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Pereira R, Romero J, Norton A, Nóbrega JM. Advancing the assessment of pacifier effects with a novel computational method. BMC Oral Health 2024; 24:87. [PMID: 38229079 DOI: 10.1186/s12903-023-03848-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 12/31/2023] [Indexed: 01/18/2024] Open
Abstract
BACKGROUND Numerous studies have demonstrated a high likelihood of malocclusions resulting from non-nutritive sucking. Consequently, quantifying the impact of pacifiers can potentially aid in preventing the development or exacerbation of malocclusions and guide the design of improved performance pacifiers. METHODS This work proposes and assesses a computational methodology that can effectively gather crucial information and provide more precise data regarding the consequences of non-nutritive pacifier sucking. The computational framework utilized is based on solids4Foam [1, 2], a collection of numerical solvers developed within the OpenFOAM® computational library [3]. The computational model focuses on the palate of a six-month-old baby and incorporates various components such as palate tissues, pacifier and tongue, and considers the negative intraoral pressure generated and the tongue displacement. Different models were tested, each offering varying levels of detail in representing the palate structure. These models range from a simplified approach, with one tissue, to a more intricate representation, involving up to five different tissues, offering a more comprehensive palate model compared to existing literature. RESULTS The analysis of results involved examining the distribution of stress on the palate surface, as well as the displacement and forces exerted on the dental crowns. By comparing the obtained results, it was possible to evaluate the precision of the approaches previously described in the literature. The findings revealed that the predictions were less accurate when using the simplified model with a single tissue for the palate, which is the most common approach proposed in the literature. In contrast, the results demonstrated that the palate model with the most intricate structure, incorporating five different tissues, yielded distinct outcomes compared to all other combinations. CONCLUSIONS The computational methodology proposed, employing the most detailed palate model, has demonstrated its effectiveness and necessity in obtaining accurate data on the impact of non-nutritive sucking habits, which are recognized as a primary contributor to the development of dental malocclusions. In the future, this approach could be extended to conduct similar studies encompassing diverse pacifier designs, sizes, and age groups. This would foster the design of innovative pacifiers that mitigate the adverse effects of non-nutritive sucking on orofacial structures.
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Affiliation(s)
- R Pereira
- IPC - Institute for Polymers and Composites, University of Minho, Azurém Campus, Guimarães, 4804-058, Portugal.
| | - J Romero
- IPC - Institute for Polymers and Composites, University of Minho, Azurém Campus, Guimarães, 4804-058, Portugal
| | - A Norton
- FMDUP - Faculdade de Medicina Dentária da Universidade do Porto, Porto, 4200-393, Portugal
| | - J M Nóbrega
- IPC - Institute for Polymers and Composites, University of Minho, Azurém Campus, Guimarães, 4804-058, Portugal
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Liu L, Yao L, Lu Z, Jiang L, Zhang X, Liu X, Zhang W, Luan X, Zhang S, Xu W, Wang T, Zhang F, Wei X, Da J, Wang J, Zhang J, Li Y, Jin H, Zhang B. Epithelial-specific deletion of FAM20A leads to short root defects. Gene 2023; 884:147731. [PMID: 37625561 DOI: 10.1016/j.gene.2023.147731] [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: 06/29/2023] [Revised: 08/17/2023] [Accepted: 08/21/2023] [Indexed: 08/27/2023]
Abstract
Short Root Defects defined by a reduced ratio of root to crown, may culminate in root resorption and subsequent tooth loss, in spite of the absence of apparent symptoms. Such defects present considerable impediments to orthodontic treatment and restoration. Recent identification of Fam20a, an emergent pseudokinase, has been associated with enamel development and tooth eruption, yet its definitive role in root formation and eruption remains ambiguous. In this research, we initially ascertained that the targeted knockout of Fam20a within the epithelium led to truncated tooth roots, irregular breaks in the epithelial root sheath initiation of the WNT signaling pathway, and decreased expression of the cell polarity-related transcription factor Cdc42 in murine models. This was concomitant with the participation of the associated epithelial root sheath developmental pathways BMP2, Gli1, and Nfic. Furthermore, we observed that Fam20a predominantly affects the intraosseous eruption phase of tooth emergence. During this phase, the osteoclast peak around the mandibular first molar in cKO mice is delayed, leading to a slower formation of the eruption pathway, ultimately resulting in delayed tooth eruption in mice. The findings of this study enrich the extant knowledge regarding the role of Fam20a, suggesting its potential regulatory function in tooth root development through the WNT/β-catenin/Cdc42 pathway.
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Affiliation(s)
- Lixue Liu
- Institute of Hard Tissue Development and Regeneration, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Lihong Yao
- Department of Stomatology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Zeyu Lu
- Institute of Hard Tissue Development and Regeneration, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Lili Jiang
- Institute of Hard Tissue Development and Regeneration, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Xiaohan Zhang
- Institute of Hard Tissue Development and Regeneration, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Xinpeng Liu
- Department of Oral and Maxillofacial Surgery, Stomatological Hospital, School of Stomatology, Southern Medical University, Guangzhou, China
| | - Wenxuan Zhang
- Institute of Hard Tissue Development and Regeneration, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Xinrui Luan
- Institute of Hard Tissue Development and Regeneration, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Shujian Zhang
- Institute of Hard Tissue Development and Regeneration, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Wenxia Xu
- Institute of Hard Tissue Development and Regeneration, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Tuo Wang
- Institute of Hard Tissue Development and Regeneration, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Fangping Zhang
- Institute of Hard Tissue Development and Regeneration, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Xuancheng Wei
- Institute of Hard Tissue Development and Regeneration, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Junlong Da
- Institute of Hard Tissue Development and Regeneration, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Jianqun Wang
- Institute of Hard Tissue Development and Regeneration, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Jiahui Zhang
- Institute of Hard Tissue Development and Regeneration, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Ying Li
- Institute of Hard Tissue Development and Regeneration, The Second Affiliated Hospital of Harbin Medical University, Harbin, China.
| | - Han Jin
- Institute of Hard Tissue Development and Regeneration, The Second Affiliated Hospital of Harbin Medical University, Harbin, China.
| | - Bin Zhang
- Institute of Hard Tissue Development and Regeneration, The Second Affiliated Hospital of Harbin Medical University, Harbin, China; Heilongjiang Academy of Medical Sciences, Harbin, China.
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Chen H, Li Y, Sun Y, Chen X, Pu Y, Sun G. Changes in condylar position and morphology after mandibular reconstruction by vascularized fibular free flap with condyle preservation. Clin Oral Investig 2023; 27:6097-6109. [PMID: 37632578 DOI: 10.1007/s00784-023-05225-6] [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: 04/25/2022] [Accepted: 08/16/2023] [Indexed: 08/28/2023]
Abstract
OBJECTS Changes in condylar position and morphology after mandibular reconstruction are important to aesthetic and functional rehabilitation. We evaluated changes in condylar position and morphology at different stages after mandibular reconstruction using vascularized fibular free flap with condyle preservation. MATERIALS AND METHODS A total of 23 patients who underwent mandibular reconstruction with fibular flap were included in this retrospective study. CT data of all patients were recorded before surgery (T0), 7 to 14 days after surgery (T1), and at least 6 months after surgery (T2). Five parameters describing the condylar position and 4 parameters describing the morphology were measured in sagittal and coronal views of CT images. The association between clinical characteristics and changes in condylar position and morphology was analyzed. A finite element model was established to investigate the stress distribution and to predict the spatial movement tendency of the condyle after reconstruction surgery. RESULTS The condylar position changed over time after mandibular reconstruction. The ipsilateral condyles moved inferiorly after surgery (T0 to T1) and continually move anteriorly, inferiorly, and laterally during long-term follow-up (T1 to T2). Contrary changes were noted in the contralateral condyles with no statistical significance. No morphological changes were detected. The relationship between clinical characteristics and changes in condylar position and morphology was not statistically significant. A consistent result was observed in the finite element analysis. CONCLUSION Condylar positions showed obvious changes over time after mandibular reconstruction with condylar preservation. Nevertheless, further studies should be conducted to evaluate the clinical function outcomes and condylar position. CLINICAL RELEVANCE These findings can form the basis for the evaluation of short-term and long-term changes in condylar position and morphology among patients who have previously undergone mandibular reconstruction by FFF with condyle preservation.
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Affiliation(s)
- Haoliang Chen
- Department of Oral and Maxillofacial Surgery, Nanjing Stomatological Hospital, Medical School of Nanjing University, 30 Zhongyang Road, Nanjing, 210008, People's Republic of China
| | - Yongheng Li
- School of Biological Science & Medical Engineering, Southeast University, Nanjing, China
| | - Yawei Sun
- Department of Oral and Maxillofacial Surgery, Nanjing Stomatological Hospital, Medical School of Nanjing University, 30 Zhongyang Road, Nanjing, 210008, People's Republic of China
| | - Xin Chen
- Department of Oral and Maxillofacial Surgery, Nanjing Stomatological Hospital, Medical School of Nanjing University, 30 Zhongyang Road, Nanjing, 210008, People's Republic of China
| | - Yumei Pu
- Department of Oral and Maxillofacial Surgery, Nanjing Stomatological Hospital, Medical School of Nanjing University, 30 Zhongyang Road, Nanjing, 210008, People's Republic of China
| | - Guowen Sun
- Department of Oral and Maxillofacial Surgery, Nanjing Stomatological Hospital, Medical School of Nanjing University, 30 Zhongyang Road, Nanjing, 210008, People's Republic of China.
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Huang J, Liu X, Wang Y, Bao C. Effect of dental follicles in minimally invasive open-eruption technique of labially impacted maxillary central incisors. HUA XI KOU QIANG YI XUE ZA ZHI = HUAXI KOUQIANG YIXUE ZAZHI = WEST CHINA JOURNAL OF STOMATOLOGY 2023; 41:197-202. [PMID: 37056186 PMCID: PMC10427249 DOI: 10.7518/hxkq.2023.2022413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 01/27/2023] [Indexed: 04/15/2023]
Abstract
OBJECTIVES To summarize the open-eruption technique of impacted anterior maxillary teeth, this study reports a technically improved operation on surgical exposure based on dental follicles and evaluates post-treatment periodontal health considering the effect of dental follicles. METHODS Patients who underwent open-eruption technique with unilateral labially impacted maxillary central incisors were selected. The impacted teeth were assigned to the experimental group, and the contralateral unimpacted maxillary central incisors were assigned to the control group. In the surgical exposure, the new technique makes use of dental follicles to manage the soft tissue, so as to preserve soft tissue for better aesthetic results and healthier periodontal tissue. Tooth length, root length, alveolar bone loss, and alveolar bone thickness were recorded after the therapy. RESULTS A total of 17 patients with unilateral maxillary central incisor impaction were successfully treated. The tooth length and root length of the two groups showed a statistically significant difference between the impacted and homonym teeth, with a shorter length in the impacted tooth (P<0.05). More labial alveolar bone loss was found in the experimental group compared with that in the control group (P<0.05). The outcomes of the cementoenamel junction width, pa- latal alveolar bone loss, and alveolar bone thickness did not indicate statistical significance between the experimental and control groups (P>0.05). CONCLUSIONS In the surgical exposure, the new technique uses dental follicles to manage the soft tissue and preserve it for better aesthetic results and healthier periodontal tissues.
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Affiliation(s)
- Jiayue Huang
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Xian Liu
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Yan Wang
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Chongyun Bao
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
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Yang PZ, Bai LY, Zhang HX, Zhao WJ, Liu Y, Wen XJ, Liu R. Efficacy of a four-curvature auxiliary arch at preventing maxillary central incisor linguoclination during orthodontic treatment: a finite element analysis. BMC Oral Health 2023; 23:144. [PMID: 36906550 PMCID: PMC10007732 DOI: 10.1186/s12903-023-02833-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 02/22/2023] [Indexed: 03/13/2023] Open
Abstract
BACKGROUND Correct torque of the incisors is beneficial in the assessment of the effects of orthodontic treatment. However, evaluating this process effectively remains a challenge. Improper anterior teeth torque angle can cause bone fenestrations and exposure of the root surface. METHODS A three-dimensional finite element model of the maxillary incisor torque controlled by a homemade four-curvature auxiliary arch was established. The four-curvature auxiliary arch placed on the maxillary incisors was divided into four different state groups, among which 2 groups had tooth extraction space retracted traction force set to 1.15 N. Initial displacements and pressure stresses of the periodontal tissue in the maxillary incisors and molars were calculated after torque forces (0.5, 1, 1.5, and 2 N) were applied to the teeth at different stable states. RESULTS The effect of using the four-curvature auxiliary arch on the incisors was significant but did not affect the position of the molars. Given the absence of tooth extraction space, when the four-curvature auxiliary arch was used in conjunction with absolute anchorage, the recommended force value was < 1.5 N. In the other 3 groups (i.e., molar ligation, molar retraction, and microimplant retraction groups), the recommended force value was < 1 N. The application of a four-curvature auxiliary arch did not influence the molar periodontal and displacement. CONCLUSION A four-curvature auxiliary arch may treat severely upright anterior teeth and correct cortical fenestrations of the bone and root surface exposure.
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Affiliation(s)
- Ping-Zhu Yang
- Department of Stomatology, Daping Hospital, Third Military Medical University (Army Medical University), Chongqing, 400042, China
| | - Li-Yun Bai
- Department of Stomatology, Daping Hospital, Third Military Medical University (Army Medical University), Chongqing, 400042, China
| | - He-Xuan Zhang
- Department of Stomatology, Daping Hospital, Third Military Medical University (Army Medical University), Chongqing, 400042, China
| | - Wen-Jun Zhao
- Department of Stomatology, Daping Hospital, Third Military Medical University (Army Medical University), Chongqing, 400042, China.,State Key Laboratory of Trauma, Burns and Combined Injury, Wound Trauma Medical Center, Daping Hospital, Third Military Medical University (Army Medical University), Chongqing, 400042, China
| | - Yu Liu
- ChuangNeng Technology (ChongQing) Co. LTD, Chongqing, 400042, China
| | - Xiu-Jie Wen
- Department of Stomatology, Daping Hospital, Third Military Medical University (Army Medical University), Chongqing, 400042, China.
| | - Rui Liu
- Department of Orthodontics, School of Dentistry, Southwest Medical University, Luzhou, 646000, China.
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Zheng L, Wang C, Hu M, Apicella A, Wang L, Zhang M, Fan Y. An innovative additively manufactured implant for mandibular injuries: Design and preparation processes based on simulation model. Front Bioeng Biotechnol 2022; 10:1065971. [PMID: 36507282 PMCID: PMC9729797 DOI: 10.3389/fbioe.2022.1065971] [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: 10/10/2022] [Accepted: 11/15/2022] [Indexed: 11/25/2022] Open
Abstract
Objective: For mandibular injury, how to utilize 3D implants with novel structures to promote the reconstruction of large mandibular bone defect is the major focus of clinical and basic research. This study proposed a novel 3D titanium lattice-like implant for mandibular injuries based on simulation model, which is designed and optimized by a biomechanical/mechanobiological approach, and the working framework for optimal design and preparation processes of the implant has been validated to tailored to specific patient biomechanical, physiological and clinical requirements. Methods: This objective has been achieved by matching and assembling different morphologies of a lattice-like implant mimicking cancellous and cortical bone morphologies and properties, namely, an internal spongy trabecular-like structure that can be filled with bone graft materials and an external grid-like structure that can ensure the mechanical bearing capacity. Finite element analysis has been applied to evaluate the stress/strain distribution of the implant and bone graft materials under physiological loading conditions to determine whether and where the implant needs to be optimized. A topological optimization approach was employed to improve biomechanical and mechanobiological properties by adjusting the overall/local structural design of the implant. Results: The computational results demonstrated that, on average, values of the maximum von-Mises stress in the implant model nodes could be decreased by 43.14% and that the percentage of optimal physiological strains in the bone graft materials can be increased from 35.79 to 93.36% since early regeneration stages. Metal additive manufacturing technology was adopted to prepare the 3D lattice-like implant to verify its feasibility for fabrication. Following the working framework proposed in this study, the well-designed customized implants have both excellent biomechanical and mechanobiological properties, avoiding mechanical failure and providing sufficient biomechanical stimuli to promote new bone regeneration. Conclusion: This study is expected to provide a scientific and feasible clinical strategy for repairing large injuries of mandibular bone defects by offering new insights into design criteria for regenerative implants.
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Affiliation(s)
- Lingling Zheng
- Key Laboratory of Biomechanics and Mechanobiology, Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, School of Engineering Medicine, Beihang University, Beijing, China
| | - Chao Wang
- Key Laboratory of Biomechanics and Mechanobiology, Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, School of Engineering Medicine, Beihang University, Beijing, China,*Correspondence: Chao Wang, ; Yubo Fan,
| | - Min Hu
- The First Medical Center of PLA General Hospital, Department of Stomatology, Beijing, China
| | - Antonio Apicella
- Polytechnique School of Engineering and Base Science, University of Campania, Aversa, CE, Italy
| | - Lizhen Wang
- Key Laboratory of Biomechanics and Mechanobiology, Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, School of Engineering Medicine, Beihang University, Beijing, China
| | - Ming Zhang
- Department of Biomedical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China
| | - Yubo Fan
- Key Laboratory of Biomechanics and Mechanobiology, Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, School of Engineering Medicine, Beihang University, Beijing, China,*Correspondence: Chao Wang, ; Yubo Fan,
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Liu R, Su Y, Yang W, Wang G, Du R, Zhong Y. Evaluation of Porous Titanium Structures and Lightweight for Mandibular Prosthesis. J Med Biol Eng 2022. [DOI: 10.1007/s40846-022-00760-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Gholamalizadeh T, Moshfeghifar F, Ferguson Z, Schneider T, Panozzo D, Darkner S, Makaremi M, Chan F, Søndergaard PL, Erleben K. Open-Full-Jaw: An open-access dataset and pipeline for finite element models of human jaw. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2022; 224:107009. [PMID: 35872385 DOI: 10.1016/j.cmpb.2022.107009] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 07/02/2022] [Accepted: 07/05/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND State-of-the-art finite element studies on human jaws are mostly limited to the geometry of a single patient. In general, developing accurate patient-specific computational models of the human jaw acquired from cone-beam computed tomography (CBCT) scans is labor-intensive and non-trivial, which involves time-consuming human-in-the-loop procedures, such as segmentation, geometry reconstruction, and re-meshing tasks. Therefore, with the current practice, researchers need to spend considerable time and effort to produce finite element models (FEMs) to get to the point where they can use the models to answer clinically-interesting questions. Besides, any manual task involved in the process makes it difficult for the researchers to reproduce identical models generated in the literature. Hence, a quantitative comparison is not attainable due to the lack of surface/volumetric meshes and FEMs. METHODS We share an open-access repository composed of 17 patient-specific computational models of human jaws and the utilized pipeline for generating them for reproducibility of our work. The used pipeline minimizes the required time for processing and any potential biases in the model generation process caused by human intervention. It gets the segmented geometries with irregular and dense surface meshes and provides reduced, adaptive, watertight, and conformal surface/volumetric meshes, which can directly be used in finite element (FE) analysis. RESULTS We have quantified the variability of our 17 models and assessed the accuracy of the developed models from three different aspects; (1) the maximum deviations from the input meshes using the Hausdorff distance as an error measurement, (2) the quality of the developed volumetric meshes, and (3) the stability of the FE models under two different scenarios of tipping and biting. CONCLUSIONS The obtained results indicate that the developed computational models are precise, and they consist of quality meshes suitable for various FE scenarios. We believe the provided dataset of models including a high geometrical variation obtained from 17 different models will pave the way for population studies focusing on the biomechanical behavior of human jaws.
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Affiliation(s)
- Torkan Gholamalizadeh
- Department of Computer Science, University of Copenhagen, Copenhagen 2100, Denmark; 3Shape A/S, Copenhagen 1060, Denmark.
| | - Faezeh Moshfeghifar
- Department of Computer Science, University of Copenhagen, Copenhagen 2100, Denmark
| | - Zachary Ferguson
- Courant Institute of Mathematical Sciences, New York University, 60 5th Ave, New York NY 10011, USA
| | - Teseo Schneider
- Department of Computer Science, University of Victoria, Victoria BC V8P 5C2, Canada
| | - Daniele Panozzo
- Courant Institute of Mathematical Sciences, New York University, 60 5th Ave, New York NY 10011, USA
| | - Sune Darkner
- Department of Computer Science, University of Copenhagen, Copenhagen 2100, Denmark
| | - Masrour Makaremi
- Dentofacial Orthopedics Department, University of Bordeaux, Bordeaux, France; Orthodontie clinic, 2 Rue des 2 Conils, Bergerac 24100, France
| | - François Chan
- Orthodontie clinic, 2 Rue des 2 Conils, Bergerac 24100, France
| | | | - Kenny Erleben
- Department of Computer Science, University of Copenhagen, Copenhagen 2100, Denmark
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Liu R, Su Y, Yang W, Wu K, Du R, Zhong Y. A Novel Design Method of Gradient Porous Structure for Stabilized and Lightweight Mandibular Prosthesis. Bioengineering (Basel) 2022; 9:bioengineering9090424. [PMID: 36134969 PMCID: PMC9495853 DOI: 10.3390/bioengineering9090424] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 08/18/2022] [Accepted: 08/18/2022] [Indexed: 11/30/2022] Open
Abstract
Compared to conventional prostheses with homogenous structures, a stress-optimized functionally gradient prosthesis will better adapt to the host bone due to its mechanical and biological advantages. Therefore, this study aimed to investigate the damage resistance of four regular lattice scaffolds and proposed a new gradient algorithm for stabilized and lightweight mandibular prostheses. Scaffolds with four configurations (regular hexahedron, regular octahedron, rhombic dodecahedron, and body-centered cubic) having different porosities underwent finite element analysis to select an optimal unit cell. Meanwhile, a homogenization algorithm was used to control the maximum stress and increase the porosity of the scaffold by adjusting the strut diameters, thereby avoiding fatigue failure and material wastage. Additionally, the effectiveness of the algorithm was verified by compression tests. The results showed that the load transmission capacity of the scaffold was strongly correlated with both configuration and porosity. Scaffolds with regular hexahedron unit cells can withstand stronger loads at the same porosity. The optimized gradient scaffold showed higher porosity and lower maximum stress than the target stress value, and the compression tests also confirmed the simulation results. A mandibular prosthesis was established using a regular hexahedron unit cell, and the strut diameters were gradually changed according to the proposed algorithm and the simulation results. Compared with the initial homogeneous prosthesis, the optimized gradient prosthesis reduced the maximum stress by 24.48% and increased the porosity by 6.82%, providing a better solution for mandibular reconstruction.
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Affiliation(s)
- Renshun Liu
- Shien-Ming Wu School of Intelligent Engineering, South China University of Technology, Guangzhou 511400, China
| | - Yuxiong Su
- Oral and Maxillofacial Surgery, Prince Philip Dental Hospital, The University of Hong Kong, Hong Kong SAR 999077, China
| | - Weifa Yang
- Oral and Maxillofacial Surgery, Prince Philip Dental Hospital, The University of Hong Kong, Hong Kong SAR 999077, China
| | - Kai Wu
- Shien-Ming Wu School of Intelligent Engineering, South China University of Technology, Guangzhou 511400, China
| | - Ruxu Du
- Guangzhou Janus Biotechnology Co., Ltd., Guangzhou 511400, China
| | - Yong Zhong
- Shien-Ming Wu School of Intelligent Engineering, South China University of Technology, Guangzhou 511400, China
- Correspondence: ; Tel.: +86-20-8118-2115
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Van den Broeck M, De Bels L, Duchateau L, Cornillie P. Time and sequence of emergence of the deciduous dentition in dogs and its applicability for age estimation. Anat Histol Embryol 2022; 51:640-657. [DOI: 10.1111/ahe.12838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 07/08/2022] [Indexed: 11/28/2022]
Affiliation(s)
- Martine Van den Broeck
- Department of Morphology, Imaging, Orthopedics, Rehabilitation and Nutrition, Faculty of Veterinary Medicine Ghent University Ghent Belgium
| | - Lobke De Bels
- Department of Morphology, Imaging, Orthopedics, Rehabilitation and Nutrition, Faculty of Veterinary Medicine Ghent University Ghent Belgium
| | - Luc Duchateau
- Biometrics Research Center, Faculty of Veterinary Medicine Ghent University Ghent Belgium
| | - Pieter Cornillie
- Department of Morphology, Imaging, Orthopedics, Rehabilitation and Nutrition, Faculty of Veterinary Medicine Ghent University Ghent Belgium
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Novel Design and Optimization of Porous Titanium Structure for Mandibular Reconstruction. Appl Bionics Biomech 2022; 2022:8686670. [PMID: 35782881 PMCID: PMC9249542 DOI: 10.1155/2022/8686670] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 05/13/2022] [Accepted: 05/30/2022] [Indexed: 12/25/2022] Open
Abstract
A porous material is considered to be a potential material that can be used to repair bone defects. However, the methods of designing of a highly porous structure within the allowable stress range remain to be researched. Therefore, this study was aimed at presenting a method for generating a three-dimensional tetrahedral porous structure characterized by low peak stress and high porosity for the reconstruction of mandibular defects. Firstly, the initial tetrahedral porous structure was fabricated with the strut diameters set to 0.4 mm and a mean cell size of 2.4 mm in the design model space. Following this, the simulation analysis was carried out. Further, a homogenization algorithm was used for homogenizing the stress distribution, increasing porosity, and controlling peak stress of the porous structure by adjusting the strut diameters. The results showed that compared with the initial porous structure, the position of the large stress regions remained unchanged, and the peak stress fluctuated slightly in the mandible and fixation system with the optimized porous structure under two occlusions. The optimized porous structure had a higher porosity and more uniform stress distribution, and the maximum stress was lower than the target stress value. The design and optimization technique of the porous structure presented in this paper can be used to control peak stress, improve porosity, and fabricate a lightweight scaffold, which provides a potential solution for mandibular reconstruction.
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12
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Li Y, Hu Y, Chen H, Meng X, Chen D, Gu H, Chen Q, Mu Z, Li Z. A novel conceptual design of a biomimetic oral implant and its biomechanical effect on the repairment of a large mandibular defect. MEDICINE IN NOVEL TECHNOLOGY AND DEVICES 2022. [DOI: 10.1016/j.medntd.2022.100147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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13
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Li L, Gao H, Wang C, Ji P, Huang Y, Wang C. Assessment of Customized Alveolar Bone Augmentation Using Titanium Scaffolds vs Polyetheretherketone (PEEK) Scaffolds: A Comparative Study Based on 3D Printing Technology. ACS Biomater Sci Eng 2022; 8:2028-2039. [PMID: 35443132 DOI: 10.1021/acsbiomaterials.2c00060] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Customized alveolar bone augmentation provides sufficient and precisely regenerated bone tissue for subsequent dental implant placement. Although some clinical cases have confirmed the successful use of the patient-specific polyetheretherketone (PEEK) scaffolds, the biomechanical property and osteogenic performance of the patient-specific PEEK scaffolds remain unclear. The objectives of this study were (1) to evaluate the space maintenance capacity and osteogenic performance of the patient-specific PEEK scaffolds for customized alveolar bone augmentation and (2) to compare the biomechanical properties of three-dimensionally printed titanium scaffolds and PEEK scaffolds. Both titanium scaffolds and PEEK scaffolds were designed and manufactured via additive manufacturing technology combined with computer-aided design (CAD). In three-point bending tests, the bending strength of the PEEK scaffold was about 1/3 that of the titanium scaffold. Accordingly, the equivalent strain value of the internal bone graft beneath the PEEK scaffold was about 3 times that beneath the titanium scaffold in finite element analysis, but the maximum deformations of both scaffolds were less than 0.05 mm. Meanwhile, in in vivo experiments, it is demonstrated that both scaffolds have similar space maintenance capacity and bone ingrowth efficiency. In conclusion, patient-specific PEEK scaffolds showed significantly lower biomechanical strength but comparable space maintenance and osteogenic properties to the titanium counterpart. Compared with traditional guided bone regeneration (GBR) surgery, both patient-specific PEEK and titanium scaffolds can achieve excellent osteogenic space maintenance ability. This study provides a preliminary basis for the clinical translation of the nonmetallic barrier membrane in customized alveolar bone augmentation.
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Affiliation(s)
- Linzhi Li
- Stomatological Hospital of Chongqing Medical University, Chongqing 401147, China.,Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing 401147, China
| | - Hui Gao
- Stomatological Hospital of Chongqing Medical University, Chongqing 401147, China.,Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing 401147, China
| | - Chunjuan Wang
- Stomatological Hospital of Chongqing Medical University, Chongqing 401147, China.,Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing 401147, China
| | - Ping Ji
- Stomatological Hospital of Chongqing Medical University, Chongqing 401147, China.,Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing 401147, China
| | - Yuanding Huang
- Stomatological Hospital of Chongqing Medical University, Chongqing 401147, China.,Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing 401147, China
| | - Chao Wang
- Stomatological Hospital of Chongqing Medical University, Chongqing 401147, China.,Key Laboratory of Biomechanics and Mechanobiology, Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, China
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14
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Vasilyeva D, Philipone E, Perschbacher SE, Chan KC. Computed Tomographic Imaging Features of Maxillary and Mandibular Melanotic Neuroectodermal Tumors of Infancy: Report of 2 Cases and Systematic Review. Oral Surg Oral Med Oral Pathol Oral Radiol 2022; 134:470-483. [DOI: 10.1016/j.oooo.2022.04.053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 04/20/2022] [Accepted: 04/30/2022] [Indexed: 10/18/2022]
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15
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Ortún-Terrazas J, Fagan MJ, Cegoñino J, Illipronti-Filho E, Del Palomar AP. Biomechanical evaluation of the unilateral crossbite on the asymmetrical development of the craniofacial complex. A mechano-morphological approach. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2022; 217:106703. [PMID: 35217305 DOI: 10.1016/j.cmpb.2022.106703] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 01/27/2022] [Accepted: 02/14/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND AND OBJECTIVE The occlusion effect on the craniofacial development is a controversial topic that has attracted the interest of many researchers but that remains unclear, mainly due to the difficulties on measure its mechanical response experimentally. This mechano-morphological relationship of the craniofacial growth is often explained by the periosteal and capsular matrices of the functional matrix hypothesis (FMH); however, its outcomes have not been analytically demonstrated yet. This computational study aims, therefore, to analytically demonstrate the mechano-morphological relationship in the craniofacial development of children with unilateral crossbite (UXB) using the finite element (FE) method. METHODS The craniofacial complex asymmetry of ten children, five of whom exhibit UXB, was 3D-analysed and compared with the biomechanical response computed from a FE analysis of each patient's occlusion. Due to the complexity of the geometry and the multitude of contacts involved, the inherent limitations of the model were evaluated by comparing computed occlusal patterns with those recorded by an occlusal analysis on 3D printed copies. RESULTS Comparison's outcomes proved the reliability of our models with just a deviation error below 6% between both approaches. Out of validation process, computational results showed that the significant elongation of mandibular branch in the contralateral side could be related to the mandibular shift and increase of thickness on the crossed side, and particularly of the posterior region. These morphological changes could be associated with periodontal overpressure (>4.7 kPa) and mandibular over deformation (0.002 ε) in that side, in agreement with the periosteal matrix's principles. Furthermore, the maxilla's transversal narrowing and the elevation of the maxillary and zygomatic regions on the crossed side were statistically demonstrated and seem to be related with their respective micro displacements at occlusion, as accounted by their specific capsule matrices. Our results were consistent with those reported clinically and demonstrated analytically the mechano-morphological relationship of children's craniofacial development based on the FMH's functional matrices. CONCLUSIONS This study is a first step in the understanding of the occlusion's effect on the craniofacial development by computational methods. Our approach could help future engineers, researchers and clinicians to understand better the aetiology of some dental malocclusions and functional disorders improve the diagnosis or even predict the craniofacial development.
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Affiliation(s)
- Javier Ortún-Terrazas
- Group of Biomaterials, Aragon Institute of Engineering Research (I3A), University of Zaragoza, Zaragoza, Spain.
| | - Michael J Fagan
- Medical and Biological Engineering, School of Engineering and Computer Science, University of Hull, Hull, United Kingdom
| | - José Cegoñino
- Group of Biomaterials, Aragon Institute of Engineering Research (I3A), University of Zaragoza, Zaragoza, Spain
| | - Edson Illipronti-Filho
- School of Dentistry, Department of Stomatology, University of São Paulo, São Paulo, Brazil
| | - Amaya Pérez Del Palomar
- Group of Biomaterials, Aragon Institute of Engineering Research (I3A), University of Zaragoza, Zaragoza, Spain
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16
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Bai L, Zheng L, Ji P, Wan H, Zhou N, Liu R, Wang C. Additively Manufactured Lattice-like Subperiosteal Implants for Rehabilitation of the Severely Atrophic Ridge. ACS Biomater Sci Eng 2022; 8:912-920. [PMID: 34984904 DOI: 10.1021/acsbiomaterials.1c00962] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Subperiosteal implants represent an alternative implant approach for cases with severe bone atrophy. Although some successful clinical cases have been reported, the biomechanical stability of subperiosteal implants remains unclear, and more data are needed to confirm the feasibility of this approach. Therefore, this study investigated the biomechanical characteristics of subperiosteal implants based on histological observation, clinical cases, and finite element analysis. Finite element analysis indicated that subperiosteal implants with a lattice-like structure could better disperse the stress to the underlying bone surface. A novel customized subperiosteal implant was then digitally designed and fabricated using an additive manufacturing technology. Six beagle dogs received such customized subperiosteal implants. Histological and microcomputed tomography examination showed new bone growth into and around the implant. Patient-specific subperiosteal implants were placed into the edentulous mandibular bone, with immediate loading. The implant was functional, without pain or infection, over a 12 month observation period. Images taken 12 months post-operatively showed new bone formation and osseointegration of the device. This indicated that 3D-printed lattice-like subperiosteal implants have sufficient stability for the rehabilitation of severely atrophic ridges.
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Affiliation(s)
- Liyun Bai
- Department of Stomatology, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing 400042, China.,College of Stomatology, Chongqing Medical University, Chongqing 401147, China
| | - Lingling Zheng
- Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing 100191, China.,ChongQing GongGangZhiHui Additive Manufacturing Technology Research Institute, Chongqing 400060, China
| | - Ping Ji
- College of Stomatology, Chongqing Medical University, Chongqing 401147, China
| | - Haoyuan Wan
- Department of Stomatology, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing 400042, China
| | - Nazi Zhou
- Department of Stomatology, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing 400042, China.,College of Stomatology, Chongqing Medical University, Chongqing 401147, China
| | - Rui Liu
- Department of Stomatology, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing 400042, China
| | - Chao Wang
- College of Stomatology, Chongqing Medical University, Chongqing 401147, China.,Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing 100191, China.,Key Laboratory of Biomechanics and Mechanobiology, Ministry of Education, Beihang University, Beijing 100191, China
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17
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Li R, She W, Luo Y, Wang J, Peng Y, Ye Q. The optimal activation of plastic aligner for canine distal movement: a three-dimensional finite element analysis. Odontology 2021; 110:305-312. [PMID: 34626315 DOI: 10.1007/s10266-021-00663-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 09/29/2021] [Indexed: 10/20/2022]
Abstract
This study aimed to investigate the optimal activation of plastic aligner for the canine distal movement by combining the stress and strain of periodontal ligament. Computer-aided design models of the upper canine, periodontal ligament, alveolar bone, and plastic aligner were constructed. The stresses and strains of periodontal ligament were acquired by fitting plastic aligner on the canine, which will cause the canine distal-direction movement. The activation of plastic aligner was set into 12 groups, including 0.050, 0.100, 0.125, 0.150, 0.175, 0.200, 0.225, 0.250, 0.275, 0.300, 0.350, and 0.400 mm. Assuming the volume-averaged hydrostatic stress (VAHS) ranging from 4.7 to 16 kPa to be the optimal stress, and an average strain no less than 0.3 to be the optimal strain. The optimal activation of plastic aligner was acquired based on the optimal stress and average strain. As the activation increased, the stress and strain of periodontal ligament increased visibly. The degree of activation of plastic aligner was nonlinearly and positively related to VAHS and average strain. According to the fitted curves, the activation corresponding to the optimal stress was 0.07-0.24 mm and the activation was not less than 0.21 mm based on the optimal strain. The optimal activation of plastic aligner for the canine distal movement was 0.21-0.24 mm in this study. The degree of activation affects the force system of orthodontic tooth movement, and it should be taken into consideration to obtain healthy and efficient tooth movement. The activation with 0.21-0.24 mm seems optimal for orthodontic tooth movement in the plastic aligner system in this study.
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Affiliation(s)
- Ruohan Li
- Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| | - Wenting She
- Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| | - Yu Luo
- Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| | - Juan Wang
- Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| | - Youjian Peng
- Renmin Hospital of Wuhan University, Wuhan, Hubei, China.
| | - Qingsong Ye
- Renmin Hospital of Wuhan University, Wuhan, Hubei, China.
- Massachusetts General Hospital, Harvard School of Dental Medicine, Boston, MA, USA.
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18
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Bastos VC, Gomez RS, Gomes CC. Revisiting the human dental follicle: From tooth development to its association with unerupted or impacted teeth and pathological changes. Dev Dyn 2021; 251:408-423. [PMID: 34324745 DOI: 10.1002/dvdy.406] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 07/16/2021] [Accepted: 07/22/2021] [Indexed: 02/06/2023] Open
Abstract
Dental follicles are involved in odontogenesis, periodontogenesis, and tooth eruption. Dental follicles are unique structures, considering that their remnants can persist within the jawbones after odontogenesis throughout life if the tooth does not erupt. Pathological changes may occur in these tissues as individuals age. The changes range from benign to life threatening. Thus, the assessment of age-related changes in dental follicles associated with unerupted teeth is of paramount importance. In this review, we summarize the physiological roles and changes in dental follicles in odontogenesis, tooth eruption, and aging, in addition to the pathological changes associated with these structures. We encourage investigators to consider this peculiar tissue as a unique model and explore its potential to clarify its importance from the viewpoints of developmental biology, tissue physiology, and pathology.
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Affiliation(s)
- Victor Coutinho Bastos
- Department of Oral Surgery and Pathology, Faculty of Dentistry, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil.,Department of Pathology, Biological Sciences Institute, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Ricardo Santiago Gomez
- Department of Oral Surgery and Pathology, Faculty of Dentistry, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Carolina Cavaliéri Gomes
- Department of Pathology, Biological Sciences Institute, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil
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19
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Zhong J, Pierantoni M, Weinkamer R, Brumfeld V, Zheng K, Chen J, Swain MV, Weiner S, Li Q. Microstructural heterogeneity of the collagenous network in the loaded and unloaded periodontal ligament and its biomechanical implications. J Struct Biol 2021; 213:107772. [PMID: 34311076 DOI: 10.1016/j.jsb.2021.107772] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 07/02/2021] [Accepted: 07/19/2021] [Indexed: 01/17/2023]
Abstract
The periodontal ligament (PDL) is a highly heterogeneous fibrous connective tissue and plays a critical role in distributing occlusal forces and regulating tissue remodeling. Its mechanical properties are largely determined by the extracellular matrix, comprising a collagenous fiber network interacting with the capillary system as well as interstitial fluid containing proteoglycans. While the phase-contrast micro-CT technique has portrayed the 3D microscopic heterogeneity of PDL, the topological parameters of its network, which is crucial to understanding the multiscale constitutive behavior of this tissue, has not been characterized quantitatively. This study aimed to provide new understanding of such microscopic heterogeneity of the PDL with quantifications at both tissue and collagen network levels in a spatial manner, by combining phase-contrast micro-CT imaging and a purpose-built image processing algorithm for fiber analysis. Both variations within a PDL and among the PDL with different shapes, i.e. round-shaped and kidney-shaped PDLs, are described in terms of tissue thickness, fiber distribution, local fiber densities, and fiber orientation (namely azimuthal and elevation angles). Furthermore, the tissue and collagen fiber network responses to mechanical loading were evaluated in a similar manner. A 3D helical alignment pattern was observed in the fiber network, which appears to regulate and adapt a screw-like tooth motion under occlusion. The microstructural heterogeneity quantified here allows development of sample-specific constitutive models to characterize the PDL's functional and pathological loading responses, thereby providing a new multiscale framework for advancing our knowledge of this complex limited mobility soft-hard tissue interface.
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Affiliation(s)
- Jingxiao Zhong
- School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, Sydney, Australia
| | - Maria Pierantoni
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel; Department of Biomedical Engineering, Lund University, Lund, Sweden
| | - Richard Weinkamer
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany
| | - Vlad Brumfeld
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel
| | - Keke Zheng
- School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, Sydney, Australia; College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK
| | - Junning Chen
- College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK
| | - Michael V Swain
- School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, Sydney, Australia
| | - Steve Weiner
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Qing Li
- School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, Sydney, Australia.
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20
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Bastos VC, Vitório JG, Martins-Chaves RR, Leite-Lima F, Lebron YAR, Moreira VR, Duarte-Andrade FF, Pereira TDSF, Santos LVDS, Lange LC, de Macedo AN, Canuto GAB, Gomes CC, Gomez RS. Age-Related Metabolic Pathways Changes in Dental Follicles: A Pilot Study. FRONTIERS IN ORAL HEALTH 2021; 2:677731. [PMID: 35048024 PMCID: PMC8757705 DOI: 10.3389/froh.2021.677731] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 05/12/2021] [Indexed: 01/10/2023] Open
Abstract
Aging is not a matter of choice; it is our fate. The “time-dependent functional decline that affects most living organisms” is coupled with several alterations in cellular processes, such as cell senescence, epigenetic alterations, genomic instability, stem cell exhaustion, among others. Age-related morphological changes in dental follicles have been investigated for decades, mainly motivated by the fact that cysts and tumors may arise in association with unerupted and/or impacted teeth. The more we understand the physiology of dental follicles, the more we are able to contextualize biological events that can be associated with the occurrence of odontogenic lesions, whose incidence increases with age. Thus, our objective was to assess age-related changes in metabolic pathways of dental follicles associated with unerupted/impacted mandibular third molars from young and adult individuals. For this purpose, a convenience sample of formalin-fixed paraffin-embedded (FFPE) dental follicles from young (<16 y.o., n = 13) and adult (>26 y.o., n = 7) individuals was selected. Samples were analyzed by high-performance liquid chromatography-mass spectrometry (HPLC-MS)-based untargeted metabolomics. Multivariate and univariate analyses were conducted, and the prediction of altered pathways was performed by mummichog and Gene Set Enrichment Analysis (GSEA) approaches. Dental follicles from young and older individuals showed differences in pathways related to C21-steroid hormone biosynthesis, bile acid biosynthesis, galactose metabolism, androgen and estrogen biosynthesis, starch and sucrose metabolism, and lipoate metabolism. We conclude that metabolic pathways differences related to aging were observed between dental follicles from young and adult individuals. Our findings support that similar to other human tissues, dental follicles associated with unerupted tooth show alterations at a metabolic level with aging, which can pave the way for further studies on oral pathology, oral biology, and physiology.
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Affiliation(s)
- Victor Coutinho Bastos
- Department of Oral Surgery and Pathology, School of Dentistry, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
- Department of Pathology, Biological Sciences Institute, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Jéssica Gardone Vitório
- Department of Oral Surgery and Pathology, School of Dentistry, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Roberta Rayra Martins-Chaves
- Department of Oral Surgery and Pathology, School of Dentistry, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Flávia Leite-Lima
- Department of Oral Surgery and Pathology, School of Dentistry, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Yuri Abner Rocha Lebron
- Department of Sanitary and Environmental Engineering, School of Engineering, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Victor Rezende Moreira
- Department of Sanitary and Environmental Engineering, School of Engineering, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Filipe Fideles Duarte-Andrade
- Department of Oral Surgery and Pathology, School of Dentistry, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | | | - Lucilaine Valéria de Souza Santos
- Department of Sanitary and Environmental Engineering, School of Engineering, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Liséte Celina Lange
- Department of Sanitary and Environmental Engineering, School of Engineering, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Adriana Nori de Macedo
- Department of Chemistry, Exact Sciences Institute, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | | | - Carolina Cavaliéri Gomes
- Department of Pathology, Biological Sciences Institute, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Ricardo Santiago Gomez
- Department of Oral Surgery and Pathology, School of Dentistry, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
- *Correspondence: Ricardo Santiago Gomez
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21
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Kuang Y, Wang C, Hu B, Feng G, Wang C, Song J. Biomechanical analysis of reinstating buccally flared maxillary 2nd molars using 3D printing anchorage supports: a 3D finite element study. Comput Methods Biomech Biomed Engin 2021; 24:1085-1096. [PMID: 33393828 DOI: 10.1080/10255842.2020.1867850] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The buccally flared maxillary 2nd molar has certain consequences on oral function and health. However, existing methods have some degree of disadvantages, such as invasion, complexity and side effects. The objectives of this study were to design anchorage systems to correct buccally flared maxillary 2nd molars and analyze their biomechanical effects by 3-dimensional (3D) finite element analysis. Finite element (FE) models of the 3D tanspalatal arches (TPAs) and 3D splints with different thicknesses and force points were constructed. The stress distribution on teeth, the hydrostatic pressure on periodontal ligaments and the initial displacement of teeth were analyzed. A total of 18 FE models were constructed and analyzed. The stress concentrated on a single anchorage tooth, and the hydrostatic pressure and initial displacement of the anchorage tooth were greater than those of the malposed 2nd molar in the 3D splint anchorage system. The stress spread on all anchorage teeth and the hydrostatic pressure and initial displacement of the anchorage tooth were less than those of the malposed 2nd molar in the 3D TPA anchorage system. Theoretically, the 3D TPA was better than the 3D splint as an anchorage to correct the buccally flared 2nd molar. A combination of 0.8 mm of thickness and mesial force point provided the optimal conditions for the 3D TPA. Further clinical studies should be conducted to verify the effects of 3D appliances.
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Affiliation(s)
- Yunchun Kuang
- College of Stomatology, Chongqing Medical University, Chongqing, China
| | - Chunjuan Wang
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China
| | - Bo Hu
- College of Stomatology, Chongqing Medical University, Chongqing, China
| | - Ge Feng
- Department of Orthodontics, College of Stomatology, Chongqing Medical University, Chongqing, China
| | - Chao Wang
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China
| | - Jinlin Song
- College of Stomatology, Chongqing Medical University, Chongqing, China.,Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
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22
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Li ZZ, Wang HT, Lee GY, Yang Y, Zou YP, Wang B, Gong CJ, Cai Y, Ren JG, Zhao JH. Bleomycin: A novel osteogenesis inhibitor of dental follicle cells via a TGF-β1/SMAD7/RUNX2 pathway. Br J Pharmacol 2020; 178:312-327. [PMID: 33068010 DOI: 10.1111/bph.15281] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 08/16/2020] [Accepted: 10/07/2020] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND AND PURPOSE Tooth eruption is a complicated process regulated by the dental follicles (DF). Our recent study discovered that tooth eruption was inhibited upon injection of bleomycin into DF. However, the mechanisms were unknown. EXPERIMENTAL APPROACH Human dental follicle cells (hDFCs) were treated by bleomycin or exogenous TGF-β1 or transfected by plasmids loading SMAD7 or shRNA targeting SMAD7, followed by osteogenesis induction assay and signalling analysis. Human fresh DF tissues and Wistar rats were used to further confirm bleomycin function. KEY RESULTS Bleomycin decreased expression of RUNX2 and osteogenic genes in hDFCs, reducing osteogenic capacity. TGF-β1 expression was up-regulated in bleomycin-treated hDFCs. The effects of exogenous TGF-β1 were similar to those of bleomycin in hDFCs. Additionally, compared to SMAD2/3, SMAD7 expression increased more in bleomycin- or TGF-β1-treated hDFCs. Overexpression of SMAD7 likewise significantly decreased RUNX2 expression and osteogenic capacity of hDFCs. Knockdown of SMAD7 markedly attenuated the inhibitory effects of bleomycin and TGF-β1 on osteogenic capacity and RUNX2 expression of hDFCs. Most importantly, changes in TGF-β1, SMAD7, and RUNX2 expressions were similar in the DF of rats and humans treated with bleomycin. CONCLUSION AND IMPLICATIONS SMAD7 was a negative regulator of osteogenic differentiation in DFCs through suppressing RUNX2 expression. Bleomycin or TGF-β1 inhibited osteogenic differentiation of DFCs via a TGF-β1/SMAD7/RUNX2 pathway. Our findings might be beneficial for enhancing the osteogenic activity of DFCs or inhibiting the eruption of undesirable teeth.
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Affiliation(s)
- Zhi-Zheng Li
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Hai-Tao Wang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Grace Y Lee
- Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Ying Yang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Yan-Ping Zou
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Bing Wang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Chu-Jie Gong
- Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Yu Cai
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China.,Department of Oral and Maxillofacial Surgery, School & Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Jian-Gang Ren
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China.,Department of Oral and Maxillofacial Surgery, School & Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Ji-Hong Zhao
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China.,Department of Oral and Maxillofacial Surgery, School & Hospital of Stomatology, Wuhan University, Wuhan, China
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Iavarone F, Olianas A, Patini R, Gallenzi P, Di Tonno L, Desiderio C, Cabras T, Manconi B, Vincenzoni F, Cordaro M, Messana I, Urbani A, Castagnola M. Top down proteomic analysis of gingival crevicular fluid in deciduous, exfoliating and permanent teeth in children. J Proteomics 2020; 226:103890. [PMID: 32629195 DOI: 10.1016/j.jprot.2020.103890] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 02/18/2020] [Accepted: 06/26/2020] [Indexed: 01/22/2023]
Abstract
Gingival Crevicular Fluid (GCF), a plasma-derived exudate present in the gingival crevice was collected from deciduous, exfoliating and permanent teeth from 20 children (60 samples) with the aim to characterize and quantify by a mass spectrometry based top-down proteomic approach, the peptide/proteins in the fluid and verify possible variations occurring during the exfoliating process. The results obtained confirmed the presence in GCF of α-Defensins 1-4, Thymosin β4 and Thymosin β10, as described in previous works and revealed the presence of other interesting peptides never described before in GCF such as specific fragments of α-1-antitrypsin, α-1-antichymotrypsin; fragments of Thymosin β4 and Thymosin β10; Fibrinopeptide A and its fragments and Fibrinopeptide B; S100A8 and S100A9, LVV Hemorphin-7 (hemoglobin chain β fragment), as well as some other peptides deriving from α and β subunits of hemoglobin. Statistical analysis evidenced different levels in 5 proteins/peptides in the three groups. Our study demonstrate that an in-depth analysis of a biological fluid like GCF, present in small amount, can provide useful information for the understanding of different biological processes like teeth eruption. Data are available via ProteomeXchange with identifier PXD016010 and PXD016049. SIGNIFICANCE: GCF due to his site-specific nature has a great potential in containing factors that are specific for action at a given site and might have diagnostic value to detect qualitative and quantitative variations of proteins/peptides composition linked to physiological or pathological conditions.
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Affiliation(s)
- Federica Iavarone
- Dipartimento di Scienze biotecnologiche di base, Cliniche intensivologiche e perioperatorie Università Cattolica del Sacro Cuore, Roma, Italy; Fondazione Policlinico Universitario A. Gemelli IRCCS, Roma, Italy.
| | - Alessandra Olianas
- Dipartimento di Scienze della Vita e dell'Ambiente, Università di Cagliari, Cagliari, Italy
| | - Romeo Patini
- Dipartimento Testa-collo e organi di senso, Università Cattolica del Sacro Cuore, Roma, Italy
| | - Patrizia Gallenzi
- Dipartimento Testa-collo e organi di senso, Università Cattolica del Sacro Cuore, Roma, Italy
| | - Laura Di Tonno
- Dipartimento Testa-collo e organi di senso, Università Cattolica del Sacro Cuore, Roma, Italy
| | - Claudia Desiderio
- Istituto di Scienze e Tecnologie Chimiche "Giulio Natta", Consiglio Nazionale delle Ricerche, Roma, Italy
| | - Tiziana Cabras
- Dipartimento di Scienze della Vita e dell'Ambiente, Università di Cagliari, Cagliari, Italy
| | - Barbara Manconi
- Dipartimento di Scienze della Vita e dell'Ambiente, Università di Cagliari, Cagliari, Italy
| | - Federica Vincenzoni
- Dipartimento di Scienze biotecnologiche di base, Cliniche intensivologiche e perioperatorie Università Cattolica del Sacro Cuore, Roma, Italy; Fondazione Policlinico Universitario A. Gemelli IRCCS, Roma, Italy
| | - Massimo Cordaro
- Dipartimento Testa-collo e organi di senso, Università Cattolica del Sacro Cuore, Roma, Italy
| | - Irene Messana
- Istituto di Scienze e Tecnologie Chimiche "Giulio Natta", Consiglio Nazionale delle Ricerche, Roma, Italy
| | - Andrea Urbani
- Dipartimento di Scienze biotecnologiche di base, Cliniche intensivologiche e perioperatorie Università Cattolica del Sacro Cuore, Roma, Italy; Fondazione Policlinico Universitario A. Gemelli IRCCS, Roma, Italy
| | - Massimo Castagnola
- Laboratorio di Proteomica e Metabonomica-IRCCS Fondazione Santa Lucia, Roma, Italy
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Biomechanical Analysis of Various Reconstructive Methods for the Mandibular Body and Ramus Defect Using a Free Vascularized Fibula Flap. BIOMED RESEARCH INTERNATIONAL 2020; 2020:8797493. [PMID: 32258153 PMCID: PMC7094202 DOI: 10.1155/2020/8797493] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Revised: 12/11/2019] [Accepted: 01/02/2020] [Indexed: 11/17/2022]
Abstract
Several different methods exist for reconstructing the mandibular body and ramus defect with the use of a free vascularized fibula flap, but none have adequately addressed the long-term mechanical stability and osseointegration. The aim of this study is to compare the biomechanics of different surgical methods and to investigate the best approach for reconstructing the mandibular body and ramus defect. Five finite element models based on different reconstructive methods were simulated. Stress, strain, and displacement of connective bone sections were calculated for five models and compared. The models were printed using a 3D printer, and stiffness was measured using an electromechanical universal testing machine. The postoperative follow-up cone beam computed tomography (CBCT) was taken at different time points to analyze bone mineral density of connective bone sections. The results showed that the “double up” (DU) model was the most efficient for reconstructing a mandibular body and ramus defect by comparing the mechanical distribution of three sections under vertical and inclined loading conditions of 100 N. The stiffness detection showed that stiffness in the DU and “double down” (DD) models was higher compared with the “single up” (SU), “single down” (SD), and “distraction osteogenesis” (DO) models. We used the DU model for the surgery, and postoperative follow-up CBCT showed that bone mineral density of each fibular connective section increased gradually with time, plateauing at 12 weeks. We conclude that a free vascularized fibula flap of the DU type was the best approach for the reconstruction of the mandibular body and ramus defect. Preoperative finite element analysis and stiffness testing were shown to be very useful for maxillofacial reconstruction.
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Jesus LMRD, Basso CSD, Castiglioni L, Monserrat AL, Arroyo MADS. Speech-language-hearing follow-up of preterm children: feeding and neuropsychomotor performance. REVISTA CEFAC 2020. [DOI: 10.1590/1982-0216/202022415119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
ABSTRACT Purpose: to establish the breastfeeding rates at hospital discharge and post-discharge, analyze neuropsychomotor development, and indicate the rehabilitation referral rate of preterm children attended by speech-language-hearing therapists. Methods: a total of 39 preterm children participated in the study. They were born at a Children and Maternity Hospital between August 2016 and January 2017 and were followed up by the speech-language-hearing therapists during the hospital stay. The Spearman’s statistical test was used. The p-value was set at 0.005; the correlation value was: r = 0.10 to 0.39, weak correlation; r = 0.40 to 0.69, moderate correlation; and r = 0.70 to 1, strong correlation. Results: of the 39 participants, 17 (43.6%) were discharged on exclusive breastfeeding; 4 (10.25%), on mixed milk feeding (breast and cup); 14 (35.9%), on mixed milk feeding (breast and baby bottle); and 4 (10.25%), on artificial milk feeding - baby bottle. After introducing solid food, 12.8% remained on breastfeeding, 38.4% on mixed milk feeding, and 48.7% in artificial milk feeding. Complementary feeding was introduced at 5 months (adjusted age). Auditory, motor and language development occurred as expected in 90% of the children, considering the milestone’s adjusted age. Conclusion: at hospital discharge, most infants were on exclusive or mixed breastfeeding. After discharge, mixed breastfeeding lasted longer, and low neuropsychomotor development impairment rates and rehabilitation referral rates were observed.
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Mechanobiologically optimization of a 3D titanium-mesh implant for mandibular large defect: A simulated study. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2019; 104:109934. [DOI: 10.1016/j.msec.2019.109934] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 05/24/2019] [Accepted: 07/01/2019] [Indexed: 12/21/2022]
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The crown-root morphology of central incisors in different skeletal malocclusions assessed with cone-beam computed tomography. Prog Orthod 2019; 20:20. [PMID: 31111270 PMCID: PMC6527728 DOI: 10.1186/s40510-019-0272-2] [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: 10/16/2018] [Accepted: 04/02/2019] [Indexed: 02/05/2023] Open
Abstract
Background To determine the discrepancy of crown-root morphology of central incisors among different types of skeletal malocclusion using cone-beam computed tomography (CBCT) and to provide guidance for proper torque expression of anterior teeth and prevention of alveolar fenestration and dehiscence. Methods In this retrospective study, a total of 108 CBCT images were obtained (ranging from 18.0 to 30.0 years, mean age 25.8 years). Patients were grouped according to routine sagittal and vertical skeletal malocclusion classification criteria. The patients in sagittal groups were all average vertical patterns, with Class I comprised 24 patients—14 females and 10 males; Class II comprised 20 patients—13 females and 7 males; and Class III comprised 22 subjects—13 females and 9 males. The patients in vertical groups were all skeletal Class I malocclusions, with low angle comprised 21 patients—12 females and 9 males; average angle comprised 24 patients; and high angle comprised 21 patients—11 females and 10 males. All the CBCT data were imported into Invivo 5.4 software to obtain a middle labio-lingual section of right central incisors. Auto CAD 2007 software was applied to measure the crown-root angulation (Collum angle), and the angle formed by a tangent to the central of the labial surface of the crown and the long axis of the crown (labial surface angle). One-way analysis of variance (ANOVA) and Scheffe’s test were used for statistical comparisons at the P < 0.05 level, and the Pearson correlation analysis was applied to investigate the association between the two measurements. Results The values of Collum angle and labial surface angle in maxillary incisor of Class II and mandibular incisor of Class III were significantly greater than other types of sagittal skeletal malocclusions (P < 0.05); no significant difference was detected among vertical skeletal malocclusions. Notably, there was also a significant positive correlation between the two measurements. Conclusions The maxillary incisor in patients with sagittal skeletal Class II malocclusion and mandibular incisor with Class III malocclusion present remarkable crown-root angulation and correspondingly considerable labial surface curvature. Equivalent deviation during bracket bonding may cause greater torque expression error and increase the risk of alveolar fenestration and dehiscence.
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Chen J, He Y, Keilig L, Reimann S, Hasan I, Weinhold J, Radlanski R, Bourauel C. Numerical investigations of bone remodelling around the mouse mandibular molar primordia. Ann Anat 2019; 222:146-152. [DOI: 10.1016/j.aanat.2018.12.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 11/07/2018] [Accepted: 12/18/2018] [Indexed: 11/25/2022]
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Mechanical Characterization of 3D-Printed Individualized Ti-Mesh (Membrane) for Alveolar Bone Defects. JOURNAL OF HEALTHCARE ENGINEERING 2019; 2019:4231872. [PMID: 30838123 PMCID: PMC6374856 DOI: 10.1155/2019/4231872] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 12/13/2018] [Indexed: 11/17/2022]
Abstract
Individualized titanium mesh holds many advantages over conventional mesh. There are few reports in the literature about the effect of mesh pore size and mesh thickness on the mechanical properties of titanium mesh. This study is designed to develop an individualized titanium mesh using computer-assisted design and additive manufacturing technology. This study will also explore the effect of different thicknesses and pore sizes of titanium mesh on its mechanical properties through 3D FEA. According to this study, the mechanical properties of titanium mesh increased when the thickness decreased (0.5 mm to 0.3 mm). With an increase in mesh diameter (3 mm to 5 mm), the mechanical properties of mesh decreased. The diameter of titanium mesh has less influence on its mechanical properties than does the thickness of the mesh. Titanium mesh with a thickness of 0.4 mm is strong enough and causes less stimulation to mucosa; therefore, it is more suitable for clinical use. In addition, parameters of titanium mesh should be decided clinically according to bone defect size, defect location, and force situation.
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Liu D, Yan B, Lei F, Li J, Wang X, Rong Q, Zhou Y. Different sliding mechanics in space closure of lingual orthodontics: a translational study by three-dimensional finite element method. Am J Transl Res 2019; 11:120-130. [PMID: 30787973 PMCID: PMC6357325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 12/23/2018] [Indexed: 06/09/2023]
Abstract
Lingual orthodontics have become popular in modern society as they do not cause aesthetic impairment. From the translational medicine point of view, the use of biomechanical analysis to solve a clinical problem has rarely been reported. Here, we combined the clinical trial and 3-D finite element (FE) method to translate the clinical problem to the FE analysis and back to clinic. Twenty upper premolar extraction cases treated with customized lingual appliances were recruited in this study. Cephalometric films and cast records analysis showed that the "bowing effect", which is a major side effect in lingual orthodontics, occurred during the first treatment stage with single lingual cable retraction. In order to translate the problem to biomechanical research, we introduced the 3-D finite element (FE) model of a customized lingual orthodontic system. The 3-D FE model including the maxilla, periodontal ligament (PDL), and dentition was constructed from human computed tomography data. The tendency of tooth movements in three dimensions and stress distribution in the PDL were analyzed by different mechanical loading methods. 3-D FE analysis confirmed the "bowing effects" and unexpected tooth movements with application of single lingual retraction force. Interestingly, we found that applying forces on both buccal and lingual sides, called "double cable" mechanics, could prevent the "bowing effect". For the clinical trial, we applied the "double cable" force during space closure stage for 4 months, and confirmed "double cable" mechanics could correct and prevent the "bowing effect" clinically. Based on our results, both buccal and lingual forces should be used during space closure in lingual orthodontics to prevent and correct the "bowing effect". Moreover, the magnitude of buccal force should not be lower than the force on the lingual side.
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Affiliation(s)
- Dawei Liu
- Department of Orthodontics, Peking University School and Hospital of StomatologyBeijing, P. R. China
- National Engineering Laboratory for Digital and Material Technology of StomatologyBeijing, P. R. China
- Beijing Key Laboratory of Digital StomatologyBeijing, P. R. China
| | - Boxi Yan
- Department of Orthodontics, Peking University School and Hospital of StomatologyBeijing, P. R. China
- National Engineering Laboratory for Digital and Material Technology of StomatologyBeijing, P. R. China
- Beijing Key Laboratory of Digital StomatologyBeijing, P. R. China
| | - Feifei Lei
- Department of Orthodontics, Peking University School and Hospital of StomatologyBeijing, P. R. China
- National Engineering Laboratory for Digital and Material Technology of StomatologyBeijing, P. R. China
- Beijing Key Laboratory of Digital StomatologyBeijing, P. R. China
| | - Jing Li
- Department of Orthodontics, Peking University School and Hospital of StomatologyBeijing, P. R. China
- National Engineering Laboratory for Digital and Material Technology of StomatologyBeijing, P. R. China
- Beijing Key Laboratory of Digital StomatologyBeijing, P. R. China
| | - Xuedong Wang
- Department of Orthodontics, Peking University School and Hospital of StomatologyBeijing, P. R. China
- National Engineering Laboratory for Digital and Material Technology of StomatologyBeijing, P. R. China
- Beijing Key Laboratory of Digital StomatologyBeijing, P. R. China
| | - Qiguo Rong
- Department of Mechanics and Engineering Science, College of Engineering, Peking UniversityBeijing, P. R. China
| | - Yanheng Zhou
- Department of Orthodontics, Peking University School and Hospital of StomatologyBeijing, P. R. China
- National Engineering Laboratory for Digital and Material Technology of StomatologyBeijing, P. R. China
- Beijing Key Laboratory of Digital StomatologyBeijing, P. R. China
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Sarrafpour B, El-Bacha C, Li Q, Zoellner H. Roles of functional strain and capsule compression on mandibular cyst expansion and cortication. Arch Oral Biol 2018; 98:1-8. [PMID: 30419484 DOI: 10.1016/j.archoralbio.2018.10.035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 10/09/2018] [Accepted: 10/26/2018] [Indexed: 12/20/2022]
Abstract
OBJECTIVE Cyst expansion in bone involves bone resorption but is often accompanied by adjacent bone formation with cortication. The mechanisms for these two apparently opposite processes remain unclear. From a mechanobiological perspective, functional strain drives bone remodeling, which involves both bone apposition and resorption. In this study, we explore the role of functional strain in cyst growth. DESIGN Using a three-dimensional finite element analysis model of a simulated cyst at the of right first mandibular molar mesial apex, we examined three loading conditions, representing biting on the right molar, left molar and incisors, respectively. Comparison was made with an identical finite element model without the simulated cyst. RESULTS Under all loading conditions, finite element analysis revealed higher strain energy density within the bone lining the cyst compared with the non-cyst model, which is consistent with bone formation and cortication observed clinically. Further analysis demonstrated overall compression of the simulated cyst capsule under all loading conditions.We interpret compression of the capsule as indicating resorption of the adjacent bone surface. CONCLUSIONS We conclude that functional stress results in dominant compression of the soft tissue capsules of bony cysts, contributing to cyst expansion. Also, functional strain becomes elevated in the bone immediately adjacent to the soft tissue cyst capsule, which may drive bone formation and cortication.
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Affiliation(s)
- Babak Sarrafpour
- The University of Sydney, Discipline of Oral Surgery, Medicine and Diagnostics, School of Dentistry, Faculty of Medicine and Health, Westmead Centre for Oral Health, Westmead Hospital, NSW 2145, Australia.
| | - Charbel El-Bacha
- The University of Sydney, Discipline of Oral Surgery, Medicine and Diagnostics, School of Dentistry, Faculty of Medicine and Health, Westmead Centre for Oral Health, Westmead Hospital, NSW 2145, Australia.
| | - Qing Li
- The University of Sydney, School of Aerospace, Mechanical and Mechatronic Engineering, Sydney, NSW 2006, Australia.
| | - Hans Zoellner
- The University of Sydney, Discipline of Oral Surgery, Medicine and Diagnostics, School of Dentistry, Faculty of Medicine and Health, Westmead Centre for Oral Health, Westmead Hospital, NSW 2145, Australia.
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Sarrafpour B, Boughton P, Farahani RM, Cox SC, Denyer G, Kelly E, Zoellner H. A method for investigating the cellular response to cyclic tension or compression in three-dimensional culture. J Mech Behav Biomed Mater 2018; 88:11-17. [PMID: 30118920 DOI: 10.1016/j.jmbbm.2018.08.006] [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: 01/19/2018] [Revised: 05/17/2018] [Accepted: 08/07/2018] [Indexed: 11/26/2022]
Abstract
We have an interest in the cellular response to mechanical stimuli, and here describe an in-vitro method to examine the response of cells cultured in a three-dimensional matrix to mechanical compressive and tensile stress. Synthetic aliphatic polyester scaffolds coated with 45S5 bioactive glass were seeded with human dental follicular cells (HDFC), and attached to well inserts and magnetic endplates in six well palates. Scaffolds were subjected to either cyclic 10% tensile deformation, or 8% compression, at 1 Hz and 2 Hz respectively for 6, 24 or 48 h, by uniaxial motion of magnetically-coupled endplates. It was possible to isolate high quality mRNA from cells in these scaffolds, as demonstrated by high RNA integrity numbers scores, and ability to perform meaningful cRNA microarray analysis, in which 669 and 727 genes were consistently upregulated, and 662 and 518 genes down regulated at all times studied under tensile and compressive loading conditions respectively. MetaCore analysis revealed the most regulated gene ontogenies under both loading conditions to be for: cytoskeletal remodelling; cell adhesion-chemokines and adhesion; cytoskeleton remodelling-TGF WNT and cytoskeletal remodelling pathways. We believe the method here described will be of value for analysis of the cellular response to cyclic loading.
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Affiliation(s)
- Babak Sarrafpour
- The University of Sydney, Faculty of Dentistry, Department of Oral Pathology and Oral Medicine, Cellular and Molecular Pathology Research Unit, Westmead Centre for Oral Health, Westmead Hospital, NSW 2145, Australia.
| | - Philip Boughton
- The University of Sydney, The Institute of Biomedical Engineering and Technology, Sydney, NSW 2006, Australia.
| | - Ramin M Farahani
- The University of Sydney, Faculty of Dentistry, Institute of Dental Research, Westmead Hospital, NSW 2145, Australia.
| | - Stephen C Cox
- The University of Sydney, Department of Oral Surgery, Westmead Centre for Oral Health, Westmead Hospital, Westmead, NSW, Australia.
| | - Gareth Denyer
- The University of Sydney, School of Molecular Bioscience, NSW 2006, Australia.
| | - Elizabeth Kelly
- The University of Sydney, Faculty of Dentistry, Department of Oral Pathology and Oral Medicine, Cellular and Molecular Pathology Research Unit, Westmead Centre for Oral Health, Westmead Hospital, NSW 2145, Australia.
| | - Hans Zoellner
- The University of Sydney, Faculty of Dentistry, Department of Oral Pathology and Oral Medicine, Cellular and Molecular Pathology Research Unit, Westmead Centre for Oral Health, Westmead Hospital, NSW 2145, Australia.
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Resorptive potential of impacted mandibular third molars: 3D simulation by finite element analysis. Clin Oral Investig 2018. [PMID: 29525922 DOI: 10.1007/s00784-018-2403-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
OBJECTIVES Previous studies have suggested a relationship between resorption in second molars and pressure from the eruptive force of the third molar. The aim of this study was to simulate functional forces in a mandible model by means of finite element analysis and then assess the biomechanical response produced by impacted third molars on the roots of the second molar. MATERIALS AND METHODS A cone beam computed tomography scan presenting an impacted mandibular third molar was segmented (Mimics V17 software). The modeling process was performed using the reverse engineering technique provided by the Rhinoceros 3D 5.0 software. The third molar position was changed in order to produce different inclinations of the impacted tooth. Bite forces were simulated to evaluate total deformation, the equivalent von Mises stress, minimum principal stress on hard tissue, and equivalent elastic strain on soft tissue. RESULTS Areas of high energy dissipation and compression stress were detected in the second molar root, independently of the inclination of the impacted third molar. In general, the horizontal position was the situation in which major stress and the amount of deformation occurred in the second and third molar regions. CONCLUSION Impacted third molars in close proximity with the adjacent tooth can generate areas of compression concentrated at the site of contact, which suggests an involvement of mechanical factors in the triggering of resorption lesions. CLINICAL RELEVANCE The results of these computational experiments contribute to the understanding of the triggering and progression of resorptive lesions in the adjacent second molar.
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Chen Y, Wang C, Huang Y, Feng T, Zou H, Fan Y. Biomechanical evaluation of the natural abutment teeth in combined tooth-implant-supported telescopic prostheses: a three-dimensional finite element analysis. Comput Methods Biomech Biomed Engin 2017; 20:967-979. [PMID: 28460543 DOI: 10.1080/10255842.2017.1319941] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Telescopic overdentures supported by the combination of natural teeth and implants have been thought a valuable treatment for the severely compromised partially edentulous patients. But the combination of teeth and implants involves highly complex biomechanical problems. This study is to evaluate biomechanical behaviors of the natural abutment teeth with the treatment of combined tooth-implant supported telescopic crown prostheses in mandible through 3D FEA. According to this study, the prosthetic option supported by a combination of teeth and implants and retained by double crowns could protect teeth and their periodontal support tissues acting as a rigid splint, and may be a valuable treatment option for partially edentulous patients with severely reduced remaining teeth in mandible.
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Affiliation(s)
- Yu Chen
- a College of Stomatology, Chongqing Medical University , Chongqing , China.,b Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education , Chongqing , China
| | - Chao Wang
- a College of Stomatology, Chongqing Medical University , Chongqing , China.,c Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences , Chongqing , China
| | - Yuanding Huang
- a College of Stomatology, Chongqing Medical University , Chongqing , China.,c Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences , Chongqing , China
| | - Tianming Feng
- a College of Stomatology, Chongqing Medical University , Chongqing , China
| | - Huawei Zou
- a College of Stomatology, Chongqing Medical University , Chongqing , China
| | - Yubo Fan
- a College of Stomatology, Chongqing Medical University , Chongqing , China.,d Laboratory for Biomechanics and Mechanobiology of Ministry of Education , School of Biological Science and Medical Engineering, Beihang University , Beijing , China
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Dorotheou D, Farsadaki V, Bochaton-Piallat ML, Giannopoulou C, Halazonetis TD, Kiliaridis S. Increased Cell Proliferation and Gene Expression of Genes Related to Bone Remodeling, Cell Adhesion and Collagen Metabolism in the Periodontal Ligament of Unopposed Molars in Growing Rats. Front Physiol 2017; 8:75. [PMID: 28239357 PMCID: PMC5301028 DOI: 10.3389/fphys.2017.00075] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 01/26/2017] [Indexed: 01/10/2023] Open
Abstract
Tooth eruption, the process by which teeth emerge from within the alveolar bone into the oral cavity, is poorly understood. The post-emergent phase of tooth eruption continues throughout life, in particular, if teeth are not opposed by antagonists. The aim of the present study was to better understand the molecular processes underlying post-emergent tooth eruption. Toward this goal, we removed the crowns of the maxillary molars on one side of the mouth of 14 young rats and examined gene expression patterns in the periodontal ligaments (PDLs) of the ipsilateral and contralateral mandibular molars, 3 and 15 days later. Nine untreated rats served as controls. Expression of six genes, Adamts18, Ostn, P4ha3, Panx3, Pth1r, and Tnmd, was upregulated in unopposed molars relative to molars with antagonists. These genes function in osteoblast differentiation and proliferation, cell adhesion and collagen metabolism. Proliferation of PDL cells also increased following loss of the antagonist teeth. Interestingly, mutations in PTH1R have been linked to defects in the post-emergent phase of tooth eruption in humans. We conclude that post-emergent eruption of unopposed teeth is associated with gene expression patterns conducive to alveolar bone formation and PDL remodeling.
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Affiliation(s)
- Domna Dorotheou
- Department of Orthodontics, University of Geneva Geneva, Switzerland
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Kang JM, Park JH, Bayome M, Oh M, Park CO, Kook YA, Mo SS. A three-dimensional finite element analysis of molar distalization with a palatal plate, pendulum, and headgear according to molar eruption stage. Korean J Orthod 2016; 46:290-300. [PMID: 27668192 PMCID: PMC5033768 DOI: 10.4041/kjod.2016.46.5.290] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 02/04/2016] [Accepted: 02/16/2016] [Indexed: 12/12/2022] Open
Abstract
Objective This study aimed to (1) evaluate the effects of maxillary second and third molar eruption status on the distalization of first molars with a modified palatal anchorage plate (MPAP), and (2) compare the results to the outcomes of the use of a pendulum and that of a headgear using three-dimensional finite element analysis. Methods Three eruption stages were established: an erupting second molar at the cervical one-third of the first molar root (Stage 1), a fully erupted second molar (Stage 2), and an erupting third molar at the cervical one-third of the second molar root (Stage 3). Retraction forces were applied via three anchorage appliance models: an MPAP with bracket and archwire, a bone-anchored pendulum appliance, and cervical-pull headgear. Results An MPAP showed greater root movement of the first molar than crown movement, and this was more noticeable in Stages 2 and 3. With the other devices, the first molar showed distal tipping. Transversely, the first molar had mesial-out rotation with headgear and mesial-in rotation with the other devices. Vertically, the first molar was intruded with an MPAP, and extruded with the other appliances. Conclusions The second molar eruption stage had an effect on molar distalization, but the third molar follicle had no effect. The application of an MPAP may be an effective treatment option for maxillary molar distalization.
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Affiliation(s)
- Ju-Man Kang
- Department of Dentistry, Graduate School, The Catholic University of Korea, Seoul, Korea
| | - Jae Hyun Park
- Postgraduate Orthodontic Program, Arizona School of Dentistry & Oral Health, A.T. Still University, Mesa, AZ, USA.; Graduate School of Dentistry, Kyung Hee University, Seoul, Korea
| | - Mohamed Bayome
- Department of Dentistry, Graduate School, The Catholic University of Korea, Seoul, Korea.; Department of Postgraduate Studies, the Universidad Autonóma del Paraguay, Asunción, Paraguay
| | - Moonbee Oh
- Department of Orthodontics, St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Chong Ook Park
- Private Practice, Seoul, Korea.; Department of Orthodontics, School of Dentistry, Seoul National University, Seoul, Korea
| | - Yoon-Ah Kook
- Department of Orthodontics, St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Sung-Seo Mo
- Department of Orthodontics, Graduate School of Clinical Dental Science, The Catholic University of Korea, Seoul, Korea
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Biomechanical investigation into the role of the periodontal ligament in optimising orthodontic force: a finite element case study. Arch Oral Biol 2016; 66:98-107. [DOI: 10.1016/j.archoralbio.2016.02.012] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 09/09/2015] [Accepted: 02/19/2016] [Indexed: 11/23/2022]
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Shiyan H, Nanquan R, Shuhao X, Xiaobing L. [Research progress on the cellular and molecular mechanisms of tooth eruption]. HUA XI KOU QIANG YI XUE ZA ZHI = HUAXI KOUQIANG YIXUE ZAZHI = WEST CHINA JOURNAL OF STOMATOLOGY 2016; 34:317-321. [PMID: 27526461 PMCID: PMC7030846 DOI: 10.7518/hxkq.2016.03.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 03/20/2016] [Indexed: 06/06/2023]
Abstract
Tooth eruption is a series of complicated physiological processes occurring once the crown is formed completely, as well as when the tooth moves toward the occasion plane. As such, the tooth moves through the alveolar bone and the oral mucosa until it finally reaches its functional position. Most studies indicate that the process of tooth eruption involves the alveolar bone, dental follicles, osteoclasts, osteoblasts, and multiple cytokines. Dental follicles regulate both resorption and formation of the alveolar bone, which is required for tooth eruption. Furthermore, root formation with periodontal ligament facilitates continuous tooth eruption. However, the exact mechanism underlying tooth eruption remains unclear. Hence, this review describes the recent research progress on the cellular and molecular mechanisms of tooth eruption.
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Abstract
The prevalence of prosthodontic treatment has been well recognized, and the need is continuously increasing with the ageing population. While the oral mucosa plays a critical role in the treatment outcome, the associated biomechanics is not yet fully understood. Using the literature available, this paper provides a critical review on four aspects of mucosal biomechanics, including static, dynamic, volumetric and interactive responses, which are interpreted by its elasticity, viscosity/permeability, apparent Poisson's ratio and friction coefficient, respectively. Both empirical studies and numerical models are analysed and compared to gain anatomical and physiological insights. Furthermore, the clinical applications of such biomechanical knowledge on the mucosa are explored to address some critical concerns, including stimuli for tissue remodelling (interstitial hydrostatic pressure), pressure–pain thresholds, tissue displaceability and residual bone resorption. Through this review, the state of the art in mucosal biomechanics and their clinical implications are discussed for future research interests, including clinical applications, computational modelling, design optimization and prosthetic fabrication.
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Affiliation(s)
- Junning Chen
- School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Rohana Ahmad
- Unit of Prosthodontics, Faculty of Dentistry, Universiti Teknologi MARA, Shah Alam 40450, Malaysia
| | - Wei Li
- School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Michael Swain
- Faculty of Dentistry, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Qing Li
- School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, Sydney, New South Wales 2006, Australia
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Chen J, Ahmad R, Suenaga H, Li W, Sasaki K, Swain M, Li Q. Shape Optimization for Additive Manufacturing of Removable Partial Dentures--A New Paradigm for Prosthetic CAD/CAM. PLoS One 2015; 10:e0132552. [PMID: 26161878 PMCID: PMC4498620 DOI: 10.1371/journal.pone.0132552] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 06/17/2015] [Indexed: 01/29/2023] Open
Abstract
With ever-growing aging population and demand for denture treatments, pressure-induced mucosa lesion and residual ridge resorption remain main sources of clinical complications. Conventional denture design and fabrication are challenged for its labor and experience intensity, urgently necessitating an automatic procedure. This study aims to develop a fully automatic procedure enabling shape optimization and additive manufacturing of removable partial dentures (RPD), to maximize the uniformity of contact pressure distribution on the mucosa, thereby reducing associated clinical complications. A 3D heterogeneous finite element (FE) model was constructed from CT scan, and the critical tissue of mucosa was modeled as a hyperelastic material from in vivo clinical data. A contact shape optimization algorithm was developed based on the bi-directional evolutionary structural optimization (BESO) technique. Both initial and optimized dentures were prototyped by 3D printing technology and evaluated with in vitro tests. Through the optimization, the peak contact pressure was reduced by 70%, and the uniformity was improved by 63%. In vitro tests verified the effectiveness of this procedure, and the hydrostatic pressure induced in the mucosa is well below clinical pressure-pain thresholds (PPT), potentially lessening risk of residual ridge resorption. This proposed computational optimization and additive fabrication procedure provides a novel method for fast denture design and adjustment at low cost, with quantitative guidelines and computer aided design and manufacturing (CAD/CAM) for a specific patient. The integration of digitalized modeling, computational optimization, and free-form fabrication enables more efficient clinical adaptation. The customized optimal denture design is expected to minimize pain/discomfort and potentially reduce long-term residual ridge resorption.
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Affiliation(s)
- Junning Chen
- School of Aerospace, Mechanical and Mechatronic Engineering, the University of Sydney, Sydney, NSW 2006, Australia
| | - Rohana Ahmad
- Unit of Prosthodontics, Faculty of Dentistry, Shah Alam & Integrative Pharmacogenomics Institute (iPROMISE), Universiti Teknologi MARA, Bandar Puncak Alam, Selangor, 42300, Malaysia
| | - Hanako Suenaga
- Division of Preventive Dentistry, Tohoku University Graduate School of Dentistry, 4–1 Seiryo-machi, Aoba-ku, Sendai, 980–8575, Japan
| | - Wei Li
- School of Aerospace, Mechanical and Mechatronic Engineering, the University of Sydney, Sydney, NSW 2006, Australia
| | - Keiichi Sasaki
- Division of Advanced Prosthetic Dentistry, Tohoku University Graduate School of Dentistry, 4–1 Seiryo-machi, Aoba-ku, Sendai, 980–8575, Japan
| | - Michael Swain
- Faculty of Dentistry, The University of Sydney, Sydney, NSW 2006, Australia
| | - Qing Li
- School of Aerospace, Mechanical and Mechatronic Engineering, the University of Sydney, Sydney, NSW 2006, Australia
- * E-mail:
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Mesial Inclination of Impacted Third Molars and Its Propensity to Stimulate External Root Resorption in Second Molars—A Cone-Beam Computed Tomographic Evaluation. J Oral Maxillofac Surg 2015; 73:379-86. [DOI: 10.1016/j.joms.2014.10.008] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Revised: 06/22/2014] [Accepted: 10/03/2014] [Indexed: 11/19/2022]
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Influence of orthotropy on biomechanics of peri-implant bone in complete mandible model with full dentition. BIOMED RESEARCH INTERNATIONAL 2014; 2014:709398. [PMID: 25530968 PMCID: PMC4235237 DOI: 10.1155/2014/709398] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 09/01/2014] [Accepted: 09/01/2014] [Indexed: 11/19/2022]
Abstract
Objective. The study was to investigate the impact of orthotropic material on the biomechanics of dental implant, based on a detailed mandible with high geometric and mechanical similarity. Materials and Methods. Multiple data sources were used to elaborate detailed biological structures and implant CAD models. In addition, an extended orthotropic material assignment methodology based on harmonic fields was used to handle the alveolar ridge region to generate compatible orthotropic fields. The influence of orthotropic material was compared with the commonly used isotropic model and simplified orthotropic model. Results. The simulation results showed that the values of stress and strain on the implant-bone interface almost increased in the orthotropic model compared to the isotropic case, especially for the cancellous bone. However, the local stress concentration was more obvious in the isotropic case compared to that in orthotropic case. The simple orthotropic model revealed irregular stress and strain distribution, compared to the isotropic model and the real orthotropic model. The influence of orthotropy was little on the implant, periodontal ligament, tooth enamel, and dentin. Conclusion. The orthotropic material has significant effect on stress and strain of implant-bone interface in the mandible, compared with the isotropic simulation. Real orthotropic mechanical properties of mandible should be emphasized in biomechanical studies of dental implants.
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Chen J, Li W, Swain MV, Ali Darendeliler M, Li Q. A periodontal ligament driven remodeling algorithm for orthodontic tooth movement. J Biomech 2014; 47:1689-95. [DOI: 10.1016/j.jbiomech.2014.02.030] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 02/18/2014] [Accepted: 02/20/2014] [Indexed: 01/07/2023]
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Mechanical stress stimulates the osteo/odontoblastic differentiation of human stem cells from apical papilla via erk 1/2 and JNK MAPK pathways. BIOMED RESEARCH INTERNATIONAL 2014; 2014:494378. [PMID: 24826377 PMCID: PMC4009119 DOI: 10.1155/2014/494378] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 03/04/2014] [Accepted: 03/04/2014] [Indexed: 01/09/2023]
Abstract
BACKGROUND INFORMATION Stem cells from apical papilla (SCAPs) are a potent candidate for the apexogenesis/apexification due to their multiple differentiation capacity. During the orthodontic treatment of developing teeth, SCAPs in vivo are usually subjected to the cyclic stress induced by compression forces. However, it remains unclear whether mechanical stress can affect the proliferation and differentiation of human SCAPs. RESULTS Human SCAPs were isolated and stimulated by 200 g mechanical stimuli for 30 min and their proliferation and differentiation capacity were evaluated in vitro at different time points. MTT and FCM results demonstrated that cell proliferation was enhanced, while TEM findings showed the morphological and ultrastructural changes in stress-treated SCAPs. ALP activity and mineralization capacity of stress-treated SCAPs were upregulated . In the meantime, higher odontogenic and osteogenic differentiation were found in stress-treated SCAPs by real-time RT-PCR and Western blot, as indicated by the expression of related markers at both mRNA and protein levels. Moreover, the protein expressions of pJNK and pERK MAPK pathways were upregulated. CONCLUSION Together, these findings suggest that mechanical stress is an important factor affecting the proliferation and differentiation of SCAPs via the activation of ERK and JNK signaling pathway.
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External root resorption of the second molar associated with third molar impaction: comparison of panoramic radiography and cone beam computed tomography. J Oral Maxillofac Surg 2014; 72:1444-55. [PMID: 24856956 DOI: 10.1016/j.joms.2014.03.023] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 03/25/2014] [Accepted: 03/25/2014] [Indexed: 02/06/2023]
Abstract
PURPOSE The aim of the present study was to compare panoramic radiography and cone beam computed tomography (CBCT) for the assessment of external root resorption (ERR) of second molars associated with impacted third molars. In addition, the prevalence of ERR in second molars and the inclinations of the third molars more associated with ERR were investigated in both imaging methods. MATERIALS AND METHODS The sample consisted of 66 individuals with maxillary and mandibular impacted third molars (n = 188) seen on panoramic radiographs and CBCT images. The presence of ERR on the adjacent second molar was investigated, and the position of the third molar was determined using Winter's classification (vertical, horizontal, mesioangular, distoangular, and transverse). Statistical analysis was performed using the χ(2) test, Fisher exact test, and 2-proportion Z test (the significance level was set at 5%). RESULTS A significantly greater number of cases of ERR (P < .0001) was diagnosed from CBCT images (n = 43, 22.88%) than panoramic radiographs (n = 10, 5.31%). The agreement between the panoramic radiographs and CBCT scans for diagnosing ERR was 4.3%. Mandibular third molars in mesioangular and horizontal inclinations were more likely to cause resorption of the adjacent teeth. CONCLUSIONS CBCT should be indicated for the diagnosis of ERR in second molars when direct contact between the mandibular second and third molars has been observed on panoramic radiographs, especially in mesioangular or horizontal impactions. Furthermore, considering the propensity of these teeth to cause ERR in second molars, third molar prophylactic extraction could be suggested.
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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]
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