1
|
Zhu Y, Zheng F, Gong Y, Zhu J, Yin D, Liu Y. Effect of occlusal contact on TMJ loading during occlusion: An in silico study. Comput Biol Med 2024; 178:108725. [PMID: 38878405 DOI: 10.1016/j.compbiomed.2024.108725] [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: 11/08/2023] [Revised: 05/08/2024] [Accepted: 06/07/2024] [Indexed: 07/24/2024]
Abstract
Alterations in occlusal features may have significant consequences, ranging from dental aesthetics to health issues. Temporomandibular joint disorders (TMDs) are often associated with joint overload, and the correlation between occlusal features and TMDs has been thoroughly discussed. In current work, we introduced a novel stomatognathic model that aligns well with in vivo experimental measurements, specifically designed to decouple the impact of occlusal contact and periodontal ligament (PDL) negative feedback on temporomandibular joint (TMJ) loading. Utilizing an in-silico approach, the simulation analysis included six symmetric occlusal contact scenarios. Furthermore, a biomechanical lever model was employed to clarify the mechanical mechanism and investigate the multi-factorial effects of TMJ overload. These findings indicate that anterior shifts in the occlusal centre lead to increased TMJ loading, particularly in occlusal contact cases with anteroposterior changes. Considering the symmetrical distribution of occlusal contact, mediolateral alterations had a more modest effect on TMJ loading. Additionally, potential negative feedback activated by principal strain of periodontal could not only alleviate joint load but also diminish occlusal force. These investigations enhance our understanding of the intricate interactions between masticatory muscles, occlusal forces, and joint contact forces, thereby providing motivation for future comprehensive studies on TMJ biomechanical overload.
Collapse
Affiliation(s)
- Yunfan Zhu
- College of Aerospace Engineering, Chongqing University, Chongqing, 400044, China
| | - Fangjie Zheng
- College of Aerospace Engineering, Chongqing University, Chongqing, 400044, China
| | - Yanji Gong
- State Key Laboratory of Oral Disease, National Center for Stomatology &National Clinical Research Center for Oral Disease, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Jinyi Zhu
- State Key Laboratory of Oral Disease, National Center for Stomatology &National Clinical Research Center for Oral Disease, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Deqiang Yin
- College of Aerospace Engineering, Chongqing University, Chongqing, 400044, China.
| | - Yang Liu
- State Key Laboratory of Oral Disease, National Center for Stomatology &National Clinical Research Center for Oral Disease, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China.
| |
Collapse
|
2
|
Bi S, Shi G. The crucial role of periodontal ligament's Poisson's ratio and tension-compression asymmetric moduli on the evaluation of tooth displacement and stress state of periodontal ligament. J Mech Behav Biomed Mater 2023; 148:106217. [PMID: 37931551 DOI: 10.1016/j.jmbbm.2023.106217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 10/26/2023] [Accepted: 10/29/2023] [Indexed: 11/08/2023]
Abstract
The hydrostatic stress in the periodontal ligament (PDL) evaluated by finite element analysis is considered an important indicator for determining an appropriate orthodontic force. The computed result of the hydrostatic stress strongly depends on the PDL material model used in the orthodontic simulation. This study aims to investigate the effects of PDL Poisson's ratio and tension-compression asymmetric moduli on both the simulated tooth displacement and the PDL hydrostatic stress. Three tension-compression symmetric and two asymmetric PDL constitutive models were selected to simulate the tensile and compressive behavior of a PDL specimen under uniaxial loading, and the resulting numerical results were compared with the in-vitro PDL experimental results reported in the literature. Subsequently, a tooth model was established, and the selected constitutive models and parameters were employed to assess the hydrostatic stress state in the PDL under two distinct loading conditions. The simulated results indicate that PDL Poisson's ratio and tension-compression asymmetry exert substantial influences on the simulated PDL hydrostatic stress. Conversely, the elastic modulus exhibits minimal impact on the PDL stress state under the identical loading conditions. Furthermore, the PDL models with tension-compression asymmetric moduli and appropriate Poisson's ratio yield more realistic hydrostatic stress. Hence, it is imperative to employ suitable Poisson's ratio and tension-compression asymmetric moduli for the purpose of characterizing the biomechanical response of the PDL in orthodontic simulations.
Collapse
Affiliation(s)
- Shaoyang Bi
- Department of Mechanics, Tianjin University, 135 Yaguan Road, Tianjin, 300354, China.
| | - Guangyu Shi
- Department of Mechanics, Tianjin University, 135 Yaguan Road, Tianjin, 300354, China
| |
Collapse
|
3
|
Armijo L, Mancl L, Dennison CR, Houg K, Romanyk D, Popowics T. In-fiber Bragg sensor measurements assess fluid effects on strain in the periodontal space of an ex-vivo swine incisor complex under mechanical loading. J Biomech 2023; 157:111729. [PMID: 37473706 DOI: 10.1016/j.jbiomech.2023.111729] [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: 10/12/2022] [Revised: 06/14/2023] [Accepted: 07/14/2023] [Indexed: 07/22/2023]
Abstract
The purpose of this study is to determine whether in-fiber Bragg grating (FBG) sensors detect changes within the periodontal ligament (PDL) of ex-vivo swine tooth-PDL-bone complex (TPBC) when manipulating fluid content. Recording strain will allow for a better understanding of the biomechanics of viscoelastic load transfer from the tooth to the PDL during chewing and/or orthodontic tooth movement, as well as replication of these dynamics in regenerated PDL tissues. FBG sensors placed within the PDL of swine incisor teeth were used to measure strain resulting from an intrusive load. Specimens were mounted in a custom platform within an MTS machine and a compressive load was applied at 0.3 mm/s to a depth of 0.5 mm and held for 10 s. Median peak strain and load and median absolute deviation (MAD) were compared: dry vs. saline (n = 19) with bias-corrected bootstrap 95% CI. Dry vs. saline conditions did not statistically differ (median peaks of 5με, 103-105 N) and recorded strains showed high repeatability (MAD of 0.82με, 0.72με, respectively). FBG sensors did not detect the fluid changes in this study, suggesting that the deformation of tissues in the PDL space collectively determine FBG strain in response to tooth loading. The repeatability of measurements demonstrates the potential for FBG sensors to assess the strain in the PDL space of an in vivo swine model.
Collapse
Affiliation(s)
- Leigh Armijo
- Dept. of Orthodontics, University of Washington School of Dentistry, Seattle, WA 98195, USA.
| | - Lloyd Mancl
- Dept. of Oral Health Sciences, University of Washington School of Dentistry, Seattle, WA 98195, USA.
| | | | - Kathryn Houg
- Dept. of Mechanical Engineering and School of Dentistry, University of Alberta, Edmonton, Alberta, Canada.
| | - Dan Romanyk
- Dept. of Mechanical Engineering and School of Dentistry, University of Alberta, Edmonton, Alberta, Canada.
| | - Tracy Popowics
- Box 357475, Dept. of Oral Health Sciences, 1959 Pacific Ave. NE, University of Washington School of Dentistry, Seattle, WA 98195, USA.
| |
Collapse
|
4
|
Najafidoust M, Hashemi A, Oskui IZ. Effect of temperature on dynamic compressive behavior of periodontal ligament. Med Eng Phys 2023; 116:103986. [PMID: 37230701 DOI: 10.1016/j.medengphy.2023.103986] [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: 06/13/2022] [Revised: 04/04/2023] [Accepted: 04/30/2023] [Indexed: 05/27/2023]
Abstract
Periodontal ligament (PDL) attaches tooth root to the surrounding bone. Its existence between tooth and jaw bone is of utmost importance due to its significant role in absorbing and distributing physiological and para-physiological loading. According to the previous studies, various mechanical tests have been performed to characterize the mechanical properties of the PDL; however, all of them have been done at room temperature. To the best of our knowledge, this is the first study in which the testing was performed at body temperature. The present research was planned to measure the dependency of PDL's viscoelastic behavior on temperature and frequency. Three different temperatures, including body and room temperature, were opted to perform the dynamic compressive tests of the bovine PDL. In addition, a Generalized Maxwell model (GMM) was presented based on empirical outcomes. At 37 °C, amounts of loss factor were found to be greater than those in 25 °C, which demonstrates that the viscous phase of the PDL in higher temperatures plays a critical role. Likewise, by raising the temperature from 25 °C to 37 °C, the model parameters show an enlargement in the viscous part and lessening in the elastic part. It was concluded that the PDL's viscosity in body temperature is much higher than that in room temperature. This model would be functional for a more accurate computational analysis of the PDL at the body temperature (37 °C) in various loading conditions such as orthodontic simulations, mastication, and impact.
Collapse
Affiliation(s)
- Mohammad Najafidoust
- Biomedical Engineering Group, Faculty of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran; Neuroscience Research Australia and Prince of Wales Clinical School, University of New South Wales, Randwick, NSW, Australia
| | - Ata Hashemi
- Biomedical Engineering Group, Faculty of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran.
| | - Iman Z Oskui
- Biomedical Engineering Group, Faculty of Biomedical Engineering, Sahand University of Technology, Tabriz, Iran.
| |
Collapse
|
5
|
Ortún-Terrazas J, Cegoñino J, Pérez Del Palomar A. In silico approach towards neuro-occlusal rehabilitation for the early correction of asymmetrical development in a unilateral crossbite patient. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2023; 39:e3688. [PMID: 36726272 DOI: 10.1002/cnm.3688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 01/09/2023] [Accepted: 01/29/2023] [Indexed: 05/13/2023]
Abstract
Neuro-occlusal rehabilitation (N.O.R.) is a discipline of the stomatognathic medicine that defends early treatments of functional malocclusions, such as unilateral crossbite, for the correction of craniofacial development, avoiding surgical procedures later in life. Nevertheless, N.O.R.'s advances have not been proved analytically yet due to the difficulties of evaluate the mechanical response after the treatment. This study aims to evaluate computationally the effect of N.O.R.'s treatments during childhood. Therefore, bilateral chewing and maximum intercuspation occlusion were modelled through a detailed finite element model of a paediatric craniofacial complex, before and after different selective grinding-alternatives. This model was subjected to the muscular forces derived from a musculoskeletal model and was validated by the occlusal contacts recorded experimentally. This approach yielded errors below 2% and reproduced successfully the occlusal, muscular, functional and mechanical imbalance before the therapies. Treatment strategies balanced the occlusal plane and reduced the periodontal overpressure (>4.7 kPa) and the mandibular over deformation (>0.002 ε) on the crossed side. Based on the principles of the mechanostat theory of bone remodelling and the pressure-tension theory of tooth movement, these findings could also demonstrate how N.O.R.'s treatments correct the malocclusion and the asymmetrical development of the craniofacial complex. Besides, N.O.R.'s treatments slightly modified the stress state and functions of the temporomandibular joints, facilitating the chewing by the unaccustomed side. These findings provide important biomechanical insights into the use of N.O.R.'s treatments for the correction of unilateral crossbite, but also encourage the application of computing methods in biomedical research and clinical practise.
Collapse
Affiliation(s)
- Javier Ortún-Terrazas
- Escuela Superior de Ingeniería y Tecnología (ESIT), Universidad Internacional de La Rioja (UNIR), Logroño, La Rioja, Spain
- Instituto Tecnológico de Aragón (ITAINNOVA), Zaragoza, Zaragoza, Spain
| | - José Cegoñino
- Instituto Tecnológico de Aragón (ITAINNOVA), Zaragoza, Zaragoza, Spain
| | | |
Collapse
|
6
|
Jepsen K, Jervøe-Storm PM, Henrichs I, Lensing I, Müller AL, Cosgarea R, Keilig L, Bourauel C, Jepsen S. Biomechanical properties of periodontal tissues in non-periodontitis and periodontitis patients assessed with an intraoral computerized electronic measurement device. Clin Oral Investig 2023; 27:797-805. [PMID: 36625961 PMCID: PMC9889448 DOI: 10.1007/s00784-023-04859-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 12/28/2022] [Indexed: 01/11/2023]
Abstract
OBJECTIVE To identify tooth mobility (TM) by time-dependent tooth displacement using an electronic intra-oral loading device (ILD) in periodontally healthy and periodontally compromised patients. MATERIALS AND METHODS Twenty-eight untreated periodontitis and 20 periodontally healthy patients [25 female and 26 male; ages: 20-81 years], contributing with 68 teeth (periodontitis: nteeth = 28; non-periodontitis: nteeth = 40), participated in the study. TM was measured in vivo by displacing central or lateral incisors to a maximum of 0.2 mm orally over durations of 0.5 s, 1 s, and 10 s with the ILD. The maximum force (Fmax) was extracted from the measured force/deflection curves for every single measurement. RESULTS Differences in TM-ILD values were found for periodontitis as compared to non-periodontitis patients derived from the same loading durations (differences of 3.9 (0.5 s), 3.1 (1 s), 2.8 (10 s), (95% CI for 0.5 s (1.2-6.7), p = 0.024; 1 s (1.4-6.0), p = 0.067; 10 s (0.2-5.3), p = 0.001), rejecting the null hypothesis of no difference (T-test) for durations of 0.5 and 10 s. There was a significant correlation of TM-ILD (Fmax) with BOP at 0.5 s (- 0.52) and with attachment loss at all time durations (- 0.47 at 0.5 s; - 0.57 at 1 s; - 0.47 at 10 s). CONCLUSIONS This clinical investigation could demonstrate that time-dependent tooth displacements using a new computerized electronic device were associated with attachment loss and bleeding on probing. CLINICAL RELEVANCE ILD can improve the monitoring of tooth mobility, as TM-ILD values reflect qualitative (inflammatory status interpreted by BOP) and quantitative parameters (interpreted as the amount of CAL loss) of periodontal disease.
Collapse
Affiliation(s)
- Karin Jepsen
- Department of Periodontology, Operative and Preventive Dentistry, University Hospital Bonn, Welschnonnenstrasse 17, 53111, Bonn, Germany.
| | - Pia-Merete Jervøe-Storm
- Department of Periodontology, Operative and Preventive Dentistry, University Hospital Bonn, Welschnonnenstrasse 17, 53111, Bonn, Germany
| | - Isabel Henrichs
- Department of Periodontology, Operative and Preventive Dentistry, University Hospital Bonn, Welschnonnenstrasse 17, 53111, Bonn, Germany
| | - Ina Lensing
- Department of Periodontology, Operative and Preventive Dentistry, University Hospital Bonn, Welschnonnenstrasse 17, 53111, Bonn, Germany
| | - Alja Larissa Müller
- Department of Periodontology, Operative and Preventive Dentistry, University Hospital Bonn, Welschnonnenstrasse 17, 53111, Bonn, Germany
| | - Raluca Cosgarea
- Department of Periodontology, Operative and Preventive Dentistry, University Hospital Bonn, Welschnonnenstrasse 17, 53111, Bonn, Germany
- Clinic for Periodontology and Peri-Implant Diseases, Philipps University Marburg, Marburg, Germany
- Clinic of Prosthodontics, Iuliu Hatieganu University Cluj-Napoca, Cluj-Napoca-Napoca, Romania
| | - Ludger Keilig
- Oral Technology, University Hospital Bonn, Bonn, Germany
- Department of Dental Prosthetics, Propaedeutics and Materials Science, University Hospital Bonn, Bonn, Germany
| | | | - Søren Jepsen
- Department of Periodontology, Operative and Preventive Dentistry, University Hospital Bonn, Welschnonnenstrasse 17, 53111, Bonn, Germany
| |
Collapse
|
7
|
Orthodontic Loads in Teeth after Regenerative Endodontics: A Finite Element Analysis of the Biomechanical Performance of the Periodontal Ligament. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12147063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The objective of this study was to analyse the stress distribution in the periodontal ligament and tooth structure of a cementum-reinforced tooth, a dentine-reinforced tooth and an immature tooth during orthodontic loads using a finite element analysis. A finite element model of a maxillary incisor and its supporting tissues was developed. The root was segmented into two parts: a part that represented a root in an immature state and an apical part that represented the tissue formed after regenerative endodontics. The apical part was given the mechanical properties of dentine or cementum. The three models underwent simulation of mesial load, palatal inclination and rotation. The mean stress values and stress distribution patterns of the periodontal ligament of the dentine- and cementum-reinforced teeth were similar in all scenarios. The maturation of the root, with either dentine or cementum, was beneficial for all scenarios, since the periodontal ligament of the immature tooth showed the highest mean stress values. Under the condition of this computational study, orthodontic loads can be applied in teeth previously treated with regenerative endodontics, since the distribution of stress is similar to those of physiologically mature teeth. In vivo studies should be performed to validate these results.
Collapse
|
8
|
Novel In Situ-Cross-Linked Electrospun Gelatin/Hydroxyapatite Nonwoven Scaffolds Prove Suitable for Periodontal Tissue Engineering. Pharmaceutics 2022; 14:pharmaceutics14061286. [PMID: 35745858 PMCID: PMC9230656 DOI: 10.3390/pharmaceutics14061286] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 06/03/2022] [Accepted: 06/14/2022] [Indexed: 12/23/2022] Open
Abstract
Periodontal diseases affect millions of people worldwide and can result in tooth loss. Regenerative treatment options for clinical use are thus needed. We aimed at developing new nonwoven-based scaffolds for periodontal tissue engineering. Nonwovens of 16% gelatin/5% hydroxyapatite were produced by electrospinning and in situ glyoxal cross-linking. In a subset of scaffolds, additional porosity was incorporated via extractable polyethylene glycol fibers. Cell colonization and penetration by human mesenchymal stem cells (hMSCs), periodontal ligament fibroblasts (PDLFs), or cocultures of both were visualized by scanning electron microscopy and 4′,6-diamidin-2-phenylindole (DAPI) staining. Metabolic activity was assessed via Alamar Blue® staining. Cell type and differentiation were analyzed by immunocytochemical staining of Oct4, osteopontin, and periostin. The electrospun nonwovens were efficiently populated by both hMSCs and PDLFs, while scaffolds with additional porosity harbored significantly more cells. The metabolic activity was higher for cocultures of hMSCs and PDLFs, or for PDLF-seeded scaffolds. Periostin and osteopontin expression was more pronounced in cocultures of hMSCs and PDLFs, whereas Oct4 staining was limited to hMSCs. These novel in situ-cross-linked electrospun nonwoven scaffolds allow for efficient adhesion and survival of hMSCs and PDLFs. Coordinated expression of differentiation markers was observed, which rendered this platform an interesting candidate for periodontal tissue engineering.
Collapse
|
9
|
Tian T, Huang HY, Wang W, Shi B, Zheng Q, Li CH. Three-dimensional finite element analysis of the effect of alveolar cleft bone graft on the maxillofacial biomechanical stabilities of unilateral complete cleft lip and palate. Biomed Eng Online 2022; 21:31. [PMID: 35596229 PMCID: PMC9123812 DOI: 10.1186/s12938-022-01000-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 05/16/2022] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND The objective is to clarify the effect of alveolar cleft bone graft on maxillofacial biomechanical stabilities, the key areas when bone grafting and in which should be supplemented with bone graft once bone resorption occurred in UCCLP (unilateral complete cleft lip and palate). METHODS Maxillofacial CAD (computer aided design) models of non-bone graft and full maxilla cleft, full alveolar cleft bone graft, bone graft in other sites of the alveolar cleft were acquired by processing the UCCLP maxillofacial CT data in three-dimensional modeling software. The maxillofacial bone EQV (equivalent) stresses and bone suture EQV strains under occlusal states were obtained in the finite element analysis software. RESULTS Under corresponding occlusal states, the EQV stresses of maxilla, pterygoid process of sphenoid bone on the corresponding side and anterior alveolar arch on the non-cleft side were higher than other maxillofacial bones, the EQV strains of nasomaxillary, zygomaticomaxillary and pterygomaxillary suture on the corresponding side were higher than other maxillofacial bone sutures. The mean EQV strains of nasal raphe, the maximum EQV stresses of posterior alveolar arch on the non-cleft side, the mean and maximum EQV strains of nasomaxillary suture on the non-cleft side in full alveolar cleft bone graft model were all significantly lower than those in non-bone graft model. The mean EQV stresses of bilateral anterior alveolar arches, the maximum EQV stresses of maxilla and its alveolar arch on the cleft side in the model with bone graft in lower 1/3 of the alveolar cleft were significantly higher than those in full alveolar cleft bone graft model. CONCLUSIONS For UCCLP, bilateral maxillae, pterygoid processes of sphenoid bones and bilateral nasomaxillary, zygomaticomaxillary, pterygomaxillary sutures, anterior alveolar arch on the non-cleft side are the main occlusal load-bearing structures before and after alveolar cleft bone graft. Alveolar cleft bone graft mainly affects biomechanical stabilities of nasal raphe and posterior alveolar arch, nasomaxillary suture on the non-cleft side. The areas near nasal floor and in the middle of the alveolar cleft are the key sites when bone grafting, and should be supplemented with bone graft when the bone resorbed in these areas.
Collapse
Affiliation(s)
- Tao Tian
- West China School of Stomatology, Sichuan University, Chengdu, 610041, Sichuan Province, The People's Republic of China
| | - Han-Yao Huang
- West China School of Stomatology, Sichuan University, Chengdu, 610041, Sichuan Province, The People's Republic of China.,West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan Province, The People's Republic of China
| | - Wei Wang
- Urumql DW Innovation InfoTech Co., Ltd., Urumqi, 830000, Xinjiang Uygur Autonomous Region, The People's Republic of China
| | - Bing Shi
- West China School of Stomatology, Sichuan University, Chengdu, 610041, Sichuan Province, The People's Republic of China.,West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan Province, The People's Republic of China
| | - Qian Zheng
- West China School of Stomatology, Sichuan University, Chengdu, 610041, Sichuan Province, The People's Republic of China. .,West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan Province, The People's Republic of China.
| | - Cheng-Hao Li
- West China School of Stomatology, Sichuan University, Chengdu, 610041, Sichuan Province, The People's Republic of China. .,West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan Province, The People's Republic of China.
| |
Collapse
|
10
|
Anatomical journals as publication platforms for dental research. Ann Anat 2022; 244:151960. [DOI: 10.1016/j.aanat.2022.151960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 05/12/2022] [Indexed: 11/22/2022]
|
11
|
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.
Collapse
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
| |
Collapse
|
12
|
Zhao Z, Wang Q, Zheng X, An N, Zhou M, Niu L, Tay FR, Chen J, Wang F. Reliability and validity of two computerised occlusion analysis systems. J Dent 2022; 118:104051. [DOI: 10.1016/j.jdent.2022.104051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/18/2022] [Accepted: 01/21/2022] [Indexed: 10/19/2022] Open
|
13
|
Gholamalizadeh T, Darkner S, Søndergaard PL, Erleben K. A multi-patient analysis of the center of rotation trajectories using finite element models of the human mandible. PLoS One 2021; 16:e0259794. [PMID: 34780529 PMCID: PMC8592475 DOI: 10.1371/journal.pone.0259794] [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: 04/26/2021] [Accepted: 10/26/2021] [Indexed: 11/30/2022] Open
Abstract
Studying different types of tooth movements can help us to better understand the force systems used for tooth position correction in orthodontic treatments. This study considers a more realistic force system in tooth movement modeling across different patients and investigates the effect of the couple force direction on the position of the center of rotation (CRot). The finite-element (FE) models of human mandibles from three patients are used to investigate the position of the CRots for different patients’ teeth in 3D space. The CRot is considered a single point in a 3D coordinate system and is obtained by choosing the closest point on the axis of rotation to the center of resistance (CRes). A force system, consisting of a constant load and a couple (pair of forces), is applied to each tooth, and the corresponding CRot trajectories are examined across different patients. To perform a consistent inter-patient analysis, different patients’ teeth are registered to the corresponding reference teeth using an affine transformation. The selected directions and applied points of force on the reference teeth are then transformed into the registered teeth domains. The effect of the direction of the couple on the location of the CRot is also studied by rotating the couples about the three principal axes of a patient’s premolar. Our results indicate that similar patterns can be obtained for the CRot positions of different patients and teeth if the same load conditions are used. Moreover, equally rotating the direction of the couple about the three principal axes results in different patterns for the CRot positions, especially in labiolingual direction. The CRot trajectories follow similar patterns in the corresponding teeth, but any changes in the direction of the force and couple cause misalignment of the CRot trajectories, seen as rotations about the long axis of the tooth.
Collapse
Affiliation(s)
- Torkan Gholamalizadeh
- Department of Computer Science, University of Copenhagen, Copenhagen, Denmark
- 3Shape A/S, Copenhagen, Denmark
- * E-mail:
| | - Sune Darkner
- Department of Computer Science, University of Copenhagen, Copenhagen, Denmark
| | | | - Kenny Erleben
- Department of Computer Science, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
14
|
Ovy EG, Romanyk DL, Flores Mir C, Westover L. Modelling and evaluating periodontal ligament mechanical behaviour and properties: A scoping review of current approaches and limitations. Orthod Craniofac Res 2021; 25:199-211. [PMID: 34355507 DOI: 10.1111/ocr.12527] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 08/02/2021] [Indexed: 11/29/2022]
Abstract
This scoping review is intended to synthesize the techniques proposed to model the tooth-periodontal ligament-bone complex (TPBC), while also evaluating the suggested periodontal ligament (PDL) material properties. It is concentrated on the recent advancements on the PDL and TPBC models, while identifying the advantages and limitations of the proposed approaches. Systematic searches were conducted up to December 2020 for articles that proposed PDL models to assess orthodontic tooth movement in Compendex, Web of Science, EMBASE, MEDLINE, PubMed, ScienceDirect, Google Scholar and Scopus databases. Although there have been many studies focused on the evaluation of PDL material properties through numerous modelling approaches, only a handful of approaches have been identified to investigate the interface properties of the PDL as a complete dynamical system (TPBC models). Past reviews on the analytical and experimental determination of the PDL properties already show a concerning range in reported output values-some nearly six orders of magnitude in difference-that strongly suggested the need for further investigation. Surprisingly, it has not yet been possible to determine a narrower range of values for the PDL material properties. Moreover, very few scientific approaches address the TPBC as an integrated complex system model. In consequence, current methods for capturing the PDL material behaviour in a clinical setting are limited and inconclusive. This synthesis encourages more systematic, pragmatic and phenomenological research in this area.
Collapse
Affiliation(s)
- Enaiyat Ghani Ovy
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - Dan L Romanyk
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - Carlos Flores Mir
- Department of Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Lindsey Westover
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, Canada
| |
Collapse
|
15
|
Schwindling FS, Bechtel KN, Zenthöfer A, Handermann R, Rammelsberg P, Rues S. In-vitro fit of experimental full-arch restorations made from monolithic zirconia. J Prosthodont Res 2021; 66:258-264. [PMID: 34305088 DOI: 10.2186/jpr.jpr_d_20_00321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
PURPOSE Fabrication inaccuracies can compromise the fit of large-span monolithic zirconia restorations. Sintering distortion is a particular problem. This study aimed to assess the fit of full-arch restorations made from mono lithic zirconia for different abutment configurations. METHODS To quantify fit inaccuracies created during the fabrication of experimental large-span restorations, an in-vitro model with eight abutment teeth was equipped with strain gauges. Ten 14-unit restorations were made from monolithic zirconia and seated on the model in turn. For each of the ten restorations, measurements were taken for three different abutment configurations-polygonal, quadrangular, and unilaterally shortened. Strains exerted during seating were recorded in the anterior-posterior and buccal-palatal directions, and the resulting horizontal forces (rhF) were calculated along with the respective abutment deflection (ad). Data were analyzed using Kruskal-Wallis tests at a significance level of 0.05. RESULTS All restorations could be seated on the multi-abutment model. The restorations exhibited fabrication misfits, tending to be too wide. Mean rhF/ad were largest for the quadrangular configuration (16.8±2.9 N/0.065 mm) and smallest for the polygonal configuration (13.6±4.5 N/0.053 mm). The largest rhF/ad were measured on abutments of the unilaterally shortened configuration, with a maximum deflection of 0.126 mm. For two of three configurations, rhF/ad were significantly larger for the distal abutments than for the other abutments. CONCLUSIONS Even if milling and sintering procedures are optimum, misfit-induced horizontal forces cannot be avoided. Because of the natural tooth mobility, however, the fit of full-arch restorations made from monolithic zirconia might be clinically acceptable.
Collapse
Affiliation(s)
| | | | - Andreas Zenthöfer
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg
| | - Rebecca Handermann
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg
| | - Peter Rammelsberg
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg
| | - Stefan Rues
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg
| |
Collapse
|
16
|
Gauthier R, Jeannin C, Attik N, Trunfio-Sfarghiu AM, Gritsch K, Grosgogeat B. Tissue Engineering for Periodontal Ligament Regeneration: Biomechanical Specifications. J Biomech Eng 2021; 143:030801. [PMID: 33067629 DOI: 10.1115/1.4048810] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Indexed: 11/08/2022]
Abstract
The periodontal biomechanical environment is very difficult to investigate. By the complex geometry and composition of the periodontal ligament (PDL), its mechanical behavior is very dependent on the type of loading (compressive versus tensile loading; static versus cyclic loading; uniaxial versus multiaxial) and the location around the root (cervical, middle, or apical). These different aspects of the PDL make it difficult to develop a functional biomaterial to treat periodontal attachment due to periodontal diseases. This review aims to describe the structural and biomechanical properties of the PDL. Particular importance is placed in the close interrelationship that exists between structure and biomechanics: the PDL structural organization is specific to its biomechanical environment, and its biomechanical properties are specific to its structural arrangement. This balance between structure and biomechanics can be explained by a mechanosensitive periodontal cellular activity. These specifications have to be considered in the further tissue engineering strategies for the development of an efficient biomaterial for periodontal tissues regeneration.
Collapse
Affiliation(s)
- R Gauthier
- Univ Lyon - Claude Bernard Lyon 1, UMR CNRS 5615, Laboratoire des Multimatériaux et Interfaces, Villeurbanne F-69622, France; Univ Lyon, Université Claude Bernard Lyon 1, Faculté d'Odontologie, Lyon 69008, France
| | - Christophe Jeannin
- Univ Lyon - Claude Bernard Lyon 1, UMR CNRS 5615, Laboratoire des Multimatériaux et Interfaces, Villeurbanne F-69622, France; Univ Lyon, Université Claude Bernard Lyon 1, Faculté d'Odontologie, Lyon 69008, France; Hospices Civils de Lyon, Service d'Odontologie, Lyon 69007, France
| | - N Attik
- Univ Lyon - Claude Bernard Lyon 1, UMR CNRS 5615, Laboratoire des Multimatériaux et Interfaces, Villeurbanne F-69622, France; Univ Lyon, Université Claude Bernard Lyon 1, Faculté d'Odontologie, Lyon 69008, France
| | | | - K Gritsch
- Univ Lyon - Claude Bernard Lyon 1, UMR CNRS 5615, Laboratoire des Multimatériaux et Interfaces, Villeurbanne F-69622, France; Univ Lyon, Université Claude Bernard Lyon 1, Faculté d'Odontologie, Lyon 69008, France; Hospices Civils de Lyon, Service d'Odontologie, Lyon 69007, France
| | - B Grosgogeat
- Univ Lyon - Claude Bernard Lyon 1, UMR CNRS 5615, Laboratoire des Multimatériaux et Interfaces, Villeurbanne F-69622, France; Univ Lyon, Université Claude Bernard Lyon 1, Faculté d'Odontologie, Lyon 69008, France; Hospices Civils de Lyon, Service d'Odontologie, Lyon 69007, France
| |
Collapse
|
17
|
Ortún-Terrazas J, Fagan MJ, Cegoñino J, Illipronti-Filho E, Pérez Del Palomar A. Towards an early 3D-diagnosis of craniofacial asymmetry by computing the accurate midplane: A PCA-based method. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2020; 191:105397. [PMID: 32092615 DOI: 10.1016/j.cmpb.2020.105397] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 01/11/2020] [Accepted: 02/13/2020] [Indexed: 06/10/2023]
Abstract
BACKGROUND AND OBJECTIVE Craniofacial asymmetry is a common growth disorder often caused by unilateral chewing. Although an early orthodontic treatment would avoid surgical procedures later in life, the uncertainty of defining the accurate sagittal midplane potentially leads to misdiagnosis and therefore inaccurate orthodontic treatment plans. This novel study aims to 3D-diagnose craniofacial complex malformations in children with unilateral crossbite (UXB) considering a midplane which compensates the asymmetric morphology. METHODS The sagittal midplane of 20 children, fifteen of whom exhibited UXB, was computed by a PCA-based method which compensates the asymmetry mirroring the 3D models obtained from cone-beam computed tomography data. Once determined, one side of the data was mirrored using the computed midplane to visualize the malformations on the hard and soft tissues by 3D-computing the distances between both halves. Additionally, 31 skull's landmarks were manually placed in each model to study the principal variation modes and the significant differences in the group of subjects with and without UXB through PCA and Mann-Whitney U test analyses respectively. RESULTS Morphological 3D-analysis showed pronounced deformities and aesthetic implications for patients with severe asymmetry (jaw deviation > 0.8 mm) in whole craniofacial system, while initial signs of asymmetry were found indistinctly in the mandible or maxilla. We detected significant (p < 0.05) malformations for example in mandibular ramus length (0.0086), maxillary palate width (0.0481) and condylar head width (0.0408). Craniofacial malformations increased the landmarks' variability in the group of patients with UXB over the control group requiring 8 variation modes more to define 99% of the sample' variability. CONCLUSIONS Our findings demonstrated the viability of early diagnosis of craniofacial asymmetry through computing the accurate sagittal midplane which compensates the individual's asymmetrical morphology. Furthermore, this study provides important computational insights into the determination of craniofacial deformities which are caused by UXB, following some empirical findings of previous clinical studies. Hence, this computational approach can be useful for the development of new software in craniofacial surgery or for its use in biomedical research and clinical practice.
Collapse
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
| | - Jose Cegoñino
- Group of Biomaterials, Aragon Institute of Engineering Research (I3A), University of Zaragoza, Zaragoza, Spain
| | - Edson Illipronti-Filho
- School of Dentistry, Department of Orthodontics and Pediatric Dentistry, 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
| |
Collapse
|
18
|
Salamati A, Chen J, Herring SW, Liu ZJ. Functional tooth mobility in young pigs. J Biomech 2020; 104:109716. [PMID: 32173029 DOI: 10.1016/j.jbiomech.2020.109716] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 12/26/2019] [Accepted: 02/18/2020] [Indexed: 01/01/2023]
Abstract
Mobility is a fundamental characteristic of mammalian teeth, and has been widely used to determine individual tooth prognosis. However, the direction and extent of tooth movement under functional loads are unknown. This study investigated maxillary molar mobility, alveolar bending, and periodontal space (PDL) fluid pressure during mastication and masseter muscle contraction in young pigs, along with PDL space measurements. Twelve three-month-old farm pigs were instrumented with some or all of the following: (1) ultrasonic crystals, one implanted into the pulp chamber of a deciduous maxillary molar and additional crystals glued onto its buccal and palatal alveolar plates; (2) rosette strain gauges affixed to the buccal and palatal of alveolar ridges; (3) a pressure transducer inserted into palatal alveolar bone facing the PDL. Tooth mobility, alveolar bending, and fluid pressure were simultaneously recorded during unrestrained feeding and subsequent masseter muscle stimulation. The PDL widths were measured using micro-CT. The results indicate that during the power stroke of mastication, (1) the molar displaced buccally and apically (192 ± 95 µm) regardless of the side of chewing; (2) compressive bone strain was greater on the buccal than on the palatal alveolar plate; and (3) PDL pressure increased during the power strok (3.63 ± 0.80 kPa). Masseter contraction produced similar results but with generally lower values. The PDL widths were larger than the range of tooth mobility, and showed no correlation with the mobility. Thus occlusal function causes buccal tipping and intrusion of maxillary molars with concomitant compression of the buccal alveolar plate and raised pressure within the PDL space.
Collapse
Affiliation(s)
- Atriya Salamati
- Depts. Orthodontics & Oral Health Sciences, University of Washington, School of Dentistry, Seattle, WA, USA; Dept. Pediatric Dentistry, Jacobi Medical Center, Bronx, NY, USA
| | - Jie Chen
- Depts. Orthodontics & Oral Health Sciences, University of Washington, School of Dentistry, Seattle, WA, USA; Dept. Stomatology, Xin Hua Hospital Affiliated to Shanghai Jiao Tong, University School of Medicine, Shanghai, China
| | - Susan W Herring
- Depts. Orthodontics & Oral Health Sciences, University of Washington, School of Dentistry, Seattle, WA, USA
| | - Zi-Jun Liu
- Depts. Orthodontics & Oral Health Sciences, University of Washington, School of Dentistry, Seattle, WA, USA.
| |
Collapse
|
19
|
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.
Collapse
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
| |
Collapse
|
20
|
Karimi A, Razaghi R, Biglari H, Rahmati SM, Sandbothe A, Hasani M. Finite element modeling of the periodontal ligament under a realistic kinetic loading of the jaw system. Saudi Dent J 2019; 32:349-356. [PMID: 33132663 PMCID: PMC7588630 DOI: 10.1016/j.sdentj.2019.10.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 09/29/2019] [Accepted: 10/20/2019] [Indexed: 11/25/2022] Open
Abstract
Purpose The stresses and deformations in the periodontal ligament (PDL) under the realistic kinetic loading of the jaw system, i.e., chewing, are difficult to be determined numerically as the mechanical properties of the PDL is variably present in different finite element (FE) models. This study was aimed to conduct a dynamic finite element (FE) simulation to investigate the role of the PDL (PDL) material models in the induced stresses and deformations using a simplified patient-specific FE model of a human jaw system. Methods To do that, a realistic kinetic loading of chewing was applied to the incisor point, contralateral, and ipsilateral condyles, through the experimentally proven trajectory approach. Three different material models, including the elasto-plastic, hyperelastic, and viscoelastic, were assigned to the PDL, and the resulted stresses of the tooth FE model were computed and compared. Results The results revealed the highest von Mises stress of 620.14 kPa and the lowest deformation of 0.16 mm in the PDL when using the hyperelastic model. The concentration of the stress in the elastoplastic and viscoelastic models was in the mid-root and apex of the PDL, while for the hyperelastic model, it was concentrated in the cervical margin. The highest deformation in the PDL regardless of the employed material model was located in the caudal direction of the tooth. The viscoelastic PDL absorbed the transmitted energy from the dentine and led to lower stress in the cancellous bone compared to the elastoplastic and hyperelastic material models. Conclusion These results have implications not only for understanding the stresses and deformations in the PDL under chewing but also for providing comprehensive information for the medical and biomechanical experts in regard of the role of the material models being used to address the mechanical behavior of the PDL in other components of the tooth.
Collapse
Affiliation(s)
- Alireza Karimi
- Department of Mechanical Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Reza Razaghi
- Department of Mechanical Engineering, University of Tabriz, Tabriz 51666, Iran.,Basir Eye Health Research Center, Tehran, Iran
| | - Hasan Biglari
- Department of Mechanical Engineering, University of Tabriz, Tabriz 51666, Iran
| | | | - Alix Sandbothe
- Children's Hospital & Medical Center, Omaha, NE, United States
| | - Mojtaba Hasani
- Department of Biomedical Engineering, Faculty of Engineering, University of Isfahan, Isfahan, Iran
| |
Collapse
|
21
|
Mehari Abraha H, Iriarte-Diaz J, Ross CF, Taylor AB, Panagiotopoulou O. The Mechanical Effect of the Periodontal Ligament on Bone Strain Regimes in a Validated Finite Element Model of a Macaque Mandible. Front Bioeng Biotechnol 2019; 7:269. [PMID: 31737614 PMCID: PMC6831558 DOI: 10.3389/fbioe.2019.00269] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 09/27/2019] [Indexed: 11/13/2022] Open
Abstract
The primary anatomical function of the periodontal ligament (PDL) is to attach teeth to their sockets. However, theoretical and constitutive mechanical models have proposed that during mastication the PDL redistributes local occlusal loads and reduces the jaw's resistance to torsional deformations. These hypotheses imply that accurately modeling the PDL's material properties and geometry in finite element analysis (FEA) is a prerequisite to obtaining precise strain and deformation data. Yet, many finite element studies of the human and non-human primate masticatory apparatus exclude the PDL or model it with simplicity, in part due to limitations in μCT/CT scan resolution and material property assignment. Previous studies testing the sensitivity of finite element models (FEMs) to the PDL have yielded contradictory results, however a major limitation of these studies is that FEMs were not validated against in vivo bone strain data. Hence, this study uses a validated and subject specific FEM to assess the effect of the PDL on strain and deformation regimes in the lower jaw of a rhesus macaque (Macaca mulatta) during simulated unilateral post-canine chewing. Our findings demonstrate that the presence of the PDL does influence local and global surface strain magnitudes (principal and shear) in the jaw. However, the PDL's effect is limited (diff. ~200-300 με) in areas away from the alveoli. Our results also show that varying the PDL's Young's Modulus within the range of published values (0.07-1750 MPa) has very little effect on global surface strains. These findings suggest that the mechanical importance of the PDL in FEMs of the mandible during chewing is dependent on the scope of the hypotheses being tested. If researchers are comparing strain gradients across species/taxa, the PDL may be excluded with minimal effect on results, but, if researchers are concerned with absolute strain values, sensitivity analysis is required.
Collapse
Affiliation(s)
- Hyab Mehari Abraha
- Moving Morphology and Functional Mechanics Laboratory, Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Jose Iriarte-Diaz
- Department of Biology, The University of the South, Sewanee, TN, United States
| | - Callum F. Ross
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL, United States
| | - Andrea B. Taylor
- Department of Basic Science, Touro University, Vallejo, CA, United States
| | - Olga Panagiotopoulou
- Moving Morphology and Functional Mechanics Laboratory, Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| |
Collapse
|
22
|
Schmidt F, Lapatki BG. Effect of variable periodontal ligament thickness and its non-linear material properties on the location of a tooth's centre of resistance. J Biomech 2019; 94:211-218. [PMID: 31427090 DOI: 10.1016/j.jbiomech.2019.07.043] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 07/31/2019] [Accepted: 07/31/2019] [Indexed: 11/29/2022]
Abstract
In orthodontics, the 3D translational and rotational movement of a tooth is determined by the force-moment system applied and the location of the tooth's centre of resistance (CR). Because of the practical constraints of in-vivo experiments, the finite element (FE) method is commonly used to determine the CR. The objective of this study was to investigate the geometric model details required for accurate CR determination, and the effect of material non-linearity of the periodontal ligament (PDL). A FE model of a human lower canine derived from a high-resolution µCT scan (voxel size: 50 µm) was investigated by applying four different modelling approaches to the PDL. These comprised linear and non-linear material models, each with uniform and realistic PDL thickness. The CR locations determined for the four model configurations were in the range 37.2-45.3% (alveolar margin: 0%; root apex: 100%). We observed that a non-linear material model introduces load-dependent results that are dominated by the PDL regions under tension. Load variation within the range used in clinical orthodontic practice resulted in CR variations below 0.3%. Furthermore, the individualized realistic PDL geometry shifted the CR towards the alveolar margin by 2.3% and 2.8% on average for the linear and non-linear material models, respectively. We concluded that for conventional clinical therapy and the generation of representative reference data, the least sophisticated modelling approach with linear material behaviour and uniform PDL thickness appears sufficiently accurate. Research applications that require more precise treatment monitoring and planning may, however, benefit from the more accurate results obtained from the non-linear constitutive law and individualized realistic PDL geometry.
Collapse
Affiliation(s)
- Falko Schmidt
- Department of Orthodontics, Centre of Dentistry, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany.
| | - Bernd Georg Lapatki
- Department of Orthodontics, Centre of Dentistry, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| |
Collapse
|
23
|
Wan W, Cheng B, Zhang C, Ma Y, Li A, Xu F, Lin M. Synergistic Effect of Matrix Stiffness and Inflammatory Factors on Osteogenic Differentiation of MSC. Biophys J 2019; 117:129-142. [PMID: 31178039 PMCID: PMC6626830 DOI: 10.1016/j.bpj.2019.05.019] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 04/18/2019] [Accepted: 05/09/2019] [Indexed: 12/22/2022] Open
Abstract
Mesenchymal stem cells (MSCs) in vivo reside in a complex microenvironment. Changes of both biochemical and biophysical cues in the microenvironment caused by inflammation affect the differentiation behaviors of MSCs. Most studies, however, only focus on either biochemical or biophysical cues, although the synergistic effect of matrix stiffness and inflammatory factors on osteogenic differentiation of MSCs has not been explored yet. Here, we showed that there was a matrix stiffness-dependent modulation in the osteogenic differentiation of human MSCs (hMSCs) with higher matrix stiffness favoring osteogenesis bias. However, when interleukin-1 β (IL-1β) was added, the osteogenic differentiation of hMSCs was suppressed, which was independent of increasing matrix stiffness. Both experimental observations and mathematical modeling confirmed that matrix stiffness and IL-1β could activate the ERK1/2 signaling and contribute to osteogenic differentiation. The p38 signaling activated by IL-1β has a strong role in inhibiting osteoblastic differentiation, thus diminishing the vital effect of ERK1/2 signaling. In addition, sensitivity analysis of the model parameters revealed that activation/deactivation dynamics of sensitive factors (e.g., FAK, ERK, and p38) also played a key role in the synergistic effect of matrix stiffness and IL-1β on the osteogenic differentiation of hMSCs. The outcomes of this study provide new insights into the synergistic effect of biochemical and biophysical microenvironments on regulating MSC differentiation.
Collapse
Affiliation(s)
- Wanting Wan
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology; Bioinspired Engineering and Biomechanics Center, Xi'an Jiaotong University, Xi'an, P.R. China
| | - Bo Cheng
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology; Bioinspired Engineering and Biomechanics Center, Xi'an Jiaotong University, Xi'an, P.R. China
| | - Cheng Zhang
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology; Bioinspired Engineering and Biomechanics Center, Xi'an Jiaotong University, Xi'an, P.R. China
| | - Yufei Ma
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology; Bioinspired Engineering and Biomechanics Center, Xi'an Jiaotong University, Xi'an, P.R. China
| | - Ang Li
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology
| | - Feng Xu
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology; Bioinspired Engineering and Biomechanics Center, Xi'an Jiaotong University, Xi'an, P.R. China
| | - Min Lin
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology; Bioinspired Engineering and Biomechanics Center, Xi'an Jiaotong University, Xi'an, P.R. China.
| |
Collapse
|
24
|
Madeira S, Mesquita-Guimarães J, Ribeiro P, Fredel M, Souza JCM, Soares D, Silva FS, Henriques B. Y-TZP/porcelain graded dental restorations design for improved damping behavior - A study on damping capacity and dynamic Young's modulus. J Mech Behav Biomed Mater 2019; 96:219-226. [PMID: 31055212 DOI: 10.1016/j.jmbbm.2019.04.033] [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: 02/18/2019] [Revised: 04/16/2019] [Accepted: 04/17/2019] [Indexed: 01/12/2023]
Abstract
The development of dental restorative materials that mimic tooth-like properties provided by graded structures, aesthetics and properties such as strength, damping capacity and the ability for a continuous remodeling according to the biomechanical solicitation is a great challenge. In this work, damping capacity and dynamic Young's modulus of Y-TZP/porcelain composites for all-ceramic dental restorations were studied. These mechanical properties were assessed by dynamic mechanical analyses (DMA) at frequencies of 1, 5 and 10 Hz, over a temperature ranging from 0 to 60 °C, simulating extreme conditions when a cold or hot drink is experienced. The results showed that porcelain and porcelain-matrix composites exhibited higher damping capacity while Y-TZP and Y-TZP-matrix composites presented higher dynamic Young's modulus. Furthermore, while damping capacity is strongly influenced by the temperature, no significant difference in dynamic Young's modulus was found. For both damping and modulus properties, no significant influence of frequency was found for the tested materials. Based on the obtained results and also on the known advantages of the graded Y-TZP/porcelain structures over traditional bi-layer solutions (e.g., improved bending strength, enhanced mechanical and thermal stress distribution), a novel design of all-ceramic restoration with damping capacity has been proposed at the end of this study. A positive impact on the long-term performance of these all-ceramic restorations may be expected.
Collapse
Affiliation(s)
- S Madeira
- Center for Micro-Electro Mechanical Systems (CMEMS), University of Minho, Campus de Azurém, 4800-058, Guimarães, Portugal.
| | - J Mesquita-Guimarães
- Center for Micro-Electro Mechanical Systems (CMEMS), University of Minho, Campus de Azurém, 4800-058, Guimarães, Portugal.
| | - P Ribeiro
- Center for Micro-Electro Mechanical Systems (CMEMS), University of Minho, Campus de Azurém, 4800-058, Guimarães, Portugal
| | - M Fredel
- Ceramic and Composite Materials Research Group (CERMAT), Federal University of Santa Catarina (UFSC), Campus Trindade, Florianópolis, SC, Brazil
| | - J C M Souza
- Center for Micro-Electro Mechanical Systems (CMEMS), University of Minho, Campus de Azurém, 4800-058, Guimarães, Portugal; Department of Dental Sciences, University Institute of Health Sciences (IUCS), CESPU, Gandra, Portugal
| | - D Soares
- Center for Micro-Electro Mechanical Systems (CMEMS), University of Minho, Campus de Azurém, 4800-058, Guimarães, Portugal
| | - F S Silva
- Center for Micro-Electro Mechanical Systems (CMEMS), University of Minho, Campus de Azurém, 4800-058, Guimarães, Portugal
| | - Bruno Henriques
- Center for Micro-Electro Mechanical Systems (CMEMS), University of Minho, Campus de Azurém, 4800-058, Guimarães, Portugal; Ceramic and Composite Materials Research Group (CERMAT), Federal University of Santa Catarina (UFSC), Campus Trindade, Florianópolis, SC, Brazil; School of Dentistry (DODT), Post-Graduate Program in Dentistry (PPGO), Federal University of Santa Catarina, Campus Trindade, 88040-900, Florianópolis, SC, Brazil.
| |
Collapse
|
25
|
Ortún-Terrazas J, Cegoñino J, Santana-Penín U, Santana-Mora U, Pérez Del Palomar A. A porous fibrous hyperelastic damage model for human periodontal ligament: Application of a microcomputerized tomography finite element model. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2019; 35:e3176. [PMID: 30628171 DOI: 10.1002/cnm.3176] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Revised: 11/21/2018] [Accepted: 12/16/2018] [Indexed: 06/09/2023]
Abstract
The periodontal ligament (PDL) is a soft biological tissue that connects the tooth with the trabecular bone of the mandible. It plays a key role in load transmission and is primarily responsible for bone resorption and most common periodontal diseases. Although several numerical studies have analysed the biomechanical response of the PDL, most did not consider its porous fibrous structure, and only a few analysed damage to the PDL. This study presents an innovative numerical formulation of a porous fibrous hyperelastic damage material model for the PDL. The model considers two separate softening phenomena: fibre alignment during loading and fibre rupture. The parameters for the material model characterization were fitted using experimental data from the literature. Furthermore, the experimental tests used for characterization were computationally modelled to verify the material parameters. A finite element model of a portion of a human mandible, obtained by microcomputerized tomography, was developed, and the proposed constitutive model was implemented for the PDL. Our results confirm that damage to the PDL may occur mainly because of overpressure of the interstitial fluid, while large forces must be applied to damage the PDL fibrous network. Moreover, this study clarifies some aspects of the relationship between PDL damage and the bone remodelling process.
Collapse
Affiliation(s)
- Javier Ortún-Terrazas
- Group of Biomaterials, Aragon Institute of Engineering Research (I3A), Department of Mechanical Engineering, University of Zaragoza, Zaragoza, Spain
| | - José Cegoñino
- Group of Biomaterials, Aragon Institute of Engineering Research (I3A), Department of Mechanical Engineering, University of Zaragoza, Zaragoza, Spain
| | - Urbano Santana-Penín
- School of Dentistry, Faculty of Medicine and Odontology, Santiago de Compostela University, Santiago de Compostela, Spain
| | - Urbano Santana-Mora
- School of Dentistry, Faculty of Medicine and Odontology, Santiago de Compostela University, Santiago de Compostela, Spain
| | - Amaya Pérez Del Palomar
- Group of Biomaterials, Aragon Institute of Engineering Research (I3A), Department of Mechanical Engineering, University of Zaragoza, Zaragoza, Spain
| |
Collapse
|
26
|
Damping and mechanical behavior of metal-ceramic composites applied to novel dental restorative systems. J Mech Behav Biomed Mater 2019; 90:239-247. [DOI: 10.1016/j.jmbbm.2018.09.046] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 09/26/2018] [Accepted: 09/27/2018] [Indexed: 12/30/2022]
|
27
|
Mechanical Properties of the Periodontal System and of Dental Constructs Deduced from the Free Response of the Tooth. JOURNAL OF HEALTHCARE ENGINEERING 2018; 2018:4609264. [PMID: 30310558 PMCID: PMC6166376 DOI: 10.1155/2018/4609264] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Accepted: 07/19/2018] [Indexed: 11/22/2022]
Abstract
The biomechanical behaviour of the periodontal ligament (PDL) is still not well understood although this topic has been studied for almost 100 years. This study reports on clinical and mathematical studies to determine the constitutive law of the PDL. A set of mechanical parameters of the tooth-PDL system is obtained, and a new method for the evaluation of these parameters from the free response of the tooth is introduced. This response is produced by repeated impacts applied to the gingival tissue in the apical part of the tooth investigated—with the aid of a Periotest exciter. A Doppler ultrasound probe is utilized to determine the response of the tooth-PDL system. The parameters evaluated from these measurements can be considered as the elastometric properties of the dental system investigated. A modal analysis/system identification method is utilized to estimate these parameters. The investigations are carried out for different teeth abutments, both with and without a dental bridge/fixed partial prosthesis (FPP). The differences between the responses of the systems in these two cases are determined with the new method proposed. They are discussed with regard to the specific purposes of the FPP. The study demonstrates that this method can provide the dentist with the necessary objective evaluations regarding the properties and health of the tooth-PDL system, as well as of the construct that is obtained after installing a dental bridge.
Collapse
|
28
|
Nonlinear Biomechanical Characteristics of the Schneiderian Membrane: Experimental Study and Numerical Modeling. BIOMED RESEARCH INTERNATIONAL 2018; 2018:2829163. [PMID: 30035119 PMCID: PMC6033247 DOI: 10.1155/2018/2829163] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 05/24/2018] [Indexed: 01/21/2023]
Abstract
Objective The aim of this study is to quantify the nonlinear mechanical behavior of the Schneiderian membrane. Methods Thirty cadaveric maxillary sinus membrane specimens were divided into the elongation testing group and the perforation testing group. Mechanical experimental measurements were taken via ex vivo experiments. Theoretical curves were compared with experimental findings to assess the effectiveness of the nonlinear mechanical properties. The FE model with nonlinear mechanical properties was used to simulate the detachment of the Schneiderian membrane under loading. Results The mean thickness of the membrane samples was 1.005 mm. The mean tensile strength obtained by testing was 6.81 N/mm2. In membrane perforation testing, the mean tensile strength and the linear elastic modulus were significantly higher than those in membrane elongation testing (P < 0.05). The mean adhesion force between the Schneiderian membrane and the bone was 0.052 N/mm. By FE modeling, the squared correlation coefficients of theoretical stress-strain curves for the nonlinear and linear models were 0.99065 and 0.94656 compared with the experimental data. Conclusions The biomechanical properties of the Schneiderian membrane were implemented into the FE model, which was applied to simulate the mechanical responses of the Schneiderian membrane in sinus floor elevation.
Collapse
|
29
|
Knaup TJ, Dirk C, Reimann S, Keilig L, Eschbach M, Korbmacher-Steiner H, Bourauel C. Time-dependent behavior of porcine periodontal ligament: A combined experimental, numeric in-vitro study. Am J Orthod Dentofacial Orthop 2018; 153:97-107. [DOI: 10.1016/j.ajodo.2017.05.034] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Revised: 05/01/2017] [Accepted: 05/01/2017] [Indexed: 10/18/2022]
|
30
|
Huang H, Tang W, Tan Q, Yan B. Development and parameter identification of a visco-hyperelastic model for the periodontal ligament. J Mech Behav Biomed Mater 2017; 68:210-215. [DOI: 10.1016/j.jmbbm.2017.01.035] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 01/03/2017] [Accepted: 01/23/2017] [Indexed: 10/20/2022]
|
31
|
Martinez Choy SE, Lenz J, Schweizerhof K, Schmitter M, Schindler HJ. Realistic kinetic loading of the jaw system during single chewing cycles: a finite element study. J Oral Rehabil 2017; 44:375-384. [DOI: 10.1111/joor.12501] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/25/2017] [Indexed: 11/29/2022]
Affiliation(s)
- S. E. Martinez Choy
- Research Group Biomechanics; Institute for Mechanics; Karlsruhe Institute of Technology (KIT); Karlsruhe Germany
| | - J. Lenz
- Research Group Biomechanics; Institute for Mechanics; Karlsruhe Institute of Technology (KIT); Karlsruhe Germany
| | - K. Schweizerhof
- Research Group Biomechanics; Institute for Mechanics; Karlsruhe Institute of Technology (KIT); Karlsruhe Germany
| | - M. Schmitter
- Department of Prosthodontics; Dental School; University of Würzburg; Würzburg Germany
| | - H. J. Schindler
- Research Group Biomechanics; Institute for Mechanics; Karlsruhe Institute of Technology (KIT); Karlsruhe Germany
| |
Collapse
|
32
|
Nikolaus A, Currey JD, Lindtner T, Fleck C, Zaslansky P. Importance of the variable periodontal ligament geometry for whole tooth mechanical function: A validated numerical study. J Mech Behav Biomed Mater 2017; 67:61-73. [DOI: 10.1016/j.jmbbm.2016.11.020] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 11/01/2016] [Accepted: 11/24/2016] [Indexed: 11/27/2022]
|
33
|
Kunert-Keil C, Gredes T, Götz W, Heinemann F. International Dentistry Research Update 2016. Ann Anat 2016; 208:94-95. [PMID: 27926463 DOI: 10.1016/j.aanat.2016.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
| | - Tomasz Gredes
- Department of Orthodontics, Technische Universität Dresden, Germany
| | - Werner Götz
- Department of Orthodontics, Oral Biology Laboratory, Rheinische Friedrich Wilhelms University of Bonn, Germany
| | - Friedhelm Heinemann
- Department of Prosthodontics, Gerodontology and Biomaterials, University of Greifswald, Germany
| |
Collapse
|
34
|
Kirschneck C, Fanghänel J, Wahlmann U, Wolf M, Roldán JC, Proff P. Interactive effects of periodontitis and orthodontic tooth movement on dental root resorption, tooth movement velocity and alveolar bone loss in a rat model. Ann Anat 2016; 210:32-43. [PMID: 27838559 DOI: 10.1016/j.aanat.2016.10.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 07/05/2016] [Accepted: 10/06/2016] [Indexed: 10/20/2022]
Abstract
BACKGROUND Many adult orthodontic patients suffer from chronic periodontitis with recurrent episodes of active periodontal inflammation. As their number is steadily increasing, orthodontists are more and more frequently challenged by respective treatment considerations. However, little is currently known regarding interactive effects on undesired dental root resorption (DRR), tooth movement velocity, periodontal bone loss and the underlying cellular and tissue reactions. MATERIAL AND METHODS A total of 63 male Fischer344 rats were used in three consecutive experiments employing 21 animals each (A/B/C), randomly assigned to 3 experimental groups (n=7, 1/2/3), respectively: (A) CBCT; (B) histology/serology; (C) RT-qPCR-(1) control; (2) orthodontic tooth movement (OTM) of the first/second upper left molars (NiTi coil spring, 0.25N); (3) OTM with experimentally induced periodontitis (cervical silk ligature). After 14days of OTM, we quantified blood leukocyte level, DRR, osteoclast activity and relative gene expression of inflammatory and osteoclast marker genes within the dental-periodontal tissue as well as tooth movement velocity and periodontal bone loss after 14 and 28 days. RESULTS The experimentally induced periodontal bone loss was significantly increased by concurrent orthodontic force application. Periodontal inflammation during OTM on the other hand significantly augmented the extent of DRR, relative expression of inflammatory/osteoclast marker genes, blood leukocyte level and periodontal osteoclast activity. In addition, contrary to previous studies, we observed a significant increase in tooth movement velocity. CONCLUSIONS Although accelerated tooth movement would be favourable for orthodontic treatment, our results suggest that orthodontic interventions should only be performed after successful systematic periodontal therapy and paused in case of recurrent active inflammation.
Collapse
Affiliation(s)
- Christian Kirschneck
- Department of Orthodontics, University Medical Centre of Regensburg, Franz-Josef-Strauß-Allee 11, D-93053 Regensburg, Germany.
| | - Jochen Fanghänel
- Department of Orthodontics, University Medical Centre of Regensburg, Franz-Josef-Strauß-Allee 11, D-93053 Regensburg, Germany.
| | - Ulrich Wahlmann
- Department of Maxillofacial Surgery, University Medical Centre of Regensburg, Franz-Josef-Strauß-Allee 11, D-93053 Regensburg, Germany.
| | - Michael Wolf
- Department of Orthodontics, Rheinische Friedrich Wilhelm University of Bonn, Welschnonnenstraße 17, D-53111 Bonn, Germany.
| | - J Camilo Roldán
- Director of the Division of Pediatric Facial Plastic Surgery and Craniofacial Anomalies, Catholic Children's Hospital Wilhelmstift, Liliencronstraße 130, D-22149 Hamburg, Germany; Lecturer at the Department of Cranio-Maxillofacial Surgery, University Medical Centre of Regensburg, Franz-Josef-Strauß-Allee 11, D-93053 Regensburg, Germany.
| | - Peter Proff
- Department of Orthodontics, University Medical Centre of Regensburg, Franz-Josef-Strauß-Allee 11, D-93053 Regensburg, Germany.
| |
Collapse
|
35
|
In vivo determination of tooth mobility after fixed orthodontic appliance therapy with a novel intraoral measurement device. Clin Oral Investig 2016; 21:1283-1289. [DOI: 10.1007/s00784-016-1881-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 06/09/2016] [Indexed: 12/20/2022]
|
36
|
Schmidt F, Geiger ME, Jäger R, Lapatki BG. Comparison of methods to determine the centre of resistance of teeth. Comput Methods Biomech Biomed Engin 2016; 19:1673-82. [DOI: 10.1080/10255842.2016.1177822] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Falko Schmidt
- Department of Orthodontics, Centre of Dentistry, University of Ulm, Ulm, Germany
| | | | - Rudolf Jäger
- Department of Orthodontics, Centre of Dentistry, University of Ulm, Ulm, Germany
| | - Bernd Georg Lapatki
- Department of Orthodontics, Centre of Dentistry, University of Ulm, Ulm, Germany
| |
Collapse
|