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Couoh LR, Bucio L, Ruvalcaba JL, Manoel B, Tang T, Gourrier A, Grandfield K. Tooth acellular extrinsic fibre cementum incremental lines in humans are formed by parallel branched Sharpey's fibres and not by its mineral phase. J Struct Biol 2024; 216:108084. [PMID: 38479547 DOI: 10.1016/j.jsb.2024.108084] [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: 11/23/2023] [Revised: 02/28/2024] [Accepted: 03/10/2024] [Indexed: 03/18/2024]
Abstract
In humans, the growth pattern of the acellular extrinsic fibre cementum (AEFC) has been useful to estimate the age-at-death. However, the structural organization behind such a pattern remains poorly understood. In this study tooth cementum from seven individuals from a Mexican modern skeletal series were analyzed with the aim of unveiling the AEFC collagenous and mineral structure using multimodal imaging approaches. The organization of collagen fibres was first determined using: light microscopy, transmission electron microscopy (TEM), electron tomography, and plasma FIB scanning electron microscopy (PFIB-SEM) tomography. The mineral properties were then investigated using: synchrotron small-angle X-ray scattering (SAXS) for T-parameter (correlation length between mineral particles); synchrotron X-ray diffraction (XRD) for L-parameter (mineral crystalline domain size estimation), alignment parameter (crystals preferred orientation) and lattice parameters a and c; as well as synchrotron X-ray fluorescence for spatial distribution of calcium, phosphorus and zinc. Results show that Sharpey's fibres branched out fibres that cover and uncover other collagen bundles forming aligned arched structures that are joined by these same fibres but in a parallel fashion. The parallel fibres are not set as a continuum on the same plane and when they are superimposed project the AEFC incremental lines due to the collagen birefringence. The orientation of the apatite crystallites is subject to the arrangement of the collagen fibres, and the obtained parameter values along with the elemental distribution maps, revealed this mineral tissue as relatively homogeneous. Therefore, no intrinsic characteristics of the mineral phase could be associated with the alternating AEFC incremental pattern.
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Affiliation(s)
- Lourdes R Couoh
- Dirección de Antropología Física, Instituto Nacional de Antropología e Historia, Paseo de la Reforma y Gandhi, Chapultepec Polanco 11560, CDMX, México.
| | - Lauro Bucio
- Laboratorio de Cristalofísica y Materiales Naturales, Instituto de Física, Universidad Nacional Autónoma de México, Ciudad Universitaria, Coyoacán 04510, CDMX, México
| | - José Luis Ruvalcaba
- Laboratorio Nacional de Ciencias para la Investigación y Conservación del Patrimonio Cultural, Instituto de Física, Universidad Nacional Autónoma de México, Ciudad Universitaria, Coyoacán 04510, CDMX, México
| | - Britta Manoel
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs 38000, Grenoble, France; Bruker AXS Advanced X-ray Solutions GmbH, Östliche Rheinbrückenstraße 49 76187, Karlsruhe, Germany
| | - Tengteng Tang
- Department of Materials Science and Engineering, McMaster University, Hamilton L8S 4L7, ON, Canada
| | | | - Kathryn Grandfield
- Department of Materials Science and Engineering, McMaster University, Hamilton L8S 4L7, ON, Canada; School of Biomedical Engineering, McMaster University, Hamilton L8S 4L7, ON, Canada.
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Zecca PA, Reguzzoni M, Protasoni M, Raspanti M. The chondro-osseous junction of articular cartilage. Tissue Cell 2023; 80:101993. [PMID: 36516570 DOI: 10.1016/j.tice.2022.101993] [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: 08/29/2022] [Revised: 11/28/2022] [Accepted: 11/29/2022] [Indexed: 12/02/2022]
Abstract
In the synovial joints the transition between the soft articular cartilage and the subchondral bone is mediated by a layer of calcified cartilage of structural and mechanical characteristics closer to those of bone. This layer, buried in the depth of articular cartilage, is not directly accessible and is mostly visualized in histological sections of decalcified tissue, where it appears as a darker strip in contact with the subchondral bone. In this study conventional histology and scanning electron microscopy (SEM) with secondary electron imaging (SE) or backscattered electron imaging (BSE) were used to discriminate the calcified and the uncalcified cartilage in high resolution on native, untreated tissue as well as in deproteinated or demineralized tissue. This approach evidenced a high heterogeneity of the calcified layer of articular cartilage. High resolution pictures revealed that the mineralization process originates by progressive accretion and confluence of individual, small mineral clusters, in a very different way from other hard tissues such as bone, dentin and mineralized tendons. Finally, selective removal of the soft matrix by thermal treatment allowed for the first time a face-on, unrestricted 3D view of the mineralization front.
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Affiliation(s)
| | | | - Marina Protasoni
- Department of Medicine & Surgery, Insubria University, Varese, Italy
| | - Mario Raspanti
- Department of Medicine & Surgery, Insubria University, Varese, Italy.
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Hinrichs C, Nicklisch N, Mardare CC, Orechovski B, Hassel AW, Kleber C, Alt KW. Incremental lines in human acellular tooth cementum - new insights by SEM analysis. Ann Anat 2022; 243:151933. [PMID: 35307556 DOI: 10.1016/j.aanat.2022.151933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 02/05/2022] [Accepted: 03/07/2022] [Indexed: 10/18/2022]
Abstract
BACKGROUND Tooth cementum covers the surface of the root dentine and is produced and laid down in thin layers continuously throughout life. Functionally, different types of tooth cementum can be distinguished, which can be roughly divided into acellular (primary cementum) and cellular (secondary cementum) forms. One main type is acellular extrinsic fibre cementum (AEFC), which covers the cervical and middle third of the root. Light microscopic examinations of transverse sections of AEFC show lamellar patterns of alternating light and dark lines called growth or incremental lines. Following mammalian research, a seasonal rhythm of incremental line formation is also assumed in humans. Previous attempts at visualising incremental lines in the AEFC by scanning electron microscopy (SEM) were not particularly successful. The aim of the present study was to detect incremental lines in the AEFC and to analyse their underlying structure by SEM. METHODS For this purpose, non-embedded and resin-embedded transverse and longitudinal sections of three single-rooted teeth obtained from different patients were investigated. The thin sections were not pre-treated (e.g. by etching, grinding or coating). RESULTS Lamellar structures, which could be identified as incremental lines, were detectable in both transverse and longitudinal sections, with transverse orientation in the cross-section and longitudinal orientation in the longitudinal section. The lamellar pattern was created by broad fibre-rich layers alternating with narrow fibre-poor layers. The orientation of the collagen fibres changed from layer to layer from transverse to radial direction. The visibility of the layered structure discovered varied significantly. CONCLUSIONS The study demonstrate that it is possible, in principle, to detect incremental lines in AEFC and to identify their basic structure using SEM. Our results suggest that the density and orientation of the fibres play an essential role in the formation of incremental lines. Functional aspects seem to be of particular importance.
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Affiliation(s)
| | - Nicole Nicklisch
- Danube Private University, Steiner Landstrasse 124, 3500 Krems-Stein, Austria.
| | - Cezarina C Mardare
- Danube Private University, Steiner Landstrasse 124, 3500 Krems-Stein, Austria; Institute of Chemical Technology of Inorganic Materials, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz, Austria.
| | - Bernhard Orechovski
- Danube Private University, Steiner Landstrasse 124, 3500 Krems-Stein, Austria.
| | - Achim W Hassel
- Danube Private University, Steiner Landstrasse 124, 3500 Krems-Stein, Austria; Institute of Chemical Technology of Inorganic Materials, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz, Austria.
| | - Christoph Kleber
- Danube Private University, Steiner Landstrasse 124, 3500 Krems-Stein, Austria; Institute of Chemical Technology of Inorganic Materials, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz, Austria.
| | - Kurt W Alt
- Danube Private University, Steiner Landstrasse 124, 3500 Krems-Stein, Austria; Institute of Prehistory and Archaeological Science, University of Basel, Spalenring 145, 4055 Basel; Switzerland.
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4
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Zuo Q, Yao J, Lu S, Du Z, Li S, Lin F, Shi W, Zhang Y, Xiao Y. The role of organic phosphate in the spatial control of periodontium complex bio-mineralization: an in vitro study. J Mater Chem B 2020; 7:5956-5965. [PMID: 31524208 DOI: 10.1039/c9tb01261c] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The periodontal structure is a particularly exquisite model of hierarchical spatial control of mineralization. Extracellular matrix control in the selective mineralization of the periodontium complex remains elusive since the extracellular matrix is a set of mineralization promoters and inhibitors. The phosphorylated proteins, which are ubiquitous in the extracellular matrix of the periodontium complex, are well-documented as primary factors in the regulation of tissue mineralization. Whether organic phosphates are key regulators in defining the interfaces between dentin, cementum, periodontal ligament and alveolar bone is an issue worthy of research. Here, we investigated the in vitro remineralization process of demineralized and dephosphorylated periodontal tissue sections. When exposed to a metastable mineralization solution, a large number of calcospherulites deposited on the surface of the dephosphorylated sections and the tissue selective mineralization were disrupted. Interestingly, on adding a dentin matrix protein-1 analogue named polyacrylic acid, the surface mineralization rate in the dephosphorylated periodontal complex reduced dramatically. In contrast, hierarchical mineralization was displayed by the demineralized section at the tissue collagen fibrillar levels in both alveolar bone and dentin regions. These results demonstrated that the organic phosphate could prevent surface mineral deposition, and the minerals could penetrate the collagen fibrils to initiate a selective and hierarchal tissue mineralization with the assistance of the dentin matrix protein-1 analogue in the periodontal complex. This study enhances our understanding of the mineralization discrepancy in the periodontal tissues, which will provide some insight into the development of biomaterials for the regeneration of soft-hard tissue interfaces.
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Affiliation(s)
- Qiliang Zuo
- Ministry Education Key Laboratory for Oral Biomedical Engineering, School of Stomatology, Wuhan University, Wuhan 430079, P. R. China.
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Turcotte CM, Green DJ, Kupczik K, McFarlin S, Schulz-Kornas E. Elevated activity levels do not influence extrinsic fiber attachment morphology on the surface of muscle-attachment sites. J Anat 2019; 236:827-839. [PMID: 31845322 DOI: 10.1111/joa.13137] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/20/2019] [Indexed: 12/17/2022] Open
Abstract
Extrinsic fibers (EFs) are a type of penetrating collagenous fiber, closely related to the periodontal ligament, which help anchor soft tissue into bone. These fibers are associated with muscle attachment sites (entheses). Their size and grouping patterns are thought to be indicative of the loading history of the muscle. EFs are of particular significance in anthropology as potential tools for the reconstruction of behavior from skeletal remains and, specifically, entheses. In this study, we used a mouse model to experimentally test how activity level alters the morphology of EF insertion sites on the bone surface of a fibrocartilaginous enthesis, the biceps brachii insertion. Further, we adapted surface metrological techniques from studies of dental wear to perform automated, quantitative and non-destructive analysis of bone surface histology. Our results show that experimentally increased activity had no significant effect on the quantity or density of EF insertions at the enthesis, nor on the size of those insertions. Although EF presence does indicate muscle attachment, activity did not have an observable effect on EF morphology.
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Affiliation(s)
- Cassandra M Turcotte
- Department of Anthropology, Center for the Advanced Study of Human Paleobiology, George Washington University, Washington, DC, USA.,Max Planck Weizmann Center for Integrative Archaeology and Anthropology, Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.,Center for the Study of Human Origins, Department of Anthropology, New York University, New York, NY, USA.,New York Consortium in Evolutionary Primatology, New York, NY, USA
| | - David J Green
- Department of Anthropology, Center for the Advanced Study of Human Paleobiology, George Washington University, Washington, DC, USA.,Department of Anatomy, Campbell University School of Osteopathic Medicine, Buies Creek, NC, USA
| | - Kornelius Kupczik
- Max Planck Weizmann Center for Integrative Archaeology and Anthropology, Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Shannon McFarlin
- Department of Anthropology, Center for the Advanced Study of Human Paleobiology, George Washington University, Washington, DC, USA
| | - Ellen Schulz-Kornas
- Max Planck Weizmann Center for Integrative Archaeology and Anthropology, Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.,Department of Cariology, Endodontology and Periodontology, University of Leipzig, Leipzig, Germany
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6
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Colard T, Falgayrac G, Bertrand B, Naji S, Devos O, Balsack C, Delannoy Y, Penel G. New Insights on the Composition and the Structure of the Acellular Extrinsic Fiber Cementum by Raman Analysis. PLoS One 2016; 11:e0167316. [PMID: 27936010 PMCID: PMC5147880 DOI: 10.1371/journal.pone.0167316] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 11/13/2016] [Indexed: 01/04/2023] Open
Abstract
Acellular extrinsic fiber cementum is a mineralized tissue that covers the cervical half of the tooth root surface. It contains mainly extrinsic or Sharpey's fibers that run perpendicular to the root surface to anchor the tooth via the periodontal ligament. Acellular cementum is continuously and slowly produced throughout life and exhibits an alternating bright and dark pattern under light microscopy. However, although a better understanding of the structural background of acellular cementum is relevant to many fields, such as cementochronology, periodontology and tissue engineering, acellular cementum remains rarely studied and poorly understood. In this work, we studied the acellular cementum at the incremental line scale of five human mandibular canines using polarized Raman spectroscopy. We provided Raman imaging analysis and polarized acquisitions as a function of the angular orientation of the sample. The results showed that mineral crystals were always parallel to collagen fibrils, and at a larger scale, we proposed an organizational model in which we found radial collagen fibers, "orthogonal" to the cementum surface, and "non-orthogonal" fibers, which consist of branching and bending radial fibers. Concerning the alternating pattern, we observed that the dark lines corresponded to smaller, more mineralized and probably more organized bands, which is consistent with the zoological assumption that incremental lines are produced during a winter rest period of acellular cementum growth.
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Affiliation(s)
- Thomas Colard
- Univ. Lille, CHU Lille, EA 7367—UTML—Unité de Taphonomie Médico-Légale, Lille, France
| | - Guillaume Falgayrac
- Univ. Lille, EA 4490—PMOI–Physiopathologie des Maladies Osseuses Inflammatoires, Lille, France
| | - Benoit Bertrand
- Univ. Lille, CHU Lille, EA 7367—UTML—Unité de Taphonomie Médico-Légale, Lille, France
| | - Stephan Naji
- CIRHUS-NYU, New York City, NY, United States of America
| | - Olivier Devos
- Univ. Lille, CNRS, UMR 8516—LASIR—Laboratoire de Spectrochimie et Raman, Lille, France
| | - Clara Balsack
- Univ. Lille, CHU Lille, EA 7367—UTML—Unité de Taphonomie Médico-Légale, Lille, France
| | - Yann Delannoy
- Univ. Lille, CHU Lille, EA 7367—UTML—Unité de Taphonomie Médico-Légale, Lille, France
| | - Guillaume Penel
- Univ. Lille, EA 4490—PMOI–Physiopathologie des Maladies Osseuses Inflammatoires, Lille, France
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7
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Lee N, Robinson J, Lu H. Biomimetic strategies for engineering composite tissues. Curr Opin Biotechnol 2016; 40:64-74. [PMID: 27010653 DOI: 10.1016/j.copbio.2016.03.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 02/27/2016] [Accepted: 03/04/2016] [Indexed: 01/22/2023]
Abstract
The formation of multiple tissue types and their integration into composite tissue units presents a frontier challenge in regenerative engineering. Tissue-tissue synchrony is crucial in providing structural support for internal organs and enabling daily activities. This review highlights the state-of-the-art in composite tissue scaffold design, and explores how biomimicry can be strategically applied to avoid over-engineering the scaffold. Given the complexity of biological tissues, determining the most relevant parameters for recapitulating native structure-function relationships through strategic biomimicry will reduce the burden for clinical translation. It is anticipated that these exciting efforts in composite tissue engineering will enable integrative and functional repair of common soft tissue injuries and lay the foundation for total joint or limb regeneration.
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Affiliation(s)
- Nancy Lee
- Biomaterials and Interface Tissue Engineering Laboratory, Department of Biomedical Engineering, Columbia University, New York, NY 10027, United States
| | - Jennifer Robinson
- Biomaterials and Interface Tissue Engineering Laboratory, Department of Biomedical Engineering, Columbia University, New York, NY 10027, United States; Division of Orthodontics, College of Dental Medicine, Columbia University, New York, NY 10032, United States
| | - Helen Lu
- Biomaterials and Interface Tissue Engineering Laboratory, Department of Biomedical Engineering, Columbia University, New York, NY 10027, United States.
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8
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Quan BD, Sone ED. Structural changes in collagen fibrils across a mineralized interface revealed by cryo-TEM. Bone 2015; 77:42-9. [PMID: 25892483 DOI: 10.1016/j.bone.2015.04.020] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 04/09/2015] [Accepted: 04/10/2015] [Indexed: 11/16/2022]
Abstract
The structure of the mineralized collagen fibril, which is the basic building block of mineralized connective tissues, is critical to its function. We use cryo-TEM to study collagen structure at a well-defined hard-soft tissue interface, across which collagen fibrils are continuous, in order to evaluate changes to collagen upon mineralization. To establish a basis for the analysis of collagen banding, we compared cryo-TEM images of rat-tail tendon collagen to a model based on the X-ray structure. While there is close correspondence of periodicity, differences in band intensity indicate fibril regions with high density but lacking order, providing new insight into collagen fibrillar structure. Across a mineralized interface, we show that mineralization results in an axial contraction of the fibril, concomitant with lateral expansion, and that this contraction occurs only in the more flexible gap region of the fibril. Nevertheless, the major features of the banding pattern are not significantly changed, indicating that the axial arrangement of molecules remains largely intact. These results suggest a mechanism by which collagen fibrils are able to accommodate large amounts of mineral without significant disruption of their molecular packing, leading to synergy of mechanical properties.
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Affiliation(s)
- Bryan D Quan
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College St., Toronto, ON, M5S 3G9, Canada
| | - Eli D Sone
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College St., Toronto, ON, M5S 3G9, Canada; Department of Materials Science and Engineering, University of Toronto, 170 College St., Toronto, ON, M5S 3E3 Canada; Faculty of Dentistry, University of Toronto, 124 Edward St., Toronto, ON, M5G 1G6, Canada.
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9
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Lausch AJ, Sone ED. A Top-down Approach to Elucidate the Role of Matrix-Bound Phosphoproteins in Control of Collagen Biomineralization. Biomacromolecules 2015; 16:1938-47. [DOI: 10.1021/acs.biomac.5b00287] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alexander J. Lausch
- Institute of Biomaterials and Biomedical Engineering, ‡Department of Materials Science & Engineering, and §Faculty of Dentistry, University of Toronto, Toronto, Ontario M5S 3G9, Canada
| | - Eli D. Sone
- Institute of Biomaterials and Biomedical Engineering, ‡Department of Materials Science & Engineering, and §Faculty of Dentistry, University of Toronto, Toronto, Ontario M5S 3G9, Canada
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10
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Jasinoski SC, Chinsamy A. Mandibular histology and growth of the nonmammaliaform cynodont Tritylodon. J Anat 2012. [DOI: 10.1111/j.1469-7580.2012.01494.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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11
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Catros S, Pothuaud L, Dard M, Fricain JC. Collagen Fibrils of Human Acellular Extrinsic Fiber Cementum. J Periodontol 2008; 79:1095-100. [DOI: 10.1902/jop.2008.070482] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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12
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Ho SP, Marshall SJ, Ryder MI, Marshall GW. The tooth attachment mechanism defined by structure, chemical composition and mechanical properties of collagen fibers in the periodontium. Biomaterials 2007; 28:5238-45. [PMID: 17870156 PMCID: PMC2423002 DOI: 10.1016/j.biomaterials.2007.08.031] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2007] [Accepted: 08/17/2007] [Indexed: 11/27/2022]
Abstract
In this study, a comparison between structure, chemical composition and mechanical properties of collagen fibers at three regions within a human periodontium, has enabled us to define a novel tooth attachment mechanism. The three regions include, (1) the enthesis region: insertion site of periodontal ligament (PDL) fibers (collagen fibers) into cementum at the root surface, (2) bulk cementum, and (3) the cementum-dentin junction (CDJ). Structurally, continuity in collagen fibers was observed from the enthesis, through bulk cementum and CDJ. At the CDJ the collagen fibers split into individual collagen fibrils and intermingled with the extracellular matrix of mantle dentin. Under wet conditions, the collagen fibers at the three regions exhibited significant swelling suggesting a composition rich in polyanionic molecules such as glycosaminoglycans. Additionally, site-specific indentation illustrated a comparable elastic modulus between collagen fibers at the enthesis (1-3 GPa) and the CDJ (2-4 GPa). However, the elastic modulus of collagen fibers within bulk cementum was higher (4-7 GPa) suggesting presence of extrafibrillar mineral. It is known that the tooth forms a fibrous joint with the alveolar bone, which is termed a gomphosis. Although narrower in width than the PDL space, the hygroscopic CDJ can also be termed as a gomphosis; a fibrous joint between cementum and root dentin capable of accommodating functional loads similar to that between cementum and alveolar bone. From an engineering perspective, it is proposed that a tooth contains two fibrous joints that accommodate the masticatory cyclic loads. These joints are defined by the attachment of dissimilar materials via graded stiffness interfaces, such as: (1) alveolar bone attached to cementum with the PDL; and (2) cementum to root dentin with the CDJ. Thus, through variations in concentrations of basic constituents, distinct regions with characteristic structures and graded properties allow for attachment and the load bearing characteristics of a tooth.
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Affiliation(s)
- Sunita P Ho
- Department of Preventive and Restorative Dental Sciences, Division of Biomaterials and Bioengineering, University of California, San Francisco, CA 94143-0758, USA.
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13
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Natali AN, Carniel EL, Pavan PG, Bourauel C, Ziegler A, Keilig L. Experimental–numerical analysis of minipig's multi-rooted teeth. J Biomech 2007; 40:1701-8. [PMID: 17074355 DOI: 10.1016/j.jbiomech.2006.08.011] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2006] [Accepted: 08/31/2006] [Indexed: 11/30/2022]
Abstract
The paper pertains to the analysis of the biomechanical behaviour of the periodontal ligament (PDL) by using a combined experimental and numerical approach. Experimental analysis provides information about a two-rooted pig premolar tooth in its socket with regard to morphological configuration and deformational response. The numerical analysis developed for the present investigation adopts a specific anisotropic hyperelastic formulation, accounting for tissue structural arrangement. The parameters to be adopted for the PDL constitutive model are evaluated with reference to data deducted from experimental in vitro tests on different specimens taken from literature. According to morphometric data relieved, solid models are provided as basis for the development of numerical models that adopt the constitutive formulation proposed. A reciprocal validation of experimental and numerical data allows for the evaluation of reliability of results obtained. The work is intended as preliminary investigation to study the correlation between mechanical status of PDL and induction to cellular activity in orthodontic treatments.
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Affiliation(s)
- A N Natali
- Centre of Mechanics of Biological Materials, University of Padova, Italy
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14
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Benjamin M, Toumi H, Ralphs JR, Bydder G, Best TM, Milz S. Where tendons and ligaments meet bone: attachment sites ('entheses') in relation to exercise and/or mechanical load. J Anat 2006; 208:471-90. [PMID: 16637873 PMCID: PMC2100202 DOI: 10.1111/j.1469-7580.2006.00540.x] [Citation(s) in RCA: 438] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/27/2005] [Indexed: 12/16/2022] Open
Abstract
Entheses (insertion sites, osteotendinous junctions, osteoligamentous junctions) are sites of stress concentration at the region where tendons and ligaments attach to bone. Consequently, they are commonly subject to overuse injuries (enthesopathies) that are well documented in a number of sports. In this review, we focus on the structure-function correlations of entheses on both the hard and the soft tissue sides of the junction. Particular attention is paid to mechanical factors that influence form and function and thus to exploring the relationship between entheses and exercise. The molecular parameters indicative of adaptation to mechanical stress are evaluated, and the basis on which entheses are classified is explained. The application of the 'enthesis organ' concept (a collection of tissues adjacent to the enthesis itself, which jointly serve the common function of stress dissipation) to understanding enthesopathies is considered and novel roles of adipose tissue at entheses are reviewed. A distinction is made between different locations of fat at entheses, and possible functions include space-filling and proprioception. The basic anchorage role of entheses is considered in detail and comparisons are explored between entheses and other biological 'anchorage' sites. The ability of entheses for self-repair is emphasized and a range of enthesopathies common in sport are reviewed (e.g. tennis elbow, golfer's elbow, jumper's knee, plantar fasciitis and Achilles insertional tendinopathies). Attention is drawn to the degenerative, rather than inflammatory, nature of most enthesopathies in sport. The biomechanical factors contributing to the development of enthesopathies are reviewed and the importance of considering the muscle-tendon-bone unit as a whole is recognized. Bony spur formation is assessed in relation to other changes at entheses which parallel those in osteoarthritic synovial joints.
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Affiliation(s)
- M Benjamin
- School of Biosciences, Cardiff University, UK.
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15
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Benjamin M, Kumai T, Milz S, Boszczyk BM, Boszczyk AA, Ralphs JR. The skeletal attachment of tendons--tendon "entheses". Comp Biochem Physiol A Mol Integr Physiol 2002; 133:931-45. [PMID: 12485684 DOI: 10.1016/s1095-6433(02)00138-1] [Citation(s) in RCA: 317] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Tendon entheses can be classed as fibrous or fibrocartilaginous according to the tissue present at the skeletal attachment site. The former can be "bony" or "periosteal", depending on whether the tendon is directly attached to bone or indirectly to it via the periosteum. At fibrocartilaginous entheses, the uncalcified fibrocartilage dissipates collagen fibre bending and tendon narrowing away from the tidemark; calcified fibrocartilage anchors the tendon to the bone and creates a diffusion barrier between the two. Where there are additional fibrocartilaginous specialisations in the tendon and/or bone next to the enthesis, an "enthesis organ" is created that reduces wear and tear. Little attention has been paid to bone at entheses, despite the obvious bearing this has on the mechanical properties of the interface and the clinical importance of avulsion fractures. Disorders at entheses (enthesopathies) are common and occur in conditions such as diffuse idiopathic skeletal hyperostosis and the seronegative spondyloarthropathies. They are also commonly seen as sporting injuries such as tennis elbow and jumper's knee.
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Affiliation(s)
- M Benjamin
- School of Biosciences, P.O. Box 911, Museum Avenue, Cardiff University, Cardiff CF10 3US, Wales, UK.
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