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Hazem A, Mărășescu FI, Țuculină MJ, Popescu AD, Popa DL, Mihai LL, Cumpătă CN, Iliescu A, Mărășescu P, Dascălu IT. Orthodontic System Modeled and Simulated with the Lingual Technique to Assess Tooth Forces. Diagnostics (Basel) 2024; 14:1171. [PMID: 38893697 PMCID: PMC11172380 DOI: 10.3390/diagnostics14111171] [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: 04/11/2024] [Revised: 05/22/2024] [Accepted: 05/29/2024] [Indexed: 06/21/2024] Open
Abstract
CBCT (cone beam computed tomography) is an imaging investigation that provides three-dimensional (3D) images of craniofacial structures. The purpose of this study is to determine the mechanical behavior of an orthodontic system where the lingual treatment technique was used in a 25-year-old female patient from whom a set of CBCT scans was used. CBCT images were processed through software programs such as Invesalius, Geomagic, and Solid Works, to create models containing virtual solids. These models were then imported into Ansys Workbench 2019 R3 (a finite element method software program) for successive simulations to generate displacement maps, deformations, stress distributions, and diagrams. We observed that in the lingual technique, the lowest force occurring on the maxillary teeth is at 1.1, while the highest force appears at 2.3. In the mandible, the lowest force occurs at 4.6, and the highest force at 3.1. The values of the forces and the results of the finite element method can represent a basis for the innovation of new orthodontic springs and also of bracket elements. Thus, by using new technologies, orthodontic practice can be significantly improved for the benefit of patients. Other virtual methods and techniques can be used in future studies, including the application of virtual reality for orthodontic diagnosis.
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Affiliation(s)
- Abbas Hazem
- Department of Orthodontics, Faculty of Dental Medicine, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania; (A.H.); (F.I.M.); (I.T.D.)
| | - Felicia Ileana Mărășescu
- Department of Orthodontics, Faculty of Dental Medicine, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania; (A.H.); (F.I.M.); (I.T.D.)
| | - Mihaela Jana Țuculină
- Department of Endodontics, Faculty of Dental Medicine, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania; (M.J.Ț.); (A.D.P.)
| | - Alexandru Dan Popescu
- Department of Endodontics, Faculty of Dental Medicine, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania; (M.J.Ț.); (A.D.P.)
| | - Dragoș Laurențiu Popa
- Department of Automotive, Transportation and Industrial Engineering, Faculty of Mechanics, University of Craiova, 200478 Craiova, Romania;
| | - Lelia Laurența Mihai
- Department of Periodontology, Faculty of Dental Medicine, University Titu Maiorescu of Bucharest, 031593 Bucharest, Romania;
| | - Cristian Niky Cumpătă
- Department of Oromaxillofacial Surgery, Faculty of Dental Medicine, University Titu Maiorescu of Bucharest, 031593 Bucharest, Romania
| | - Alexandru Iliescu
- Department of Oral Rehabilitation, Faculty of Dental Medicine, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania;
| | - Petre Mărășescu
- Department of Dental Prothesis Tehnology, Faculty of Dental Medicine, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania
| | - Ionela Teodora Dascălu
- Department of Orthodontics, Faculty of Dental Medicine, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania; (A.H.); (F.I.M.); (I.T.D.)
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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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Lone SB, Zeeshan R, Khadim H, Khan MA, Khan AS, Asif A. Synthesis, monomer conversion, and mechanical properties of polylysine based dental composites. J Mech Behav Biomed Mater 2024; 151:106398. [PMID: 38237205 DOI: 10.1016/j.jmbbm.2024.106398] [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: 11/20/2023] [Revised: 01/08/2024] [Accepted: 01/09/2024] [Indexed: 02/03/2024]
Abstract
OBJECTIVE The aim of this study was to synthesize a new bioactive and antibacterial composite by incorporating reactive calcium phosphate and antibacterial polylysine into a resin matrix and evaluate the effect of these fillers on structural analysis, degree of monomer conversion, mechanical properties, and bioactivity of these newly developed polypropylene based dental composites. METHODOLOGY Stock monomers were prepared by mixing urethane dimethacrylate and polypropylene glycol dimethacrylate and combined with 40 wt% silica to make experimental control (E-C). The other three experimental groups contained a fixed percentage of silica (40 wt%), monocalcium phosphate monohydrate, and β-tri calcium phosphate (5 wt% each) with varying amounts of polylysine (PL). These groups include E-CCP0 (0 wt% PL), E-CCP5 (5 wt% PL) and E-CCP10 (10 wt% PL). The commercial control used was Filtek™ Z250 3M ESPE. The degree of conversion was assessed by using Fourier transform infrared spectroscopy (FTIR). Compressive strength and Vicker's micro hardness testing were evaluated after 24 h of curing the samples. For bioactivity, prepared samples were placed in simulated body fluid for 0, 1, 7, and 28 days and were analyzed using a scanning electron microscope (SEM). SPSS 23 was used to analyze the data and one-way ANOVA and post hoc tukey's test were done, where the significant level was set ≤0.05. RESULTS Group E-C showed better mechanical properties than other experimental and commercial control groups. Group E-C showed the highest degree of conversion (72.72 ± 1.69%) followed by E-CCP0 (72.43 ± 1.47%), Z250 (72.26 ± 1.75%), E-CCP10 (71.07 ± 0.19%), and lowest value was shown by E-CCP5 (68.85 ± 7.23%). In shear bond testing the maximum value was obtained by E-C. The order in decreasing value of bond strength is E-C (8.13 ± 3.5 MPa) > Z250 (2.15 ± 1.1 MPa) > E-CCP10 (2.08 ± 2.1 MPa) > E-CCP5 (0.94 ± 0.8 MPa) > E-CCP0 (0.66 ± 0.2 MPa). In compressive testing, the maximum strength was observed by commercial control i.e., Z250 (210.36 ± 18 MPa) and E-C (206.55 ± 23 MPa), followed by E-CCP0 (108.06 ± 19 MPa), E-CCP5 (94.16 ± 9 MPa), and E-CCP10 (80.80 ± 13 MPa). The maximum number of hardness was shown by E-C (93.04 ± 8.23) followed by E-CCP0 (38.93 ± 9.21) > E-CCP10 (35.21 ± 12.31) > E-CCP5 (34.34 ± 12.49) > Z250 (25 ± 2.61). SEM images showed that the maximum apatite layer as shown by E-CCP10 and the order followed as E-CCP10 > E-CCP5 > E-CCP0 >Z250> E-C. CONCLUSION The experimental formulation showed an optimal degree of conversion with compromised mechanical properties when the polylysine percentage was increased. Apatite layer formation and polylysine at the interface may result in remineralization and ultimately lead to the prevention of secondary caries formation.
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Affiliation(s)
- Saadia Bano Lone
- Department of Dental Materials, Rashid Latif Dental College, Lahore, Pakistan
| | - Rabia Zeeshan
- Interdisciplinary Research Centre in Biomedical Materials, COMSATS University Islamabad, Lahore Campus, Lahore, Pakistan
| | - Hina Khadim
- Interdisciplinary Research Centre in Biomedical Materials, COMSATS University Islamabad, Lahore Campus, Lahore, Pakistan
| | - Muhammad Adnan Khan
- Department of Dental Materials, Institute of Basic Medical Sciences, Khyber Medical University Peshawar, Peshawar, Pakistan
| | - Abdul Samad Khan
- Department of Restorative Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Anila Asif
- Interdisciplinary Research Centre in Biomedical Materials, COMSATS University Islamabad, Lahore Campus, Lahore, Pakistan.
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Li Y, Yang Z, Tong L, Yang J, Wang J, Wen Y. Wall thickness analysis method for judging the degree of lower extremity long bone healing. Sci Rep 2023; 13:20650. [PMID: 38001361 PMCID: PMC10673992 DOI: 10.1038/s41598-023-48212-3] [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: 11/19/2022] [Accepted: 11/23/2023] [Indexed: 11/26/2023] Open
Abstract
To evaluate the possibility of judging the degree of bone healing by wall thickness analysis provide reference for quantitative analysis of bone healing. Patients with lower limb fracture from April 2014 to October 2019 were recruited and divided into bone healing (group A), poor bone healing (group B), and nonunion (group C). Models were built in Mimics 20.0 with DICOM 3.0 data obtained from patient's CT. Three-dimensional geometric models of unaffected limb and affected limb after simulated removal of internal fixation were established, corresponding to basic phase and simulated phase, respectively. Wall thickness analysis was performed to obtain median wall thickness after meshing. R2 (median wall thickness ratio), R4 (CT value ratio), and R5 (healing index ratio) were obtained by calculating the ratio of each value in simulated phase to that in basic phase. Receiver operating characteristic curve analysis was used to evaluate the ability of Wall Thickness Analysis to indicate fracture healing. 112 CT scans of 79 patients were included in the study. The frequency of categorization in groups A, B, and C was 49, 37 and 26, respectively. The median R2 in groups A, B, and C was 0.91, 0.80, and 0.67, respectively (group A > group B > group C, all P < 0.05). The best cutoff point for R2 in predicting bone healing was 0.84, and predicting bone nonunion was 0.74. The Wall Thickness Analysis can be used to quantitatively evaluate fracture healing state, with median wall thickness ratio as a more intuitive and reliable judgment index.
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Affiliation(s)
- Ying Li
- Department of Orthopedics, Air Force Hospital of Eastern Theater Command, Nanjing, Jiangsu, China
- Department of Clinical Medicine, Anhui Medical University, Hefei, Anhui, China
| | - Zhiwei Yang
- Department of Orthopedics, Air Force Hospital of Eastern Theater Command, Nanjing, Jiangsu, China
| | - Liangcheng Tong
- Department of Orthopedics, Air Force Hospital of Eastern Theater Command, Nanjing, Jiangsu, China
| | - Junsheng Yang
- Department of Orthopedics, Air Force Hospital of Eastern Theater Command, Nanjing, Jiangsu, China
| | - Jianling Wang
- Department of Orthopedics, Air Force Hospital of Eastern Theater Command, Nanjing, Jiangsu, China
| | - Yaoke Wen
- School of Mechanical Engineering, Nanjing University of Science and Technology, No. 200 Xiaolingwei, Nanjing, 210094, Jiangsu, China.
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Țuculină MJ, Staicu AN, Munteanu MC, Cumpătă CN, Dimitriu B, Rîcă AM, Beznă MC, Popa DL, Popescu AD, Țîrcă T. Study on the Restoration of Class II Carious Cavities by Virtual Methods: Simulation of Mechanical Behavior. J Funct Biomater 2023; 14:354. [PMID: 37504849 PMCID: PMC10381501 DOI: 10.3390/jfb14070354] [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: 06/11/2023] [Revised: 07/02/2023] [Accepted: 07/03/2023] [Indexed: 07/29/2023] Open
Abstract
The restoration of class II cavities is predominantly carried out with composite materials. Due to the high failure rate in restoring this type of cavity, composite materials with much-improved properties and new application techniques have been promoted. The study aimed to analyze the mechanical behavior of several topical composite materials (nanocomposites, nanohybrids and ormocer) using different application techniques. In a lower second molar, a class II occlusal cavity was prepared. As filling materials, we used the following combinations: Admira Fusion and Admira Fusion Flow, Grandio and Grandio Flow, Filtek Supreme XT and Filtek Supreme Flow. These were applied using a snow plow, injection molded and Bichacho techniques. Three-dimensional scanning of the molar with the prepared cavity was performed, and then scanning of each layer of added composite material was performed, obtaining three-dimensional models. The virtual molar models were analyzed with software specific to the finite element analysis method, where their physical-mechanical properties were entered and assigned to the components of the virtual molar. Simulations at high forces specific to bruxism were then carried out and analyzed, and compared. The values of displacements and strain, for all six analyzed situations, are relatively small (range from 5.25 × 10-6-3.21 × 10-5 for displacement, 6.22 × 10-3-4.34 × 10-3 for strain), which validates all three methods and the materials used. As far as the stress values are concerned, they are similar for all methods (250-300 MPa), except for the snow plow and injection-molded techniques using Grandio and Grandio Flow composites, where the maximum von Mises stress value was more than double (approximately 700 MPa). When using the combination of Grandio and Grandio Flow materials, the 1 mm thickness of the fluid composite layer was found to have a major influence on occlusal forces damping as opposed to 0.5 mm. Therefore, the Bichacho technique is indicated at the expense of the snow plow and injection-molded techniques. The composite materials used by us in this study are state-of-the-art, with clear indications for restoring cavities resulting from the treatment of carious lesions. However, their association and application technique in the case of Class II cavities is of clinical importance for resistance to masticatory forces.
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Affiliation(s)
- Mihaela Jana Țuculină
- Department of Endodontics, Faculty of Dentistry, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania
| | - Adela Nicoleta Staicu
- Department of Endodontics, Faculty of Dentistry, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania
| | - Maria Cristina Munteanu
- Department of Oral and Maxillofacial Surgery, Faculty of Dental Medicine, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania
| | - Cristian Niky Cumpătă
- Faculty of Dental Medicine, University Titu Maiorescu of Bucharest, 67A Gheorghe Petrascu Str., 031593 Bucharest, Romania
| | - Bogdan Dimitriu
- Department of Endodontics, Faculty of Dentistry, University of Medicine and Pharmacy Carol Davila Bucharest, 050474 Bucharest, Romania
| | - Ana Maria Rîcă
- Department of Endodontics, Faculty of Dentistry, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania
| | - Maria Cristina Beznă
- Department of Pathophysiology, Faculty of Dentistry, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania
| | - Dragoș Laurențiu Popa
- Department of Automotive, Transportation and Industrial Engineering, Faculty of Mechanics, University of Craiova, 200478 Craiova, Romania
| | - Alexandru Dan Popescu
- Department of Endodontics, Faculty of Dentistry, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania
| | - Tiberiu Țîrcă
- Department of Oro-Dental Prevention, Faculty of Dental Medicine, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania
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Yoon Y, Lee MJ, Kang I, Oh S. Evaluation of Biomechanical Stability of Teeth Tissue According to Crown Materials: A Three-Dimensional Finite Element Analysis. MATERIALS (BASEL, SWITZERLAND) 2023; 16:4756. [PMID: 37445067 DOI: 10.3390/ma16134756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 06/18/2023] [Accepted: 06/27/2023] [Indexed: 07/15/2023]
Abstract
The biomechanical effects of dental tissue according to various dental crown materials were investigated using finite element analysis. Bone, prepared tooth, root canal, and periodontal ligament were modeled based on computed tomography. Depending on the characteristics of the crown material, it was classified into zirconia, hybrid ceramic, gold alloy, and acrylic resin. A loading force of 200 N was applied in the vertical direction to the occlusal surface of the crown, and analysis was performed under the condition that all interfaces were tied. The results demonstrate that the highest von Mises stress was shown in the prepared tooth of the acrylic resin model, which is a temporary prosthesis, and the pulpal pressure was also the highest. Additionally, among the final prosthesis, the highest stress was shown in the hybrid ceramic model prepared teeth. The properties of restoration materials can be a factor influencing the tooth structure. Thus, in order to make a correct decision when selecting a material for restorative treatment, it is necessary to understand, analyze, and evaluate the properties of these restoration materials.
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Affiliation(s)
- Youngjae Yoon
- Department of Oral and Maxillofacial Surgery, School of Dentistry, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Myung-Jin Lee
- Department of Dental Hygiene, Division of Health Science, Baekseok University, Cheonan 31065, Republic of Korea
| | - Inyeong Kang
- School of Mechanical Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Sanghwan Oh
- Department of Dental Hygiene, Konyang University, Daejeon 35365, Republic of Korea
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Sender RS, Strait DS. The biomechanics of tooth strength: testing the utility of simple models for predicting fracture in geometrically complex teeth. J R Soc Interface 2023; 20:20230195. [PMID: 37376873 PMCID: PMC10300505 DOI: 10.1098/rsif.2023.0195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 06/12/2023] [Indexed: 06/29/2023] Open
Abstract
Teeth must fracture foods while avoiding being fractured themselves. This study evaluated dome biomechanical models used to describe tooth strength. Finite-element analysis (FEA) tested whether the predictions of the dome models applied to the complex geometry of an actual tooth. A finite-element model was built from microCT scans of a human M3. The FEA included three loading regimes simulating contact between (i) a hard object and a single cusp tip, (ii) a hard object and all major cusp tips and (iii) a soft object and the entire occlusal basin. Our results corroborate the dome models with respect to the distribution and orientation of tensile stresses, but document heterogeneity of stress orientation across the lateral enamel. This implies that high stresses might not cause fractures to fully propagate between cusp tip and cervix under certain loading conditions. The crown is most at risk of failing during hard object biting on a single cusp. Geometrically simple biomechanical models are valuable tools for understanding tooth function but do not fully capture aspects of biomechanical performance in actual teeth whose complex geometries may reflect adaptations for strength.
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Affiliation(s)
- Rachel S. Sender
- Department of Anthropology, Washington University in St Louis, St Louis, MO 63013, USA
| | - David S. Strait
- Department of Anthropology, Washington University in St Louis, St Louis, MO 63013, USA
- Paleo-Research Institute, University of Johannesburg, Auckland Park, Gauteng 2092, South Africa
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Grine FE, Mongle CS, Kollmer W, Romanos G, du Plessis A, Maureille B, Braga J. Hypercementosis in Late Pleistocene Homo sapiens fossils from Klasies River Main Site, South Africa. Arch Oral Biol 2023; 149:105664. [PMID: 36889227 DOI: 10.1016/j.archoralbio.2023.105664] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 02/23/2023] [Accepted: 02/26/2023] [Indexed: 03/06/2023]
Abstract
OBJECTIVE To examine early Homo sapiens fossils from the Late Pleistocene site of Klasies River Main Site, South Africa for evidence of hypercementosis. The specimens represent seven adult individuals dated to between 119,000 and 58,000 years ago. These observations are contextualized in relation to the incidences of hypercementosis among recent human populations and fossil human samples and the potential etiologies of hypercementosis. DESIGN The fossils were investigated utilizing micro-CT and nano-CT scanning to visualize and measure cementum apposition on permanent incisor, premolar and molar roots. Cementum thickness was measured at mid-root level, and the volume of the cementum sleeve was calculated for the two fossil specimens that display marked hypercementosis. RESULTS Two of the fossils display no evidence of cementum hypertrophy. Three exhibit moderate cementum thickening, barely attaining the quantitative threshold for hypercementosis. Two evince marked hypercementosis. One of the Klasies specimens with marked hypercementosis is judged to be an older individual with periapical abscessing. The second specimen is a younger adult, and seemingly similar in age to other Klasies fossils that exhibit only minimal cementum apposition. However, this second specimen exhibits dento-alveolar ankylosis of the premolar and molars. CONCLUSIONS These two fossils from Klasies River Main Site provide the earliest manifestation of hypercementosis in Homo sapiens.
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Affiliation(s)
- Frederick E Grine
- Department of Anthropology, Stony Brook University, Stony Brook, NY 11794, USA; Department of Anatomical Sciences, Stony Brook University, Stony Brook, NY 11794, USA.
| | - Carrie S Mongle
- Department of Anthropology, Stony Brook University, Stony Brook, NY 11794, USA; Turkana Basin Institute, Stony Brook University, Stony Brook, NY 11794, USA
| | - William Kollmer
- Department of Anthropology, Stony Brook University, Stony Brook, NY 11794, USA; Department of Periodontology, Stony Brook University School of Dental Medicine, Stony Brook, NY 11794, USA
| | - Georgios Romanos
- Department of Periodontology, Stony Brook University School of Dental Medicine, Stony Brook, NY 11794, USA
| | - Anton du Plessis
- Department of Physics, Stellenbosch University, Stellenbosch 7602, South Africa; Object Research Systems, 460 Saint-Catherine St. W, Montreal, Quebec H3B 1A7, Canada
| | - Bruno Maureille
- Université de Bordeaux, CNRS, Ministère de la Culture, PACEA, UMR5199, F-33600 Pessac, France
| | - José Braga
- Center for Anthrobiology & Genomics Institute of Toulouse, CNRS UMR 5288, Université de Toulouse, Université Paul Sabatier, 37 allées Jules Guesde, Toulouse 31000, France
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10
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Sharp AC, Dutel H, Watson PJ, Gröning F, Crumpton N, Fagan MJ, Evans SE. Assessment of the mechanical role of cranial sutures in the mammalian skull: Computational biomechanical modelling of the rat skull. J Morphol 2023; 284:e21555. [PMID: 36630615 PMCID: PMC10107956 DOI: 10.1002/jmor.21555] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 01/03/2023] [Accepted: 01/05/2023] [Indexed: 01/13/2023]
Abstract
Cranial sutures are fibrocellular joints between the skull bones that are progressively replaced with bone throughout ontogeny, facilitating growth and cranial shape change. This transition from soft tissue to bone is reflected in the biomechanical properties of the craniofacial complex. However, the mechanical significance of cranial sutures has only been explored at a few localised areas within the mammalian skull, and as such our understanding of suture function in overall skull biomechanics is still limited. Here, we sought to determine how the overall strain environment is affected by the complex network of cranial sutures in the mammal skull. We combined two computational biomechanical methods, multibody dynamics analysis and finite element analysis, to simulate biting in a rat skull and compared models with and without cranial sutures. Our results show that including complex sutures in the rat model does not substantially change overall strain gradients across the cranium, particularly strain magnitudes in the bones overlying the brain. However, local variations in strain magnitudes and patterns can be observed in areas close to the sutures. These results show that, during feeding, sutures may be more important in some regions than others. Sutures should therefore be included in models that require accurate local strain magnitudes and patterns of cranial strain, particularly if models are developed for analysis of specific regions, such as the temporomandibular joint or zygomatic arch. Our results suggest that, for mammalian skulls, cranial sutures might be more important for allowing brain expansion during growth than redistributing biting loads across the cranium in adults.
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Affiliation(s)
- Alana C Sharp
- Department of Musculoskeletal and Ageing Sciences, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK.,Department of Cell and Developmental Biology, University College London, London, UK
| | - Hugo Dutel
- Department of Engineering, University of Hull, Hull, UK.,Faculty of Science, School of Earth Sciences, University of Bristol, Bristol, UK
| | | | - Flora Gröning
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen, UK
| | - Nick Crumpton
- Department of Cell and Developmental Biology, University College London, London, UK
| | | | - Susan E Evans
- Department of Cell and Developmental Biology, University College London, London, UK
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11
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Hunter-Schreger Band configuration in human molars reveals more decussation in the lateral enamel of 'functional' cusps than 'guiding' cusps. Arch Oral Biol 2022; 142:105524. [PMID: 36029738 DOI: 10.1016/j.archoralbio.2022.105524] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 08/11/2022] [Accepted: 08/15/2022] [Indexed: 11/21/2022]
Abstract
OBJECTIVES Enamel prism decussation, which manifests as Hunter-Schreger Bands (HSB), is considered a mechanism to mitigate crack propagation. During the chewing cycle, the 'functional' cusps that are involved in Phase II crushing and grinding experience more complex patterns of stress than do those that 'guide' the molars into occlusion (Phase I). This study examines HSB configuration in the lateral enamel of human molars to identify potential differences between these cusps as predicted from their functional distinctions. DESIGN Measurements were recorded from scanning electron micrographs of sections through the mesial cusps of unworn permanent molars. For each section, HSB packing density and the relative thickness of decussated enamel were quantified in the cuspal and middle segments of lateral enamel over the guiding and functional cusps. RESULTS No clear trend from first to third molars in HSB configuration was found in either jaw. In maxillary molars, the functional cusp displays higher HSB packing density in the cuspal and middle segments, and relatively thicker decussated enamel in the cuspal segment than does the guiding cusp. In mandibular molars, the functional cusp displays higher HSB packing density in the middle segment than does the guiding cusp, but no difference in relative thickness was found between them. Enamel of mandibular molars shows weaker decussation than maxillary molars. CONCLUSIONS The results suggest that guiding cusps are intrinsically more susceptible to crack propagation than functional cusps in human permanent molars. Structural factors such as enamel decussation should be considered when interpreting enamel chipping patterns in dietary contexts.
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12
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Duta A, Popa DL, Vintila DD, Buciu G, Dina NA, Ionescu A, Berceanu MC, Calin DC. An Experimental and Virtual Approach to Hip Revision Prostheses. Diagnostics (Basel) 2022; 12:diagnostics12081952. [PMID: 36010302 PMCID: PMC9406961 DOI: 10.3390/diagnostics12081952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 08/08/2022] [Accepted: 08/10/2022] [Indexed: 11/16/2022] Open
Abstract
(1) Introduction: The changes in the joint morphology inevitably lead to prosthesis, but the hip pathology is complex. The hip arthroplasty is a therapeutic solution and can be caused, most frequently, by primary and secondary coxarthrosis due to or followed by traumatic conditions. The main aim of this study was to find the method of revision hip prosthesis that preserves as much bone material as possible and has sufficiently good mechanical strength. (2) Materials and Methods: In this study, in a first step, the two revision prostheses were performed on bone components taken from an animal (cow), and then, they were tested on a mechanical testing machine until the prostheses physically failed, and the force causing their failure was determined. (3) Results: These prostheses were then modelled in a virtual environment and tested using the finite element method (FEM) in order to determine their behaviour under loading from normal human gait. Displacement, strain, and stress maps were obtained. (4) Discussion: Discussions on hip revision prostheses, method, and theory analysis are presented at the end of the paper. (5) Conclusions: Important conclusions are drawn based on comparative analyses. The main conclusion shows that the both orthopaedic prostheses provide a very good resistance.
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Affiliation(s)
- Alina Duta
- Faculty of Mechanics, University of Craiova, 200512 Craiova, Romania
| | - Dragos-Laurentiu Popa
- Faculty of Mechanics, University of Craiova, 200512 Craiova, Romania
- Correspondence: (D.-L.P.); (G.B.)
| | | | - Gabriel Buciu
- Faculty of Nursing, Titu Maiorescu University, 210102 Targu Jiu, Romania
- Correspondence: (D.-L.P.); (G.B.)
| | | | - Adriana Ionescu
- Faculty of Mechanics, University of Craiova, 200512 Craiova, Romania
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13
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Correlation of Bone Material Model Using Voxel Mesh and Parametric Optimization. MATERIALS 2022; 15:ma15155163. [PMID: 35897595 PMCID: PMC9369889 DOI: 10.3390/ma15155163] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/21/2022] [Accepted: 07/22/2022] [Indexed: 11/24/2022]
Abstract
The authors present an algorithm for determining the stiffness of the bone tissue for individual ranges of bone density. The paper begins with the preparation and appropriate mechanical processing of samples from the bovine femur and their imaging using computed tomography and then processing DICOM files in the MIMICS system. During the processing of DICOM files, particular emphasis was placed on defining basic planes along the sides of the samples, which improved the representation of sample geometry in the models. The MIMICS system transformed DICOM images into voxel models from which the whole bone FE model was built in the next step. A single voxel represents the averaged density of the real sample in a very small finite volume. In the numerical model, it is represented by the HEX8 element, which is a cube. All voxels were divided into groups that were assigned average equivalent densities. Then, the previously prepared samples were loaded to failure in a three-point bending test. The force waveforms as a function of the deflection of samples were obtained, based on which the global stiffness of the entire sample was determined. To determine the stiffness of each averaged voxel density value, the authors used advanced optimization analyses, during which numerical analyses were carried out simultaneously, independently mapping six experimental tests. Ultimately, the use of genetic algorithms made it possible to select a set of stiffness parameters for which the error of mapping the global stiffness for all samples was the smallest. The discrepancies obtained were less than 5%, which the authors considered satisfactory by the authors for such a heterogeneous medium and for samples collected from different parts of the bone. Finally, the determined data were validated for the sample that was not involved in the correlation of material parameters. The stiffness was 7% lower than in the experimental test.
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14
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Popescu AD, Popa DL, Nicola AG, Dascălu IT, Petcu C, Tircă T, Tuculina MJ, Mocanu H, Staicu AN, Gheorghiță LM. Post Placement and Restoration of Endodontically Treated Canines: A Finite Element Analysis Study. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19158928. [PMID: 35897304 PMCID: PMC9332447 DOI: 10.3390/ijerph19158928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Revised: 07/18/2022] [Accepted: 07/21/2022] [Indexed: 02/04/2023]
Abstract
The purpose of this study was to show the improved outcomes of restoring endodontically treated teeth with fiberglass posts compared to restorations using metal posts. In our study, we used the Finite Element Method (FEM), which is based on the principle that a physical model that supports a given load distributes the stress throughout its volume. We sought to assess what stress results in a tooth when it is restored using a fiberglass post compared to restoration using a metal post. The finite element analysis showed that a system consisting of a tooth with a fiberglass post is more stable in terms of the maximum stress than a system consisting of a tooth with a metal post. The maximum displacements and deformations were obtained in the case of a canine restored with a fiberglass post, which showed that this system had a high elasticity, therefore, higher strength than a canine restored with a metal post, which had high rigidity.
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Affiliation(s)
- Alexandru Dan Popescu
- Department of Endodontics, Faculty of Dental Medicine, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania; (A.D.P.); (C.P.); (A.N.S.); (L.M.G.)
| | - Dragoș Laurențiu Popa
- Department of Automotive, Transportation and Industrial Engineering, Faculty of Mechanics, University of Craiova, 200478 Craiova, Romania
- Correspondence: (D.L.P.); (M.J.T.)
| | - Andreea Gabriela Nicola
- Department of Oro-Dental Prevention, Faculty of Dental Medicine, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania; (A.G.N.); (T.T.)
| | - Ionela Teodora Dascălu
- Department of Orthodontics, Faculty of Dental Medicine, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania;
| | - Cristian Petcu
- Department of Endodontics, Faculty of Dental Medicine, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania; (A.D.P.); (C.P.); (A.N.S.); (L.M.G.)
| | - Tiberiu Tircă
- Department of Oro-Dental Prevention, Faculty of Dental Medicine, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania; (A.G.N.); (T.T.)
| | - Mihaela Jana Tuculina
- Department of Endodontics, Faculty of Dental Medicine, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania; (A.D.P.); (C.P.); (A.N.S.); (L.M.G.)
- Correspondence: (D.L.P.); (M.J.T.)
| | - Horia Mocanu
- Faculty of Dental Medicine, University Titu Maiorescu of Bucharest, 031593 Bucharest, Romania;
| | - Adela Nicoleta Staicu
- Department of Endodontics, Faculty of Dental Medicine, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania; (A.D.P.); (C.P.); (A.N.S.); (L.M.G.)
| | - Lelia Mihaela Gheorghiță
- Department of Endodontics, Faculty of Dental Medicine, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania; (A.D.P.); (C.P.); (A.N.S.); (L.M.G.)
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15
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Ortún-Terrazas J, Fagan MJ, Cegoñino J, Illipronti-Filho E, Del Palomar AP. Biomechanical evaluation of the unilateral crossbite on the asymmetrical development of the craniofacial complex. A mechano-morphological approach. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2022; 217:106703. [PMID: 35217305 DOI: 10.1016/j.cmpb.2022.106703] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 01/27/2022] [Accepted: 02/14/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND AND OBJECTIVE The occlusion effect on the craniofacial development is a controversial topic that has attracted the interest of many researchers but that remains unclear, mainly due to the difficulties on measure its mechanical response experimentally. This mechano-morphological relationship of the craniofacial growth is often explained by the periosteal and capsular matrices of the functional matrix hypothesis (FMH); however, its outcomes have not been analytically demonstrated yet. This computational study aims, therefore, to analytically demonstrate the mechano-morphological relationship in the craniofacial development of children with unilateral crossbite (UXB) using the finite element (FE) method. METHODS The craniofacial complex asymmetry of ten children, five of whom exhibit UXB, was 3D-analysed and compared with the biomechanical response computed from a FE analysis of each patient's occlusion. Due to the complexity of the geometry and the multitude of contacts involved, the inherent limitations of the model were evaluated by comparing computed occlusal patterns with those recorded by an occlusal analysis on 3D printed copies. RESULTS Comparison's outcomes proved the reliability of our models with just a deviation error below 6% between both approaches. Out of validation process, computational results showed that the significant elongation of mandibular branch in the contralateral side could be related to the mandibular shift and increase of thickness on the crossed side, and particularly of the posterior region. These morphological changes could be associated with periodontal overpressure (>4.7 kPa) and mandibular over deformation (0.002 ε) in that side, in agreement with the periosteal matrix's principles. Furthermore, the maxilla's transversal narrowing and the elevation of the maxillary and zygomatic regions on the crossed side were statistically demonstrated and seem to be related with their respective micro displacements at occlusion, as accounted by their specific capsule matrices. Our results were consistent with those reported clinically and demonstrated analytically the mechano-morphological relationship of children's craniofacial development based on the FMH's functional matrices. CONCLUSIONS This study is a first step in the understanding of the occlusion's effect on the craniofacial development by computational methods. Our approach could help future engineers, researchers and clinicians to understand better the aetiology of some dental malocclusions and functional disorders improve the diagnosis or even predict the craniofacial development.
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Affiliation(s)
- Javier Ortún-Terrazas
- Group of Biomaterials, Aragon Institute of Engineering Research (I3A), University of Zaragoza, Zaragoza, Spain.
| | - Michael J Fagan
- Medical and Biological Engineering, School of Engineering and Computer Science, University of Hull, Hull, United Kingdom
| | - José Cegoñino
- Group of Biomaterials, Aragon Institute of Engineering Research (I3A), University of Zaragoza, Zaragoza, Spain
| | - Edson Illipronti-Filho
- School of Dentistry, Department of Stomatology, University of São Paulo, São Paulo, Brazil
| | - Amaya Pérez Del Palomar
- Group of Biomaterials, Aragon Institute of Engineering Research (I3A), University of Zaragoza, Zaragoza, Spain
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16
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Silvester CM, Kullmer O, Hillson S. A dental revolution: The association between occlusion and chewing behaviour. PLoS One 2021; 16:e0261404. [PMID: 34910787 PMCID: PMC8673603 DOI: 10.1371/journal.pone.0261404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 12/01/2021] [Indexed: 11/19/2022] Open
Abstract
Dentistry is confronted with the functional and aesthetic consequences that result from an increased prevalence of misaligned and discrepant dental occlusal relations in modern industrialised societies. Previous studies have indicated that a reduction in jaw size in response to softer and more heavily processed foods during and following the Industrial Revolution (1,700 CE to present) was an important factor in increased levels of poor dental occlusion. The functional demands placed on the masticatory system play a crucial role in jaw ontogenetic development; however, the way in which chewing behaviours changed in response to the consumption of softer foods during this period remains poorly understood. Here we show that eating more heavily processed food has radically transformed occlusal power stroke kinematics. Results of virtual 3D analysis of the dental macrowear patterns of molars in 104 individuals dating to the Industrial Revolution (1,700-1,900 CE), and 130 of their medieval and early post-medieval antecedents (1,100-1,700 CE) revealed changes in masticatory behaviour that occurred during the early stages of the transition towards eating more heavily processed foods. The industrial-era groups examined chewed with a reduced transverse component of jaw movement. These results show a diminished sequence of occlusal contacts indicating that a dental revolution has taken place in modern times, involving a dramatic shift in the way in which teeth occlude and wear during mastication. Molar macrowear suggests a close connection between progressive changes in chewing since the industrialization of food production and an increase in the prevalence of poor dental occlusion in modern societies.
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Affiliation(s)
| | - Ottmar Kullmer
- Department of Paleoanthropology, Senckenberg Research Institute and Natural History Museum Frankfurt, Frankfurt, Germany
- Department of Palaeobiology and Environment, Institute of Ecology, Evolution, and Diversity, Johann Wolfgang Goethe University, Frankfurt, Germany
| | - Simon Hillson
- Institute of Archaeology, University College London, London, United Kingdom
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17
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Apel Z, Vafaeian B, Apel DB, Hussain A. Occlusal stresses in beveled versus non-beveled tooth preparation. BIOMEDICAL ENGINEERING ADVANCES 2021. [DOI: 10.1016/j.bea.2021.100010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
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18
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Alemayehu DB, Jeng YR. Three-Dimensional Finite Element Investigation into Effects of Implant Thread Design and Loading Rate on Stress Distribution in Dental Implants and Anisotropic Bone. MATERIALS 2021; 14:ma14226974. [PMID: 34832374 PMCID: PMC8624479 DOI: 10.3390/ma14226974] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 11/06/2021] [Accepted: 11/16/2021] [Indexed: 12/18/2022]
Abstract
Variations in the implant thread shape and occlusal load behavior may result in significant changes in the biological and mechanical properties of dental implants and surrounding bone tissue. Most previous studies consider a single implant thread design, an isotropic bone structure, and a static occlusal load. However, the effects of different thread designs, bone material properties, and loading conditions are important concerns in clinical practice. Accordingly, the present study performs Finite Element Analysis (FEA) simulations to investigate the static, quasi-static and dynamic response of the implant and implanted bone material under various thread designs and occlusal loading directions (buccal-lingual, mesiodistal and apical). The simulations focus specifically on the von Mises stress, displacement, shear stress, compressive stress, and tensile stress within the implant and the surrounding bone. The results show that the thread design and occlusal loading rate have a significant effect on the stress distribution and deformation of the implant and bone structure during clinical applications. Overall, the results provide a useful insight into the design of enhanced dental implants for an improved load transfer efficiency and success rate.
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Affiliation(s)
- Dawit-Bogale Alemayehu
- Department of Biomedical Engineering, National Cheng Kung University (NCKU), Tainan 70101, Taiwan;
| | - Yeau-Ren Jeng
- Department of Biomedical Engineering, National Cheng Kung University (NCKU), Tainan 70101, Taiwan;
- School of Smart Semiconductor and Sustainable Manufacturing, National Cheng Kung University (NCKU), Tainan 70101, Taiwan
- Medical Device Innovation Center (MDIC), National Cheng Kung University (NCKU), Tainan 70101, Taiwan
- Correspondence: ; Tel.: +886-933278212
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19
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Smith AL, Robinson C, Taylor AB, Panagiotopoulou O, Davis J, Ward CV, Kimbel WH, Alemseged Z, Ross CF. Comparative biomechanics of the Pan and Macaca mandibles during mastication: finite element modelling of loading, deformation and strain regimes. Interface Focus 2021; 11:20210031. [PMID: 34938438 PMCID: PMC8361577 DOI: 10.1098/rsfs.2021.0031] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/09/2021] [Indexed: 10/17/2023] Open
Abstract
The mechanical behaviour of the mandibles of Pan and Macaca during mastication was compared using finite element modelling. Muscle forces were calculated using species-specific measures of physiological cross-sectional area and scaled using electromyographic estimates of muscle recruitment in Macaca. Loading regimes were compared using moments acting on the mandible and strain regimes were qualitatively compared using maps of principal, shear and axial strains. The enlarged and more vertically oriented temporalis and superficial masseter muscles of Pan result in larger sagittal and transverse bending moments on both working and balancing sides, and larger anteroposterior twisting moments on the working side. The mandible of Pan experiences higher principal strain magnitudes in the ramus and mandibular prominence, higher transverse shear strains in the top of the symphyseal region and working-side corpus, and a predominance of sagittal bending-related strains in the balancing-side mandible. This study lays the foundation for a broader comparative study of Hominidae mandibular mechanics in extant and fossil hominids using finite element modelling. Pan's larger and more vertical masseter and temporalis may make it a more suitable model for hominid mandibular biomechanics than Macaca.
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Affiliation(s)
- Amanda L. Smith
- Department of Anatomy, Pacific Northwest University of Health Sciences, 200 University Parkway, Yakima, WA 98901, USA
- Department of Organismal Biology and Anatomy, University of Chicago, 1027 East 57th Street, Chicago, IL 60637, USA
| | - Chris Robinson
- Department of Biological Sciences, Bronx Community College, Bronx, NY 10453, USA
| | | | - Olga Panagiotopoulou
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Melbourne, Victoria 3800, Australia
| | - Julian Davis
- Department of Engineering, University of Southern Indiana, 8600 University Boulevard, Evansville, IN 47712, USA
| | - Carol V. Ward
- Department of Pathology and Anatomical Sciences, One Hospital Drive, University of Missouri, Columbia, MO 65212, USA
| | - William H. Kimbel
- School of Human Evolution and Social Change, Arizona State University, Tempe, AZ 85287-4101, USA
| | - Zeresenay Alemseged
- Department of Organismal Biology and Anatomy, University of Chicago, 1027 East 57th Street, Chicago, IL 60637, USA
| | - Callum F. Ross
- Department of Organismal Biology and Anatomy, University of Chicago, 1027 East 57th Street, Chicago, IL 60637, USA
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20
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Bone Stress Evaluation with and without Cortical Bone Using Several Dental Restorative Materials Subjected to Impact Load: A Fully 3D Transient Finite-Element Study. MATERIALS 2021; 14:ma14195801. [PMID: 34640200 PMCID: PMC8510134 DOI: 10.3390/ma14195801] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2021] [Revised: 09/18/2021] [Accepted: 10/01/2021] [Indexed: 12/14/2022]
Abstract
Statement of problem. Previous peri-implantitis, peri-implant bone regeneration, or immediate implant placement postextraction may be responsible for the absence of cortical bone. Single crown materials are then relevant when dynamic forces are transferred into bone tissue and, therefore, the presence (or absence) of cortical bone can affect the long-term survival of the implant. Purpose: the purpose of this study is to assess the biomechanical response of dental rehabilitation when selecting different crown materials in models with and without cortical bone. Methods: several crown materials were considered for modeling six types of crown rehabilitation: full metal (MET), metal-ceramic (MCER), metal-composite (MCOM), peek-composite (PKCOM), carbon fiber-composite (FCOM), and carbon fiber-ceramic (FCCER). An impact-load dynamic finite-element analysis was carried out on all the 3D models of crowns mentioned above to assess their mechanical behavior against dynamic excitation. Implant-crown rehabilitation models with and without cortical bone were analyzed to compare how the load-impact actions affect both type of models. Results: numerical simulation results showed important differences in bone tissue stresses. The results show that flexible restorative materials reduce the stress on the bone and would be especially recommendable in the absence of cortical bone. Conclusions: this study demonstrated that more stress is transferred to the bone when stiffer materials (metal and/or ceramic) are used in implant supported rehabilitations; conversely, more flexible materials transfer less stress to the implant connection. Also, in implant-supported rehabilitations, more stress is transferred to the bone by dynamic forces when cortical bone is absent.
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21
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Gvetadze RS, Strekalov AA, Smerdov AA. [Study of the effect of the occlusal surface of a natural tooth and fixed partial dentures supported by dental implants on the stress distribution by finite element analysis]. STOMATOLOGII︠A︡ 2021; 100:13-18. [PMID: 34180619 DOI: 10.17116/stomat202110003113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE To study the effect of the occlusal surface of a natural tooth, cement-retained and screw-retained fixed partial dentures supported by dental implants and the coefficient of friction on the stress distribution in the peri-implant bone at maximum and minimum principal stresses. MATERIAL AND METHODS Study of maximum and minimum principal stresses in models with natural teeth and artificial crowns supported by dental implants, taking into account the coefficient of friction using the finite element analysis. RESULTS In models represented by fixed partial dentures supported by dental implants and a natural tooth, the maximum tensile stresses arise in the cortical bone in the cervical region of the artificial crown, and the maximum compressive stresses occur both in the cortical layer in the cervical region of the artificial crown and in the cervical region of the tooth. In models with two fixed partial dentures supported by dental implants or two natural teeth, the stress distributions in the cortical layers in the upper and lower jaw are almost identical. CONCLUSION Modeling the antagonist and adding to the FEA model is important in order to determine the precise and realistic direction of the resulting force vector. Amplification of the number of contact areas should be considered when modeling the occlusal surface of artificial crowns supported by dental implants.
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Affiliation(s)
- R Sh Gvetadze
- Central Research Institute of Dentistry and Maxillofacial Surgery, Moscow, Russia
| | - A A Strekalov
- Central Research Institute of Dentistry and Maxillofacial Surgery, Moscow, Russia
| | - A A Smerdov
- Central Research Institute of Dentistry and Maxillofacial Surgery, Moscow, Russia
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22
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A 3D Finite Element Analysis Model of Single Implant-Supported Prosthesis under Dynamic Impact Loading for Evaluation of Stress in the Crown, Abutment and Cortical Bone Using Different Rehabilitation Materials. MATERIALS 2021; 14:ma14133519. [PMID: 34202625 PMCID: PMC8269525 DOI: 10.3390/ma14133519] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Revised: 06/13/2021] [Accepted: 06/18/2021] [Indexed: 12/19/2022]
Abstract
In the literature, many researchers investigated static loading effects on an implant. However, dynamic loading under impact loading has not been investigated formally using numerical methods. This study aims to evaluate, with 3D finite element analysis (3D FEA), the stress transferred (maximum peak and variation in time) from a dynamic impact force applied to a single implant-supported prosthesis made from different materials. A 3D implant-supported prosthesis model was created on a digital model of a mandible section using CAD and reverse engineering. By setting different mechanical properties, six implant-supported prostheses made from different materials were simulated: metal (MET), metal-ceramic (MCER), metal-composite (MCOM), carbon fiber-composite (FCOM), PEEK-composite (PKCOM), and carbon fiber-ceramic (FCCER). Three-dimensional FEA was conducted to simulate the collision of 8.62 g implant-supported prosthesis models with a rigid plate at a speed of 1 m/s after a displacement of 0.01 mm. The stress peak transferred to the crown, titanium abutment, and cortical bone, and the stress variation in time, were assessed.
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Computational biomechanical modelling of the rabbit cranium during mastication. Sci Rep 2021; 11:13196. [PMID: 34162932 PMCID: PMC8222361 DOI: 10.1038/s41598-021-92558-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 06/08/2021] [Indexed: 11/08/2022] Open
Abstract
Although a functional relationship between bone structure and mastication has been shown in some regions of the rabbit skull, the biomechanics of the whole cranium during mastication have yet to be fully explored. In terms of cranial biomechanics, the rabbit is a particularly interesting species due to its uniquely fenestrated rostrum, the mechanical function of which is debated. In addition, the rabbit processes food through incisor and molar biting within a single bite cycle, and the potential influence of these bite modes on skull biomechanics remains unknown. This study combined the in silico methods of multi-body dynamics and finite element analysis to compute musculoskeletal forces associated with a range of incisor and molar biting, and to predict the associated strains. The results show that the majority of the cranium, including the fenestrated rostrum, transmits masticatory strains. The peak strains generated over all bites were found to be attributed to both incisor and molar biting. This could be a consequence of a skull shape adapted to promote an even strain distribution for a combination of infrequent incisor bites and cyclic molar bites. However, some regions, such as the supraorbital process, experienced low peak strain for all masticatory loads considered, suggesting such regions are not designed to resist masticatory forces.
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Qin W, Cong M, Liu D, Ren X. A robotic chewing simulator supplying six-axis mandibular motion, high occlusal force, and a saliva environment for denture tests. Proc Inst Mech Eng H 2021; 235:751-761. [PMID: 33757320 DOI: 10.1177/09544119211005601] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Six-axis motion is essential for the evaluation of the wear failure modes of dental prostheses with complete teeth morphologies, and a high occlusal force capacity is vital for static clenching and dynamic bruxism. Additionally, the saliva environment influences abrasive particles and crack growth. The present research was aimed at the development of a six-axis masticatory and saliva simulator with these capacities. The masticatory simulator was designed based on a six-axis parallel mechanism, and the saliva simulator consisted of a saliva circuit and a temperature control loop. A control system of the masticatory and saliva simulators was constructed. The operating interface includes a centric occlusal position search, a static test, a dynamic test, a saliva supply, and data reporting. The motion and force performances of the masticatory simulator were evaluated. The flow rate and temperature change of the saliva simulator were calculated. For the occlusal position-searching, the driving amplitude is linear with the moving variables during minor one-axis motion. For the static tests, the force capacity of the driving chain is 3540 N, while for the dynamic tests, the force capacity is 1390 N. The flow rate of the saliva is 0.18-51.84 mL/min, and the saliva can effectively wet the prosthesis without the risk of overflow. Moreover, the saliva temperature can increase from room temperature (23°C) to body temperature (37°C) in about 6 min. The proposed DUT-2 simulator with six-axis motion, high force, and a salvia environment provides an in vitro testing approach to validate numerical simulation results and explain the clinical failure modes of prostheses. The centric occlusal position-searching, static tests, and dynamic tests could therefore be executed using a single testing machine. Moreover, the proposed device is more compact than previously reported six-axis masticatory simulators, including the Bristol simulator and DUT-1 simulator.
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Affiliation(s)
- Wenlong Qin
- School of Mechanical Engineering, Dalian University of Technology, Dalian, China
| | - Ming Cong
- School of Mechanical Engineering, Dalian University of Technology, Dalian, China
| | - Dong Liu
- School of Mechanical Engineering, Dalian University of Technology, Dalian, China
| | - Xiang Ren
- College of Stomatology, Dalian Medical University, Dalian, China
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Ramos GF, Ramos NC, Alves LMM, Kaizer MR, Borges ALS, Campos TMB, Melo RM. Failure probability and stress distribution of milled porcelain-zirconia crowns with bioinspired/traditional design and graded interface. J Mech Behav Biomed Mater 2021; 119:104438. [PMID: 33798936 DOI: 10.1016/j.jmbbm.2021.104438] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 09/14/2020] [Accepted: 02/26/2021] [Indexed: 10/21/2022]
Abstract
OBJECTIVE To evaluate the failure probability and stress distribution of traditional and bioinspired porcelain-zirconia milled crowns, with and without silica infiltration (graded zirconia). METHODS Traditional crown design had a zirconia infrastructure veneered with porcelain; Bioinspired, had a porcelain infrastructure with translucent-zirconia veneer; Graded and Graded Bioinspired crowns had their zirconia layer infiltrated by silica (n = 25). The cameo surface of each crown (porcelain or zirconia) was glazed. The restoration layers were fused by a vitreous connector and the crowns were adhesively cemented to dies. The specimens were then mechanically cycled in a sliding machine using 100 N load at 4 Hz. The specimens were tested until 2 × 106 cycles, and every 0.5 × 106 cycles the crowns were evaluated under stereomicroscopy for the presence of failures. The stress distribution was inspected with Finite Element Analyses. RESULTS The predominant failure modes for the Traditional and Graded crowns were delamination and cracking, respectively. The Weibull parameters beta and eta were, respectively: Traditional 1.30 and 2.3 × 106 cycles, and Graded 1.95 and 2.3 × 106 cycles. Thus, the Traditional and Graded crowns presented greater susceptibility to failure due to fatigue, while the Bioinspired and Graded Bioinspired crowns showed no fatigue effect using 100N load, showing beta = 1 and eta of approximately 17 × 106 cycles. Also, through finite element analyses, it was verified that the Bioinspired and Graded Bioinspired crowns presented the best stress distribution on both crowns and dental structures. SIGNIFICANCE Bioinspired and Graded Bioinspired crowns had the lowest failure probability and better stress distribution and may be considered robust long lasting restorations.
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Affiliation(s)
- G F Ramos
- Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP), Institute of Science and Technology, 777 Eng. Francisco José Longo Avenue, 12245-000, São José Dos Campos, SP, Brazil.
| | - N C Ramos
- Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP), Institute of Science and Technology, 777 Eng. Francisco José Longo Avenue, 12245-000, São José Dos Campos, SP, Brazil; College of Dentistry, Sao Francisco University (USF), 218 Sao Francisco de Assis Avenue, 12916-900, Bragança Paulista, SP, Brazil.
| | - L M M Alves
- Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP), Institute of Science and Technology, 777 Eng. Francisco José Longo Avenue, 12245-000, São José Dos Campos, SP, Brazil.
| | - M R Kaizer
- College of Dentistry, Positivo University (UP), 5300 Prof. Pedro Viriato Parigot de Souza Street, 81280-330, Curitiba, PR, Brazil.
| | - A L S Borges
- Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP), Institute of Science and Technology, 777 Eng. Francisco José Longo Avenue, 12245-000, São José Dos Campos, SP, Brazil.
| | - T M B Campos
- Physics Department, Technological Institute of Aeronatics (ITA), 50 Praça Marechal Eduardo Gomes, 12228-900, São José Dos Campos, SP, Brazil.
| | - R M Melo
- Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP), Institute of Science and Technology, 777 Eng. Francisco José Longo Avenue, 12245-000, São José Dos Campos, SP, Brazil.
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Goodacre CJ, Roberts WE, Goldstein G, Wiens JP. Does the Stomatognathic System Adapt to Changes in Occlusion? Best Evidence Consensus Statement. J Prosthodont 2020; 30:5-11. [PMID: 33350537 DOI: 10.1111/jopr.13310] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 09/28/2020] [Indexed: 12/17/2022] Open
Abstract
PURPOSE The purpose of this Best Evidence Consensus Statement was to evaluate the existing literature on the stomatognathic system's ability to adapt to occlusal changes. MATERIALS AND METHODS The search term stomatognathic system was not useful as it resulted in over 400,000 results nor was the search term temporomandibular joint adaptation with 738 results due to the large number of references not related to the topic. The terms stomatognathic system adaptation to occlusal changes (186 results), teeth flexion (139 results), muscle adaptation to dental occlusion (278 results), and occlusal changes and neuroplasticity (11 results) provided the best selection of articles related to the topic. Limiting the above searches to systematic reviews and randomized controlled clinical trials resulted in multiple publications that were related to the question.9-13 Other literature reviews, data-based publications, and expert opinion resources have been included due to their relationship to the question. RESULTS From the extensive list of search results, 242 articles were determined to be potentially related to the focus question and were evaluated with 56 being included in this paper. It was determined that the stomatognathic system adapts to occlusal changes through the temporomandibular joint, muscles, teeth and bone. The dynamically modified periosteum on the articulator surfaces of the condyle and fossa has a unique load-bearing morphology with 3 subarticular layers of fibrocartilage that absorb and dissipate both peak (impact) and sustained loads. Adaptability of the TMJs and muscles can be documented through studies where artificially produced occlusal interferences were placed in patients and those study participants with normal temporomandibular joints (TMJs) adapted fairly well whereas those with a previous history of temporomandibular disorders (TMD) did not adapt as well. CONCLUSIONS Available evidence indicates patients generally adapt to the occlusal change inherent in orthodontic treatment, mandibular advancement surgery, and the use of mandibular advancement devices. The head and neck muscles also adapt to occlusal changes in patients without a history of TMD. The dentition adapts to changes through the bone and periodontal ligaments as well as the ability of teeth to undergo slight flexion under masticatory loading. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Charles J Goodacre
- Distinguished Professor, Advanced Education Program in Implant Dentistry, Loma Linda University School of Dentistry, Loma Linda, CA
| | - W Eugene Roberts
- Professor Emeritus of Orthodontics, Adjunct Professor, Mechanical Engineering, Indiana University & Purdue University, Indianapolis, IN
| | | | - Jonathan P Wiens
- Adjunct Clinical Professor, Department of Restorative Dentistry, University of Detroit Mercy School of Dentistry, Detroit, Michigan
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Relationships of Stresses on Alveolar Bone and Abutment of Dental Implant from Various Bite Forces by Three-Dimensional Finite Element Analysis. BIOMED RESEARCH INTERNATIONAL 2020; 2020:7539628. [PMID: 32149132 PMCID: PMC7049827 DOI: 10.1155/2020/7539628] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Revised: 12/02/2019] [Accepted: 01/23/2020] [Indexed: 11/24/2022]
Abstract
Occlusal trauma caused by improper bite forces owing to the lack of periodontal membrane may lead to bone resorption, which is still a problem for the success of dental implant. In our study, to avoid occlusal trauma, we put forward a hypothesis that a microelectromechanical system (MEMS) pressure sensor is settled on an implant abutment to track stress on the abutment and predict the stress on alveolar bone for controlling bite forces in real time. Loading forces of different magnitudes (0 N–100 N) and angles (0–90°) were applied to the crown of the dental implant of the left central incisor in a maxillary model. The stress distribution on the abutment and alveolar bone were analyzed using a three-dimensional finite element analysis (3D FEA). Then, the quantitative relation between them was derived using Origin 2017 software. The results show that the relation between the loading forces and the stresses on the alveolar bone and abutment could be described as 3D surface equations associated with the sine function. The appropriate range of stress on the implant abutment is 1.5 MPa–8.66 MPa, and the acceptable loading force range on the dental implant of the left maxillary central incisor is approximately 6 N–86 N. These results could be used as a reference for the layout of MEMS pressure sensors to maintain alveolar bone dynamic remodeling balance.
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Ibrahim RO, Al-Zahawi AR, Sabri LA. Mechanical and thermal stress evaluation of PEEK prefabricated post with different head design in endodontically treated tooth: 3D-finite element analysis. Dent Mater J 2020; 40:508-518. [PMID: 32999141 DOI: 10.4012/dmj.2020-053] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
An endodontic post is required to retain and support the core restoration in case of insufficient remaining coronal dentin after root canal therapy. This study analyzed the biomechanical and thermal behavior of PEEK prefabricated post after choosing the head design that produces the least amount of stress on the core and remaining tooth structure. These results were compared with the most common commercially available prefabricated post, which is titanium and glass fiber post. Thus a CBCT scanning of a maxillary central incisor with its supporting structure was used to construct a 3D solid model of an endodontically treated teeth for finite element analysis (FEA). The restored tooth with the spherical head design of PEEK prefabricated post yielded a more benign stress distribution and repairable failure mode on the crown, luting cement, core, and dentin under both mechanical and thermal loads, followed by glass fiber post and titanium post respectively.
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Affiliation(s)
- Rawa Omar Ibrahim
- Conservative Department, College of Dentistry, University of Sulaimani
| | | | - Laith Abed Sabri
- Department of Mechatronics, Al-Khwarizmi College of Engineering, University of Baghdad
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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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Fung S, Lee J, Yong R, Ranjitkar S, Kaidonis J, Pilbrow V, Panagiotopoulou O, Fiorenza L. A functional analysis of Carabelli trait in Australian aboriginal dentition. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2020; 174:375-383. [PMID: 32779189 DOI: 10.1002/ajpa.24120] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 06/16/2020] [Accepted: 07/08/2020] [Indexed: 12/24/2022]
Abstract
OBJECTIVES Carabelli is a nonmetric dental trait variably expressed as a small pit to a prominent cusp in the maxillary molars of modern humans. Investigations on the occurrence and expression rates of this trait have been conducted extensively, tracing its origin to genetic sources. However, there remains a lack of understanding about its potential role in chewing. In this study, we examine molar macrowear with the aim of reconstructing Carabelli trait occlusal dynamics occurring during chewing. METHODS We have examined 96 deciduous and permanent maxillary molars of children and young adults from Yuendumu, an Australian Aboriginal population that was at an early stage of transition from a nomadic and hunter-gatherer way of life to a more settled existence. We apply a well-established method, called Occlusal Fingerprint Analysis, which is a digital approach for analyzing dental macrowear allowing the reconstruction of jaw movements required to produce wear pattern specific to each tooth. RESULTS Carabelli trait slightly enlarges the surface functional area, especially in those molars where this feature is expressed in its cuspal form and it is closer to the occlusal plane. Moreover, the highly steep contact planes would also indicate that Carabelli wear areas contribute to increasing the shearing abilities of the occluded teeth, which are particularly important when processing fibrous and tough foods. CONCLUSIONS The macrowear analysis suggests that Carabelli trait in the Aboriginal people from Yuendumu slightly enhanced occlusion and probably played some functional role during mastication. Future biomechanical and microwear analyses could provide additional information on the mechanical adaptation of Carabelli trait in modern human dentition.
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Affiliation(s)
- Sarah Fung
- Monash Biomedicine Discovery Institute, Department of Anatomy and Developmental Biology, Monash University, Melbourne, Victoria, Australia
| | - Jinyoung Lee
- Monash Biomedicine Discovery Institute, Department of Anatomy and Developmental Biology, 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
| | - Varsha Pilbrow
- Australian Institute of Archaeology, La Trobe University, Melbourne, Victoria, Australia
| | - Olga Panagiotopoulou
- Monash Biomedicine Discovery Institute, Department of Anatomy and Developmental Biology, Monash University, Melbourne, Victoria, Australia
| | - Luca Fiorenza
- Monash Biomedicine Discovery Institute, Department of Anatomy and Developmental Biology, Monash University, Melbourne, Victoria, Australia.,Earth Sciences, University of New England, Armidale, New South Wales, Australia
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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: 1.0] [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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Ortún-Terrazas J, Cegoñino J, Pérez Del Palomar A. In silico study of cuspid' periodontal ligament damage under parafunctional and traumatic conditions of whole-mouth occlusions. A patient-specific evaluation. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2020; 184:105107. [PMID: 31629157 DOI: 10.1016/j.cmpb.2019.105107] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 09/28/2019] [Accepted: 10/01/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND AND OBJECTIVE Although traumatic loading has been associated with periodontal ligament (PDL) damage and therefore with several oral disorders, the damage phenomena and the traumatic loads involved are still unclear. The complex composition and extremely thin size of the PDL make experimentation difficult, requiring computational studies that consider the macroscopic loading conditions, the microscopic composition and fine detailed geometry of the tissue. In this study, a new methodology to analyse the damage phenomena in the collagen network and the extracellular matrix of the PDL caused by parafunctional and traumatic occlusal forces was proposed. METHODS The entire human mandible and a portion thereof containing a full cuspid tooth were separately modelled using finite element analysis based on computed tomography and micro-computed tomography images, respectively. The first model was experimentally validated by occlusion analysis and subjected to the muscle loads produced during hard and soft chewing, traumatic cuspid occlusion, grinding, clenching, and simultaneous grinding and clenching. The occlusal forces computed by the first model were subsequently applied to the single tooth model to evaluate damage to the collagen network and the extracellular matrix of the PDL. RESULTS Early occlusal contact on the left cuspid tooth guided the mandible to the more occluded side (16.5% greater in the right side) and absorbed most of the lateral load. The intrusive occlusal loads on the posterior teeth were 0.77-13.3% greater than those on the cuspid. According to our findings, damage to the collagen network and the extracellular matrix of the PDL could occur in traumatic and grinding conditions, mainly due to fibre overstretching (>60%) and interstitial fluid overpressure (>4.7 kPa), respectively. CONCLUSIONS Our findings provide important biomechanical insights into the determination of damage mechanisms which are caused by mechanical loading and the key role of the porous-fibrous behaviour of the PDL in parafunctional and traumatic loading scenarios. Besides, the 3D loading conditions computed from occlusal contacts will help future studies in the design of new orthodontics appliances and encourage the application of computing methods in medical practice.
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Affiliation(s)
- Javier Ortún-Terrazas
- Group of Biomaterials, Aragon Institute of Engineering Research (I3A), University of Zaragoza, Zaragoza, Spain.
| | - José Cegoñino
- Group of Biomaterials, Aragon Institute of Engineering Research (I3A), University of Zaragoza, Zaragoza, Spain
| | - Amaya Pérez Del Palomar
- Group of Biomaterials, Aragon Institute of Engineering Research (I3A), University of Zaragoza, Zaragoza, Spain
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Development of the mandibular curve of spee and maxillary compensating curve: A finite element model. PLoS One 2019; 14:e0221137. [PMID: 31877131 PMCID: PMC6932755 DOI: 10.1371/journal.pone.0221137] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Accepted: 10/28/2019] [Indexed: 11/29/2022] Open
Abstract
The curved planes of the human dentition seen in the sagittal view, the mandibular curve of Spee and the maxillary compensating curve, have clinical importance to modern dentistry and potential relevance to the craniofacial evolution of hominins. However, the mechanism providing the formation of these curved planes is poorly understood. To explore this further, we use a simplified finite element model, consisting of maxillary and mandibular “blocks”, developed to simulate tooth eruption, and forces opposing eruption, during simplified masticatory function. We test our hypothesis that curved occlusal planes develop from interplay between tooth eruption, occlusal load, and mandibular movement. Our results indicate that our simulation of rhythmic chewing movement, tooth eruption, and tooth eruption inhibition, applied concurrently, results in a transformation of the contacting maxillary and mandibular block surfaces from flat to curved. The depth of the curvature appears to be dependent on the radius length of the rotating (chewing) movement of the mandibular block. Our results suggest mandibular function and maxillo-mandibular spatial relationship may contribute to the development of human occlusal curvature.
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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: 11] [Impact Index Per Article: 2.2] [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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Limjeerajarus N, Dhammayannarangsi P, Phanijjiva A, Tangsripongkul P, Jearanaiphaisarn T, Pittayapat P, Limjeerajarus CN. Comparison of ultimate force revealed by compression tests on extracted first premolars and FEA with a true scale 3D multi-component tooth model based on a CBCT dataset. Clin Oral Investig 2019; 24:211-220. [PMID: 31079245 DOI: 10.1007/s00784-019-02919-8] [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] [Received: 08/20/2018] [Accepted: 04/29/2019] [Indexed: 12/28/2022]
Abstract
OBJECTIVE The aim of this study was to develop a new method for creating a multi-component and true scale 3-dimensional (3D) model of a human tooth based on cone-beam computed tomography (CBCT) images. MATERIALS AND METHODS First maxillary premolar tooth model was reconstructed from a patient's CBCT images. The 2D serial sections were used to create the 3D model. This model was used for finite element analysis (FEA). Model validation was performed by comparing the ultimate compressive force (UF) obtained experimentally using a universal testing machine and from simulation. The simulations of three component-omitting models (silicone, cementum, and omitting both) were performed to analyze the maximum (max.) principal stress and stress distribution. RESULTS The simulation-based UF indicating tooth fracture was 637 N, while the average UF in the in vitro loading was 651 N. The discrepancy between the simulation-based UF and the experimental UF was 2.2%. From the simulation, the silicone-omitting models showed a significant change in max. principal stress, resulting in a UF error of 26%, whereas there was no notable change in the cementum-omitting model. CONCLUSION This study, for the first time, developed a true scale multi-component 3D model from CBCT for predicting stress distribution in a human tooth. CLINICAL RELEVANCE This study proposed a method to create 3D modeling from CBCT in a true scale and multi-component manner. The PDL-like component-omitting simulation led to a higher error value of UF, indicating the importance of multi-component tooth modeling in FEA. Tooth 3D modeling could help determine mechanical failure in dental treatments in a more precise manner.
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Affiliation(s)
- Nuttapol Limjeerajarus
- Research Center for Advanced Energy Technology, Faculty of Engineering, Thai-Nichi Institute of Technology, Bangkok, 10250, Thailand
| | - Phetcharat Dhammayannarangsi
- Research Center for Advanced Energy Technology, Faculty of Engineering, Thai-Nichi Institute of Technology, Bangkok, 10250, Thailand
| | - Anon Phanijjiva
- Research Center for Advanced Energy Technology, Faculty of Engineering, Thai-Nichi Institute of Technology, Bangkok, 10250, Thailand
| | - Pavita Tangsripongkul
- Department of Operative Dentistry, Faculty of Dentistry, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Thanomsuk Jearanaiphaisarn
- Department of Operative Dentistry, Faculty of Dentistry, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Pisha Pittayapat
- Department of Radiology, Faculty of Dentistry, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Chalida Nakalekha Limjeerajarus
- Department of Physiology, Faculty of Dentistry, Chulalongkorn University, Bangkok, 10330, Thailand. .,Center of Excellence for Regenerative Dentistry, Faculty of Dentistry, Chulalongkorn University, Bangkok, 10330, Thailand.
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Brune A, Stiesch M, Eisenburger M, Greuling A. The effect of different occlusal contact situations on peri-implant bone stress - A contact finite element analysis of indirect axial loading. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2019; 99:367-373. [PMID: 30889710 DOI: 10.1016/j.msec.2019.01.104] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 01/21/2019] [Accepted: 01/23/2019] [Indexed: 11/17/2022]
Abstract
Implant restoration is one of the basic treatments in dentistry today, yet implant loss from occlusal overload is still a problem. Complex biomechanical problems such as occlusal overload are often analyzed by means of the finite element method. This numerical method makes it possible to analyze in detail the influence that different loading situations have upon implants and tissues, which is a key element in optimizing these dental procedures. This study was designed to investigate the stress distribution in peri-implant bone of a single-tooth implant crown using the finite element method. The load was applied indirectly via an occluding tooth through a three and five contact setup into the implant crown. The friction coefficient values between the crown and antagonist were varied between 0.1 and 1.0. Additionally, three crowns with cusp inclinations of 20°, 30° and 40° were modeled. Non-linear contact computations indicated that an increase in friction changed the direction and magnitude of contact forces, which also led to reduced stresses in the bone. Furthermore, the stress magnitudes were higher when cusps of a greater inclination were used. The intensity of stress alterations was strongly dependent on the distribution and number of contacts, and the contact force vector. In maximum intercuspation, a resulting axial load due to well-distributed contacts prevented high stresses in bone even with high cusp inclinations and low friction. Therefore for long-term clinical success, particular attention should be paid to occlusal adjustment so as to prevent oblique loading onto dental implant restorations.
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Affiliation(s)
- Annike Brune
- Department of Prosthetic Dentistry and Biomedical Materials Science, Hannover Medical School, 30625 Hannover, Germany.
| | - Meike Stiesch
- Department of Prosthetic Dentistry and Biomedical Materials Science, Hannover Medical School, 30625 Hannover, Germany.
| | - Michael Eisenburger
- Department of Prosthetic Dentistry and Biomedical Materials Science, Hannover Medical School, 30625 Hannover, Germany.
| | - Andreas Greuling
- Department of Prosthetic Dentistry and Biomedical Materials Science, Hannover Medical School, 30625 Hannover, Germany.
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Liu D, Yan B, Lei F, Li J, Wang X, Rong Q, Zhou Y. Different sliding mechanics in space closure of lingual orthodontics: a translational study by three-dimensional finite element method. Am J Transl Res 2019; 11:120-130. [PMID: 30787973 PMCID: PMC6357325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 12/23/2018] [Indexed: 06/09/2023]
Abstract
Lingual orthodontics have become popular in modern society as they do not cause aesthetic impairment. From the translational medicine point of view, the use of biomechanical analysis to solve a clinical problem has rarely been reported. Here, we combined the clinical trial and 3-D finite element (FE) method to translate the clinical problem to the FE analysis and back to clinic. Twenty upper premolar extraction cases treated with customized lingual appliances were recruited in this study. Cephalometric films and cast records analysis showed that the "bowing effect", which is a major side effect in lingual orthodontics, occurred during the first treatment stage with single lingual cable retraction. In order to translate the problem to biomechanical research, we introduced the 3-D finite element (FE) model of a customized lingual orthodontic system. The 3-D FE model including the maxilla, periodontal ligament (PDL), and dentition was constructed from human computed tomography data. The tendency of tooth movements in three dimensions and stress distribution in the PDL were analyzed by different mechanical loading methods. 3-D FE analysis confirmed the "bowing effects" and unexpected tooth movements with application of single lingual retraction force. Interestingly, we found that applying forces on both buccal and lingual sides, called "double cable" mechanics, could prevent the "bowing effect". For the clinical trial, we applied the "double cable" force during space closure stage for 4 months, and confirmed "double cable" mechanics could correct and prevent the "bowing effect" clinically. Based on our results, both buccal and lingual forces should be used during space closure in lingual orthodontics to prevent and correct the "bowing effect". Moreover, the magnitude of buccal force should not be lower than the force on the lingual side.
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Affiliation(s)
- Dawei Liu
- Department of Orthodontics, Peking University School and Hospital of StomatologyBeijing, P. R. China
- National Engineering Laboratory for Digital and Material Technology of StomatologyBeijing, P. R. China
- Beijing Key Laboratory of Digital StomatologyBeijing, P. R. China
| | - Boxi Yan
- Department of Orthodontics, Peking University School and Hospital of StomatologyBeijing, P. R. China
- National Engineering Laboratory for Digital and Material Technology of StomatologyBeijing, P. R. China
- Beijing Key Laboratory of Digital StomatologyBeijing, P. R. China
| | - Feifei Lei
- Department of Orthodontics, Peking University School and Hospital of StomatologyBeijing, P. R. China
- National Engineering Laboratory for Digital and Material Technology of StomatologyBeijing, P. R. China
- Beijing Key Laboratory of Digital StomatologyBeijing, P. R. China
| | - Jing Li
- Department of Orthodontics, Peking University School and Hospital of StomatologyBeijing, P. R. China
- National Engineering Laboratory for Digital and Material Technology of StomatologyBeijing, P. R. China
- Beijing Key Laboratory of Digital StomatologyBeijing, P. R. China
| | - Xuedong Wang
- Department of Orthodontics, Peking University School and Hospital of StomatologyBeijing, P. R. China
- National Engineering Laboratory for Digital and Material Technology of StomatologyBeijing, P. R. China
- Beijing Key Laboratory of Digital StomatologyBeijing, P. R. China
| | - Qiguo Rong
- Department of Mechanics and Engineering Science, College of Engineering, Peking UniversityBeijing, P. R. China
| | - Yanheng Zhou
- Department of Orthodontics, Peking University School and Hospital of StomatologyBeijing, P. R. China
- National Engineering Laboratory for Digital and Material Technology of StomatologyBeijing, P. R. China
- Beijing Key Laboratory of Digital StomatologyBeijing, P. R. China
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Lee JS, Choi HI, Lee H, Ahn SJ, Noh G. Biomechanical effect of mandibular advancement device with different protrusion positions for treatment of obstructive sleep apnoea on tooth and facial bone: A finite element study. J Oral Rehabil 2018; 45:948-958. [DOI: 10.1111/joor.12709] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 06/30/2018] [Accepted: 08/15/2018] [Indexed: 12/13/2022]
Affiliation(s)
- Ji-Soo Lee
- Department of Dentistry; Graduate School; Kyung Hee University; Seoul Korea
| | - Hye-In Choi
- Center for Bionics; Korea Institute of Science and Technology (KIST); Seoul Korea
| | - Hyeonjong Lee
- Division of Fixed Prosthodontics and Biomaterials; Clinique of Universitaire Medicine Dentaire; University of Geneva; Geneva Switzerland
| | - Su-Jin Ahn
- Department of Biomaterials & Prosthodontics; Kyung Hee University Hospital at Gangdong; School of Dentistry; Kyung Hee University; Seoul Korea
| | - Gunwoo Noh
- School of Mechanical Engineering; Kyungpook National University; Daegu Korea
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Oxilia G, Bortolini E, Martini S, Papini A, Boggioni M, Buti L, Figus C, Sorrentino R, Townsend G, Kaidonis J, Fiorenza L, Cristiani E, Kullmer O, Moggi‐Cecchi J, Benazzi S. The physiological linkage between molar inclination and dental macrowear pattern. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2018; 166:941-951. [PMID: 29633246 PMCID: PMC6120545 DOI: 10.1002/ajpa.23476] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 02/14/2018] [Accepted: 03/21/2018] [Indexed: 11/06/2022]
Abstract
OBJECTIVES Exact symmetry and perfect balance between opposite jaw halves, as well as between antagonistic teeth, is not frequently observed in natural masticatory systems. Research results show that asymmetry in our body, skull, and jaws is often related to genetic, epigenetic, environmental and individual ontogenetic factors. Our study aims to provide evidence for a significant link between masticatory asymmetry and occlusal contact between antagonist teeth by testing the hypothesis that tooth inclination is one of the mechanisms driving distribution of wear in masticatory phases in addition to dietary and cultural habits. MATERIALS AND METHODS The present work investigates the relationship between dental macrowear patterns and tooth inclinations on a sample of complete maxillary and mandibular 3D models of dental arches from 19 young and adult Yuendumu Aboriginal individuals. The analysis was carried out on first molars (M1) from all quadrants. Occlusal Fingerprint Analysis was used for the quantification of macrowear patterns, and 2D cross-sectional geometric analysis was carried out to investigate asymmetry in dental arches. RESULTS The asymmetry is highly variable on both arches, and it is associated with differences in the inclination of upper M1 crowns. Each molar has variable inclination (buccal/lingual) which influence tooth to tooth contact, producing greater or lesser variation in wear pattern. Interindividual variability of morphological variation of the occlusal relationship has to be considered in macrowear analysis. DISCUSSION Our results suggest that overall asymmetry in the masticatory apparatus in modern humans affects occlusal contact areas between antagonist teeth influencing macrowear and chewing efficiency during ontogeny.
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Affiliation(s)
- Gregorio Oxilia
- Department of Oral and Maxillo Facial SciencesSapienza University, Via Caserta 6Roma 00161Italy
- Department of BiologyUniversity of Florence, Via del Proconsolo, 12Firenze 50122Italy
- Department of Cultural HeritageUniversity of Bologna, Via degli Ariani 1Ravenna 48121Italy
| | - Eugenio Bortolini
- Department of Cultural HeritageUniversity of Bologna, Via degli Ariani 1Ravenna 48121Italy
| | - Sergio Martini
- Dental Lab Technician, via Milani, 1ParonaVerona 37124Italy
| | - Andrea Papini
- Dentist's Surgery, via Walter Tobagi 35Prato 59100Italy
| | - Marco Boggioni
- Dentist's Surgery, via D'Andrade 34/207Genova Sestri Ponente 16154Italy
| | - Laura Buti
- Department of Cultural HeritageUniversity of Bologna, Via degli Ariani 1Ravenna 48121Italy
| | - Carla Figus
- Department of Cultural HeritageUniversity of Bologna, Via degli Ariani 1Ravenna 48121Italy
| | - Rita Sorrentino
- Department of Cultural HeritageUniversity of Bologna, Via degli Ariani 1Ravenna 48121Italy
- Department of Biological, Geological and Environmental Sciences—BiGeAUniversity of Bologna, Via Selmi 3Bologna 40126Italy
| | - Grant Townsend
- Adelaide Dental SchoolThe University of AdelaideAdelaideAustralia
| | - John Kaidonis
- Adelaide Dental SchoolThe University of AdelaideAdelaideAustralia
| | - Luca Fiorenza
- Department of Anatomy and Developmental BiologyMonash UniversityMelbourneVIC 3800Australia
- Earth SciencesUniversity of New EnglandArmidaleNSW 2351Australia
| | - Emanuela Cristiani
- Department of Oral and Maxillo Facial SciencesSapienza University, Via Caserta 6Roma 00161Italy
| | - Ottmar Kullmer
- Senckenberg Research Institute, Senckenberganlage 25Frankfurt am Main 60325Germany
- Department of Paleobiology and EnvironmentInstitute of Ecology, Evolution, and Diversity, Johann Wolfgang Goethe University, Max‐von‐Laue‐Str. 13Frankfurt 60438Germany
| | - Jacopo Moggi‐Cecchi
- Department of BiologyUniversity of Florence, Via del Proconsolo, 12Firenze 50122Italy
| | - Stefano Benazzi
- Department of Cultural HeritageUniversity of Bologna, Via degli Ariani 1Ravenna 48121Italy
- Department of Human EvolutionMax Planck Institute for Evolutionary Anthropology, Deutscher Platz 6Leipzig 04103Germany
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Di Vincenzo F, Profico A, Bernardini F, Cerroni V, Dreossi D, Schlager S, Zaio P, Benazzi S, Biddittu I, Rubini M, Tuniz C, Manzi G. Digital reconstruction of the Ceprano calvarium (Italy), and implications for its interpretation. Sci Rep 2017; 7:13974. [PMID: 29070804 PMCID: PMC5656598 DOI: 10.1038/s41598-017-14437-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 09/13/2017] [Indexed: 12/03/2022] Open
Abstract
The Ceprano calvarium was discovered in fragments on March 1994 near the town of Ceprano in southern Latium (Italy), embedded in Middle Pleistocene layers. After reconstruction, its morphological features suggests that the specimen belongs to an archaic variant of H. heidelbergensis, representing a proxy for the last common ancestor of the diverging clades that respectively led to H. neanderthalensis and H. sapiens. Unfortunately, the calvarium was taphonomically damaged. The postero-lateral vault, in particular, appears deformed and this postmortem damage may have influenced previous interpretations. Specifically, there is a depression on the fragmented left parietal, while the right cranial wall is warped and angulated. This deformation affected the shape of the occipital squama, producing an inclination of the transverse occipital torus. In this paper, after X-ray microtomography (μCT) of both the calvarium and several additional fragments, we analyze consistency and pattern of the taphonomic deformation that affected the specimen, before the computer-assisted retrodeformation has been performed; this has also provided the opportunity to reappraise early attempts at restoration. As a result, we offer a revised interpretation for the Ceprano calvarium’s original shape, now free from the previous uncertainties, along with insight for its complex depositional and taphonomic history.
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Affiliation(s)
- Fabio Di Vincenzo
- Dipartimento di Biologia Ambientale, Sapienza Università di Roma, Roma, Italy.,Istituto Italiano di Paleontologia Umana, Roma, Italy
| | - Antonio Profico
- Dipartimento di Biologia Ambientale, Sapienza Università di Roma, Roma, Italy.,Istituto Italiano di Paleontologia Umana, Roma, Italy
| | - Federico Bernardini
- Centro Fermi - Museo Storico della Fisica e Centro di Studi e Ricerche 'Enrico Fermi', Roma, Italy.,The 'Abdus Salam' International Centre for Theoretical Physics, Trieste, Italy
| | - Vittorio Cerroni
- Italian Ministry of Culture, Anthropological Service, Roma, Italy
| | | | - Stefan Schlager
- Department Biological Anthropology, University Medical Center, Freiburg, Germany
| | - Paola Zaio
- Italian Ministry of Culture, Anthropological Service, Roma, Italy
| | - Stefano Benazzi
- Department of Cultural Heritage, University of Bologna, Bologna, Italy.,Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | | | - Mauro Rubini
- Istituto Italiano di Paleontologia Umana, Roma, Italy.,Italian Ministry of Culture, Anthropological Service, Roma, Italy.,Dipartimento di Archeologia, Università di Foggia, Foggia, Italy
| | - Claudio Tuniz
- Centro Fermi - Museo Storico della Fisica e Centro di Studi e Ricerche 'Enrico Fermi', Roma, Italy.,The 'Abdus Salam' International Centre for Theoretical Physics, Trieste, Italy.,Centre for Archaeological Science, University of Wollongong, Wollongong, Australia
| | - Giorgio Manzi
- Dipartimento di Biologia Ambientale, Sapienza Università di Roma, Roma, Italy. .,Istituto Italiano di Paleontologia Umana, Roma, Italy.
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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: 1.7] [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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Panagiotopoulou O, Iriarte-Diaz J, Wilshin S, Dechow PC, Taylor AB, Mehari Abraha H, Aljunid SF, Ross CF. In vivo bone strain and finite element modeling of a rhesus macaque mandible during mastication. ZOOLOGY 2017; 124:13-29. [PMID: 29037463 DOI: 10.1016/j.zool.2017.08.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Revised: 08/25/2017] [Accepted: 08/25/2017] [Indexed: 12/29/2022]
Abstract
Finite element analysis (FEA) is a commonly used tool in musculoskeletal biomechanics and vertebrate paleontology. The accuracy and precision of finite element models (FEMs) are reliant on accurate data on bone geometry, muscle forces, boundary conditions and tissue material properties. Simplified modeling assumptions, due to lack of in vivo experimental data on material properties and muscle activation patterns, may introduce analytical errors in analyses where quantitative accuracy is critical for obtaining rigorous results. A subject-specific FEM of a rhesus macaque mandible was constructed, loaded and validated using in vivo data from the same animal. In developing the model, we assessed the impact on model behavior of variation in (i) material properties of the mandibular trabecular bone tissue and teeth; (ii) constraints at the temporomandibular joint and bite point; and (iii) the timing of the muscle activity used to estimate the external forces acting on the model. The best match between the FEA simulation and the in vivo experimental data resulted from modeling the trabecular tissue with an isotropic and homogeneous Young's modulus and Poisson's value of 10GPa and 0.3, respectively; constraining translations along X,Y, Z axes in the chewing (left) side temporomandibular joint, the premolars and the m1; constraining the balancing (right) side temporomandibular joint in the anterior-posterior and superior-inferior axes, and using the muscle force estimated at time of maximum strain magnitude in the lower lateral gauge. The relative strain magnitudes in this model were similar to those recorded in vivo for all strain locations. More detailed analyses of mandibular strain patterns during the power stroke at different times in the chewing cycle are needed.
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Affiliation(s)
- Olga Panagiotopoulou
- Moving Morphology & Functional Mechanics Laboratory, School of Biomedical Sciences, The University of Queensland, St Lucia, Brisbane, QLD 4072, Australia; Department of Anatomy and Developmental Biology, School of Biomedical Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Melbourne, Victoria 3800, Australia
| | - José Iriarte-Diaz
- Department of Oral Biology, University of Illinois, 801 S. Paulina St., Chicago, IL 60612, USA
| | - Simon Wilshin
- Department of Biomedical Sciences, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire AL9 7TA, United Kingdom
| | - Paul C Dechow
- Department of Biomedical Sciences, College of Dentistry, Texas A&M University, 3302 Gaston Ave., Dallas, TX 75246, USA
| | - Andrea B Taylor
- Department of Basic Science, Touro University, 1310 Club Drive, Mare Island, Vellejo, CA 94592, USA
| | - Hyab Mehari Abraha
- Moving Morphology & Functional Mechanics Laboratory, School of Biomedical Sciences, The University of Queensland, St Lucia, Brisbane, QLD 4072, Australia
| | - Sharifah F Aljunid
- Materialise Unit 5-01, Menara OBYU, No. 4, Jalan PJU 8/8A, Damansara Perdana, 47820 Petaling Jaya, Selangor, Malaysia
| | - Callum F Ross
- Department of Organismal Biology and Anatomy, University of Chicago, 1027 E. 57th St., Chicago, IL 60637, USA.
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Asahara M, Takai M. Estimation of diet in extinct raccoon dog species by the molar ratio method. ACTA ZOOL-STOCKHOLM 2016. [DOI: 10.1111/azo.12179] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Masakazu Asahara
- College of Liberal Arts and Sciences; Mie University; Kurima-Machiya-Cho Tsu Mie 514-8507 Japan
| | - Masanaru Takai
- Primate Research Institute; Kyoto University; Inuyama Aichi 484-8506 Japan
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