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Akkoç Hİ, Keskin C, Aslantaş K. Dynamic analysis of a NiTi rotary file by using finite element analysis: Effect of cross-section and pitch length. AUST ENDOD J 2024; 50:649-657. [PMID: 39361526 DOI: 10.1111/aej.12892] [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: 07/01/2024] [Revised: 09/02/2024] [Accepted: 09/19/2024] [Indexed: 10/05/2024]
Abstract
This study assessed stress distribution, maximum stress values and fatigue life of experimentally designed NiTi rotary files with different cross-sectional geometry and pitch length using finite element analysis (FEA). Four cross-sectional shapes (Convex triangle, S-shaped, Triple helix and Concave triangle) and two pitch lengths (2 mm and 3 mm) were tested in simulated root canals with curvatures of 30°, 45° and 60°. The FEA results indicated that convex triangle and triple helix geometries exhibited lower stress values compared to the S-shaped and concave triangle designs. Increasing the canal curvature angle resulted in higher stress values, with the S-shaped instrument showing the most significant increase (up to 12%). Instruments with shorter pitch lengths showed more even stress distribution enhancing fatigue life. The maximum stress was concentrated 5-8 mm from the tip, varying across cutting edges, with S-shaped sections experiencing the lowest forces but higher stress due to lower moments of inertia.
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Affiliation(s)
- Halil İbrahim Akkoç
- Mechanical Engineering Department, Faculty of Technology, University of Afyon Kocatepe, Afyon, Turkey
| | - Cangül Keskin
- Department of Endodontics, Faculty of Dentistry, Ondokuz Mayıs University, Samsun, Turkey
| | - Kubilay Aslantaş
- Mechanical Engineering Department, Faculty of Technology, University of Afyon Kocatepe, Afyon, Turkey
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Hernaiz-García M, Zanolli C, Martín-Francés L, Mazurier A, Benazzi S, Sarig R, Fu J, Kullmer O, Fiorenza L. Masticatory habits of the adult Neanderthal individual BD 1 from La Chaise-de-Vouthon (France). AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2024; 184:e24926. [PMID: 38420653 DOI: 10.1002/ajpa.24926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 02/05/2024] [Accepted: 02/18/2024] [Indexed: 03/02/2024]
Abstract
OBJECTIVES The analysis of dental wear provides a useful approach for dietary and cultural habit reconstructions of past human populations. The analysis of macrowear patterns can also be used to better understand the individual chewing behavior and to investigate the biomechanical responses during different biting scenarios. The aim of this study is to evaluate the diet and chewing performance of the adult Neanderthal Bourgeois-Delaunay 1 (BD 1) and to investigate the relationship between wear and cementum deposition under mechanical demands. MATERIALS AND METHODS The macrowear pattern of BD 1 was analyzed using the occlusal fingerprint analysis method. We propose a new method for the bilateral measurement of the cementum volume along both buccal and lingual sides of the molar root. RESULTS BD 1's anterior dentition is more affected by wear compared to the posterior one. The macrowear pattern suggest a normal chewing behavior and a mixed-diet coming from temperate environments. The teeth on the left side of the mandible display greater levels of wear, as well as the buccal side of the molar crowns. The cementum analysis shows higher buccal volume along the molar roots. DISCUSSION BD1 could have been preferably chewing on the left side of the mandible. The exploitation of various food resources suggested by the macrowear analysis is compatible with the environmental reconstructions. Finally, the greater wear on the buccal side of the molar occlusal surface and the greater volume of cementum in that side of the molar roots offers a preliminary understanding about the potential correlation between dental wear and cementum deposition.
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Affiliation(s)
- María Hernaiz-García
- Monash Biomedicine Discovery Institute, Department of Anatomy and Developmental Biology, Monash University, Melbourne, Australia
| | | | - Laura Martín-Francés
- Monash Biomedicine Discovery Institute, Department of Anatomy and Developmental Biology, Monash University, Melbourne, Australia
- Department of Paleobiology, CENIEH, Burgos, Spain
| | - Arnaud Mazurier
- CNRS, Institut de Chimie des Milieux et Matériaux de Poitiers-IC2MP, Université de Poitiers, Poitiers, France
| | - Stefano Benazzi
- Department of Cultural Heritage, University of Bologna, Ravenna, Italy
| | - Rachel Sarig
- Department of Oral Biology, The Goldschleger School of Dental Medicine, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Dan David Center for Human Evolution and Biohistory Research, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel
| | - Jing Fu
- Department of Mechanical and Aerospace Engineering, Monash University, Melbourne, Australia
| | - Ottmar Kullmer
- Division of Palaeoanthropology, Senckenberg Research Institute and Natural History Museum Frankfurt, Frankfurt am Main, Germany
- Department of Palaeobiology and Environment, Institute of Ecology, Evolution, and Diversity, Goethe University, Frankfurt, Germany
| | - Luca Fiorenza
- Monash Biomedicine Discovery Institute, Department of Anatomy and Developmental Biology, Monash University, Melbourne, Australia
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Najafzadeh A, Hernaiz-García M, Benazzi S, Chen B, Hublin JJ, Kullmer O, Pokhojaev A, Sarig R, Sorrentino R, Vazzana A, Fiorenza L. Finite element analysis of Neanderthal and early Homo sapiens maxillary central incisor. J Hum Evol 2024; 189:103512. [PMID: 38461589 DOI: 10.1016/j.jhevol.2024.103512] [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: 01/09/2023] [Revised: 02/12/2024] [Accepted: 02/13/2024] [Indexed: 03/12/2024]
Abstract
Neanderthal anterior teeth are very large and have a distinctive morphology characterized by robust 'shovel-shaped' crowns. These features are frequently seen as adaptive responses in dissipating heavy mechanical loads resulting from masticatory and non-masticatory activities. Although the long-standing debate surrounding this hypothesis has played a central role in paleoanthropology, is still unclear if Neanderthal anterior teeth can resist high mechanical loads or not. A novel way to answer this question is to use a multidisciplinary approach that considers together tooth architecture, dental wear and jaw movements. The aim of this study is to functionally reposition the teeth of Le Moustier 1 (a Neanderthal adolescent) and Qafzeh 9 (an early Homo sapiens adolescent) derived from wear facet mapping, occlusal fingerprint analysis and physical dental restoration methods. The restored dental arches are then used to perform finite element analysis on the left central maxillary incisor during edge-to-edge occlusion. The results show stress distribution differences between Le Moustier 1 and Qafzeh 9, with the former displaying higher tensile stress in enamel around the lingual fossa but lower concentration of stress in the lingual aspect of the root surface. These results seem to suggest that the presence of labial convexity, lingual tubercle and of a large root surface in Le Moustier 1 incisor helps in dissipating mechanical stress. The absence of these dental features in Qafzeh 9 is compensated by the presence of a thicker enamel, which helps in reducing the stress in the tooth crown.
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Affiliation(s)
- Ali Najafzadeh
- Monash Biomedicine Discovery Institute, Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, 3800, Australia; Department of Mechanical and Aerospace Engineering, Monash University, Melbourne, VIC, 3800, Australia
| | - María Hernaiz-García
- Monash Biomedicine Discovery Institute, Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, 3800, Australia
| | - Stefano Benazzi
- Department of Cultural Heritage, University of Bologna, Ravenna, 48121, Italy
| | - Bernard Chen
- Department of Surgery, The University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Jean-Jacques Hublin
- Chaire de Paléoanthropologie, CIRB (UMR 7241-U1050), Collège de France, 11, Place Marcelin-Berthelot, 75231, Paris, Cedex 05, France; Max Planck Institute for Evolutionary Anthropology, Leipzig, 04103, Germany
| | - Ottmar Kullmer
- Division of Palaeoanthropology, Senckenberg Research Institute and Natural History Museum Frankfurt, Frankfurt a. M, 60325, Germany; Department of Palaeobiology and Environment, Institute of Ecology, Evolution, and Diversity, Goethe University, Frankfurt a. M, 60438, Germany
| | - Ariel Pokhojaev
- Department of Oral Biology, The Goldschleger School of Dental Medicine, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 69978, Israel
| | - Rachel Sarig
- Department of Oral Biology, The Goldschleger School of Dental Medicine, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 69978, Israel; Dan David Center for Human Evolution and Biohistory Research, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 69978, Israel
| | - Rita Sorrentino
- Department of Cultural Heritage, University of Bologna, Ravenna, 48121, Italy; Department of Biological, Geological and Environmental Sciences, University of Bologna, Bologna, 40126, Italy
| | - Antonino Vazzana
- Department of Cultural Heritage, University of Bologna, Ravenna, 48121, Italy
| | - Luca Fiorenza
- Monash Biomedicine Discovery Institute, Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, 3800, Australia.
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Ornaghi HL, Monticeli FM, Agnol LD. A Review on Polymers for Biomedical Applications on Hard and Soft Tissues and Prosthetic Limbs. Polymers (Basel) 2023; 15:4034. [PMID: 37836083 PMCID: PMC10575019 DOI: 10.3390/polym15194034] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 09/29/2023] [Accepted: 09/30/2023] [Indexed: 10/15/2023] Open
Abstract
In the past decades, there has been a significant increase in the use of polymers for biomedical applications. The global medical polymer market size was valued at USD 19.92 billion in 2022 and is expected to grow at a CAGR of 8.0% from 2023 to 2030 despite some limitations, such as cost (financial limitation), strength compared to metal plates for bone fracture, design optimization and incorporation of reinforcement. Recently, this increase has been more pronounced due to important advances in synthesis and modification techniques for the design of novel biomaterials and their behavior in vitro and in vivo. Also, modern medicine allows the use of less invasive surgeries and faster surgical sutures. Besides their use in the human body, polymer biomedical materials must have desired physical, chemical, biological, biomechanical, and degradation properties. This review summarizes the use of polymers for biomedical applications, mainly focusing on hard and soft tissues, prosthetic limbs, dental applications, and bone fracture repair. The main properties, gaps, and trends are discussed.
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Affiliation(s)
- Heitor Luiz Ornaghi
- Mantova Indústria de Tubos Plásticos Ltd.a., R. Isidoro Fadanelli, 194-Centenário, Caxias do Sul 95045-137, RS, Brazil
| | - Francisco Maciel Monticeli
- Department of Aerospace Structures and Materials, Faculty of Aerospace Engineering, Delft University of Technology, 2628 CD Delft, The Netherlands;
| | - Lucas Dall Agnol
- Postgraduate Program in Materials Science and Engineering (PGMAT), University of Caxias do Sul, Caxias do Sul 95070-560, RS, Brazil;
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Abdulzahra NZ. Ultrasonic shock wave generated by laser as an alternative method to find different bone properties. Lasers Med Sci 2023; 38:138. [PMID: 37318619 DOI: 10.1007/s10103-023-03793-3] [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: 02/28/2023] [Accepted: 05/20/2023] [Indexed: 06/16/2023]
Abstract
Biological materials have been increasingly examined in recent years. What motivates such studies is the need for a comprehensive mechanistic, structural link that will aid future designs of manufactured analogs. Non-destructive laser testing (NDLT) describes the non-damaging material testing method employing a laser. They deny damaging or inducing helpfulness to give information about a material or component and find their physical properties; the experimental study examined bone's physical characteristics for two types (dental and rib) of sheep that is 1 year old. The classical methods depends on microtensile and microhardness compared with NDLT data depending on studying images in high-resolution optical microscopy by studying the laser effect induced by different energies of nanosecond Nd:YAG laser. In laser-induced shock peening (LSP), the forward velocity of the shock wave depends on the bone type related to the rate of ionization of the excited atoms. It noted that the shock measurements at laser intensity 14 GW/cm2 show that the peak pressures typically are 3.1 and 4.1 GPa for dental and rib bones, respectively. The particle velocity for the rib is 962 m/s. In contrast, dental bones are 752 m/s, the shock force for rib bones is 1.9 kN, while dental force is 2 kN. Mechanical properties show that the Young modulus by NDLT is 8.7 GPa for rib and 13.3 GPa for dental bones; it consisted of the classical tensile method, and the hardness measurement by NDLT consisted of Vickers hardness for rib and dental bones. Furthermore, the rib bones show less wear coefficient than the teeth, whose values (4.33 and 5.55 × 10-14 m2/N) for rib and teeth, respectively. Dependent on NDLT and classical results and calculations, the NDLT results have good agreement with classical methods; it is a good technique employed as an alternative method to find acoustic material properties and mechanical properties; NDLT is a suitable, precision, accurate, cheaper, and non-distractive manner applied to examine the acoustic properties of bone and biological materials in the future.
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Baghani Z, Soheilifard R, Bayat S. How Does the First Molar Root Location Affect the Critical Stress Pattern in the Periodontium? A Finite Element Analysis. JOURNAL OF DENTISTRY (SHIRAZ, IRAN) 2023; 24:182-193. [PMID: 37388195 PMCID: PMC10300141 DOI: 10.30476/dentjods.2022.93271.1704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Revised: 01/02/2022] [Accepted: 03/12/2022] [Indexed: 07/01/2023]
Abstract
Statement of the Problem The first molar root location plays a pivotal role in neutralization of forces applied to the teeth to prevent injury. Purpose This study aimed to assess the effect of maxillary and mandibular first molar root location on biomechanical behavior of the periodontium under vertical and oblique loadings. Materials and Method In this three-dimensional (3D) finite element analysis (FEA), the maxillary and mandibular first molars and their periodontium were modeled. The Young's modulus and the Poisson's ratio for the enamel, dentin, dental pulp, periodontal ligament (PDL), and cortical and cancellous bones were adopted from previous studies. The changes in maximum von Misses stress (MVMS) values of each component were analyzed. Results The MVMS values were the highest in the enamel followed by dentin, cortical bone, cancellous bone, and PDL. The maxillary and mandibular first molars with different root locations and their periodontium showed different biomechanical behaviors under the applied loads. Conclusion An interesting finding was that the stress concentration point in the path of load degeneration changed from the cervical third in dentin to the apical third in the cancellous bone, which can greatly help in detection of susceptible areas over time.
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Affiliation(s)
- Zahra Baghani
- Dept. of Periodontics, Faculty of Dentistry, Sabzevar University of Medical Sciences, Sabzevar, Iran
| | - Reza Soheilifard
- Dept. of Mechanical Engineering Hakim Sabzevari University Sabzevar, Iran
| | - Sahar Bayat
- Student, Dept. of Civil Engineering, Hakim Sabzevari University, Sabzevar, Iran
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Morse PE, Pampush JD, Kay RF. Dental topography of the Oligocene anthropoids Aegyptopithecus zeuxis and Apidium phiomense: Paleodietary insights from analysis of wear series. J Hum Evol 2023; 180:103387. [PMID: 37245335 DOI: 10.1016/j.jhevol.2023.103387] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Revised: 04/19/2023] [Accepted: 04/21/2023] [Indexed: 05/30/2023]
Abstract
Fossil primate dietary inference is enhanced when ascertained through multiple, distinct proxies. Dental topography can be used to assess changes in occlusal morphology with macrowear, providing insight on tooth use and function across the lifespans of individuals. We measured convex Dirichlet normal energy-a dental topography metric reflecting occlusal sharpness of features such as cusps and crests-in macrowear series of the second mandibular molars of two African anthropoid taxa from ∼30 Ma (Aegyptopithecus zeuxis and Apidium phiomense). Wear was quantified via three proxies: occlusal dentine exposure, inverse relief index, and inverse occlusal relief. The same measurements were calculated on macrowear series of four extant platyrrhine taxa (Alouatta, Ateles, Plecturocebus, and Sapajus apella) to provide an analogical framework for dietary inference in the fossil taxa. We predicted that Ae. zeuxis and Ap. phiomense would show similar patterns in topographic change with wear to one another and to extant platyrrhine frugivores like Ateles and Plecturocebus. The fossil taxa have similar distributions of convex Dirichlet normal energy to one another, and high amounts of concave Dirichlet normal energy 'noise' in unworn molars-a pattern shared with extant hominids that may distort dietary interpretations. Inverse relief index was the most useful wear proxy for comparison among the taxa in this study which possess disparate enamel thicknesses. Contrary to expectations, Ae. zeuxis and Ap. phiomense both resemble S. apella in exhibiting an initial decline in convex Dirichlet normal energy followed by an increase at the latest stages of wear as measured by inverse relief index, lending support to previous suggestions that hard-object feeding played a role in their dietary ecology. Based on these results and previous analyses of molar shearing quotients, microwear, and enamel microstructure, we suggest that Ae. zeuxis had a pitheciine-like strategy of seed predation, whereas Ap. phiomense potentially consumed berry-like compound fruits with hard seeds.
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Affiliation(s)
- Paul E Morse
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO 80045, USA; Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA.
| | - James D Pampush
- Department of Exercise Science, High Point University, High Point, NC 27260, USA; Department of Physician Assistant Studies, High Point University, High Point, NC 27260, USA
| | - Richard F Kay
- Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA; Division of Earth and Climate Sciences, Nicholas School, Duke University, Durham, NC 27708, USA
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Mathematical tools for recovery of the load on the fissure according to the micro-CT results. J Mech Behav Biomed Mater 2023; 138:105625. [PMID: 36623401 DOI: 10.1016/j.jmbbm.2022.105625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 12/06/2022] [Accepted: 12/12/2022] [Indexed: 12/24/2022]
Abstract
In the present paper X-ray microtomographic research of a molar tooth was conducted. The study revealed regions with a reduced mineral density in the vicinity of the fissure tip. The basic assumption investigated is that corrosion induced enamel mineral density decrease is enhanced by high tensile stresses generated by mechanical load on the occlusal surface of the tooth during crushing of food. Magnitude and location of tensile stress concentration occurs at the fissure tip and may be determined by solving the problem of the stress-strain state of the tooth crown enamel with a wedge-shaped notch. The study of stresses in the vicinity of fissure tip make it possible to construct the boundaries of enhanced enamel virtual fracture. Comparison of the sizes and locations of areas with a reduced enamel mineral density with the sizes and locations of areas of virtual enamel fracture made it possible to establish their approximate congruence. This circumstance made it possible to recreate by mathematical means the nature and magnitude of the force load on the lateral surface of the fissure. Degree of influence of the main parameters of the fissure on the geometrical characteristics of the virtual fracture, such as its area and diameters, were determined.
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Gholamalizadeh T, Moshfeghifar F, Ferguson Z, Schneider T, Panozzo D, Darkner S, Makaremi M, Chan F, Søndergaard PL, Erleben K. Open-Full-Jaw: An open-access dataset and pipeline for finite element models of human jaw. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2022; 224:107009. [PMID: 35872385 DOI: 10.1016/j.cmpb.2022.107009] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 07/02/2022] [Accepted: 07/05/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND State-of-the-art finite element studies on human jaws are mostly limited to the geometry of a single patient. In general, developing accurate patient-specific computational models of the human jaw acquired from cone-beam computed tomography (CBCT) scans is labor-intensive and non-trivial, which involves time-consuming human-in-the-loop procedures, such as segmentation, geometry reconstruction, and re-meshing tasks. Therefore, with the current practice, researchers need to spend considerable time and effort to produce finite element models (FEMs) to get to the point where they can use the models to answer clinically-interesting questions. Besides, any manual task involved in the process makes it difficult for the researchers to reproduce identical models generated in the literature. Hence, a quantitative comparison is not attainable due to the lack of surface/volumetric meshes and FEMs. METHODS We share an open-access repository composed of 17 patient-specific computational models of human jaws and the utilized pipeline for generating them for reproducibility of our work. The used pipeline minimizes the required time for processing and any potential biases in the model generation process caused by human intervention. It gets the segmented geometries with irregular and dense surface meshes and provides reduced, adaptive, watertight, and conformal surface/volumetric meshes, which can directly be used in finite element (FE) analysis. RESULTS We have quantified the variability of our 17 models and assessed the accuracy of the developed models from three different aspects; (1) the maximum deviations from the input meshes using the Hausdorff distance as an error measurement, (2) the quality of the developed volumetric meshes, and (3) the stability of the FE models under two different scenarios of tipping and biting. CONCLUSIONS The obtained results indicate that the developed computational models are precise, and they consist of quality meshes suitable for various FE scenarios. We believe the provided dataset of models including a high geometrical variation obtained from 17 different models will pave the way for population studies focusing on the biomechanical behavior of human jaws.
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Affiliation(s)
- Torkan Gholamalizadeh
- Department of Computer Science, University of Copenhagen, Copenhagen 2100, Denmark; 3Shape A/S, Copenhagen 1060, Denmark.
| | - Faezeh Moshfeghifar
- Department of Computer Science, University of Copenhagen, Copenhagen 2100, Denmark
| | - Zachary Ferguson
- Courant Institute of Mathematical Sciences, New York University, 60 5th Ave, New York NY 10011, USA
| | - Teseo Schneider
- Department of Computer Science, University of Victoria, Victoria BC V8P 5C2, Canada
| | - Daniele Panozzo
- Courant Institute of Mathematical Sciences, New York University, 60 5th Ave, New York NY 10011, USA
| | - Sune Darkner
- Department of Computer Science, University of Copenhagen, Copenhagen 2100, Denmark
| | - Masrour Makaremi
- Dentofacial Orthopedics Department, University of Bordeaux, Bordeaux, France; Orthodontie clinic, 2 Rue des 2 Conils, Bergerac 24100, France
| | - François Chan
- Orthodontie clinic, 2 Rue des 2 Conils, Bergerac 24100, France
| | | | - Kenny Erleben
- Department of Computer Science, University of Copenhagen, Copenhagen 2100, Denmark
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Marcé-Nogué J. One step further in biomechanical models in palaeontology: a nonlinear finite element analysis review. PeerJ 2022; 10:e13890. [PMID: 35966920 PMCID: PMC9373974 DOI: 10.7717/peerj.13890] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 07/21/2022] [Indexed: 01/19/2023] Open
Abstract
Finite element analysis (FEA) is no longer a new technique in the fields of palaeontology, anthropology, and evolutionary biology. It is nowadays a well-established technique within the virtual functional-morphology toolkit. However, almost all the works published in these fields have only applied the most basic FEA tools i.e., linear materials in static structural problems. Linear and static approximations are commonly used because they are computationally less expensive, and the error associated with these assumptions can be accepted. Nonetheless, nonlinearities are natural to be used in biomechanical models especially when modelling soft tissues, establish contacts between separated bones or the inclusion of buckling results. The aim of this review is to, firstly, highlight the usefulness of non-linearities and secondly, showcase these FEA tool to researchers that work in functional morphology and biomechanics, as non-linearities can improve their FEA models by widening the possible applications and topics that currently are not used in palaeontology and anthropology.
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Affiliation(s)
- Jordi Marcé-Nogué
- Department of Mechanical Engineering, Universitat Rovira i Virgili Tarragona, Tarragona, Catalonia, Spain
- Institut Català de Paleontologia, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Catalonia, Spain
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Fiorenza L, Harty T, Janocha MM, Kullmer O, Nguyen HN, Bortolini E, Benazzi S. Understanding dietary ecology in great apes from dental macrowear analysis. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2022. [PMCID: PMC9544277 DOI: 10.1002/ajpa.24533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Objectives Dietary diversity in primates is reflected in their dental morphology, with differences in size and shape of teeth. The objective of this study is to investigate the relationship between molar morphology and macrowear patterns in Pongo, Gorilla, and Pan to obtain dietary information. Methods We have examined 68 second lower molars using the Occlusal Fingerprint Analysis method including 18 chimpanzees, 28 gorillas, and 22 orangutans. We selected only molars from wildshot specimens characterized by a moderate degree of wear. High‐resolution digital models of teeth were created using a white scanning light system with a resolution of 45 μm. Results The macrowear patterns of Pan were significantly different from those of Gorilla and of Pongo, differences that are mostly due to shearing wear. Gorilla and Pongo macrowear patterns are dominated by phase II areas, followed by lingual phase I facets, while in Pan we observe a significant increase in buccal phase I facets. The latter group also displays the highest macrowear variation across the sample examined in this study. Conclusions The molar macrowear patterns of the great apes analyzed in this study did not confirm our initial hypothesis of finding larger crushing and grinding areas in Pongo and more shearing wear in Gorilla. Pan shows the most variable macrowear, which is probably associated with their more flexible diet. The similarity between Pongo and Gorilla macrowear patterns may be due to a larger intake of mechanically challenging foods that could obfuscate dietary wear signals generated by softer foods.
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Affiliation(s)
- Luca Fiorenza
- Biomedicine Discovery Institute, Department of Anatomy and Developmental Biology Monash University Melbourne Victoria Australia
| | - Teagan Harty
- Biomedicine Discovery Institute, Department of Anatomy and Developmental Biology Monash University Melbourne Victoria Australia
| | - Marcel M. Janocha
- Division of Palaeoanthropology Senckenberg Research Institute and Natural History Museum Frankfurt Frankfurt am Main Germany
- Department of Palaeobiology and Environment, Institute of Ecology Evolution, and Diversity, Goethe University Frankfurt Germany
| | - Ottmar Kullmer
- Division of Palaeoanthropology Senckenberg Research Institute and Natural History Museum Frankfurt Frankfurt am Main Germany
- Department of Palaeobiology and Environment, Institute of Ecology Evolution, and Diversity, Goethe University Frankfurt Germany
| | - Huynh N. Nguyen
- School of Mechanical Engineering Hanoi University of Science and Technology Hanoi Vietnam
| | - Eugenio Bortolini
- Department of Archaeology and Anthropology, Institución Milá y Fontanals de investigación en Humanidades Consejo Superior de Investigaciones Científicas (IMF – CSIC) Barcelona Spain
- Culture and Socio‐Ecological Dynamics, Department of Humanities Universitat Pompeu Fabra Barcelona Spain
| | - Stefano Benazzi
- Department of Cultural Heritage University of Bologna Ravenna Italy
- Department of Human Evolution Max Planck Institute for Evolutionary Anthropology Leipzig Germany
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Sign-oriented Dirichlet Normal Energy: Aligning Dental Topography and Dental Function in the R-package molaR. J MAMM EVOL 2022. [DOI: 10.1007/s10914-022-09616-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Lee J, Fung S, Yong R, Ranjitkar S, Kaidonis J, Evans AR, Fiorenza L. Tooth wear development in the Australian Aboriginal dentition from Yuendumu: A longitudinal study. PLoS One 2021; 16:e0254151. [PMID: 34242291 PMCID: PMC8270463 DOI: 10.1371/journal.pone.0254151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 06/22/2021] [Indexed: 11/29/2022] Open
Abstract
The analysis of dental wear, at both the microscopic and macroscopic scale, is one of the most widely used tools in archeology and anthropology to reconstruct the diet and lifestyle of past human populations. Biomechanical studies have indicated that tooth wear helps to dissipate the mechanical load over the crown surface, thus reducing the risk of tooth fracture. To date, there are only a few studies that have examined functional tooth wear variation in modern humans. Here we propose to study masticatory efficiency through the use of the Occlusal Fingerprint Analysis method, a well-developed digital approach that allows the reconstruction of the occlusal dynamics occurring during mastication. The aim of this study is to provide the first longitudinal quantitative data of molar and premolar macrowear patterns within a functional context. We examined the mixed and permanent dentition of one Australian Aboriginal child (from ages 8 to 17) from Yuendumu, using high-resolution surface scans of dental casts including both upper and lower arches. Our results suggest that the occlusal macrowear patterns of this individual did not significantly change through time. Occlusal contact parameters such as functional area, inclination and direction remain relatively unaltered throughout childhood and adolescence, indicating little change in the masticatory function of this individual. The functional tooth wear pattern in this individual did not change longitudinally indicating the degree of masticatory efficiency has most probably remained unaltered.
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Affiliation(s)
- Jinyoung Lee
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Sarah Fung
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Robin Yong
- Adelaide Dental School, University of Adelaide, Adelaide, South Australia, Australia
| | - Sarbin Ranjitkar
- Adelaide Dental School, University of Adelaide, Adelaide, South Australia, Australia
| | - John Kaidonis
- Adelaide Dental School, University of Adelaide, Adelaide, South Australia, Australia
| | - Alistair R. Evans
- School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
- Geosciences, Museums Victoria, Melbourne, Victoria, Australia
| | - Luca Fiorenza
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
- Earth Sciences, University of New England, Armidale, New South Wales, Australia
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Karagic N, Meyer A, Hulsey CD. Phenotypic Plasticity in Vertebrate Dentitions. Integr Comp Biol 2021; 60:608-618. [PMID: 32544244 DOI: 10.1093/icb/icaa077] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Vertebrates interact directly with food items through their dentition, and these interactions with trophic resources could often feedback to influence tooth structure. Although dentitions are often considered to be a fixed phenotype, there is the potential for environmentally induced phenotypic plasticity in teeth to extensively influence their diversity. Here, we review the literature concerning phenotypic plasticity of vertebrate teeth. Even though only a few taxonomically disparate studies have focused on phenotypic plasticity in teeth, there are a number of ways teeth can change their size, shape, or patterns of replacement as a response to the environment. Elucidating the underlying physiological, developmental, and genetic mechanisms that generate phenotypic plasticity can clarify its potential role in the evolution of dental phenotypes.
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Affiliation(s)
- Nidal Karagic
- Department for Zoology and Evolutionary Biology, University of Konstanz, Universitätsstraße 10, Konstanz, 78467, Germany
| | - Axel Meyer
- Department for Zoology and Evolutionary Biology, University of Konstanz, Universitätsstraße 10, Konstanz, 78467, Germany
| | - C Darrin Hulsey
- Department for Zoology and Evolutionary Biology, University of Konstanz, Universitätsstraße 10, Konstanz, 78467, Germany
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15
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Li L, Chen H, Zhao Y, Wang Y, Sun Y. Design of occlusal wear facets of fixed dental prostheses driven by personalized mandibular movement. J Prosthet Dent 2021; 128:33-41. [PMID: 33549341 DOI: 10.1016/j.prosdent.2020.09.055] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 09/13/2020] [Accepted: 09/14/2020] [Indexed: 11/16/2022]
Abstract
STATEMENT OF PROBLEM Existing virtual articulators simulate mandibular movement by using various parameters and are used to design restorations. However, they are not able to reproduce actual patient movements, and the designs of occlusal wear facets by them and by personalized mandibular movement have not been compared. PURPOSE The purpose of this clinical study was to establish a clinical application protocol for a virtual articulator based on previous research and to evaluate the accuracy of the occlusal wear facets designed by it. MATERIAL AND METHODS The gypsum casts of 12 participants were scanned with a cast scanner as the original data. A single crown, 3-unit splinted crowns, a 5-unit fixed partial denture, and a fixed complete denture were virtually prepared on the digital mandibular casts by using the Geomagic Studio 2013 software program. High points were created at the wear facets, and corresponding digital wax patterns with occlusal interferences were generated. The exocad software program was used to design corresponding restorations with the copy method. Static (STA restoration) and dynamic (DYN restoration) occlusal adjustments were carried out with the built-in virtual articulator. The mandibular movements of participants were recorded by the novel virtual articulator system, and the occlusal surfaces of the digital wax patterns were adjusted (FUN restoration). The restorations adjusted with the 3 methods were compared with the original data. The mean value and root mean square (RMS) of 3D deviation and positive volumes (V+) in the occlusal direction were measured. Depending on the normality, 1-way ANOVA and the Kruskal-Wallis test were used to analyze the influence of occlusal surface design methods on the morphology of occlusal wear facets (α=.05). RESULTS The mean deviation of the 4 kinds of STA restorations ranged from 0.19 mm to 0.22 mm, the DYN restorations from 0.13 mm to 0.17 mm, and the FUN restorations from 0.03 mm to 0.09 mm. A significant difference was found between the STA and FUN restorations of the 3-unit splinted crowns and 5-unit fixed partial dentures (Ρ=.013, Ρ=.021). The mean values of 3D deviation and V+ decreased from the STA group to the DYN group and then to the FUN group. The RMS and V+ were statistically similar (Ρ>.05). CONCLUSIONS The preliminary results of the study indicate that the FUN 3-unit splinted crowns and 5-unit fixed partial dentures designed with the self-developed virtual articulator were better than the STA restorations. The FUN restorations were more coincident with the morphology of the wear facets on the original teeth.
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Affiliation(s)
- Linlin Li
- Doctoral student, Faculty of Prosthodontics, Center of Digital Dentistry, Peking University School and Hospital of Stomatology & National Engineering Laboratory for Digital and Material Technology of Stomatology & Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health & Beijing Key Laboratory of Digital Stomatology, National Clinical Research Center for Oral Diseases, Beijing, PR China
| | - Hu Chen
- Attending Doctor, Faculty of Prosthodontics, Center of Digital Dentistry, Peking University School and Hospital of Stomatology & National Engineering Laboratory for Digital and Material Technology of Stomatology & Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health & Beijing Key Laboratory of Digital Stomatology, National Clinical Research Center for Oral Diseases, Beijing, PR China
| | - Yijiao Zhao
- Senior Engineer, Faculty of Prosthodontics, Center of Digital Dentistry, Peking University School and Hospital of Stomatology & National Engineering Laboratory for Digital and Material Technology of Stomatology & Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health & Beijing Key Laboratory of Digital Stomatology, National Clinical Research Center for Oral Diseases, Beijing, PR China
| | - Yong Wang
- Professor, Faculty of Prosthodontics, Center of Digital Dentistry, Peking University School and Hospital of Stomatology & National Engineering Laboratory for Digital and Material Technology of Stomatology & Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health & Beijing Key Laboratory of Digital Stomatology, National Clinical Research Center for Oral Diseases, Beijing, PR China
| | - Yuchun Sun
- Professor, Faculty of Prosthodontics, Center of Digital Dentistry, Peking University School and Hospital of Stomatology & National Engineering Laboratory for Digital and Material Technology of Stomatology & Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health & Beijing Key Laboratory of Digital Stomatology, National Clinical Research Center for Oral Diseases, Beijing, PR China.
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16
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Li L, Chen H, Li W, Wang Y, Sun Y. The Effect of Residual Dentition on the Dynamic Adjustment of Wear Facet Morphology on a Mandibular First Molar Crown. J Prosthodont 2020; 30:351-355. [PMID: 33210775 DOI: 10.1111/jopr.13290] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/12/2020] [Indexed: 12/14/2022] Open
Abstract
PURPOSE To evaluate the effect of different residual dentitions on the dynamic adjustment of wear facet morphology on a single mandibular first molar crown with a virtual articulator. MATERIALS AND METHODS Gypsum casts (N = 12) of natural full dentitions were mounted on an articulator and scanned. The mandibular right first molar (#46) was prepared and a copy of the tooth before it was prepared and used to design the crown. The wear facets on the original #46 were selected and elevated by 0.3 mm in the occlusal direction to generate high points. The #46 with high points was segmented to create a digital wax pattern. Then different teeth were virtually removed to generate 4 types of residual dentitions: Type I (no teeth), Type II (adjacent teeth), Type III (ipsilateral posterior teeth and canine), and Type IV (all teeth). The crowns were adjusted dynamically with different residual teeth to guide mandibular movement of the virtual articulator. Three-dimensional deviations, negative and positive volumes between crowns and wear facets on the original #46 were analyzed. The Kruskal-Wallis test was used to analyze the results. RESULTS The mean deviation values and positive volumes decreased with the decrease in residual teeth, and the negative volumes showed an opposite trend. The mean deviation values, root mean square, and positive volumes were not significantly different. The negative volume of the crowns of Type I was different from that of Type IV (p = 0.031). CONCLUSIONS Residual dentition affects the dynamic adjustment of wear facet morphology. When there are insufficient residual teeth, mandibular movements should be accurately measured.
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Affiliation(s)
- Linlin Li
- Center of Digital Dentistry, Faculty of Prosthodontics, Peking University School and Hospital of Stomatology & National Engineering Laboratory for Digital and Material Technology of Stomatology & Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health & Beijing Key Laboratory of Digital Stomatology, National Clinical Research Center for Oral Diseases, Beijing, PR China
| | - Hu Chen
- Center of Digital Dentistry, Faculty of Prosthodontics, Peking University School and Hospital of Stomatology & National Engineering Laboratory for Digital and Material Technology of Stomatology & Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health & Beijing Key Laboratory of Digital Stomatology, National Clinical Research Center for Oral Diseases, Beijing, PR China
| | - Weiwei Li
- Center of Digital Dentistry, Faculty of Prosthodontics, Peking University School and Hospital of Stomatology & National Engineering Laboratory for Digital and Material Technology of Stomatology & Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health & Beijing Key Laboratory of Digital Stomatology, National Clinical Research Center for Oral Diseases, Beijing, PR China
| | - Yong Wang
- Center of Digital Dentistry, Faculty of Prosthodontics, Peking University School and Hospital of Stomatology & National Engineering Laboratory for Digital and Material Technology of Stomatology & Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health & Beijing Key Laboratory of Digital Stomatology, National Clinical Research Center for Oral Diseases, Beijing, PR China
| | - Yuchun Sun
- Center of Digital Dentistry, Faculty of Prosthodontics, Peking University School and Hospital of Stomatology & National Engineering Laboratory for Digital and Material Technology of Stomatology & Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health & Beijing Key Laboratory of Digital Stomatology, National Clinical Research Center for Oral Diseases, Beijing, PR China
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Pultanasarn P, Thaungwilai K, Singhatanadgid P, Prateepsawangwong B, Singhatanadgit W. Composite core-supported stainless steel crowns enhance fracture resistance of severely damaged primary posterior teeth. PEDIATRIC DENTAL JOURNAL 2020. [DOI: 10.1016/j.pdj.2020.07.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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18
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秦 文, 丛 明, 任 翔, 刘 冬. [Stress analysis of the molar with the all-ceramic crown prosthesis based on centric occlusal optimization]. SHENG WU YI XUE GONG CHENG XUE ZA ZHI = JOURNAL OF BIOMEDICAL ENGINEERING = SHENGWU YIXUE GONGCHENGXUE ZAZHI 2020; 37:802-808. [PMID: 33140603 PMCID: PMC10320551 DOI: 10.7507/1001-5515.201902013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Indexed: 11/03/2022]
Abstract
Stress distribution of denture is an important criterion to evaluate the reasonableness of technological parameters, and the bite force derived from the antagonist is the critical load condition for the calculation of stress distribution. In order to improve the accuracy of stress distribution as much as possible, all-ceramic crown of the mandibular first molar with centric occlusion was taken as the research object, and a bite force loading method reflecting the actual occlusal situation was adopted. Firstly, raster scanning and three dimensional reconstruction of the occlusal surface of molars in the standard dental model were carried out. Meanwhile, the surface modeling of the bonding surface was carried out according to the preparation process. Secondly, the parametric occlusal analysis program was developed with the help of OFA function library, and the genetic algorithm was used to optimize the mandibular centric position. Finally, both the optimized case of the mesh model based on the results of occlusal optimization and the referenced case according to the cusp-fossa contact characteristics were designed. The stress distribution was analyzed and compared by using Abaqus software. The results showed that the genetic algorithm was suitable for solving the occlusal optimization problem. Compared with the reference case, the optimized case had smaller maximum stress and more uniform stress distribution characteristics. The proposed method further improves the stress accuracy of the prosthesis in the finite element model. Also, it provides a new idea for stress analysis of other joints in human body.
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Affiliation(s)
- 文龙 秦
- 大连理工大学 机械工程学院(辽宁大连 116024)School of Mechanical Engineering, Dalian University of Technology, Dalian, Liaoning 116024, P.R.China
| | - 明 丛
- 大连理工大学 机械工程学院(辽宁大连 116024)School of Mechanical Engineering, Dalian University of Technology, Dalian, Liaoning 116024, P.R.China
| | - 翔 任
- 大连理工大学 机械工程学院(辽宁大连 116024)School of Mechanical Engineering, Dalian University of Technology, Dalian, Liaoning 116024, P.R.China
| | - 冬 刘
- 大连理工大学 机械工程学院(辽宁大连 116024)School of Mechanical Engineering, Dalian University of Technology, Dalian, Liaoning 116024, P.R.China
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19
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秦 文, 丛 明, 任 翔, 刘 冬. [Equivalent modeling and evaluation of molars using point-contact higher kinematic pair based on occlusal dynamic analysis]. SHENG WU YI XUE GONG CHENG XUE ZA ZHI = JOURNAL OF BIOMEDICAL ENGINEERING = SHENGWU YIXUE GONGCHENGXUE ZAZHI 2020; 37:614-621. [PMID: 32840078 PMCID: PMC10319553 DOI: 10.7507/1001-5515.201906021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Indexed: 11/03/2022]
Abstract
As a representative part of the oral system and masticatory robot system, the modeling method of the dental model is an important factor influencing the accuracy of the multi-body dynamic model. Taking the right first molars of the masticatory robot as the research object, an equivalent model, point-contact higher kinematic pair composed of v-shaped surface and sphere surface, was proposed. Firstly, the finite element method was used to analyze the occlusal dynamics of the original model in three static contact cases (intrusive contact, centric occlusion, and extrusive contact) and one dynamic chewing case, and the expected bite force was obtained. Secondly, the Hertz contact model was adopted to establish the analytical expression of the bite force of the equivalent model in three static contact cases. The normal vectors and contact stiffness in the expression were designed according to the expected bite force. Finally, the bite force performance of the equivalent model in three static contact cases and one dynamic chewing case was evaluated. The results showed that the equivalent model could achieve the equivalent bite force of 8 expected items in the static contact cases. Meanwhile, the bite force in the early and late stages of the dynamic chewing case coincides well with the original model. In the middle stage, a certain degree of impact is introduced, but it can be weakened by subsequent trajectory planning. The equivalent modeling scheme of the dental model proposed in this paper further improves the accuracy of the dynamic model of the multi-body system. It provides a new idea for the dynamic modeling of other complex human contacts.
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Affiliation(s)
- 文龙 秦
- 大连理工大学 机械工程学院(辽宁大连 116024)School of Mechanical Engineering, Dalian University of Technology, Dalian, Liaoning 116024, P.R.China
| | - 明 丛
- 大连理工大学 机械工程学院(辽宁大连 116024)School of Mechanical Engineering, Dalian University of Technology, Dalian, Liaoning 116024, P.R.China
| | - 翔 任
- 大连理工大学 机械工程学院(辽宁大连 116024)School of Mechanical Engineering, Dalian University of Technology, Dalian, Liaoning 116024, P.R.China
| | - 冬 刘
- 大连理工大学 机械工程学院(辽宁大连 116024)School of Mechanical Engineering, Dalian University of Technology, Dalian, Liaoning 116024, P.R.China
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20
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Martínez de Pinillos M, Martín-Francés L, de Castro JMB, García-Campos C, Modesto-Mata M, Martinón-Torres M, Vialet A. Inner morphological and metric characterization of the molar remains from the Montmaurin-La Niche mandible: The Neanderthal signal. J Hum Evol 2020; 145:102739. [DOI: 10.1016/j.jhevol.2019.102739] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 11/06/2019] [Accepted: 11/20/2019] [Indexed: 10/24/2022]
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21
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Fiorenza L, Menter CG, Fung S, Lee J, Kaidonis J, Moggi-Cecchi J, Townsend G, Kullmer O. The functional role of the Carabelli trait in early and late hominins. J Hum Evol 2020; 145:102816. [PMID: 32580080 DOI: 10.1016/j.jhevol.2020.102816] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 04/17/2020] [Accepted: 04/17/2020] [Indexed: 01/04/2023]
Abstract
The Carabelli trait is a dental feature that forms along the lingual margin of the protocone of deciduous and permanent maxillary molars. It is variably expressed, ranging from a small pit or furrow to a large cusp, and its development seems to be associated with crown size and molar cusp spatial configuration. The degree of expression of the Carabelli trait differs systematically between hominin taxa, and for this reason, it has been used extensively in the reconstruction of their phylogeny. However, the functional implications of having a large Carabelli trait remain unclear. In this study, we analyze the macrowear pattern of maxillary molars of early and late hominins using the occlusal fingerprint analysis method, an approach based on digital models of teeth that helps in reconstructing occlusal dynamics occurring during mastication. Tooth crowns with a small Carabelli cusp generally exhibit larger wear contact areas that extended cervically, while two additional new occlusal contact areas are common in teeth characterized by a large Carabelli cusp. These wear areas are created at the beginning of the chewing cycle, when occluding with the slopes of the lingual groove of the lower molars, between the metaconid and entoconid cusps. Advancing tooth wear leads to a slight enlargement of Carabelli occlusal contacts increasing their functional area. A steep inclination could be mechanically important in food reduction and in balancing the functional load distribution during mastication contacts. Steep wear areas are particularly developed in primates that process foods characterized by tough and fibrous textural properties. Future biomechanical and microwear texture analyses could provide additional information on the mechanical adaptation of this dental trait.
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Affiliation(s)
- Luca Fiorenza
- Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, 3800, Australia; Earth Sciences, University of New England, Armidale, NSW, 2351, Australia.
| | - Colin G Menter
- Department of Biology, University of Florence, 50122, Firenze, Italy
| | - Sarah Fung
- Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, 3800, Australia
| | - Jinyoung Lee
- Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, 3800, Australia
| | - John Kaidonis
- Adelaide Dental School, University of Adelaide, Adelaide, SA, 5005, Australia
| | | | - Grant Townsend
- Adelaide Dental School, University of Adelaide, Adelaide, SA, 5005, Australia
| | - Ottmar Kullmer
- Department of Paleoanthropology, Senckenberg Research Institute and Natural History Museum Frankfurt, Senckenberganlage 25, 60325 Frankfurt a. M., Germany; Department of Paleobiology and Environment, Institute of Ecology, Evolution, and Diversity, Johann Wolfgang Goethe University, Max-von-Laue-Str. 13, 60438, Frankfurt, Germany
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22
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Lockey AL, Alemseged Z, Hublin JJ, Skinner MM. Maxillary molar enamel thickness of Plio-Pleistocene hominins. J Hum Evol 2020; 142:102731. [DOI: 10.1016/j.jhevol.2019.102731] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 11/19/2019] [Accepted: 12/02/2019] [Indexed: 11/30/2022]
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23
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Dental macrowear and cortical bone distribution of the Neanderthal mandible from Regourdou (Dordogne, Southwestern France). J Hum Evol 2019; 132:174-188. [PMID: 31203846 DOI: 10.1016/j.jhevol.2019.05.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 05/04/2019] [Accepted: 05/04/2019] [Indexed: 01/10/2023]
Abstract
Tooth wear is an important feature for reconstructing diet, food processing and cultural habits of past human populations. In particular, occlusal wear facets can be extremely useful for detecting information about diet and non-masticatory behaviors. The aim of this study is to reconstruct the diet and cultural behavior of the Neanderthal specimen Regourdou 1 (Dordogne, Southern France) from the analysis of the macrowear pattern, using the occlusal fingerprint analysis method. In addition, we have also examined whether there is any association between the observed dental macrowear and mandibular bone distribution and root dentine thickness. The posterior dentition of Regourdou 1 is characterized by an asymmetric wear pattern, with the right side significantly more worn than the left. In contrast, the left lower P3 shows a more advanced wear than the right premolar, with unusual semicircular enamel wear facets. The results from occlusal fingerprint analysis of this unique pattern suggest tooth-tool uses for daily task activities. Moreover, the left buccal aspect of the mandibular cortical bone is thicker than its right counterpart, and the left P3 has a thicker radicular dentine layer than its antimere. These results show a certain degree of asymmetry in cortical bone topography and dentine tissue that could be associated with the observed dental macrowear pattern. The molar macrowear pattern also suggests that Regourdou 1 had a mixed diet typical of those populations living in temperate deciduous woodlands and Mediterranean habitats, including animal and plant foods. Although this study is limited to one Neanderthal individual, future analyses based on a larger sample may further assist us to better understand the existing relationship between mandibular architecture, occlusal wear and the masticatory apparatus in humans.
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24
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Zanolli C, Pan L, Dumoncel J, Kullmer O, Kundrát M, Liu W, Macchiarelli R, Mancini L, Schrenk F, Tuniz C. Inner tooth morphology of Homo erectus from Zhoukoudian. New evidence from an old collection housed at Uppsala University, Sweden. J Hum Evol 2018; 116:1-13. [DOI: 10.1016/j.jhevol.2017.11.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 10/31/2017] [Accepted: 11/02/2017] [Indexed: 01/10/2023]
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25
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Ledogar JA, Benazzi S, Smith AL, Weber GW, Carlson KB, Dechow PC, Grosse IR, Ross CF, Richmond BG, Wright BW, Wang Q, Byron C, Carlson KJ, De Ruiter DJ, Pryor Mcintosh LC, Strait DS. The Biomechanics of Bony Facial "Buttresses" in South African Australopiths: An Experimental Study Using Finite Element Analysis. Anat Rec (Hoboken) 2017; 300:171-195. [PMID: 28000396 DOI: 10.1002/ar.23492] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Revised: 08/29/2016] [Accepted: 09/06/2016] [Indexed: 11/08/2022]
Abstract
Australopiths exhibit a number of derived facial features that are thought to strengthen the face against high and/or repetitive loads associated with a diet that included mechanically challenging foods. Here, we use finite element analysis (FEA) to test hypotheses related to the purported strengthening role of the zygomatic root and "anterior pillar" in australopiths. We modified our previously constructed models of Sts 5 (Australopithecus africanus) and MH1 (A. sediba) to differ in the morphology of the zygomatic root, including changes to both the shape and positioning of the zygomatic root complex, in addition to creating variants of Sts 5 lacking anterior pillars. We found that both an expanded zygomatic root and the presence of "anterior pillars" reinforce the face against feeding loads. We also found that strain orientations are most compatible with the hypothesis that the pillar evolved to resist loads associated with premolar loading, and that this morphology has an ancillary effect of strengthening the face during all loading regimes. These results provide support for the functional hypotheses. However, we found that an anteriorly positioned zygomatic root increases strain magnitudes even in models with an inflated/reinforced root complex. These results suggest that an anteriorly placed zygomatic root complex evolved to enhance the efficiency of bite force production while facial reinforcement features, such as the anterior pillar and the expanded zygomatic root, may have been selected for in part to compensate for the weakening effect of this facial configuration. Anat Rec, 300:171-195, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Justin A Ledogar
- Zoology Division, School of Environmental and Rural Science, University of New England, Armidale, NSW, 2351, Australia.,Department of Anthropology, University at Albany, Albany, New York
| | - Stefano Benazzi
- Department of Cultural Heritage, University of Bologna, Ravenna, 48121, Italy.,Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, 04103, Germany
| | - Amanda L Smith
- Department of Anthropology, University at Albany, Albany, New York.,Department of Anthropology, Washington University in St. Louis, St. Louis, Missouri
| | - Gerhard W Weber
- Department of Anthropology, University of Vienna, Vienna, A-1090, Austria
| | - Keely B Carlson
- Department of Anthropology, Texas A&M University, College Station, Texas
| | - Paul C Dechow
- School of Science and Mathematics, Abraham Baldwin Agricultural College, Tifton, Georgia 30605
| | - Ian R Grosse
- Department of Mechanical and Industrial Engineering, University of Massachusetts, Amherst, Massachusetts
| | - Callum F Ross
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, Illinois
| | - Brian G Richmond
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, 04103, Germany.,Division of Anthropology, American Museum of Natural History, New York, New York
| | - Barth W Wright
- Department of Anatomy, Kansas City University of Medicine and Biosciences, Kansas City, Missouri
| | - Qian Wang
- School of Science and Mathematics, Abraham Baldwin Agricultural College, Tifton, Georgia 30605
| | - Craig Byron
- Department of Biology, Mercer University, Macon, Georgia
| | - Kristian J Carlson
- Department of Cell and Neurobiology, Keck School of Medicine, University of Southern California, Los Angeles, California.,Evolutionary Studies Institute, University of the Witwatersrand, Wits, 2050, South Africa
| | - Darryl J De Ruiter
- Department of Anthropology, Texas A&M University, College Station, Texas.,Evolutionary Studies Institute, University of the Witwatersrand, Wits, 2050, South Africa
| | - Leslie C Pryor Mcintosh
- School of Science and Mathematics, Abraham Baldwin Agricultural College, Tifton, Georgia 30605
| | - David S Strait
- Department of Anthropology, University at Albany, Albany, New York.,Department of Anthropology, Washington University in St. Louis, St. Louis, Missouri
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Was Mesopithecus a seed eating colobine? Assessment of cracking, grinding and shearing ability using dental topography. J Hum Evol 2017; 112:79-92. [DOI: 10.1016/j.jhevol.2017.09.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 08/28/2017] [Accepted: 09/05/2017] [Indexed: 11/20/2022]
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Buti L, Le Cabec A, Panetta D, Tripodi M, Salvadori PA, Hublin JJ, Feeney RNM, Benazzi S. 3D enamel thickness in Neandertal and modern human permanent canines. J Hum Evol 2017; 113:162-172. [PMID: 29054166 PMCID: PMC5667889 DOI: 10.1016/j.jhevol.2017.08.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 07/27/2017] [Accepted: 08/03/2017] [Indexed: 01/07/2023]
Abstract
Enamel thickness figures prominently in studies of human evolution, particularly for taxonomy, phylogeny, and paleodietary reconstruction. Attention has focused on molar teeth, through the use of advanced imaging technologies and novel protocols. Despite the important results achieved thus far, further work is needed to investigate all tooth classes. We apply a recent approach developed for anterior teeth to investigate the 3D enamel thickness of Neandertal and modern human (MH) canines. In terms of crown size, the values obtained for both upper and lower unworn/slightly worn canines are significantly greater in Neandertals than in Upper Paleolithic and recent MH. The 3D relative enamel thickness (RET) is significantly lower in Neandertals than in MH. Moreover, differences in 3D RET values between the two groups appear to decrease in worn canines beginning from wear stage 3, suggesting that both the pattern and the stage of wear may have important effects on the 3D RET value. Nevertheless, the 3D average enamel thickness (AET) does not differ between the two groups. In both groups, 3D AET and 3D RET indices are greater in upper canines than in lower canines, and overall the enamel is thicker on the occlusal half of the labial aspect of the crown, particularly in MH. By contrast, the few early modern humans investigated show the highest volumes of enamel while for all other components of 3D enamel, thickness this group holds an intermediate position between Neandertals and recent MH. Overall, our study supports the general findings that Neandertals have relatively thinner enamel than MH (as also observed in molars), indicating that unworn/slightly worn canines can be successfully used to discriminate between the two groups. Further studies, however, are needed to understand whether these differences are functionally related or are the result of pleiotropic or genetic drift effects.
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Affiliation(s)
- Laura Buti
- Department of Cultural Heritage, University of Bologna, V. Ariani, 1, 48121 Ravenna, Italy.
| | - Adeline Le Cabec
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany; ESRF - The European Synchrotron, 71, Avenue des Martyrs, CS 40220, F-38043 Grenoble Cédex 9, France.
| | - Daniele Panetta
- Institute of Clinical Physiology - CNR, Via Moruzzi, 1, 56127 Pisa, Italy.
| | - Maria Tripodi
- Institute of Clinical Physiology - CNR, Via Moruzzi, 1, 56127 Pisa, Italy.
| | - Piero A Salvadori
- Institute of Clinical Physiology - CNR, Via Moruzzi, 1, 56127 Pisa, Italy.
| | - Jean-Jacques Hublin
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany.
| | - Robin N M Feeney
- UCD School of Medicine, Health Science Centre, University College Dublin, Belfield, Dublin 4, Ireland.
| | - Stefano Benazzi
- Department of Cultural Heritage, University of Bologna, V. Ariani, 1, 48121 Ravenna, Italy; Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany.
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28
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Margherita C, Oxilia G, Barbi V, Panetta D, Hublin JJ, Lordkipanidze D, Meshveliani T, Jakeli N, Matskevich Z, Bar-Yosef O, Belfer-Cohen A, Pinhasi R, Benazzi S. Morphological description and morphometric analyses of the Upper Palaeolithic human remains from Dzudzuana and Satsurblia caves, western Georgia. J Hum Evol 2017; 113:83-90. [PMID: 29054170 DOI: 10.1016/j.jhevol.2017.07.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 07/24/2017] [Accepted: 07/24/2017] [Indexed: 11/16/2022]
Affiliation(s)
- Cristiana Margherita
- Department of Cultural Heritage, University of Bologna, Via Ddegli Ariani 1, 48121 Ravenna, Italy
| | - Gregorio Oxilia
- Department of Cultural Heritage, University of Bologna, Via Ddegli Ariani 1, 48121 Ravenna, Italy; Department of Biology, University of Florence, Via Ddel Proconsolo 12, 50122 Firenze, Italy
| | - Veronica Barbi
- Department of Cultural Heritage, University of Bologna, Via Ddegli Ariani 1, 48121 Ravenna, Italy
| | | | - Jean-Jacques Hublin
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
| | | | | | - Nino Jakeli
- Georgian National Museum, Department of Prehistory, Tbilisi, Georgia
| | | | - Ofer Bar-Yosef
- Department of Anthropology, Peabody Museum, Harvard University, 11 Divinity Avenue, Cambridge, MA 02138, USA
| | - Anna Belfer-Cohen
- The Institute of Archaeology, The Hebrew University of Jerusalem, Mount Scopus, Jerusalem 91905, Israel
| | - Ron Pinhasi
- School of Archaeology and Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland; Department of Anthropology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria.
| | - Stefano Benazzi
- Department of Cultural Heritage, University of Bologna, Via Ddegli Ariani 1, 48121 Ravenna, Italy; Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany.
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29
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Knight-Sadler J, Fiorenza L. Tooth Wear Inclination in Great Ape Molars. Folia Primatol (Basel) 2017; 88:223-236. [DOI: 10.1159/000478775] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 06/18/2017] [Indexed: 11/19/2022]
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30
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Further morphological evidence on South African earliest Homo lower postcanine dentition: Enamel thickness and enamel dentine junction. J Hum Evol 2016; 96:82-96. [DOI: 10.1016/j.jhevol.2016.05.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 05/03/2016] [Accepted: 05/04/2016] [Indexed: 11/23/2022]
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31
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Benazzi S, Nguyen HN, Kullmer O, Kupczik K. Dynamic Modelling of Tooth Deformation Using Occlusal Kinematics and Finite Element Analysis. PLoS One 2016; 11:e0152663. [PMID: 27031836 PMCID: PMC4816422 DOI: 10.1371/journal.pone.0152663] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 03/17/2016] [Indexed: 11/18/2022] Open
Abstract
Background Dental biomechanics based on finite element (FE) analysis is attracting enormous interest in dentistry, biology, anthropology and palaeontology. Nonetheless, several shortcomings in FE modeling exist, mainly due to unrealistic loading conditions. In this contribution we used kinematics information recorded in a virtual environment derived from occlusal contact detection between high resolution models of an upper and lower human first molar pair (M1 and M1, respectively) to run a non-linear dynamic FE crash colliding test. Methodology MicroCT image data of a modern human skull were segmented to reconstruct digital models of the antagonistic right M1 and M1 and the dental supporting structures. We used the Occlusal Fingerprint Analyser software to reconstruct the individual occlusal pathway trajectory during the power stroke of the chewing cycle, which was applied in a FE simulation to guide the M1 3D-path for the crash colliding test. Results FE analysis results showed that the stress pattern changes considerably during the power stroke, demonstrating that knowledge about chewing kinematics in conjunction with a morphologically detailed FE model is crucial for understanding tooth form and function under physiological conditions. Conclusions/Significance Results from such advanced dynamic approaches will be applicable to evaluate and avoid mechanical failure in prosthodontics/endodontic treatments, and to test material behavior for modern tooth restoration in dentistry. This approach will also allow us to improve our knowledge in chewing-related biomechanics for functional diagnosis and therapy, and it will help paleoanthropologists to illuminate dental adaptive processes and morphological modifications in human evolution.
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Affiliation(s)
- Stefano Benazzi
- Department of Cultural Heritage, University of Bologna, Ravenna, Italy.,Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Huynh Nhu Nguyen
- Department of Biomaterials, Max-Planck-Institute of Colloids and Interfaces, Potsdam, Germany
| | - Ottmar Kullmer
- Department of Palaeoanthropology and Messel Research, Senckenberg Research Institute, Frankfurt am Main, Germany
| | - Kornelius Kupczik
- Max Planck Weizmann Center for Integrative Archaeology and Anthropology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
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32
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Constantino PJ, Borrero‐Lopez O, Pajares A, Lawn BR. Simulation of enamel wear for reconstruction of diet and feeding behavior in fossil animals: A micromechanics approach. Bioessays 2015; 38:89-99. [DOI: 10.1002/bies.201500094] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | - Oscar Borrero‐Lopez
- Departamento de Ingeniería MecánicaEnergética y de los MaterialesUniversidad de ExtremaduraBadajozSpain
| | - Antonia Pajares
- Departamento de Ingeniería MecánicaEnergética y de los MaterialesUniversidad de ExtremaduraBadajozSpain
| | - Brian R. Lawn
- Materials Measurement LaboratoryNational Institute of Standards and TechnologyGaithersburgMDUSA
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33
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Oxilia G, Peresani M, Romandini M, Matteucci C, Spiteri CD, Henry AG, Schulz D, Archer W, Crezzini J, Boschin F, Boscato P, Jaouen K, Dogandzic T, Broglio A, Moggi-Cecchi J, Fiorenza L, Hublin JJ, Kullmer O, Benazzi S. Earliest evidence of dental caries manipulation in the Late Upper Palaeolithic. Sci Rep 2015; 5:12150. [PMID: 26179739 PMCID: PMC4504065 DOI: 10.1038/srep12150] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 06/17/2015] [Indexed: 11/09/2022] Open
Abstract
Prehistoric dental treatments were extremely rare, and the few documented cases are known from the Neolithic, when the adoption of early farming culture caused an increase of carious lesions. Here we report the earliest evidence of dental caries intervention on a Late Upper Palaeolithic modern human specimen (Villabruna) from a burial in Northern Italy. Using Scanning Electron Microscopy we show the presence of striations deriving from the manipulation of a large occlusal carious cavity of the lower right third molar. The striations have a “V”-shaped transverse section and several parallel micro-scratches at their base, as typically displayed by cutmarks on teeth. Based on in vitro experimental replication and a complete functional reconstruction of the Villabruna dental arches, we confirm that the identified striations and the associated extensive enamel chipping on the mesial wall of the cavity were produced ante-mortem by pointed flint tools during scratching and levering activities. The Villabruna specimen is therefore the oldest known evidence of dental caries intervention, suggesting at least some knowledge of disease treatment well before the Neolithic. This study suggests that primitive forms of carious treatment in human evolution entail an adaptation of the well-known toothpicking for levering and scratching rather than drilling practices.
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Affiliation(s)
- Gregorio Oxilia
- 1] Department of Biology, University of Florence, Via del Proconsolo, 12, 50122 Firenze, Italy [2] Department of Cultural Heritage, University of Bologna, Via degli Ariani 1, 48121 Ravenna, Italy [3] Sezione di Scienze Preistoriche e Antropologiche, Dipartimento di Studi Umanistici, Corso Ercole I d'Este 32, Università di Ferrara, 44100 Ferrara, Italy
| | - Marco Peresani
- Sezione di Scienze Preistoriche e Antropologiche, Dipartimento di Studi Umanistici, Corso Ercole I d'Este 32, Università di Ferrara, 44100 Ferrara, Italy
| | - Matteo Romandini
- Sezione di Scienze Preistoriche e Antropologiche, Dipartimento di Studi Umanistici, Corso Ercole I d'Este 32, Università di Ferrara, 44100 Ferrara, Italy
| | - Chiara Matteucci
- Department of Cultural Heritage, University of Bologna, Via degli Ariani 1, 48121 Ravenna, Italy
| | - Cynthianne Debono Spiteri
- 1] Plant Foods in Hominin Dietary Ecology Research Group, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany [2] Institut für Ur- und Frühgeschichte und Archäologie des Mittelaters, Eberhard Karls Universität Tübingen, Schloss Hohentübingen, 72070 Tübingen, Germany
| | - Amanda G Henry
- 1] Plant Foods in Hominin Dietary Ecology Research Group, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany [2] Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
| | - Dieter Schulz
- Dental Workshop Bensheim, Private Laboratory for Training, Research and Methods, Siegfriedstraße 104, 64646 Heppenheim, Germany
| | - Will Archer
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
| | - Jacopo Crezzini
- 1] CeSQ, Centro Studi sul Quaternario ONLUS., Via Nuova dell'Ammazzatoio 7, I-52037 Sansepolcro (Arezzo), Italy [2] Università degli Studi di Siena, Dipartimento di Scienze Fisiche, della Terra e dell'Ambiente, Unità di Ricerca Preistoria e Antropologia, Via Laterina 8, 53100 Siena, Italy
| | - Francesco Boschin
- 1] CeSQ, Centro Studi sul Quaternario ONLUS., Via Nuova dell'Ammazzatoio 7, I-52037 Sansepolcro (Arezzo), Italy [2] Università degli Studi di Siena, Dipartimento di Scienze Fisiche, della Terra e dell'Ambiente, Unità di Ricerca Preistoria e Antropologia, Via Laterina 8, 53100 Siena, Italy
| | - Paolo Boscato
- Università degli Studi di Siena, Dipartimento di Scienze Fisiche, della Terra e dell'Ambiente, Unità di Ricerca Preistoria e Antropologia, Via Laterina 8, 53100 Siena, Italy
| | - Klervia Jaouen
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
| | - Tamara Dogandzic
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
| | - Alberto Broglio
- Sezione di Scienze Preistoriche e Antropologiche, Dipartimento di Studi Umanistici, Corso Ercole I d'Este 32, Università di Ferrara, 44100 Ferrara, Italy
| | - Jacopo Moggi-Cecchi
- 1] Department of Biology, University of Florence, Via del Proconsolo, 12, 50122 Firenze, Italy [2] Università degli Studi di Siena, Dipartimento di Scienze Fisiche, della Terra e dell'Ambiente, Unità di Ricerca Preistoria e Antropologia, Via Laterina 8, 53100 Siena, Italy
| | - Luca Fiorenza
- 1] Department of Anatomy and Developmental Biology, Monash University,Melbourne VIC 3800, Australia [2] Earth Sciences, University of New England, Armidale NSW 2351, Australia
| | - Jean-Jacques Hublin
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
| | - Ottmar Kullmer
- Senckenberg Research Institute, Senckenberganlage 25, 60325 Frankfurt am Main, Germany
| | - Stefano Benazzi
- 1] Department of Cultural Heritage, University of Bologna, Via degli Ariani 1, 48121 Ravenna, Italy [2] Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
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Smith AL, Benazzi S, Ledogar JA, Tamvada K, Smith LCP, Weber GW, Spencer MA, Dechow PC, Grosse IR, Ross CF, Richmond BG, Wright BW, Wang Q, Byron C, Slice DE, Strait DS. Biomechanical implications of intraspecific shape variation in chimpanzee crania: moving toward an integration of geometric morphometrics and finite element analysis. Anat Rec (Hoboken) 2015; 298:122-44. [PMID: 25529239 PMCID: PMC4274755 DOI: 10.1002/ar.23074] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 10/11/2014] [Indexed: 11/05/2022]
Abstract
In a broad range of evolutionary studies, an understanding of intraspecific variation is needed in order to contextualize and interpret the meaning of variation between species. However, mechanical analyses of primate crania using experimental or modeling methods typically encounter logistical constraints that force them to rely on data gathered from only one or a few individuals. This results in a lack of knowledge concerning the mechanical significance of intraspecific shape variation that limits our ability to infer the significance of interspecific differences. This study uses geometric morphometric methods (GM) and finite element analysis (FEA) to examine the biomechanical implications of shape variation in chimpanzee crania, thereby providing a comparative context in which to interpret shape-related mechanical variation between hominin species. Six finite element models (FEMs) of chimpanzee crania were constructed from CT scans following shape-space Principal Component Analysis (PCA) of a matrix of 709 Procrustes coordinates (digitized onto 21 specimens) to identify the individuals at the extremes of the first three principal components. The FEMs were assigned the material properties of bone and were loaded and constrained to simulate maximal bites on the P(3) and M(2) . Resulting strains indicate that intraspecific cranial variation in morphology is associated with quantitatively high levels of variation in strain magnitudes, but qualitatively little variation in the distribution of strain concentrations. Thus, interspecific comparisons should include considerations of the spatial patterning of strains rather than focus only on their magnitudes.
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Affiliation(s)
- Amanda L. Smith
- Department of Anthropology, University at Albany, 1400 Washington Avenue, Albany, NY, 12222, USA
| | - Stefano Benazzi
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz, 6 04103 Leipzig, Germany
- Department of Cultural Heritage, University of Bologna, Via degli Ariani 1, Ravenna 48121, Italy
| | - Justin A. Ledogar
- Department of Anthropology, University at Albany, 1400 Washington Avenue, Albany, NY, 12222, USA
| | - Kelli Tamvada
- Department of Anthropology, University at Albany, 1400 Washington Avenue, Albany, NY, 12222, USA
| | - Leslie C. Pryor Smith
- Department of Biomedical Sciences, Texas A & M University Baylor College of Dentistry, 3302 Gaston Avenue, Dallas, TX, 75246, USA
| | - Gerhard W. Weber
- Department of Anthropology, University of Vienna, Althanstr. 14, A-1090 Vienna, Austria
| | - Mark A. Spencer
- School of Human Evolution and Social Change, Arizona State University, Box 874101, Tempe, AZ, 85287-4104
- Biology, South Mountain Community College, 7050 S. 24 Street, Phoenix, AZ, 85042
| | - Paul C. Dechow
- Department of Biomedical Sciences, Texas A & M University Baylor College of Dentistry, 3302 Gaston Avenue, Dallas, TX, 75246, USA
| | - Ian R. Grosse
- Department of Mechanical & Industrial Engineering, University of Massachusetts, 160 Governor's Drive, Amherst, MA, 01003-2210
| | - Callum F. Ross
- Department of Organismal Biology & Anatomy, University of Chicago, 1027 East 57th 30 Street, Chicago, IL, 60637, USA
| | - Brian G. Richmond
- Center for the Advanced Study of Hominid Paleobiology, Department of Anthropology, The George Washington University, 2110 G St. NW, Washington, D. C., 20052, USA
- Human Origins Program, National Museum of Natural History, Smithsonian Institution, Washington, D. C., 20560, USA
- Division of Anthropology, American Museum of Natural History, Central Park West at 79 Street, New York, NY 10024-5192
| | - Barth W. Wright
- Department of Anatomy, Kansas City University of Medicine and Biosciences, 1750 Independence Avenue, Kansas City, MO, 64106-1453, USA
| | - Qian Wang
- Division of Basic Medical Sciences, Mercer University School of Medicine, 1550 College Street, Macon, GA, 31207, USA
| | - Craig Byron
- Department of Biology, Mercer University, 1400 Coleman Avenue, Macon, GA, 31207, USA
| | - Dennis E. Slice
- Department of Anthropology, University of Vienna, Althanstr. 14, A-1090 Vienna, Austria
- School of Computational Science & Department of Biological Science, Florida State University, Dirac Science Library, Tallahassee, FL, 32306-4120
| | - David S. Strait
- Department of Anthropology, University at Albany, 1400 Washington Avenue, Albany, NY, 12222, USA
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Benazzi S, Nguyen HN, Kullmer O, Hublin JJ. Exploring the biomechanics of taurodontism. J Anat 2014; 226:180-8. [PMID: 25407030 DOI: 10.1111/joa.12260] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/26/2014] [Indexed: 01/01/2023] Open
Abstract
Taurodontism (i.e. enlarged pulp chamber with concomitant apical displacement of the root bi/trifurcation) is considered a dental anomaly with relatively low incidence in contemporary societies, but it represents a typical trait frequently found in Neandertal teeth. Four hypotheses can be envisioned to explain the high frequency in Neandertals: adaptation to a specific occlusal loading regime (biomechanical advantage), adaptation to a high attrition diet, pleiotropic or genetic drift effects. In this contribution we used finite element analysis (FEA) and advanced loading concepts based on macrowear information to evaluate whether taurodontism supplies some dental biomechanical advantages. Loads were applied to the digital model of the lower right first molar (RM1 ) of the Neandertal specimen Le Moustier 1, as well as to the digital models of both a shortened and a hyper-taurodontic version of Le Moustier RM1 . Moreover, we simulated a scenario where an object is held between teeth and pulled in different directions to investigate whether taurodontism might be useful for para-masticatory activities. Our results do not show any meaningful difference among all the simulations, pointing out that taurodontism does not improve the functional biomechanics of the tooth and does not favour para-masticatory pulling activities. Therefore, taurodontism should be considered either an adaptation to a high attrition diet or most likely the result of pleiotropic or genetic drift effects. Finally, our results have important implications for modern dentistry during endodontic treatments, as we observed that filling the pulp chamber with dentine-like material increases tooth stiffness, and ultimately tensile stresses in the crown, thus favouring tooth failure.
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Affiliation(s)
- Stefano Benazzi
- Department of Cultural Heritage, University of Bologna, Ravenna, Italy; Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
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Le Luyer M, Rottier S, Bayle P. Brief communication: Comparative patterns of enamel thickness topography and oblique molar wear in two early neolithic and medieval population samples. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2014; 155:162-72. [DOI: 10.1002/ajpa.22562] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 06/11/2014] [Accepted: 06/16/2014] [Indexed: 11/06/2022]
Affiliation(s)
- Mona Le Luyer
- Université de Bordeaux; CNRS, MCC, UMR 5199 PACEA, Équipe A3P, Bâtiment B8, Allée Geoffroy St Hilaire; CS 50023 33615 Pessac Cedex France
| | - Stéphane Rottier
- Université de Bordeaux; CNRS, MCC, UMR 5199 PACEA, Équipe A3P, Bâtiment B8, Allée Geoffroy St Hilaire; CS 50023 33615 Pessac Cedex France
| | - Priscilla Bayle
- Université de Bordeaux; CNRS, MCC, UMR 5199 PACEA, Équipe A3P, Bâtiment B8, Allée Geoffroy St Hilaire; CS 50023 33615 Pessac Cedex France
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37
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Kupczik K, Lev-Tov Chattah N. The adaptive significance of enamel loss in the mandibular incisors of cercopithecine primates (Mammalia: Cercopithecidae): a finite element modelling study. PLoS One 2014; 9:e97677. [PMID: 24831704 PMCID: PMC4022739 DOI: 10.1371/journal.pone.0097677] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Accepted: 04/23/2014] [Indexed: 11/19/2022] Open
Abstract
In several primate groups enamel is reduced or absent from the lingual (tongue) side of the mandibular incisor crowns akin to other placental and marsupial mammalian groups such as rodents, lagomorphs and wombats. Here we investigate the presumed adaptation of crowns with unilateral enamel to the incision of tough foods in cercopithecines, an Old World monkey subfamily, using a simulation approach. We developed and validated a finite element model of the lower central incisor of the rhesus macaque (Macaca mulatta) with labial enamel only to compute three-dimensional displacements and maximum principal stresses on the crown subjected to compressive loads varying in orientation. Moreover, we developed a model of a macaque incisor with enamel present on both labial and lingual aspects, thus resembling the ancestral condition found in the sister taxon, the leaf-eating colobines. The results showed that, concomitant with experimental results, the cercopithecine crown with unilateral enamel bends predominantly towards the inside of the mouth, while displacements decreased when both labial and lingual enamel are present. Importantly, the cercopithecine incisor crown experienced lower maximum principal stress on the lingual side compared to the incisor with enamel on the lingual and labial aspects under non-axial loads directed either towards the inside or outside of the mouth. These findings suggest that cercopithecine mandibular incisors are adapted to a wide range of ingestive behaviours compared to colobines. We conclude that the evolutionary loss of lingual enamel in cercopithecines has conferred a safeguard against crown failure under a loading regime assumed for the ingestion (peeling, scraping) of tough-skinned fruits.
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Affiliation(s)
- Kornelius Kupczik
- Max Planck Weizmann Center for Integrative Archaeology and Anthropology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
- Institut für Spezielle Zoologie und Evolutionsbiologie, Friedrich-Schiller-Universität Jena, Jena, Germany
| | - Netta Lev-Tov Chattah
- The Department of Identification and Forensic Science, Israel National Police, Jerusalem, Israel
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Barani A, Bush MB, Lawn BR. Role of multiple cusps in tooth fracture. J Mech Behav Biomed Mater 2014; 35:85-92. [PMID: 24755003 DOI: 10.1016/j.jmbbm.2014.03.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Revised: 03/18/2014] [Accepted: 03/27/2014] [Indexed: 11/25/2022]
Abstract
The role of multiple cusps in the biomechanics of human molar tooth fracture is analysed. A model with four cusps at the bite surface replaces the single dome structure used in previous simulations. Extended finite element modelling, with provision to embed longitudinal cracks into the enamel walls, enables full analysis of crack propagation from initial extension to final failure. The cracks propagate longitudinally around the enamel side walls from starter cracks placed either at the top surface (radial cracks) or from the tooth base (margin cracks). A feature of the crack evolution is its stability, meaning that extension occurs steadily with increasing applied force. Predictions from the model are validated by comparison with experimental data from earlier publications, in which crack development was followed in situ during occlusal loading of extracted human molars. The results show substantial increase in critical forces to produce longitudinal fractures with number of cuspal contacts, indicating a capacity for an individual tooth to spread the load during mastication. It is argued that explicit critical force equations derived in previous studies remain valid, at the least as a means for comparing the capacity for teeth of different dimensions to sustain high bite forces.
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Affiliation(s)
- Amir Barani
- School of Mechanical and Chemical Engineering, The University of Western Australia, WA 6009, Australia
| | - Mark B Bush
- School of Mechanical and Chemical Engineering, The University of Western Australia, WA 6009, Australia
| | - Brian R Lawn
- School of Mechanical and Chemical Engineering, The University of Western Australia, WA 6009, Australia; Materials Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg MD 20899, USA
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