Refining the Quadratic Crown Height Method of age estimation: do elk teeth wear quadratically with age?

Teeth are the basis for the best methods for estimating the age-at-death of archaeological and paleontological faunal remains, because they change by eruption and wear throughout an individual's life and because they preserve well. However, age-at-death can be difficult to estimate when teeth are isolated or when no known-age reference sample is available. For these reasons, researchers developed the Quadratic Crown Height Method (QCHM), a set of quadratic formulae that can be used to predict age-at-death from tooth crown height, when unworn crown height and the ages when the tooth erupts and when its crown height should reach zero can be estimated. Previous tests of the QCHM suggest that modified equations could improve the method. Here, we use crown height measurements on a sample of 226 known-age Rocky Mountain elk (Cervus elaphus) to perform such modifications. We adjust the age at which each tooth type's crown height reaches zero from the species' potential ecological longevity or average maximum life span to an age that we empirically estimate for each tooth type. We also empirically assess whether for different elk teeth the exponent in the QCHM formula is actually equal to 2; it is for M1, but for P4 it is about 1, indicating a roughly linear relationship. The exponents for M2 and M3 are intermediate, being closer to 1.5. Because different teeth wear at different rates and wear completely away at different ages, we recommend that researchers use the modified equations provided here to estimate age-at-death for samples of Cervus elaphus.     

Molar crown height: not always a reliable method for the evaluation of age-at-death

In this study, we tested the validity of molar crown height, which changes according to the degree of tooth wear, for the evaluation of age-at-death. The sample consisted of 372 first and second molars (lower and upper) from 157 individuals of known sex and age-at-death. For each molar, we measured the height of the two cusps most subjected to wear (protocone and hypocone for the upper M1 and M2; protoconid and hypoconid for the lower M1 and M2). The correlation between crown height and age-at-death was assessed by linear regression analysis. The resulting models were not very robust since a significant correlation was only found for a small part of the sample, at best (maxillary M1) around 35%. The result slightly improved when bucco-lingual diameter (BL diameter), ante-mortem tooth loss and dental caries were considered, mainly for the maxillary M2 for which the model using age-at-death and BL diameter as independent variables explained 47% of the sample (p < 0.001).     

The use of dental crown heights for constructing age profiles of red deer and similar species in archaeological samples

The analysis of dental crown heights in a sample of known-age American Red deer (known in America as “elk”) has permitted the derivation of formulae for the prediction of age from crown height. The ages predicted from crown heights closely approximate true ages, when both predicted and true ages are grouped into broad, but still useful age classes. At least for the Red deer or “elk” dP₄, M₂ and M₃, age prediction formulae very similar to the empirically derived ones may be constructed by making certain hypothetical assumptions about the nature and rate of crown attrition. This suggests that these assumptions may be used to construct age prediction formulae in situations where an empirical relationship between age and crown height has not been or cannot be established. With certain provisos noted in the text, the age prediction formulae that result will probably provide reasonably reliable age profiles for the numerous ungulate species whose teeth are similar in structure to those of Red deer or “elk” and at least as hypsodont.     

Absolute age and tooth eruption and wear sequences in sheep and goat: determining age-at-death in zooarchaeology using a modern control sample

This paper seeks to improve our understanding of the relationship between mandibular tooth eruption and wear sequences and absolute age in modern sheep and goat. While the relationship between tooth eruption and wear and absolute age has been investigated for primitive breeds in parts of the Old World, our pilot study extends the applicability of this research to modern breeds and to another geographic region (North America). A modern control sample of two species of domestic caprines – Ovis aries (sheep) and Capra hircus (goats) from Manitoba, Canada – are used to evaluate the two major systems for analyzing mandibular tooth wear and eruption (Payne and Grant) and for assigning an absolute age-at-death. In order to compare the two systems, an absolute age for Grant's Mandibular Wear Stages was established for the first time, previously demonstrated only for Payne's system. The analysis confirmed that there is a very high correlation between the known age and estimated age based on tooth eruption and wear. However, Payne's system generated far coarser age-at-death profiles, which lowers its utility in constructing harvest profiles. Grant's system is recommended for ageing be utilized since it can yield more sensitive age estimations. In conclusion, it is possible to utilize the modern caprine breeds to establish the relationship between tooth eruption and wear and absolute age to reconstruct age and season of death of archaeological samples.     

Stature estimation in a central Patagonian prehispanic population: development of new models considering specific body proportions

Stature estimation of individuals from extinct human populations is a classic topic in anthropology. The estimations, using regression formulae generated from different reference samples, display different results. This fact is related to inter‐populational differences in body proportions, which is a phenotypic trait mainly correlated with climatic parameters. The aim of this paper is to address the problem of stature estimation of an archaeological skeletal sample from Patagonia – a region for which there are no specific models available – using different methods and considering differences in body proportions between reference and target populations. The sample used in this analysis is composed of 35 Late Holocene adults of both sexes recovered in central Patagonia (Argentina). The stature of each individual was first reconstructed using the anatomical method [Fully G. 1956 . Une nouvelle me´thode de de´termination de la taille. Annales Medicine Legale 35 : 266–273], which has no assumptions on body proportions. The results were compared with estimations based on 32 different regression formulae [Trotter M, Gleser G. 1958. A re‐evaluation of estimation of stature based on measurements taken during life and the long bones after death. American Journal of Physical Anthropology 16 : 79–124. 10.1002/ajpa.1330160106] and three femur/stature ratios [Feldesman MR, Fountain RL. 1996. Race specificity and the femur/stature ratio. American Journal of Physical Anthropology 100 : 207–224. 10.1002/(SICI)1096‐8644(199606)]. The average reconstructed stature was 160.8 cm for females (95% confidence band = 155.6–166.2 cm), and 170.5 cm for males (95% confidence band = 168.8–172.2 cm). Most of the comparisons of the regression formulae and femur/stature ratios showed significant differences, which are explained by differences in body proportions between the Patagonian sample and the ones chosen as reference. Finally, a set of new equations was developed using simple regression techniques. It is suggested that whenever possible, population‐specific formulae should be used in archaeological studies. In any other situation, the choice of a reference population should be made by taking into account its geographic (latitudinal) provenance. Copyright © 2009 John Wiley & Sons, Ltd.     

Sex estimation using cervical dental measurements in an archaeological population from Iran

Sex estimation of skeletal remains is one of the major components of forensic identification of unknown individuals. Teeth are a potential source of information on sex and are often recovered in archaeological or forensic contexts due to their post-mortem longevity. Currently, there is limited data on dental sexual dimorphism of archaeological populations from Iran. This paper represents the first study to provide a dental sex estimation method for Iron Age populations. The current study was conducted on the skeletal remains of 143 adults from two Iron Age populations in close temporal and geographic proximity in the Solduz Valley (West Azerbaijan Province of Iran). Mesiodistal and buccolingual cervical measurements of 1334 maxillary and mandibular teeth were used to investigate the degree of sexual dimorphism in permanent dentition and to assess their applicability in sex estimation. Data was analysed using discriminant function analysis (SPSS 23), and posterior probabilities were calculated for all produced formulae. The results showed that incisors and canines were the most sexually dimorphic teeth, providing percentages of correct sex classification between 86.4 and 100 % depending on the measurement used. The combination of canines and other teeth improved significantly the level of correct sex classification. The highest percentages of sex classification were obtained by the combination of canines and incisors (100 %) and canines and molars (92.3 %). The present study provided the first reference standards for sex estimation using odontometric data in an Iranian archaeological population. Cervical measurements were found to be of value for sex assessment, and the method presented here can be a useful tool for establishing accurate demographic data from skeletal remains of the Iron Age from Iran.     

A dental study comparing age estimations of the human remains from the Swedish warship Vasa

The great Swedish warship Vasa capsized and sank in Stockholm harbour on her maiden voyage in 1628. The ship was raised from the seabed in 1961 and skeletal remains were recovered from at least 25 individuals, with teeth and jaws from 17 of them. The skeletal material was odontologically examined, including dental radiographs. Teeth lost both ante‐mortem and post‐mortem were recorded and variations in tooth anatomy noted. Acquired changes were recorded including enamel hypoplasia, attrition, dental caries and periodontal recession. Age estimations based on a separate odontological study, osteological changes and tooth attrition had been made in 1989. Ages were estimated additionally by three non‐destructive dental methods based on (a) the length of the apical translucent zone, (b) selected measurements both on intact teeth and from ratios on dental radiographs and (c) ratios of the length and width measurements on dental radiographs from selected teeth. Several sources of post‐mortem changes had been observed, among them vivianite in 33 teeth from four individuals. The results of the dental examination showed that few teeth had been lost ante‐mortem, there was a low caries rate and little loss of periodontal attachments. With few exceptions, there is fairly good agreement between the different methods of estimating age. Age estimates based on dental attrition were, however, significantly different from the other dental methods and age estimates calculated from apical translucency ought to be regarded with scepticism due to post‐mortem changes. The chronological ages of the victims will never be known, but age estimates based on all the age‐markers available will probably reach a fairly close approximation. Copyright © 1999 John Wiley & Sons, Ltd.     

Assessment of the Season of Death of Ancient Human from Cementum Annual Layers

Ground sections of the teeth of five humans from the burial grounds of Bronze Age Kalmykia (Russia) were studied. In the teeth of an old man and a child we found no cementum layers. In three other individuals (15–30 years old), analysis of the cementum layers allowed us to estimate age-at-death and season of death. The estimated seasons of death coincided with the seasons of the burials assessed using other methods. This investigation revealed the possibility of assessing the season of death of ancient humans less than 30 years old with permanent dentition, when several teeth in alveoli from the same specimen are available.     

Application of non-adult Bayesian dental age assessment methods to skeletal remains: the Spitalfields collection

The aim of this study was to test with non-adult skeletons the quality of a recently published dental age assessment method based on Bayes' theorem. The test sample consisted of dental X-rays from 16 individuals (range 2.6–15.1 years) recovered from the crypt of Christ Church, Spitalfields, London, for which age-at-death and sex were known. The training sample consisted of dental X-rays from 1346 girls and 1040 boys (range 1.9–16.0 years). Bayesian dental age assessment method was alternatively used with dependent and independent assumptions; the dependent Bayesian method (DBM) and independent Bayesian method (IBM), respectively. Moreover, both DBM and IBM were used alternatively with sex-specific standards and with non-sex-specific standard. Due to the training sample age distribution, both methods are efficient between 5.0 and 14.0 years. Whatever the method or the sex standard used, when dental age was different from chronological age, the discrepancy did not exceed one age group of one year. DBM produced tighter dental age 100% confidence intervals than IBM for the majority of assessments. The observed stability between results produced according to the type of sex standard used (i.e. sex-specific or non-sex-specific), and the number of teeth studied (range 4–7), is worthy of note for both archaeological and forensic contexts.     

The demographic,socio‐economic and temporal contextualisation of the Universitat Autònoma de Barcelona collection of identified human skeletons (UAB collection)

Identified human skeletal collections are those in which basic demographic data (sex, age and biological origin) are known and are crucial for developing and testing osteological methodologies. It is important that the identified collection be contextualised, and in this way the collection will be considered a reference collection. To contextualise a collection requires documentation of the basic demographic data of the individuals (sex, age, year of birth, geographical area) as well as information concerning the socio‐economic and temporal context in which the individuals lived. The contextualisation of an identified collection is very important so the researchers can understand the ‘point of reference’ when applying a method to it or developing a new method. The purpose of this study is to contextualise the identified skeletal collection of the Universitat Autónoma de Barcelona (UAB) which currently contains 35 adult skeletons of both sexes. To carry out the objectives of the present study, the information about the individuals was collected from cemetery registers and compared with the information of the demographic and statistic public institutions of Spain. The results indicate that the UAB collection is formed only by Spanish nationals who mainly lived during the 20th century in Granollers (Barcelona, Spain). Both sexes are equally represented and all of the individuals are adults. They reflect the most current adult population structure of Catalonia and be treated as a Catalan reference sample of adults living in the 20th century. This collection offers special opportunities for demographic analysis, including validation studies of skeletal ageing and sexing methods that target adult individuals. The collection can also be used in conjunction with other reference samples to investigate secular and populational change in cranial form, sexual dimorphism and stature. Copyright © 2010 John Wiley & Sons, Ltd.     

A novel method for integrated age and sex determination from archaeological cattle mandibles

Analysis of ancient cattle husbandry is compromised by the need for conventional analysis of sex and age at death to use different elements of the skeleton, usually from different individuals. We demonstrate a technique using aDNA acquired from cattle mandibles and combined with age-at-death estimation based on dental eruption in the same specimens. Application to small sample groups from two sites in Na h-Eileanan Siar (the Scottish Western Isles) show a high success rate, and demonstrates the potential for a more nuanced interpretation of ancient cattle husbandry.     

Evaluating human skeletal growth: An Anglo-Saxon example

Cross-sectional growth data were obtained from the skeletal remains of non-adults from the Raunds Anglo-Saxon site. Standard measurements of the diaphyseal lengths of the long bones of the upper and lower limbs and the maximum breadth of the ilium were recorded in order to construct skeletal growth profiles (SGP). In addition regression equations were used to estimate diaphyseal length from proximal and distal shaft widths, and epiphyseal breadth data for fragmentary remains. The skeletal measurements were then plotted against age estimates determined by the dental formation standards of Moorrees, Fanning and Hunt, and Anderson, Thompson and Popovich. The growth data were compared with sixth to seventh century German, ninth century Slavic and modern Caucasian data. With the exception of the ancient Slavic material, the Anglo-Saxon remains demonstrated the smallest rates of growth. Diaphyseal ageing curves derived from the Anglo-Saxon sample were tested for applicability on the non-adult cohorts of the Berinsfield and Exeter Anglo-Saxon/Early Medieval samples. Differences were observed between diaphyseal age as determined from the skeletal growth profiles for Raunds and calcification age assessed for individuals within the test samples. It is proposed that variation in long bone growth as well as dental age confounds consistent and reliable ageing of skeletal remains based on diaphyseal length. Assessment of changes in health and evaluation of methodological problems inherent to studies of skeletal growth from archaeological populations are discussed. Population comparisons for changes in general health are recommended over individual assessments.     

Sample-specific (universal) metric approaches for determining the sex of immature human skeletal remains using permanent tooth dimensions

In this paper, three approaches for developing sample-specific sex determination methods of immature skeletal remains based on permanent tooth dimensions are proposed and tested using a sample of identified skeletons. The sample comprises adult and subadult individuals selected from the Lisbon documented skeletal collection, housed at the National Museum of Natural History in Lisbon, Portugal. Faciolingual and mesiodistal diameters were the tooth dimensions utilized. In the first approach, sex-specific logistic regression formulae based on adult tooth dimensions are developed and then used to determine the sex of the subadult sample. The second and third approaches are based on the sectioning point procedure, which uses the overall mean of a measurement (tooth diameter) collected from the sample as the discriminant criteria for determining the sex of the individuals in that sample. While in the second approach the adult overall mean of each dimension is used as the discriminant criteria for determining the sex of the subadults, in the third approach it is the subadult overall mean of each dimension that comprises the discriminant criteria that is applied back to the subadults for determining sex. Results show that the canines are the teeth with the highest sexual dimorphism and methods of sex determination based on canine dimensions provide correct allocation accuracies between 58.8% and 100% depending on the diameter and the approach that is being used. Canine faciolingual dimensions provide the best overall results. Combinations of measurements from the same and different teeth do not increase significantly the accuracy of the methods and approaches. Some of the problems of subadult sex determination methods based on adult tooth dimensions result from differing levels of sexual dimorphism between the adult and subadult segment of the sample. Mortality or cultural bias may increase or decrease the sexual dimorphism of the subadults compared to the adults. Small subadult samples utilized in this study may also raise questions regarding the accuracy of the three different sample-specific approaches. However, high consistency of results using the canine and different approaches, suggests that adult and subadult canine dimensions can be reliable sex discriminators of immature skeletal remains in archaeological samples. The major advantage of the approaches presented here is that they can be used to derive sample-specific methods and, therefore, eliminate the problem of applying morphological or metric methods to individuals originating from a population that differs from the one that contributed to the development of the method.     

On the accuracy of estimating living stature from skeletal length in the grave and by linear regression

This study evaluates a method for obtaining stature estimates for populations represented by skeletal material, with individuals buried in a supine position. During the excavation of a Danish mediaeval cemetery, in situ skeletal length in the grave was measured from a point above the cranial point farthest from the body to the most distal point of the talus. The measurement was made with a folding rule placed on the sagittal midline of the skeleton, allowed to follow any curvature of the skeleton in situ. In the laboratory, stature was reconstructed anatomically, and this stature was regarded as an accurate estimate of living stature. Stature was also reconstructed from femur length by two linear regression procedures: 1) by sample and sex specific formulae, employing a leave‐one‐out approach, and 2) by sex wise formulae for Euro‐Americans from Trotter & Gleser (1952, American Journal of Physical Anthropology 10 : 463–514). Skeletal length in the grave and the two stature estimates based on linear regression were compared to anatomically reconstructed stature. Skeletal length in the grave estimated anatomically reconstructed stature with practically no bias (95% CI: −1.3–1.5 cm). Sample specific regression formulae estimated anatomically reconstructed stature also with no bias (95% CI: −1.2–1.1 cm). In contrast, statures calculated from Trotter & Gleser's regression formulae estimated anatomically reconstructed stature with a bias of about 4 cm (95% CI: 3.3–5.0 cm). Estimates of stature variance were biased for all three estimation procedures. However, for samples of adults, an adjusted variance estimate can be obtained by subtracting 8.7 cm² from the variance obtained from skeletal lengths in the grave. It is recommended to measure skeletal length in the grave whenever possible, and use this measurement for estimating statures for prehistoric and early historic populations. Copyright © 2005 John Wiley & Sons, Ltd.     

The periodontal disease status of the historical population of Assos

The science of anthropology obtains data on health, disease and death from ancient populations. Research on the skeletal remains of human teeth and surrounding tissues provides useful information on the evolutionary perspective of dental and periodontal diseases. The aim of this study was to determine the prevalence and severity of periodontal diseases in the skeletal remains of 33 Assos inhabitants of the 4th century BC. Three age groups were constituted for the studied population. Periodontal disease status was determined based on the textural and architectural variations of the interdental septum and the extent of bone loss. It was found that the prevalence of periodontal diseases increased with age. The severity of periodontal bone loss also increased with age and the mean alveolar bone loss between age groups was statistically significant (P = 0.004). This analysis of the dental health of ancient populations provides insights into the aetiology, patterns and distribution of periodontitis, which has a very complex disease pathogenesis. Copyright © 2005 John Wiley & Sons, Ltd.     

Maxillary Sinus Infection in a 19th‐Century Almshouse Skeletal Sample

In 1984, the Monroe County Parks Department in the Highland Park section of Rochester, New York, accidentally unearthed part of an unmarked cemetery while landscaping. The cemetery was in use from approximately 1826 to 1863 and was associated with the Monroe County Almshouse. Anthropological examination of dental and skeletal pathology revealed a high incidence of dental infection, known to occasionally be a causal agent of maxillary sinus infection. Therefore, maxillary sinus infections in this sample were studied to ascertain their relationship with dental infections, sex, and age at death. The maxillary sinuses of 99 skeletons were examined for evidence of infection. The presence, location, type and extent of dental infections in the posterior teeth were also recorded. Half the sample exhibited bone remodelling in the maxillary sinus (54 individuals). Dental infections were observed in 82 individuals. Forty‐eight demonstrated signs of dental infection and maxillary sinusitis. Statistical analysis revealed that dental infection and maxillary sinus infection were not statistically related. Rather, a rhinogenic method of infection seems likely, which would appear related to the squalid air quality the 19th‐century poor were exposed to in the almshouse and city tenements. Copyright © 2016 John Wiley & Sons, Ltd.     

Comments on the chronology of the younger stone age in Varanger,North Norway

Age determination at death of skeletal remains can prove difficult. The teeth are often well preserved and could present the only means for an age evaluation. Based on the closure of skull sutures and dental attrition, the age of a Stone Age man was judged to be about 60 years when he succumbed. This has now been verified by means of measuring the extent of root dentin transparency. The importance of teamwork in difficult cases regarding assessment of age in skeletal remains is pointed out.     

Rickets and child abuse: the case of a two year old girl from the 4th century in Lisieux (Normandy)

The burial of a child of two years of age from the 4^th century site of Lisieux‐Michelet (Calvados, France) was examined for bone hyperplasia and a variety of mechanical deformations recognized in association with skeletal trauma. Results of DNA analysis of bone using the PCR method identified this child as female. Microscopic features of the teeth (interglobular dentine) and a sample taken from the tibia conclusively determined that this child suffered from vitamin D‐resistant rickets and possibly X‐linked hypophosphataemic rickets as its most common form of occurrence. In addition, evidence for child abuse is suspected based on the presence of cranial and tooth fractures and the appearance of successive plaque‐like endocranial (meningeal) appositions. This is the first palaeopathological report of child abuse in antiquity. Copyright © 2002 John Wiley & Sons, Ltd.