Evolving humanity, emerging worlds
Manchester, UK; 5th-10th August 2013
Health, ageing and life: recent knowledge revealed in dental anthropology
Location University Place 4.207
Date and Start Time 09 Aug, 2013 at 09:00
Teeth from archaeological sites give us diverse information on health, ageing and life in ancient peoples. This panel discusses recent topics in dental anthropology, especially those in paleoanthropology, dental morphology and primatology are welcomed.
Teeth are the hardest parts of a human body and retain traces of life for long time. Thus, they have been studied as an important organ in physical anthropology. This panel session, taking the subject of "teeth of mankind" as its key, offers various interesting topics unlocked from the subject. We welcome entries from a wide range of fields such as: Paleopathological areas which not only conduct differential diagnoses on diseases traced out from teeth of ancient human skeletons, but also make clear the relationships between dietary habits, social environments and sanitary conditions and diseases of ancient people; Dental morphology based on evolutional phylogenetic viewpoints, which analyses the characteristics observed in teeth from fossil hominids to modern humans with the use of dental crown measurements and non-metric scoring technique. In addition, we also welcome topics on teeth of primates as long as they are committed to human dental anthropology. Although teeth are very small organs, the information they imply is extremely large. By this panel session, we would like to offer an opportunity to present the latest topics on dental paleopathology, dental morphology and other relevant dental anthropological studies which contribute to elucidate the health, ageing and life of ancient and modern humans.
This panel is closed to new paper proposals.
Dental anthropological and clinical characters observed in teeth excavated from Ikenohata site Tokyo in the Edo era 1603-1866.
Teeth excavated from Ikenohata site in Tokyo were observed from anthropological and clinical point of view. The traces of “ohaguro” which was a custom of dyeing teeth black were found using energy dispersive X-ray spectrometry. Polished surfaces by “fusayouji” which was a toothpick widely used at that time were also found.
Skeletal materials including teeth excavated from Ikenohata archaeological site demonstrate evidences of dental care, oral habits and pathological condition prevailed in Edo, the former Japanese capital from 1603 to 1866. The traces of "ohaguro" which was a custom of dyeing teeth black and was difficult to be detected in the archaeological materials were found using energy dispersive X-ray spectrometry, because blackening solution contained dissolved iron in acetic acid. Tooth polishing sand began to be used by ordinary people in the Edo era, too. Polished surfaces by using "fusayouji" which was a specially designed toothpick with tooth brush at its end made of willow wood were also found in many teeth. The site was in the graveyard of a temple in down town Tokyo, in which mainly commoners were buried. The incidences of dental caries and enamel hypoplasia were also investigated, and the results were compared with other sites of the same period.
Periodontal disease observed on wild chimpanzee skulls collected in the Kalinzu Forest, Uganda
The Aims of this paper were to investigate morbidity rate of periodontal disease using museum collection of wild chimpanzee skulls, and to evaluate life history of wild great ape populations through oral and dental disease. Long-term research information on wild chimpanzees would give us some hint.
Two of four wild chimpanzee skulls with teeth loss caused by periodontal disease were collected in the Kalinzu Forest, Uganda. One individual was a relatively old female. She lost her lower left incisors. And most of her dentitions had dental caries. The other individual was a young male. He lost almost all molars except upper left third molar and two upper left premolars. The Kalinzu Forest is the place where long-term project of chimpanzee studies going on. Ecological information of chimpanzees in the Kalinzu Forest is available. According to museum collection of wild shoot chimpanzees, about 25% of them had teeth loss by periodontal disease whereas a morbidity rate of periodontal disease among gorilla was only 2%. Gorilla has very high frequency of dental trauma because their diet contains very tough food items like barks or bamboo shoots. Broken tooth with open pulp was main infection parts of dental caries. And it cause of tooth loss for gorilla. On the other hand chimpanzee has caries infection on interproximal surface, buccal surface of lower tooth, or lingual surface of upper tooth. Chimpanzee's caries pattern is very similar to prehistoric human populations. Diet of chimpanzee and prehistoric human populations contain many carbohydrates but diet of gorilla contains less carbohydrates. Sometimes chimpanzees lose many teeth and still they can survive after tooth loss.
Dental caries and periodontal disease in Jomon people in Japan
Jomon people of Japan had high caries rates, unparalleled by any other hunters and gathers in the world. The reasons are thought to be (1) their high-carbohydrate, plant-based diet and (2) rapid aging due to excessive physical stress. Thus, they developed periodontal disease in their early middle age, resulting in multiple root caries.
The Japanese Neolithic period lasted 10,000 years until the Jomon period ended 2700 years ago. My study determined that the caries rates in Jomon people were much higher than other hunters and gathers in the world. The high caries rates in the Jomon people were strongly dependent on high-starch, plant-based diet. In addition, they aged rapidly due to their difficult living environment, i.e., severe environmental stress. Their carious lesion did not develop on the occlusal surfaces where many carious lesions in modern people are located. Jomon people had marked attrition, causing flat occlusal surfaces. This condition was speculated to decrease susceptibility to occlusal caries. They developed periodontal disease in their early middle age, resulting in the exposure of roots to the oral environment. Roots are covered cementum which is softer than enamel. Thus, multiple root caries was thought to have occurred in the Jomon people. Root caries is a type of caries often seen in the modern elderly. The high rate of root caries suggests rapid aging in the Jomon people and that individuals in that society had a short life span.
Non-metric tooth crown traits in a contemporary and two Aboriginal populations in Sri Lanka: Comparison with other world populations
We investigated the frequencies of non-metric tooth crown traits in a contemporary and two aboriginal populations in Sri Lanka. 13 traits in 150 dental plaster casts were observed. All the populations showed “Indodont” dental pattern while Veddas showed a genetic drift from the modern Sri Lankans.
This study was conducted to determine the frequencies of non-metric tooth crown traits in a contemporary and two aboriginal Vedda populations (Dambana and Anuradhapura) in Sri Lanka and to investigate the affinities of these morphological variations with those of other world populations. Fifty dental plaster casts from each population were observed. The Arizona State University dental anthropology system was adopted for classification of the 13 traits observed. Affinities among the contemporary and two aboriginal populations of Sri Lanka and other world populations were expressed in two dimensions of the principle coordinate analysis. Cusp number in mandibular second molar and Hypocone absence in maxillary second molar had the highest frequency and Shoveling and Double Shoveling in the maxillary central incisor had the lowest frequency in all three populations. Contemporary Sri Lankans had higher occurrence of Cusp of Carabelli's in maxillary first molar and Deflecting wrinkle in mandibular first molar. Dambana Vedda had higher prevalence of Cusp 7 in mandibular first molar. Anuradhapura Vedda had lower prevalence of Y groove pattern in mandibular second molar, Interruption groove in maxillary lateral incisor and Cusp 6 in mandibular first molar. The principal coordinate analysis showed that the contemporary Sri Lankans, Dambana and Anuradhapura Vedda located with the Western Eurasia population groups. While showing close affinities with early South Asian populations, Dambana and Anuradhapura Veddas were deviating away from the contemporary Sri Lankans in the second principal coordinate axis showing their genetic drift from the modern Sri Lankans.
Observations of lingual surface attrition of dentition from sedentary hunter-gatherers of Jomon
We report a distinctive dental wear pattern in Jomon individuals, who exhibit clear attritional facets on the lingual cervical regions of the maxillary molars. Macro- and micro-level comparisons may provide possible etiologies or meanings of this special type of wear.
To date, a distinctive dental wear pattern known as LSMAT, or "lingual surface attrition of the maxillary anterior teeth," has been documented in world-wide prehistoric samples. We report here a different version of wear, lingual surface attrition of the maxillary molars, which were identified on a male and a female Jomon specimens, from Mukaidai shell mound along the Tokyo Bay, Japan. The male individual exhibits clear attritional facets on the mesio-lingual enamel-cement junctions of the maxillary M1 and M2, where the dentine patches are exposed. Although not conspicuous, the same attritional facets are observed in several Jomon specimens. We compare the macro- and micro-level observations on them and those of LSMAT etc, and discuss possible etiologies and the meanings of this peculiar type of attrition.
The demographic transition and demic migration in prehistoric East/Southeast Asia: an exploration using nonmetric dental traits
The demographic transition throughout prehistoric East/Southeast Asia is explored using batteries of nonmetric dental traits. Agriculturally driven demic expansion during the Neolithic, associated with genetic exchange with pre-existing hunter-gatherers, is demonstrated.
Eastern Eurasia is believed to have been occupied by anatomically modern Homo sapiens (AMH) from at least 60kya, followed by near simultaneous dispersals from the southern region into sub-continental Sahul. AMHs occupying the northern region colonized the Americas much later, after 20kya. Elucidating the biological relationships between early AMH colonizers and the present-day inhabitants of the region is fundamental to resolving questions surrounding the migration history of this area. Non-metric dental trait analysis provides a powerful tool for mapping out the genetic landscape of past and present day East/Southeast Asia. This study, using dental data sets spanning the late Pleistocene through to Neolithic (and later) periods, demonstrates an apparent genetic discontinuity between pre- and post-Neolithic populations. Events occurring during the Neolithic, it would seem, were pivotal in terms of the micro-evolutionary history of this region. Moreover, we demonstrate a close affinity between pre-Neolithic Hoabinhian and Australo-Melanesian samples on the one hand, and a northern source for contemporary Southeast Asians on the other hand. We argue that pre-Neolithic foragers descended from the first AMH colonizers of Southeast Asia, sharing common ancestry with present-day Australian Aboriginal and Melanesian populations. The eventual outcome of this was large scale integration with a population-language-agriculture dispersal package originating to the north in East Asia, ultimately contributing to the modern Southeast Asian morphology.
This panel is closed to new paper proposals.