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John S, Devi P, Chundawat P, Sankar R, Gupta S. Analysis of non-metric dental traits for ethnicity identification in a mixed population of Uttar Pradesh. J Forensic Leg Med 2024; 107:102755. [PMID: 39293286 DOI: 10.1016/j.jflm.2024.102755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2024] [Revised: 09/11/2024] [Accepted: 09/12/2024] [Indexed: 09/20/2024]
Abstract
BACKGROUND Forensic odontology involves the identification of individuals through dental records, making it a crucial tool in legal investigations. Non-metric dental traits (NMDT), which are variations in dental morphology play a key role as these traits are inherited characteristics that can help establish biological relationships or ancestry. Thus, we aim to assess the frequency and variability of NMDT in the human dentition of four ethnically mixed populations in Uttar Pradesh. This study can aid in the future by maintaining records of ethnic groups and their variability, which can be crucial for disaster victim management and forensic odontology. METHODS The study was conducted on a total of 100 patients coming to the OPD of Oral Medicine and Oral Pathology and Microbiology of King George's Medical University from January 2022 to July 2023. Impressions of both arches were made for participants using irreversible hydrocolloid (alginate), and casts were examined under a stereomicroscope to assess 15 different morphological characteristics. RESULTS NMDTs such as winging, shoveling, double-shoveling interruption groove, canine mesial ridge, hypocone, metacone, carabelli's trait, peg-shaped incisors, peg-shaped molar, premolar lingual cusp variation, deflecting wrinkle, protostylid, metaconulid, entoconulid was evaluated. The NMDTS were evaluated in four different ethnics Nordics, Mediterranean, Oriental Mediterranean, and Protoaustraloid amongst which various traits showed a statistically significant variation among the population of Uttar Pradesh. CONCLUSION The sample studied presented confirmed supernumerary traits like metacone, protostylid, carabellis trait, metaconulid, premolar lingual cusp variation, and deflecting wrinkle were seen highest in Nordic, Mediterranean, Oriental Mediterranean, and Protoaustraloid ethnicity have a significant association with the Uttar Pradesh population.
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Affiliation(s)
- Sharon John
- Department of Oral & Maxillofacial Pathology and Oral Microbiology, King George's Medical University, Lucknow, India.
| | - Priya Devi
- Department of Oral & Maxillofacial Pathology and Oral Microbiology, King George's Medical University, Lucknow, India.
| | - Prashasti Chundawat
- Department of Oral & Maxillofacial Pathology and Oral Microbiology, King George's Medical University, Lucknow, India.
| | - Roshna Sankar
- Department of Oral & Maxillofacial Pathology and Oral Microbiology, King George's Medical University, Lucknow, India.
| | - Shalini Gupta
- Department of Oral & Maxillofacial Pathology and Oral Microbiology, King George's Medical University, Lucknow, India.
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2
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Peer M, Sarig R. The effect of burning on dental tissue: A macroscopic and microscopic investigation. Forensic Sci Int 2024; 358:111987. [PMID: 38547582 DOI: 10.1016/j.forsciint.2024.111987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Revised: 03/03/2024] [Accepted: 03/13/2024] [Indexed: 04/30/2024]
Abstract
Teeth are considered unique as fingerprints for identification purposes. Their structure and resilience mean they can remain for thousands and millions of years withstanding extreme conditions, including burning. During burning, bones undergo carbonization at approximately 400°C and calcination at approximately 700°C. This study aimed to investigate the effects of carbonization and calcination on dental tissue. It involved nondestructive analyses of 58 extracted human teeth before and after burning, using x-ray diffraction, micro-CT, and high-resolution confocal microscopy. The results revealed that during carbonization, dentin volume decreased in two thirds of the sample, accompanied by crack formation and significant reduction in hydroxyapatite crystal size (p<0.001). During calcination, dentin volume decreased in all teeth, along with a significant deepening of the cracks (p<0.001), while enamel crystal size increased slightly. Initial changes in teeth occurred at lower temperatures than had once been assumed, as indicated by the cracks during carbonization, and there was up to a 36% decrease in dentin volume during calcination, which should be considered when measuring burnt teeth. The results of this research provide new insight into understanding dental tissue response to burning. Thus, dental remains may contribute to the knowledge needed to reconstruct anthropological and forensic scenarios involving burning.
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Affiliation(s)
- Michal Peer
- The Department of Oral Biology, the Maurice and Gabriela Goldschleger School of Dental Medicine, Faculty of Medicine and Health Sciences, Tel Aviv University, Tel Aviv 69978, Israel; The Shmunis Family Anthropology Institute, Dan David Center for Human Evolution and Biohistory Research, Faculty of Medicine and Health Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
| | - Rachel Sarig
- The Department of Oral Biology, the Maurice and Gabriela Goldschleger School of Dental Medicine, Faculty of Medicine and Health Sciences, Tel Aviv University, Tel Aviv 69978, Israel; The Shmunis Family Anthropology Institute, Dan David Center for Human Evolution and Biohistory Research, Faculty of Medicine and Health Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
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3
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Štamfelj I, Hitij T, Strmšek L. Radix entomolaris and radix paramolaris: A cone-beam computed tomography study of permanent mandibular molars in a large sample from Slovenia. Arch Oral Biol 2024; 157:105842. [PMID: 37979392 DOI: 10.1016/j.archoralbio.2023.105842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Revised: 10/29/2023] [Accepted: 11/01/2023] [Indexed: 11/20/2023]
Abstract
OBJECTIVES To investigate the prevalence, unilateral/bilateral concurrency, and external morphology of permanent mandibular molars (PMMs) with radix entomolaris (RE) and radix paramolaris (RP) in a sample from Slovenia. DESIGN Medium field-of-view cone-beam computed tomography images of 1315 participants (681 males, 634 females) aged 13-90 years (mean age 45.5) were retrospectively examined. A total of 1363 first, 1824 second, and 1314 third PMMs were evaluated. The external morphology of the affected teeth was categorized according to Carlsen and Alexandersen's classifications. RESULTS The individual-level RE frequencies in the first, second, and third PMMs were 1.6%, 1.9%, and 10.1%, respectively. The respective RP frequencies were 0%, 1.8%, and 3.2%. The first PMMs exclusively exhibited type A RE morphology, whereas in the second and third PMMs, types B and AC morphologies predominated. Bilateral concurrence rates were low (0-7.1%), with the exception of type A RE in first PMMs (62.5%). RE occurrences in the first and second PMMs were correlated (odds ratio = 70.2; 95% confidence interval 17.4 -282.7; P < 0.001). In concurrent cases, the second PMM followed its anterior neighbor in expressing type A morphology, and conversely, all affected second PMMs standing next to a two-rooted first PMM exhibited non-type A morphology. CONCLUSIONS In this sample, the first and second PMMs exhibited low supernumerary root frequencies comparable to those of other European samples. The third PMM was most often affected. The presence of RE on the first PMM increased the possibility of its presence on the adjacent second PMM and vice versa.
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Affiliation(s)
- Iztok Štamfelj
- Department of Dental Diseases and Dental Morphology, Faculty of Medicine, University of Ljubljana, Hrvatski trg 6, SI-1000 Ljubljana, Slovenia; Department of Operative Dentistry and Endodontics, University Medical Center Ljubljana, Hrvatski trg 6, SI-1000 Ljubljana, Slovenia.
| | - Tomaž Hitij
- Department of Dental Diseases and Dental Morphology, Faculty of Medicine, University of Ljubljana, Hrvatski trg 6, SI-1000 Ljubljana, Slovenia; Institute for Palaeobiology and Evolution, Novi trg 59, SI-1241 Kamnik, Slovenia
| | - Lucija Strmšek
- Department of Dental Diseases and Dental Morphology, Faculty of Medicine, University of Ljubljana, Hrvatski trg 6, SI-1000 Ljubljana, Slovenia
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4
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Chapple SA, Skinner MM. A tooth crown morphology framework for interpreting the diversity of primate dentitions. Evol Anthropol 2023; 32:240-255. [PMID: 37486115 DOI: 10.1002/evan.21994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 03/25/2023] [Accepted: 06/19/2023] [Indexed: 07/25/2023]
Abstract
Variation in tooth crown morphology plays a crucial role in species diagnoses, phylogenetic inference, and the reconstruction of the evolutionary history of the primate clade. While a growing number of studies have identified developmental mechanisms linked to tooth size and cusp patterning in mammalian crown morphology, it is unclear (1) to what degree these are applicable across primates and (2) which additional developmental mechanisms should be recognized as playing important roles in odontogenesis. From detailed observations of lower molar enamel-dentine junction morphology from taxa representing the major primate clades, we outline multiple phylogenetic and developmental components responsible for crown patterning, and formulate a tooth crown morphology framework for the holistic interpretation of primate crown morphology. We suggest that adopting this framework is crucial for the characterization of tooth morphology in studies of dental development, discrete trait analysis, and systematics.
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Affiliation(s)
- Simon A Chapple
- School of Anthropology and Conservation, University of Kent, Canterbury, UK
| | - Matthew M Skinner
- School of Anthropology and Conservation, University of Kent, Canterbury, UK
- Department of Human Origins, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
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5
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Ohshima H, Mishima K. Oral biosciences: The annual review 2022. J Oral Biosci 2023; 65:1-12. [PMID: 36740188 DOI: 10.1016/j.job.2023.01.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Accepted: 01/25/2023] [Indexed: 02/05/2023]
Abstract
BACKGROUND The Journal of Oral Biosciences is devoted to advancing and disseminating fundamental knowledge concerning every aspect of oral biosciences. HIGHLIGHT This review features review articles in the fields of "Bone Cell Biology," "Tooth Development & Regeneration," "Tooth Bleaching," "Adipokines," "Milk Thistle," "Epithelial-Mesenchymal Transition," "Periodontitis," "Diagnosis," "Salivary Glands," "Tooth Root," "Exosome," "New Perspectives of Tooth Identification," "Dental Pulp," and "Saliva" in addition to the review articles by the winner of the "Lion Dental Research Award" ("Plastic changes in nociceptive pathways contributing to persistent orofacial pain") presented by the Japanese Association for Oral Biology. CONCLUSION The review articles in the Journal of Oral Biosciences have inspired its readers to broaden their knowledge about various aspects of oral biosciences. The current editorial review introduces these exciting review articles.
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Affiliation(s)
- Hayato Ohshima
- Division of Anatomy and Cell Biology of the Hard Tissue, Department of Tissue Regeneration and Reconstruction, Niigata University Graduate School of Medical and Dental Sciences, 2-5274 Gakkocho-dori, Chuo-ku, Niigata 951-8514, Japan.
| | - Kenji Mishima
- Division of Pathology, Department of Oral Diagnostic Sciences, Showa University School of Dentistry, 1-5-8, Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan
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6
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Morita W, Morimoto N, Otsu K, Miura T. Stripe and spot selection in cusp patterning of mammalian molar formation. Sci Rep 2022; 12:9149. [PMID: 35701484 PMCID: PMC9197828 DOI: 10.1038/s41598-022-13539-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 05/25/2022] [Indexed: 11/09/2022] Open
Abstract
Tooth development is governed largely by epithelial-mesenchymal interactions and is mediated by numerous signaling pathways. This type of morphogenetic processes has been explained by reaction-diffusion systems, especially in the framework of a Turing model. Here we focus on morphological and developmental differences between upper and lower molars in mice by modeling 2D pattern formation in a Turing system. Stripe vs. spot patterns are the primary types of variation in a Turing model. We show that the complexity of the cusp cross-sections can distinguish between stripe vs. spot patterns, and mice have stripe-like upper and spot-like lower molar morphologies. Additionally, our computational modeling that incorporates empirical data on tooth germ growth traces the order of cusp formation and relative position of the cusps in upper and lower molars in mice. We further propose a hypothetical framework of developmental mechanism that could help us understand the evolution of the highly variable nature of mammalian molars associated with the acquisition of the hypocone and the increase of lophedness.
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Affiliation(s)
- Wataru Morita
- Department of Anthropology, National Museum of Nature and Science, Ibaraki, Japan.
| | - Naoki Morimoto
- Laboratory of Physical Anthropology, Department of Zoology, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Keishi Otsu
- Division of Developmental Biology and Regenerative Medicine, Department of Anatomy, Iwate Medical University, Iwate, Japan
| | - Takashi Miura
- Department of Anatomy and Cell Biology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
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7
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The biological significance of tooth identification based on developmental and evolutional viewpoints. J Oral Biosci 2022; 64:287-302. [DOI: 10.1016/j.job.2022.05.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 05/11/2022] [Accepted: 05/13/2022] [Indexed: 11/22/2022]
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8
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Evolution and development of the mammalian multicuspid teeth. J Oral Biosci 2022; 64:165-175. [DOI: 10.1016/j.job.2022.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 03/28/2022] [Accepted: 03/29/2022] [Indexed: 11/20/2022]
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9
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King TR, Myers TJ, Armstrong KN, Archer M, Hand SJ. Sheath-tailed bats (Chiroptera: Emballonuridae) from the early Pleistocene Rackham's Roost Site, Riversleigh World Heritage Area, and the distribution of northern Australian emballonurid species. PeerJ 2021; 9:e10857. [PMID: 33665024 PMCID: PMC7916536 DOI: 10.7717/peerj.10857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 01/07/2021] [Indexed: 11/20/2022] Open
Abstract
Sheath-tailed bats (Family Emballonuridae) from the early Pleistocene Rackham’s Roost Site cave deposit in the Riversleigh World Heritage Area, north-western Queensland are the oldest recorded occurrence for the family in Australia. The fossil remains consist of maxillary and dentary fragments, as well as isolated teeth, but until now their precise identity has not been assessed. Our study indicates that at least three taxa are represented, and these are distinguished from other Australian emballonurids based on morphometric analysis of craniodental features. Most of the Rackham’s Roost Site emballonurid remains are referrable to the modern species Taphozous georgianus Thomas, 1915, but the extant species T. troughtoni Tate, 1952 also appears to be present, as well as a very large, as-yet undetermined species of Saccolaimus Temminck, 1838. We identify craniodental features that clearly distinguish T. georgianus from the externally very similar T. troughtoni. Results suggest that the distributions of T. georgianus and T. troughtoni may have overlapped in north-western Queensland since at least the early Pleistocene.
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Affiliation(s)
- Tyler R King
- Earth and Sustainability Science Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Troy J Myers
- Earth and Sustainability Science Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Kyle N Armstrong
- School of Biological Sciences, The University of Adelaide, Adelaide, SA, Australia.,South Australian Museum, North Terrace, Adelaide, SA, Australia
| | - Michael Archer
- Earth and Sustainability Science Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Suzanne J Hand
- Earth and Sustainability Science Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW, Australia
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Abstract
A major challenge in evolutionary developmental biology is to understand how genetic mutations underlie phenotypic changes. In principle, selective pressures on the phenotype screen the gene pool of the population. Teeth are an excellent model for understanding evolutionary changes in the genotype-phenotype relationship since they exist throughout vertebrates. Genetically modified mice (mutants) with abnormalities in teeth have been used to explore tooth development. The relationship between signaling pathways and molar shape, however, remains elusive due to the high intrinsic complexity of tooth crowns. This hampers our understanding of the extent to which developmental factors explored in mutants explain developmental and phenotypic variation in natural species that represent the consequence of natural selection. Here we combine a novel morphometric method with two kinds of data mining techniques to extract data sets from the three-dimensional surface models of lower first molars: i) machine learning to maximize classification accuracy of 22 mutants, and ii) phylogenetic signal for 31 Murinae species. Major shape variation among mutants is explained by the number of cusps and cusp distribution on a tooth crown. The distribution of mutant mice in morphospace suggests a nonlinear relationship between the signaling pathways and molar shape variation. Comparative analysis of mutants and wild murines reveals that mutant variation overlaps naturally occurring diversity, including more ancestral and derived morphologies. However, taxa with transverse lophs are not fully covered by mutant variation, suggesting experimentally unexplored developmental factors in the evolutionary radiation of Murines.
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11
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Morita W, Morimoto N, Kono RT, Suwa G. Metameric variation of upper molars in hominoids and its implications for the diversification of molar morphogenesis. J Hum Evol 2019; 138:102706. [PMID: 31785453 DOI: 10.1016/j.jhevol.2019.102706] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 10/20/2019] [Accepted: 10/20/2019] [Indexed: 11/18/2022]
Abstract
Metameric variation of molar size is in part associated with the dietary adaptations of mammals and results from slight alterations of developmental processes. Humans and great apes exhibit conspicuous variation in tooth morphology both between taxa and across tooth types. However, the manner in which metameric variation in molars emerged among apes and humans via evolutionary alterations in developmental processes remains largely unknown. In this study, we compare the enamel-dentine junction of the upper molars of humans-which closely correlates with morphology of the outer enamel surface and is less affected by wear-with that of the other extant hominoids: chimpanzees, bonobos, gorillas, orangutans, and gibbons. We used the morphometric mapping method to quantify and visualize three-dimensional morphological variation, and applied multivariate statistical analyses. Results revealed the following: 1) extant hominoids other than humans share a common pattern of metameric variation characterized by a largely linear change in morphospace; this indicates a relatively simple graded change in metameric molar shape; 2) intertaxon morphological differences become less distinct from the mesial to distal molars; and 3) humans diverge from the extant ape pattern in exhibiting a distinct metameric shape change trajectory in the morphospace. The graded shape change and lower intertaxon resolution from the mesial to distal molars are consistent with the concept of a 'key' tooth. The common metameric pattern observed among the extant nonhuman hominoids indicates that developmental patterns underlying metameric variation were largely conserved during ape evolution. Furthermore, the human-specific metameric pattern suggests considerable developmental modifications in the human lineage.
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Affiliation(s)
- Wataru Morita
- Developmental Biology Program, Institute of Biotechnology, University of Helsinki, Helsinki, Finland; Department of Oral Functional Anatomy, Faculty of Dental Medicine, Hokkaido University, Hokkaido, Japan.
| | - Naoki Morimoto
- Laboratory of Physical Anthropology, Department of Zoology, Graduate School of Science, Kyoto University, Kyoto, Japan.
| | - Reiko T Kono
- Faculty of Letters, Keio University, Kanagawa, Japan
| | - Gen Suwa
- The University Museum, The University of Tokyo, Tokyo, Japan
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12
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Woods C, Fernee C, Browne M, Zakrzewski S, Dickinson A. The potential of statistical shape modelling for geometric morphometric analysis of human teeth in archaeological research. PLoS One 2017; 12:e0186754. [PMID: 29216199 PMCID: PMC5720725 DOI: 10.1371/journal.pone.0186754] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2017] [Accepted: 10/07/2017] [Indexed: 01/15/2023] Open
Abstract
This paper introduces statistical shape modelling (SSM) for use in osteoarchaeology research. SSM is a full field, multi-material analytical technique, and is presented as a supplementary geometric morphometric (GM) tool. Lower mandibular canines from two archaeological populations and one modern population were sampled, digitised using micro-CT, aligned, registered to a baseline and statistically modelled using principal component analysis (PCA). Sample material properties were incorporated as a binary enamel/dentin parameter. Results were assessed qualitatively and quantitatively using anatomical landmarks. Finally, the technique’s application was demonstrated for inter-sample comparison through analysis of the principal component (PC) weights. It was found that SSM could provide high detail qualitative and quantitative insight with respect to archaeological inter- and intra-sample variability. This technique has value for archaeological, biomechanical and forensic applications including identification, finite element analysis (FEA) and reconstruction from partial datasets.
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Affiliation(s)
- Christopher Woods
- Bioengineering Sciences Research Group, University of Southampton, Highfield Campus, Highfield, Southampton, United Kingdom
| | - Christianne Fernee
- Department of Archaeology, University of Southampton, Avenue Campus, Highfield, Southampton, United Kingdom
| | - Martin Browne
- Bioengineering Sciences Research Group, University of Southampton, Highfield Campus, Highfield, Southampton, United Kingdom
| | - Sonia Zakrzewski
- Department of Archaeology, University of Southampton, Avenue Campus, Highfield, Southampton, United Kingdom
| | - Alexander Dickinson
- Bioengineering Sciences Research Group, University of Southampton, Highfield Campus, Highfield, Southampton, United Kingdom
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13
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Ortiz A, Bailey SE, Hublin JJ, Skinner MM. Homology, homoplasy and cusp variability at the enamel-dentine junction of hominoid molars. J Anat 2017; 231:585-599. [PMID: 28718921 PMCID: PMC5603786 DOI: 10.1111/joa.12649] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/02/2017] [Indexed: 12/25/2022] Open
Abstract
Evolutionary studies of mammalian teeth have generally concentrated on the adaptive and functional significance of dental features, whereas the role of development on phenotypic generation and as a source of variation has received comparatively little attention. The present study combines an evolutionary biological framework with state-of-the-art imaging techniques to examine the developmental basis of variation of accessory cusps. Scholars have long used the position and relatedness of cusps to other crown structures as a criterion for differentiating between developmentally homologous and homoplastic features, which can be evaluated with greater accuracy at the enamel-dentine junction (EDJ). Following this approach, we collected digital models of the EDJ and outer enamel surface of more than 1000 hominoid teeth to examine whether cusp 5 of the upper molars (UM C5) and cusps 6 and 7 of the lower molars (LM C6 and LM C7) were associated each with a common developmental origin across species. Results revealed that each of these cusps can develop in a variety of ways, in association with different dental tissues (i.e. oral epithelium, enamel matrix) and dental structures (i.e. from different cusps, crests and cingula). Both within and between species variability in cusp origin was highest in UM C5, followed by LM C7, and finally LM C6. The lack of any species-specific patterns suggests that accessory cusps in hominoids are developmentally homoplastic and that they may not be useful for identifying phylogenetic homology. An important and unanticipated finding of this study was the identification of a new taxonomically informative feature at the EDJ of the upper molars, namely the post-paracone tubercle (PPT). We found that the PPT was nearly ubiquitous in H. neanderthalensis and the small sample of Middle Pleistocene African and European humans (MPAE) examined, differing significantly from the low frequencies observed in all other hominoids, including Pleistocene and recent H. sapiens. We emphasize the utility of the EDJ for human evolutionary studies and demonstrate how features that look similar at the external surface may be the product of different developmental patterns. This study also highlights the importance of incorporating both developmental and morphological data into evolutionary studies in order to gain a better understanding of the evolutionary significance of dental and skeletal features.
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Affiliation(s)
- Alejandra Ortiz
- Institute of Human Origins, School of Human Evolution and Social Change, Arizona State University, Tempe, AZ, USA
| | - Shara E Bailey
- Department of Anthropology, Center for the Study of Human Origins, New York University, New York, NY, USA
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Jean-Jacques Hublin
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Matthew M Skinner
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
- School of Anthropology and Conservation, University of Kent, Canterbury, UK
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14
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Pan L, Thackeray JF, Dumoncel J, Zanolli C, Oettlé A, de Beer F, Hoffman J, Duployer B, Tenailleau C, Braga J. Intra-individual metameric variation expressed at the enamel-dentine junction of lower post-canine dentition of South African fossil hominins and modern humans. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2017; 163:806-815. [DOI: 10.1002/ajpa.23240] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 04/17/2017] [Accepted: 04/17/2017] [Indexed: 11/05/2022]
Affiliation(s)
- Lei Pan
- Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences; Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences; Beijing 100044 China
- Laboratoire d'Anthropobiologie Moléculaire et d'Imagerie de Synthèse, UMR 5288 CNRS-Université de Toulouse (Paul Sabatier); Toulouse 31000 France
| | - John Francis Thackeray
- Evolutionary Studies Institute and School of Geosciences, University of the Witwatersrand, PO WITS; Johannesburg 2050 South Africa
| | - Jean Dumoncel
- Laboratoire d'Anthropobiologie Moléculaire et d'Imagerie de Synthèse, UMR 5288 CNRS-Université de Toulouse (Paul Sabatier); Toulouse 31000 France
| | - Clément Zanolli
- Laboratoire d'Anthropobiologie Moléculaire et d'Imagerie de Synthèse, UMR 5288 CNRS-Université de Toulouse (Paul Sabatier); Toulouse 31000 France
| | - Anna Oettlé
- Department of Anatomy, School of Medicine, Faculty of Health Sciences; University of Pretoria; Pretoria South Africa
| | - Frikkie de Beer
- Radiation Science Department; South African Nuclear Energy Corporation (Necsa); Pelindaba North West Province South Africa
| | - Jakobus Hoffman
- Radiation Science Department; South African Nuclear Energy Corporation (Necsa); Pelindaba North West Province South Africa
| | - Benjamin Duployer
- Centre Inter-universitaire de Recherche et d'Ingénierie des Matériaux, UMR 5085 CNRS-Université de Toulouse (Paul Sabatier); Toulouse Cedex 9 31062 France
| | - Christophe Tenailleau
- Centre Inter-universitaire de Recherche et d'Ingénierie des Matériaux, UMR 5085 CNRS-Université de Toulouse (Paul Sabatier); Toulouse Cedex 9 31062 France
| | - José Braga
- Laboratoire d'Anthropobiologie Moléculaire et d'Imagerie de Synthèse, UMR 5288 CNRS-Université de Toulouse (Paul Sabatier); Toulouse 31000 France
- Evolutionary Studies Institute and School of Geosciences, University of the Witwatersrand, PO WITS; Johannesburg 2050 South Africa
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15
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Oral Biosciences: The annual review 2016. J Oral Biosci 2017. [DOI: 10.1016/j.job.2016.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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