, as well as the morphometric analysis of the skulls, led us to attribute them an African origin. While historical sources document the trade of slaves by the Portuguese since the 15^th century, so far no slave cemetery was excavated in Portugal. The study of their lives and deaths has been accomplished by historical documents. Therefore, this sample provides a unique opportunity to learn more about captive individuals who were brought to Portugal in the modern period. The present work focuses in the intentional dental modifications presented by several of these individuals. A total of 113 subjects have teeth that can be evaluated for the presence of intentional modifications. Of these, 55.8% individuals present dental modifications on their anterior dentition, 42.9% exhibiting modifications on both upper and lower teeth. The incisors were the most frequently modified teeth, followed by the canines. Both men and women as adults and sub‐adults have dental intentional modifications. In most individuals, dental modifications involved the removal of the mesial and distal angles, which is comparable with sub‐Saharan African practices. However, we cannot infer a more specific origin for these slaves only based on dental modification's type and pattern because several ethnic groups modify teeth in the same way. Copyright © 2015 John Wiley & Sons, Ltd.     

The ESR geochronology and geology of the open‐air Palaeolithic deposits in Bollschweil,Germany*

This paper presents ESR (electron spin resonance) ages of rhinoceros and equine tooth enamel from the open‐air Palaeolithic site of Bollschweil on the western edge of the Black Forest near Freiburg, Germany. Bollschweil is one of very few archaeological sites in southern Germany to yield Lower or Middle Palaeolithic faunal and lithic materials from a buried, open‐air context. The geological context of the archaeological remains indicates that the loessic sediments have been reworked. Excavation at this site yielded a cold‐period fauna characterized by bones of mammoth, horse, large bovids and wooly rhinoceros. In the absence of any clear chronostratigraphic marker horizons, the age of the finds could not be determined without the use of a chronometric dating method. Lithic artefacts from the site, including a handaxe and a side scraper, suggest either a Middle Pleistocene or early Late Pleistocene age. The ESR dating results indicate that the deposit enclosing the archaeological finds should be assigned to oxygen isotope stage (OIS) 6, although there exists some possibility that some teeth were deposited later, in OIS 5.     

Recording dental caries in archaeological human remains

Dental caries is an important condition to record in archaeological collections, but the way in which recording is carried out has a large effect on the way in which the results can be interpreted. In living populations, dental caries is a disease that shows a strong relationship with age. Both the nature of carious lesions and their frequency change with successive age groups from childhood to elderly adulthood. There is also a progression in the particular teeth in the dentition which are most commonly affected and, in general, the molars and premolars are involved much more frequently than the canines and incisors. Lower teeth are usually affected more than upper, although the condition usually involves the right and left sides fairly equally. In the high tooth wear rate populations represented by many archaeological and museum collections, there is a complex relationship between the form of lesions and the state of wear, which adds yet another range of factors to the changing pattern of caries with increasing age. In the same populations, chipping, fracture and anomalous abrasion of teeth are also common, and these contribute similarly to the distribution and forms of carious lesion observed. Amongst the living, the pattern of ante‐mortem tooth loss is important in understanding caries and, in archaeological material, there is also the complicating factor of post‐mortem tooth loss. Finally, there is the question of diagnosis. There are diagnostic problems even in epidemiological studies of living patients and, for archaeological specimens, diagenetic change and the variable preservation of different parts of the dentition add further complications. For all these reasons, it is difficult to define any one general index of dental caries to represent the complete dentition of each individual, which would be universally suitable for studying a full range of collections from archaeological sites or museums. Variation in the nature of collections, their preservation, tooth wear, and ante‐mortem and post‐mortem tooth loss mean that when such a general index appears to differ between sites, there could be many other reasons for this, in addition to any genuine differences in caries incidence and pattern that might have been present. It is suggested here that the best approach is instead to make comparisons separately for each tooth type, age group, sex, lesion type and potential lesion site on the tooth. Copyright © 2001 John Wiley & Sons, Ltd.     

A Case of Early Childhood Caries from Late Roman Ancaster,England

This paper presents a differential diagnosis of pathological changes observed in the deciduous dentition of a child aged 3–4 years, recovered from a Late Roman (c. ad 270–410) cemetery at Ancaster, England. The entire maxillary dentition exhibited areas of missing enamel and erosion of the underlying dentine, which was most pronounced at the lingual surfaces of the anterior teeth, and lingual and occlusal surfaces of the molars. Additionally, the mandibular second molars and mandibular right first molar displayed superficial enamel erosion of the buccal surfaces. Radiography indicated normal enamel density, and no further dental pathology was identified. Conditions considered in a differential diagnosis included amelogenesis imperfecta, fluorosis, perimolysis, xerostomia‐related caries and early childhood caries (ECC). The nature and distribution of lesions implicates ECC – also known as ‘nursing caries’ or ‘baby‐bottle caries’ – as the most probable diagnosis. The potential significance of the findings for studies of infant health and feeding practices in past populations is discussed. Copyright © 2015 John Wiley & Sons, Ltd.     

Phosphatic mineralization of seeds from archaeological sites

Recent investigations of botanical material from archaeological sites have provided seeds and plant remains exhibiting a crystalline or semi-crystalline appearance. X-ray diffraction and partial chemical analysis have revealed that the particular plant materials had been replaced by calcium phosphate. Using systematic sampling and retrieval techniques a significant body of data has been accumulated. Most mineralized botanical evidence has been recovered from faecal deposits, in particular cess pits and garderobes, and has provided an important source of information about aspects of diet of past populations.