1
|
Liu M, Wu B, Yang F, Jiang D, Izadikhah I, Chen Y, Li N, Yan B. Understanding the hierarchical structure of collagen fibers of the human periodontal ligament: Implications for biomechanical characteristics. Acta Biomater 2024:S1742-7061(24)00532-4. [PMID: 39299626 DOI: 10.1016/j.actbio.2024.09.016] [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: 05/02/2024] [Revised: 09/03/2024] [Accepted: 09/11/2024] [Indexed: 09/22/2024]
Abstract
The periodontal ligament (PDL) is a unique fibrous connective tissue that regulates periodontal homeostasis mechanisms. Its biomechanical properties primarily reside in the hierarchical and non-uniform collagenous network. This study aimed to investigate the region-specific structure and composition of collagen fibers in the PDL at various scales and to explore their relationship with mechanical properties in a split-mouth design. Fresh human cadaver transverse PDL specimens of maxillary anterior teeth were categorized into cervical, middle, and apical groups. These specimens were analyzed via Masson's trichrome staining, scanning electron microscopy, picrosirius red (PSR) staining, three-dimensional (3D) reconstruction, Raman spectroscopy, and uniaxial tensile test. Statistical analyses were performed to compare the structural, compositional, and tensile properties among the groups. Notably, the middle PDL samples exhibited superior tensile strength and higher fiber area fraction than the other two transverse sections. Despite a higher mineral-to-matrix ratio and a different collagen secondary structure, the apical PDL demonstrated a relatively weaker tensile strength, possibly associated with its discovered sparser collagen fiber areal fraction. The cervical region, characterized by a mediocre fiber areal fraction, displayed diminished tensile strength. The 3D reconstructed collagenous network model and PSR staining exposed the fiber interaction and the micropores. Microscale porosity and variations in collagen secondary structure, particularly in the apical region, suggest adaptive mechanisms for accommodating compressive forces and maintaining functional integrity. Variance in the tensile properties of samples in different force directions indicated the significant influence of fiber orientation and root level on tissue mechanics. STATEMENT OF SIGNIFICANCE: This study provides critical insights into the biomechanical and structural properties of the human periodontal ligament (PDL), particularly focusing on the underexplored anterior teeth. Through advanced techniques like SEM, histological staining, 3D reconstruction, Raman spectroscopy, and tensile testing, we reveal significant regional variations in PDL collagen organization, composition, and biomechanical properties. Our findings address a crucial knowledge gap concerning the material mechanics of the PDL, offering a foundational understanding for future periodontal tissue engineering and biomimetic material development. This multi-scale analysis underscores the importance of both mesoscale structural characteristics and nanoscale molecular structures in maintaining PDL mechanical integrity.
Collapse
Affiliation(s)
- Mao Liu
- Department of Orthodontics, The Affiliated Stomatological Hospital of Nanjing Medical University, Nanjing 210029, China; State Key Laboratory Cultivation Base of Research, Prevention and Treatment for Oral Diseases, Nanjing Medical University, Nanjing 210029, China; Jiangsu Province Engineering Research Center of Stomatological Translational Medicine, Nanjing 210029, China
| | - Bin Wu
- College of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing 210037, China
| | - Fan Yang
- Department of Orthodontics, The Affiliated Stomatological Hospital of Nanjing Medical University, Nanjing 210029, China; State Key Laboratory Cultivation Base of Research, Prevention and Treatment for Oral Diseases, Nanjing Medical University, Nanjing 210029, China; Jiangsu Province Engineering Research Center of Stomatological Translational Medicine, Nanjing 210029, China
| | - Di Jiang
- College of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing 210037, China
| | - Iman Izadikhah
- Department of Orthodontics, The Affiliated Stomatological Hospital of Nanjing Medical University, Nanjing 210029, China; State Key Laboratory Cultivation Base of Research, Prevention and Treatment for Oral Diseases, Nanjing Medical University, Nanjing 210029, China; Jiangsu Province Engineering Research Center of Stomatological Translational Medicine, Nanjing 210029, China
| | - Yingyu Chen
- Department of Orthodontics, The Affiliated Stomatological Hospital of Nanjing Medical University, Nanjing 210029, China; State Key Laboratory Cultivation Base of Research, Prevention and Treatment for Oral Diseases, Nanjing Medical University, Nanjing 210029, China; Jiangsu Province Engineering Research Center of Stomatological Translational Medicine, Nanjing 210029, China
| | - Na Li
- College of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing 210037, China
| | - Bin Yan
- Department of Orthodontics, The Affiliated Stomatological Hospital of Nanjing Medical University, Nanjing 210029, China; State Key Laboratory Cultivation Base of Research, Prevention and Treatment for Oral Diseases, Nanjing Medical University, Nanjing 210029, China; Jiangsu Province Engineering Research Center of Stomatological Translational Medicine, Nanjing 210029, China.
| |
Collapse
|
2
|
Sterkenburgh TR, Hartl B, Peham C, Nowak M, Kyllar M, Kau S. Temporomandibular joint biomechanics and equine incisor occlusal plane maintenance. Front Bioeng Biotechnol 2023; 11:1249316. [PMID: 37799811 PMCID: PMC10549988 DOI: 10.3389/fbioe.2023.1249316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 08/21/2023] [Indexed: 10/07/2023] Open
Abstract
In equine dentistry, the physiological incisor occlusal surface is visually perceived as a plane with a distinct inclination to the head's coronal plane, extending rostro-ventrally to caudo-dorsally. To better understand the formation of this inclined plane and its connection to dental wear, we investigated the hypothesis that it arises from masticatory movements and the considerable distance between mandibular articular heads and the incisor occlusal surfaces, acting as the three points of support for the mandibles. Leveraging data from a large-scale clinical study involving static and dynamic orthodontic measurements in horses, we approximated the mandibular movement range where incisor occlusion and dental wear occur. By introducing and testing a segment coordinate system, we explored possible angular deviations from the occlusal plane caused by mandibular roll and pitch rotations during two lateral mandibular movement patterns, protrusion and retrusion. Theoretical biomechanical calculations and simulations confirmed the visual perception of the incisor occlusal surface as a plane. To further examine our assumptions, we employed a simple mechanical simulator to assess incisor normal occlusion and provoked malocclusions (diagonal, smile, and frown bite) by modifying temporomandibular joint (TMJ) movement patterns. The results from clinical investigations were corroborated by both the theoretical analysis and mechanical simulations, strengthening our understanding of the biomechanical basis behind the physiological incisor occlusal plane maintenance in horses. These findings have significant implications for equine dental health and contribute to a thorough understanding of TMJ dynamics.
Collapse
Affiliation(s)
- Tomas Rudolf Sterkenburgh
- Polyclinic for Dental Preservation and Periodontology, University of Leipzig, Leipzig, Germany
- Department of Industrial Engineering, Business Administration and Statistics, DEGIN Doctoral Program, Universidad Politécnica de Madrid, Madrid, Spain
| | - Bettina Hartl
- Department of Pathobiology, Institute of Morphology, Vetmeduni Vienna, Vienna, Austria
| | - Christian Peham
- Department of Companion Animals and Horses, Movement Science Group, University Clinic for Horses, Vetmeduni Vienna, Vienna, Austria
| | - Michael Nowak
- Veterinary Practice Dr. M. Nowak, Equine Clinic Meerbusch, Meerbusch, Germany
| | - Michal Kyllar
- Department of Pathobiology, Institute of Morphology, Vetmeduni Vienna, Vienna, Austria
| | - Silvio Kau
- Department of Pathobiology, Institute of Morphology, Vetmeduni Vienna, Vienna, Austria
| |
Collapse
|
3
|
Guo H, Bai X, Wang X, Qiang J, Sha T, Shi Y, Zheng K, Yang Z, Shi C. Development and regeneration of periodontal supporting tissues. Genesis 2022; 60:e23491. [PMID: 35785409 DOI: 10.1002/dvg.23491] [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: 04/13/2022] [Revised: 06/01/2022] [Accepted: 06/13/2022] [Indexed: 11/08/2022]
Abstract
Periodontal tissues, including gingiva, cementum, periodontal ligament, and alveolar bone, play important roles in oral health. Under physiological conditions, periodontal tissues surround and support the teeth, maintaining the stability of the teeth and distributing the chewing forces. However, under pathological conditions, with the actions of various pathogenic factors, the periodontal tissues gradually undergo some irreversible changes, that is, gingival recession, periodontal ligament rupture, periodontal pocket formation, alveolar bone resorption, eventually leading to the loosening and even loss of the teeth. Currently, the regenerations of the periodontal tissues are still challenging. Therefore, it is necessary to study the development of the periodontal tissues, the principles and processes of which can be used to develop new strategies for the regeneration of periodontal tissues. This review summarizes the development of periodontal tissues and current strategies for periodontal healing and regeneration.
Collapse
Affiliation(s)
- Hao Guo
- Department of Oral Pathology, Hospital of Stomatology, Jilin University, Changchun, China.,Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling, Changchun, China
| | - Xueying Bai
- Department of Oral Pathology, Hospital of Stomatology, Jilin University, Changchun, China.,Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling, Changchun, China
| | - Xiaoling Wang
- Department of Oral Pathology, Hospital of Stomatology, Jilin University, Changchun, China.,Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling, Changchun, China
| | - Jinbiao Qiang
- Department of Oral Pathology, Hospital of Stomatology, Jilin University, Changchun, China.,Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling, Changchun, China
| | - Tong Sha
- Department of Oral Pathology, Hospital of Stomatology, Jilin University, Changchun, China.,Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling, Changchun, China
| | - Yan Shi
- Department of Oral Pathology, Hospital of Stomatology, Jilin University, Changchun, China.,Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling, Changchun, China
| | - Kaijuan Zheng
- Department of Oral Pathology, Hospital of Stomatology, Jilin University, Changchun, China.,Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling, Changchun, China
| | - Zhenming Yang
- Department of Oral Pathology, Hospital of Stomatology, Jilin University, Changchun, China.,Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling, Changchun, China
| | - Ce Shi
- Department of Oral Pathology, Hospital of Stomatology, Jilin University, Changchun, China.,Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling, Changchun, China
| |
Collapse
|
4
|
Sterkenburgh T, Schulz-Kornas E, Nowak M, Staszyk C. A Computerized Simulation of the Occlusal Surface in Equine Cheek Teeth: A Simplified Model. Front Vet Sci 2022; 8:789133. [PMID: 35047585 PMCID: PMC8761981 DOI: 10.3389/fvets.2021.789133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 11/22/2021] [Indexed: 11/13/2022] Open
Abstract
Equine mastication, as well as dental wear patterns, is highly important for the development of treatments in equine dentistry. During the last decades, the stress and strain distributions of equine teeth have been successfully simulated using finite element analysis. Yet, to date, there is no simulation available for dental tooth wear in equines. In this study, we developed a simplified two-dimensional computer simulation of dental wear. It provides a first tentative explanation for the development of the marked physiological inclination of the occlusal surface and for pathological conditions such as sharp enamel points in equine cheek teeth. The mechanical properties of the dental structures as well as the movement of the mandible during the equine chewing cycle were simulated according to previously published data. The simulation setup was optimized in preliminary test runs. Further simulations were conducted varying the lateral excursion of the mandible and the presence or absence of incisor contact during the chewing cycle. The results of simulations showed clear analogies to tooth wear patterns in living equids, including the formation of wear abnormalities. Our analysis indicates that small variations in the pattern of movement during the masticatory cycle, as well as incisor contacts, are leading to marked changes in the occlusal tooth wear patterns. This opens new research avenues to better understand the development of dental wear abnormalities in equines and might have serious implications on captive animal health, welfare, and longevity.
Collapse
Affiliation(s)
- Tomas Sterkenburgh
- Veterinary Practice Dr. M. Nowak, Equine Clinic Meerbusch, Meerbusch, Germany
| | - Ellen Schulz-Kornas
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.,Department of Cariology, Endodontology and Periodontology, University of Leipzig, Leipzig, Germany
| | - Michael Nowak
- Veterinary Practice Dr. M. Nowak, Equine Clinic Meerbusch, Meerbusch, Germany
| | - Carsten Staszyk
- Institute of Veterinary-Anatomy, Histology and Embryology, Justus-Liebig-University Gießen, Giessen, Germany
| |
Collapse
|
5
|
Dixon PM. Equine dental disease – no longer a neglected field of study. EQUINE VET EDUC 2021. [DOI: 10.1111/eve.13477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- P. M. Dixon
- The Royal (Dick) School of Veterinary Studies and The Roslin Institute The University of Edinburgh Midlothian UK
| |
Collapse
|
6
|
Kau S, Failing K, Staszyk C. Computed Tomography (CT)-Assisted 3D Cephalometry in Horses: Interincisal Angulation of Clinical Crowns. Front Vet Sci 2020; 7:434. [PMID: 32851019 PMCID: PMC7403475 DOI: 10.3389/fvets.2020.00434] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 06/16/2020] [Indexed: 11/13/2022] Open
Abstract
The angle encompassed between opposing incisors in horses is assumed to decline with age. Previous studies merely consider the overall profile view of clinical crowns presuming a generalized angle, neglecting potential tooth position-dependent differences. Cephalometric measurements from 3D computed tomographic thick-slab reconstructions of single incisors within a global reference frame were used to determine clinical crown interincisal angulation (IIA) of 48 horses. Based on predefined dentoalveolar landmarks, IIA was defined as the angle enclosed by the respective labial axis of the clinical crown (LACC). A measurement repeatability analysis was conducted including a comparison of third incisor teeth IIA with data obtained by cephalometric implementation of previously described landmarks for third incisor teeth (lingual/palatal border). The age-related angle course and differences between tooth positions were investigated considering LACCs of permanent incisors. Determining IIA by LACCs exhibited a high level of reproducibility applying for all tooth positions (mean coefficient of variation = 0.65 %; mean SD ± 0.89°). The comparison method for third incisor teeth revealed two times higher mean dispersion of repeated measurements, P = 0.017. A non-linear model slightly increased predictability of angular changes over time as against linearity assumption. The angle decline was more distinctive in younger horses and appears to approach a final value in older ones. Third incisor teeth exhibited significantly higher angle decline compared to first and second incisor teeth, P < 0.0001. According to the results, age determination of horses using clinical crown IIA is not recommended. Rather, 3D cephalometry may provide a promising tool to determine interdental and dentofacial angles of distinct tooth positions in health and disease.
Collapse
Affiliation(s)
- Silvio Kau
- Department of Pathobiology, Institute of Topographic Anatomy, University of Veterinary Medicine Vienna, Vienna, Austria
- Faculty of Veterinary Medicine, Institute of Veterinary-Anatomy, -Histology and -Embryology, Justus-Liebig-University Gießen, Gießen, Germany
| | - Klaus Failing
- Unit for Biomathemathics and Data Processing, Faculty of Veterinary Medicine, Justus-Liebig-University Gießen, Gießen, Germany
| | - Carsten Staszyk
- Faculty of Veterinary Medicine, Institute of Veterinary-Anatomy, -Histology and -Embryology, Justus-Liebig-University Gießen, Gießen, Germany
| |
Collapse
|
7
|
Szulakowski M, Mageed M, Steinberg T, Winter K, Gerlach K. Scintigraphic evaluation of cheek teeth in clinically sound horses. Vet Rec 2019; 185:481. [PMID: 31391285 DOI: 10.1136/vr.105459] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 07/11/2019] [Accepted: 07/11/2019] [Indexed: 11/04/2022]
Abstract
Dental disorders are one of the top-ranking clinical domains in equine practice. Scintigraphy has emerged as a useful diagnostic imaging modality for equine dental diseases. There is a paucity of the normal scintigraphic uptake and its correlation with age. This prospective, cross-sectional, descriptive and pilot-designed study aimed to describe the radioisotope uptake (RU) patterns of the reserved crown and periodontal bone of the maxillary and mandibular cheek teeth (CT) in clinically sound horses and to evaluate the age effect on RU. For this purpose, 60 horses that underwent a bone scintigraphy for reason unrelated to head were included and divided equally into four age groups. Regions of interests (ROIs) were positioned around alveolar and periodontal bone of each maxillary and mandibular CT including their reserve crown, and a reference ROI positioned at the mandibular ramus. The count per pixel of each ROI was measured using a dedicated software and the RU ratio relative to the reference region was calculated. The results showed that the maxillary and mandibular CT had a standard RU pattern, where it increased from rostral to caudal, and peaked in the middle of dental arcades and decreased slightly towards the last CT. The maxillary CT had a higher RU compared with the mandibular CT, and there was no significant difference in the maxillary and mandibular CT uptake between age groups. This information may aid veterinarians evaluating potentially abnormal dental scintigraphy.
Collapse
Affiliation(s)
- Marcin Szulakowski
- Tierklinik Lüsche GmbH, Bakum, Germany.,Pferdepraxis Niemendal, Rheinbach, Germany
| | | | | | - Karsten Winter
- Institute of Anatomy, University of Leipzig, Leipzig, Germany
| | - Kerstin Gerlach
- University Equine Hospital, University of Leipzig, Leipzig, Germany
| |
Collapse
|
8
|
Wang C, Zhou X, Chen Y, Zhang J, Chen W, Svensson P, Wang K. Somatosensory profiling of patients with plaque-induced gingivitis: a case–control study. Clin Oral Investig 2019; 24:875-882. [DOI: 10.1007/s00784-019-02963-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 05/16/2019] [Indexed: 11/24/2022]
|
9
|
Staszyk C. [Clinical anatomy of the horse: teeth and dentition]. Tierarztl Prax Ausg G Grosstiere Nutztiere 2015; 43:375-86; quiz 387. [PMID: 26603675 DOI: 10.15653/tpg-150822] [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: 10/07/2015] [Accepted: 10/19/2015] [Indexed: 11/22/2022]
Abstract
The routine inspection of the equine oral cavity allows a numerical assessment of the teeth and provides information about positional changes within the dentition. By use of appropriate dental equipment, the occlusal surfaces of all teeth can be inspected and diagnosed. However, neither the teeth nor their occlusal surfaces are constant structures. Instead, equine teeth and, in particular, their occlusal surfaces are subjected to continuous morphological and positional changes due to the effects of aging and the equine-specific high amount of occlusal wear. Therefore, it is mandatory to define anatomical criteria, which allow us to distinguish between anatomical variations and pathological conditions. Moreover, an unambiguous nomenclature with regard to the equine-specific dental anatomy is essential. This article provides a tutorial overview of the equine dental anatomy as well as recent findings in the field of equine dentistry. Special attention is paid to dynamic changes within both individual teeth and dentition.
Collapse
Affiliation(s)
- C Staszyk
- Prof. Dr. Carsten Staszyk, Fachtierarzt für Anatomie, Institut für Veterinär-Anatomie, -Histologie und -Embryologie, Fachbereich Veterinärmedizin, Justus-Liebig-Universität Gießen, Frankfurter Straße 98, 35392 Gießen, E-Mail:
| |
Collapse
|
10
|
Staszyk C, Suske A, Pöschke A. Equine dental and periodontal anatomy: A tutorial review. EQUINE VET EDUC 2015. [DOI: 10.1111/eve.12317] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- C. Staszyk
- Institute of Veterinary Anatomy, Histology and Embryology; Faculty of Veterinary Medicine; Justus-Liebig University; Giessen Germany
| | - A. Suske
- Institute of Veterinary Anatomy, Histology and Embryology; Faculty of Veterinary Medicine; Justus-Liebig University; Giessen Germany
| | - A. Pöschke
- Institute of Veterinary Anatomy, Histology and Embryology; Faculty of Veterinary Medicine; Justus-Liebig University; Giessen Germany
| |
Collapse
|
11
|
Affiliation(s)
- J. Easley
- Equine Veterinary Practice; LLC; Shelbyville Kentucky USA
| | - S. Odenweller
- Equine Veterinary Practice; LLC; Shelbyville Kentucky USA
| |
Collapse
|
12
|
Rawlinson J, Carmalt JL. Extraction techniques for equine incisor and canine teeth. EQUINE VET EDUC 2014. [DOI: 10.1111/eve.12252] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- J. Rawlinson
- Department of Clinical Sciences; College of Veterinary Medicine and Biomedical Sciences; Colorado State University; Fort Collins USA
| | - J. L. Carmalt
- Western College of Veterinary Medicine; University of Saskatchewan; Saskatoon Canada
| |
Collapse
|
13
|
Schrock P, Lüpke M, Seifert H, Staszyk C. Three-dimensional anatomy of equine incisors: tooth length, enamel cover and age related changes. BMC Vet Res 2013; 9:249. [PMID: 24321365 PMCID: PMC3878928 DOI: 10.1186/1746-6148-9-249] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Accepted: 11/22/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Equine incisors are subjected to continuous occlusal wear causing multiple, age related changes of the extragingival crown. It is assumed that the occlusal wear is compensated by continued tooth elongation at the apical ends of the teeth. In this study, μCT-datasets offered the opportunity to analyze the three-dimensional appearance of the extra- and intraalveolar parts of the enamel containing dental crown as well as of the enamel-free dental root. Multiple morphometric measurements elucidated age related, morphological changes within the intraalveolar part of the incisors. RESULTS Equine incisors possess a unique enamel cover displaying large indentations on the mesial and distal sides. After eruption tooth elongation at the apical end outbalances occlusal wear for two to four years resulting in increasing incisor length in this period of time. Remarkably, this maximum length is maintained for about ten years, up to a tooth age of 13 to 15 years post eruption. Variances in the total length of individual teeth are related to different Triadan positions (central-, middle- and corner incisors) as well as to the upper and lower arcades. CONCLUSION Equine incisors are able to fully compensate occlusal wear for a limited period of time. However, after this ability ceases, it is expected that a diminished intraalveolar tooth length will cause massive changes in periodontal biomechanics. The time point of these morphodynamic and biomechanical changes (13 to 15 years post eruption) occurs in coincidence with the onset of a recently described destructive disease of equine incisor (equine odontoclastic tooth resorption and hypercementosis) in aged horses. However, further biomechanical, cell biological and microbiological investigations are needed to elucidate a correlation between age related changes of incisor morphology and this disease.
Collapse
Affiliation(s)
| | | | | | - Carsten Staszyk
- Institute for Veterinary-Anatomy, -Histology and -Embryology, Faculty for Veterinary Medicine, Justus-Liebig-University Giessen, Frankfurter Str, 98, D-35392 Giessen, Germany (formerly Institute of Anatomy, University of Veterinary Medicine Hannover, Bischofsholer Damm 15, D-30173 Hannover, Germany.
| |
Collapse
|
14
|
Finite element analysis of equine incisor teeth. Part 1: Determination of the material parameters of the periodontal ligament. Vet J 2013; 198:583-9. [DOI: 10.1016/j.tvjl.2013.10.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 09/02/2013] [Accepted: 10/07/2013] [Indexed: 11/22/2022]
|
15
|
Schrock P, Lüpke M, Seifert H, Staszyk C. Finite element analysis of equine incisor teeth. Part 2: Investigation of stresses and strain energy densities in the periodontal ligament and surrounding bone during tooth movement. Vet J 2013; 198:590-8. [DOI: 10.1016/j.tvjl.2013.10.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 09/03/2013] [Accepted: 10/07/2013] [Indexed: 11/28/2022]
|
16
|
Finite element analysis in 3-D models of equine cheek teeth. Vet J 2012; 193:391-6. [DOI: 10.1016/j.tvjl.2012.02.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Revised: 02/20/2012] [Accepted: 02/22/2012] [Indexed: 11/21/2022]
|
17
|
Cordes V, Lüpke M, Gardemin M, Seifert H, Staszyk C. Periodontal biomechanics: finite element simulations of closing stroke and power stroke in equine cheek teeth. BMC Vet Res 2012; 8:60. [PMID: 22607543 PMCID: PMC3583254 DOI: 10.1186/1746-6148-8-60] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Accepted: 05/20/2012] [Indexed: 11/21/2022] Open
Abstract
Background In equine dentistry periodontal diseases, especially periapical inflammation, are
frequently occurring problems. Anachoresis is believed to be the most common cause
for the development of such disorders. Nevertheless, there is still no
substantiated explanation why settlement of pathogen microorganisms occurs in
equine periodontal tissues. It is expected that excessive strains and stresses
occurring in the periodontal ligament (PDL) during the horse’s chewing cycle
might be a predisposing factor. In this study this assumption was examined by
finite element (FE) analyses on virtual 3-D models of equine maxillary and
mandibular cheek teeth, established on the basis of μCT datasets.
Calculations were conducted both under conditions of closing and power stroke. Results Results showed a uniform distribution of low stresses and strain energy density
(SED) during closing stroke, whereas during power stroke an occurrence of high
stresses and SED could be observed in the PDL near the alveolar crest and in
periapical regions. Conclusion The concentration of forces during power stroke in these specific areas of the PDL
may cause local tissue necrosis and inflammation and thus establish a suitable
environment for the settlement of microorganisms.
Collapse
Affiliation(s)
- Vanessa Cordes
- Institute of Anatomy, University of Veterinary Medicine Hannover, Bischofsholer Damm 15, Hannover, D-30173, Germany.
| | | | | | | | | |
Collapse
|
18
|
Mensing N, Gasse H, Hambruch N, Haeger JD, Pfarrer C, Staszyk C. Isolation and characterization of multipotent mesenchymal stromal cells from the gingiva and the periodontal ligament of the horse. BMC Vet Res 2011; 7:42. [PMID: 21810270 PMCID: PMC3161857 DOI: 10.1186/1746-6148-7-42] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Accepted: 08/02/2011] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND The equine periodontium provides tooth support and lifelong tooth eruption on a remarkable scale. These functions require continuous tissue remodeling. It is assumed that multipotent mesenchymal stromal cells (MSC) reside in the periodontal ligament (PDL) and play a crucial role in regulating physiological periodontal tissue regeneration. The aim of this study was to isolate and characterize equine periodontal MSC. Tissue samples were obtained from four healthy horses. Primary cell populations were harvested and cultured from the gingiva, from three horizontal levels of the PDL (apical, midtooth and subgingival) and for comparison purposes from the subcutis (masseteric region). Colony-forming cells were grown on uncoated culture dishes and typical in vitro characteristics of non-human MSC, i.e. self-renewal capacity, population doubling time, expression of stemness markers and trilineage differentiation were analyzed. RESULTS Colony-forming cell populations from all locations showed expression of the stemness markers CD90 and CD105. In vitro self-renewal capacity was demonstrated by colony-forming unit fibroblast (CFU-F) assays. CFU-efficiency was highest in cell populations from the apical and from the mid-tooth PDL. Population doubling time was highest in subcutaneous cells. All investigated cell populations possessed trilineage differentiation potential into osteogenic, adipogenic and chondrogenic lineages. CONCLUSIONS Due to the demonstrated in vitro characteristics cells were referred to as equine subcutaneous MSC (eSc-MSC), equine gingival MSC (eG-MSC) and equine periodontal MSC (eP-MSC). According to different PDL levels, eP-MSC were further specified as eP-MSC from the apical PDL (eP-MSCap), eP-MSC from the mid-tooth PDL (eP-MSCm) and eP-MSC from the subgingival PDL (eP-MSCsg). Considering current concepts of cell-based regenerative therapies in horses, eP-MSC might be promising candidates for future clinical applications in equine orthopedic and periodontal diseases.
Collapse
Affiliation(s)
- Niels Mensing
- Institute of Anatomy, University of Veterinary Medicine Hannover, Bischofsholer Damm 15, D-30173 Hannover, Germany
| | | | | | | | | | | |
Collapse
|
19
|
Lake SP, Miller KS, Elliott DM, Soslowsky LJ. Effect of fiber distribution and realignment on the nonlinear and inhomogeneous mechanical properties of human supraspinatus tendon under longitudinal tensile loading. J Orthop Res 2009; 27:1596-602. [PMID: 19544524 PMCID: PMC2813200 DOI: 10.1002/jor.20938] [Citation(s) in RCA: 214] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Tendon exhibits nonlinear stress-strain behavior that may be partly due to movement of collagen fibers through the extracellular matrix. While a few techniques have been developed to evaluate the fiber architecture of other soft tissues, the organizational behavior of tendon under load has not been determined. The supraspinatus tendon (SST) of the rotator cuff is of particular interest for investigation due to its complex mechanical environment and corresponding inhomogeneity. In addition, SST injury occurs frequently with limited success in treatment strategies, illustrating the need for a better understanding of SST properties. Therefore, the objective of this study was to quantitatively evaluate the inhomogeneous tensile mechanical properties, fiber organization, and fiber realignment under load of human SST utilizing a novel polarized light technique. Fiber distributions were found to become more aligned under load, particularly during the low stiffness toe-region, suggesting that fiber realignment may be partly responsible for observed nonlinear behavior. Fiber alignment was found to correlate significantly with mechanical parameters, providing evidence for strong structure-function relationships in tendon. Human SST exhibits complex, inhomogeneous mechanical properties and fiber distributions, perhaps due to its complex loading environment. Surprisingly, histological grade of degeneration did not correlate with mechanical properties.
Collapse
Affiliation(s)
- Spencer P Lake
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, University of Pennsylvania, 424 Stemmler Hall, Philadelphia, Pennsylvania 19104-6081
| | | | | | | |
Collapse
|
20
|
Warhonowicz M, Staszyk C, Gasse H. Immunohistochemical detection of matrix metalloproteinase-1 in the periodontal ligament of equine cheek teeth. Tissue Cell 2007; 39:369-76. [PMID: 17915275 DOI: 10.1016/j.tice.2007.07.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2007] [Revised: 06/28/2007] [Accepted: 07/11/2007] [Indexed: 11/27/2022]
Abstract
The hypsodont equine cheek tooth erupts continuously throughout life. The collagen fibers of the periodontal ligament (PDL) have to remodel constantly to allow the tooth to move in an occlusal direction. Remodeling of the collagen fiber bundles needs to be well-coordinated in order to maintain functional tooth support. The aim of this study was to examine the role of matrix metalloproteinase-1 (MMP-1) in the collagen remodeling of the equine PDL under physiological conditions. Specimens containing the PDL interposed between the dental cementum and the alveolar bone were taken from nine Warmblood horses at three designated horizontal levels: subgingival, middle, and apical. The expression of MMP-1 was detected immunohistochemically. MMP-1 was found to be present in the specimens of all horses. Immunopositive fibroblasts/fibrocytes were accumulated within individual single collagen fascicles. Our results suggest that MMP-1 induced collagen degradation plays a central role in the physiological remodeling of the equine PDL. The distribution of MMP-1 positive fascicles indicates well-directed remodeling which occurs as an asynchronous process, so that only single collagen fascicles are remodeled at the same time. Due to this remodeling of one fascicle at a time, the overall anchorage of the tooth is preserved at all times.
Collapse
Affiliation(s)
- M Warhonowicz
- Institute of Anatomy, University of Veterinary Medicine Hannover, Bischofsholer Damm 15, D-30173 Hannover, Germany
| | | | | |
Collapse
|
21
|
Warhonowicz M, Staszyk C, Rohn K, Gasse H. The equine periodontium as a continuously remodeling system: morphometrical analysis of cell proliferation. Arch Oral Biol 2006; 51:1141-9. [PMID: 16895722 DOI: 10.1016/j.archoralbio.2006.05.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2006] [Revised: 05/28/2006] [Accepted: 05/31/2006] [Indexed: 10/24/2022]
Abstract
OBJECTIVE The hypsodont equine cheek tooth erupts continuously throughout life. Tooth eruption is inevitably associated with a remodeling of the periodontium. One major process of remodeling in the PDL is cell proliferation. The aim of this study was to detect cell proliferation at different sites of the equine PDL in order to examine the dynamics of the periodontal cell population. DESIGN Specimens from nine warm-blood horses were taken-- containing the PDL interposed between the cementum and the alveolar bone--at three designated levels: subgingival, middle, and apical. Cell proliferation was detected immunohistochemically by use of anti-Ki-67 in combination with an elaborate morphometrical procedure using an image-analysis program. Three zones of the PDL were distinguished in each specimen: a zone next to the dental cementum, a central zone, and a zone next to the alveolar bone. The PDL was divided into three levels and three zones, resulting in nine defined regions of interest. RESULTS The proliferation index was high at the apical level and in the zone next to the alveolar bone. The opposite was true of cell density, which was high at the subgingival level and in a zone next to the dental cementum. CONCLUSIONS Evaluation and statistical analysis of the parameters proliferation index and cell density in distinct, biologically appropriate sites of the equine PDL suggest the presence of dynamic processes like cell migration by which the cells of the PDL move from an area next to the alveolar bone towards the dental cementum, and in an apico-occlusal direction. Furthermore, our study confirms the close relationship between cell proliferation, cell migration, and eruption.
Collapse
Affiliation(s)
- Maren Warhonowicz
- Institute of Anatomy, University of Veterinary Medicine Hannover, Bischofsholer Damm 15, D-30173 Hannover, Germany
| | | | | | | |
Collapse
|