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Baghdassarian HM, Lewis NE. Resource allocation in mammalian systems. Biotechnol Adv 2024; 71:108305. [PMID: 38215956 DOI: 10.1016/j.biotechadv.2023.108305] [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: 08/03/2023] [Revised: 12/17/2023] [Accepted: 12/18/2023] [Indexed: 01/14/2024]
Abstract
Cells execute biological functions to support phenotypes such as growth, migration, and secretion. Complementarily, each function of a cell has resource costs that constrain phenotype. Resource allocation by a cell allows it to manage these costs and optimize their phenotypes. In fact, the management of resource constraints (e.g., nutrient availability, bioenergetic capacity, and macromolecular machinery production) shape activity and ultimately impact phenotype. In mammalian systems, quantification of resource allocation provides important insights into higher-order multicellular functions; it shapes intercellular interactions and relays environmental cues for tissues to coordinate individual cells to overcome resource constraints and achieve population-level behavior. Furthermore, these constraints, objectives, and phenotypes are context-dependent, with cells adapting their behavior according to their microenvironment, resulting in distinct steady-states. This review will highlight the biological insights gained from probing resource allocation in mammalian cells and tissues.
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Affiliation(s)
- Hratch M Baghdassarian
- Bioinformatics and Systems Biology Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA; Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Nathan E Lewis
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA; Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA.
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Ben Achour A, Apfeld F, Lauer G, Bräuer C, Leonhardt H, Franke A, Lipphaus A, Teicher U, Witzel U, Schröder TA. Development of a test bench for biomechanical simulation-a preliminary study of mandibular forces. Front Bioeng Biotechnol 2024; 12:1335159. [PMID: 38468690 PMCID: PMC10925755 DOI: 10.3389/fbioe.2024.1335159] [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: 11/08/2023] [Accepted: 02/07/2024] [Indexed: 03/13/2024] Open
Abstract
Purpose: The aim of this study is to develop a test bench, which integrates different complexity levels and enables in that way a flexible and dynamic testing for mid and long term intervals as well as testing of maximum loads till implant failure of different osteosynthesis systems on the mandible. Material and Methods: For this purpose, an analysis of the state of the art regarding existing test benches was combined with interviews of clinical experts to acquire a list of requirements. Based on these requirements a design for a modular test bench was developed. During the implementation of the test stand, functional tests were continuously carried out and improvements made. Depending on the level of complexity, the test bench can be used either as an incorporated variant or as a standalone solution. In order to verify the performance and the degree of fulfilment of the requirements of these two variants of the test bench, preliminary studies were carried out for all levels of complexity. In these preliminary studies, commercially available osteosynthesis and reconstruction plates were investigated for their biomechanical behaviour and compared with data from the literature. Results: In total, fourteen test runs were performed for the different levels of complexity. Firstly, five test runs were executed to test the simplified load scenario in the incorporated variant of the test bench. High forces could be transmitted without failure of the miniplates. Secondly a quasi-static test scenario was examined using the incorporated variant with simplified load insertion. Five experiments with a number of cycles between 40,896 and 100,000 cycles were carried out. In one case the quasi-static testing resulted in a fracture of the tested reconstruction plate with a failure mode similar to the clinical observations of failure. The last four test runs were carried out using the standalone variant of the test bench simulating complex load patterns via the insertion of forces through imitated muscles. During the test runs joint forces were measured and the amplitude and vector of the resulting joint forces were calculated for both temporomandibular joints. Differences in the force transmission depending on the implant system in comparison to the zero sample could be observed. Conclusion: The presented modular test bench showed to be applicable for examination of the biomechanical behavior of the mandible. It is characterized by the adjustability of the complexity regarding the load patterns and enables the subsequent integration of further sensor technologies. Follow-up studies are necessary to further qualify and optimize the test bench.
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Affiliation(s)
- Anas Ben Achour
- Fraunhofer Institute for Machine Tools and Forming Technology IWU, Dresden, Germany
| | - Florian Apfeld
- Fraunhofer Institute for Machine Tools and Forming Technology IWU, Dresden, Germany
- Biomechanics Research Group, Chair of Product Development, Faculty of Mechanical Engineering, Ruhr University Bochum, Bochum, Germany
| | - Günter Lauer
- Department of Oral and Maxillofacial Surgery, University Hospital Carl Gustav Carus Dresden, Technische Universität Dresden, Dresden, Germany
| | - Christian Bräuer
- Department of Oral and Maxillofacial Surgery, Facial Plastic Surgery, University of Rostock, Rostock, Germany
| | - Henry Leonhardt
- Department of Oral and Maxillofacial Surgery, University Hospital Carl Gustav Carus Dresden, Technische Universität Dresden, Dresden, Germany
| | - Adrian Franke
- Department of Oral and Maxillofacial Surgery, University Hospital Carl Gustav Carus Dresden, Technische Universität Dresden, Dresden, Germany
| | - Andreas Lipphaus
- Biomechanics Research Group, Chair of Product Development, Faculty of Mechanical Engineering, Ruhr University Bochum, Bochum, Germany
| | - Uwe Teicher
- Fraunhofer Institute for Machine Tools and Forming Technology IWU, Dresden, Germany
| | - Ulrich Witzel
- Biomechanics Research Group, Chair of Product Development, Faculty of Mechanical Engineering, Ruhr University Bochum, Bochum, Germany
| | - Tom Alexander Schröder
- Department of Oral and Maxillofacial Surgery, University Hospital Carl Gustav Carus Dresden, Technische Universität Dresden, Dresden, Germany
- Else Kröner Fresenius Center for Digital Health, Technische Universität Dresden, Dresden, Germany
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Türp JC. Kuhn's long shadow: Two incommensurable paradigms. Cranio 2022; 40:183-184. [PMID: 35234577 DOI: 10.1080/08869634.2022.2031172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Jens Christoph Türp
- University Center for Dental Medicine Basel UZB, University of Basel, Basel, Switzerland
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Nozad Mojaver Y, Tawadros P, Moura Ferreira P, Whittle T, Murray GM. Threshold variations of medial pterygoid single motor units during vertical or horizontal force tasks. J Oral Rehabil 2021; 48:1314-1326. [PMID: 34510487 DOI: 10.1111/joor.13257] [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: 03/17/2021] [Revised: 08/19/2021] [Accepted: 09/01/2021] [Indexed: 11/28/2022]
Abstract
OBJECTIVES To test the hypotheses that (a) the force thresholds at onset of medial pterygoid muscle single motor unit (SMU) activity do not decrease with an increase in the rate of force generation in standardised vertical or horizontal jaw-force tasks, and (b) there is evidence for functional heterogeneity within the medial pterygoid muscle. METHODS In 14 healthy participants, electromyographic recordings of the right medial pterygoid muscle were performed with intramuscular fine-wire electrodes during four isometric force tasks: vertical, horizontal contralateral, horizontal protrusion and horizontal ipsilateral, performed at two rates of force development (slow ramp, fast ramp). Computer tomography scans confirmed electrode location within the muscle, which was divided into medial and lateral parts. Force thresholds of onset of discriminated SMUs were compared between rates in each task; significance accepted at p < 0.05. RESULTS Of 45 SMU force thresholds studied in one or more tasks, there was no significant difference between slow and fast ramp within each force task, except slow ramp thresholds from the lateral part during the vertical force task were significantly higher than fast ramp thresholds. Reversals of recruitment order between tasks provided evidence for functional heterogeneity within the muscle. Force thresholds of the vertical tasks (range: 1-292.6 N) were mostly higher than for the horizontal tasks (range: 0.1-12.5 N). CONCLUSION The data are consistent with the proposal that the medial pterygoid muscle stabilises the jaw in the vertical plane during isometric force generation in the jaw closing, as well as horizontal directions.
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Affiliation(s)
- Yalda Nozad Mojaver
- Faculty of Medicine and Health, Sydney Dental School, Westmead Hospital Centre for Oral Health, The University of Sydney, Westmead, Australia
| | - Paul Tawadros
- Faculty of Medicine and Health, Sydney Dental School, Westmead Hospital Centre for Oral Health, The University of Sydney, Westmead, Australia
| | - Polyana Moura Ferreira
- Faculty of Medicine and Health, Sydney Dental School, Westmead Hospital Centre for Oral Health, The University of Sydney, Westmead, Australia
| | - Terry Whittle
- Faculty of Medicine and Health, Sydney Dental School, Westmead Hospital Centre for Oral Health, The University of Sydney, Westmead, Australia
| | - Greg M Murray
- Faculty of Medicine and Health, Sydney Dental School, Westmead Hospital Centre for Oral Health, The University of Sydney, Westmead, Australia
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Pachnicz D, Stróżyk P. A Biomechanical Analysis of Muscle Force Changes After Bilateral Sagittal Split Osteotomy. Front Physiol 2021; 12:679644. [PMID: 34149457 PMCID: PMC8209381 DOI: 10.3389/fphys.2021.679644] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 05/10/2021] [Indexed: 11/13/2022] Open
Abstract
A basic procedure affecting maxillofacial geometry is the bilateral sagittal split osteotomy. During the surgery, the bony segments are placed in a new position that provides the correct occlusion. Changes in the geometry of the mandible will affect the surrounding structures and will have a significant impact on the functioning of the masticatory system. As a result of the displacement of the bone segment, the biomechanical conditions change, i.e., the load and the position of the muscles. The primary aim of this study was to determine the changes in the values of the muscular forces caused by mandible geometry alteration. The study considered the translation and rotation of the distal segment, as well as rotations of the proximal segments in three axes. Calculations were performed for the unilateral, static loading of a model based on rigid body mechanics. Muscles were modeled as spring elements, and a novel approach was used to determine muscle stiffness. In addition, an attempt was made, based on the results obtained for single displacements separately, to determine the changes in muscle forces for geometries with complex displacements. Based on the analysis of the results, it was shown that changes in the geometry of the mandibular bone associated with the bilateral sagittal split osteotomy will have a significant effect on the values of the masticatory muscle forces. Displacement of the distal segment has the greatest effect from -21.69 to 26.11%, while the proximal segment rotations affected muscle force values to a less extent, rarely exceeding 1%. For Yaw and Pitch rotations, the opposite effect of changes within one muscle is noticed. Changes in muscle forces for complex geometry changes can be determined with a high degree of accuracy by the appropriate summation of results obtained for simple cases.
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Affiliation(s)
- Dominik Pachnicz
- Faculty of Mechanical Engineering, Wrocław University of Science and Technology, Wrocław, Poland
| | - Przemysław Stróżyk
- Department of Mechanics, Materials and Biomedical Engineering, Wrocław University of Science and Technology, Wrocław, Poland
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Nozad Mojaver Y, Tawadros PB, Moura Ferreira P, Whittle T, Murray GM. Single motor units from the medial pterygoid muscle can be active during isometric horizontal and vertical forces. J Oral Rehabil 2019; 46:998-1008. [PMID: 31206789 DOI: 10.1111/joor.12831] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 05/30/2019] [Accepted: 06/09/2019] [Indexed: 12/27/2022]
Abstract
OBJECTIVES To determine (a) whether the medial pterygoid muscle is active in an isometric vertical force task and in isometric horizontal force tasks in the contralateral, protrusion and ipsilateral directions; (b) whether the same single motor units (SMUs) could be active across different directions of isometric force generation; and (c) whether different regions of the medial pterygoid muscle exhibit different patterns of SMU activation during the generation of any one direction of isometric force. METHODS Intramuscular electromyographic (EMG) recordings were made from the right medial pterygoid muscle in 15 healthy participants during isometric force tasks: vertical and horizontal contralateral, protrusion and ipsilateral. A computed tomography scan divided the EMG recording site into a medial or lateral part in each participant. Single motor units were discriminated in each task. RESULTS Medial pterygoid SMU activity was recorded in 100% of participants for the vertical biting tasks, 86% of participants for the horizontal contralateral and horizontal protrusion tasks and 57% of the horizontal ipsilateral tasks. Of the 72 SMUs that were discriminated, 36% were active in all tasks; 18% were active only in the vertical tasks and 17% were active in the vertical, horizontal contralateral and horizontal protrusion tasks. The proportion of SMUs that was active in at least 1 horizontal task in the lateral part (33/39) was significantly higher than the proportion (21/33) in the medial part (Chi-Square, P < 0.05). CONCLUSION The data are consistent with a stabilisation role for the medial pterygoid muscle in isometric jaw forces in the vertical and horizontal planes.
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Affiliation(s)
- Yalda Nozad Mojaver
- Jaw Function and Orofacial Pain Research Unit, Sydney Dental School, Faculty of Medicine and Health, Westmead Hospital Centre for Oral Health, The University of Sydney, Westmead, New South Wales, Australia
| | - Paul B Tawadros
- Jaw Function and Orofacial Pain Research Unit, Sydney Dental School, Faculty of Medicine and Health, Westmead Hospital Centre for Oral Health, The University of Sydney, Westmead, New South Wales, Australia
| | - Polyana Moura Ferreira
- Jaw Function and Orofacial Pain Research Unit, Sydney Dental School, Faculty of Medicine and Health, Westmead Hospital Centre for Oral Health, The University of Sydney, Westmead, New South Wales, Australia
| | - Terry Whittle
- Jaw Function and Orofacial Pain Research Unit, Sydney Dental School, Faculty of Medicine and Health, Westmead Hospital Centre for Oral Health, The University of Sydney, Westmead, New South Wales, Australia
| | - Greg M Murray
- Jaw Function and Orofacial Pain Research Unit, Sydney Dental School, Faculty of Medicine and Health, Westmead Hospital Centre for Oral Health, The University of Sydney, Westmead, New South Wales, Australia
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Zheng K, Liao Z, Yoda N, Fang J, Chen J, Zhang Z, Zhong J, Peck C, Sasaki K, Swain MV, Li Q. Investigation on masticatory muscular functionality following oral reconstruction – An inverse identification approach. J Biomech 2019; 90:1-8. [DOI: 10.1016/j.jbiomech.2019.04.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 04/04/2019] [Accepted: 04/04/2019] [Indexed: 11/28/2022]
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Möhlhenrich SC, Kniha K, Szalma J, Ayoub N, Hölzle F, Wolf M, Modabber A, Raith S. Stress distribution in mandibular donor site after harvesting bone grafts of various sizes from the ascending ramus of a dentate mandible by finite element analysis. Clin Oral Investig 2018; 23:2265-2271. [PMID: 30288605 DOI: 10.1007/s00784-018-2671-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 09/26/2018] [Indexed: 12/01/2022]
Abstract
PURPOSE Harvesting bone from the ascending ramus of the mandible is a common procedure. However, mandibular fracture may occur after grafting bone blocks. This study aimed to investigate the resulting force distribution of stress and strain in the mandibular donor site after harvesting bone grafts of different sizes and various loadings. METHODS Finite element analysis was performed for virtual harvesting of bone blocks of nine different sizes between 15 × 20 and 25 × 30 mm and three different chewing loads (incisal, ipsilateral and contralateral). von Mises stress and first principal stress distributions were measured. RESULTS von Mises stress was distributed between 35.01 (10 × 15 mm graft, incisal load) and 333.25 MPa (30 × 20 mm graft ipsilateral load), whereas first principal stress distributions were between 48.27 (10 × 15 mm graft, incisal load) and 414.69 MPa (30 × 20 mm graft ipsilateral load). In general, the least stress was observed with incisal load followed by ipsilateral load and finally contralateral load. The critical value of 133 MPa was found after removing almost all grafts with a width of 20 or 30 mm. CONCLUSIONS Incisal loading led to less stress compared with contralateral and ipsilateral loads. Increasing graft size led to increasing weakness of the donor site. Graft width exerted a greater influence on stress development than its height. CLINICAL RELEVANCE Ipsilateral chewing and increasing width of the bone graft result in maximum stress in the mandibular donor side, and critical values regarding to the possibility of fractures are already to expect from a graft size of 20 × 15 mm.
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Affiliation(s)
- Stephan Christian Möhlhenrich
- Department of Orthodontics and Dentofacial Orthopedics, RWTH Aachen University Hospital, Pauwelsstraße 30, 52074, Aachen, Germany. .,Department of Oral and Maxillofacial Surgery, University Hospital of Aachen, Pauwelsstraße 30, 52074, Aachen, Germany.
| | - Kristian Kniha
- Department of Oral and Maxillofacial Surgery, University Hospital of Aachen, Pauwelsstraße 30, 52074, Aachen, Germany
| | - József Szalma
- Department of Oral and Maxillofacial Surgery, University of Pecs, Dischka Győző str. 5, Pecs, 7621, Hungary
| | - Nassim Ayoub
- Department of Oral and Maxillofacial Surgery, University Hospital of Aachen, Pauwelsstraße 30, 52074, Aachen, Germany
| | - Frank Hölzle
- Department of Oral and Maxillofacial Surgery, University Hospital of Aachen, Pauwelsstraße 30, 52074, Aachen, Germany
| | - Michael Wolf
- Department of Orthodontics and Dentofacial Orthopedics, RWTH Aachen University Hospital, Pauwelsstraße 30, 52074, Aachen, Germany
| | - Ali Modabber
- Department of Oral and Maxillofacial Surgery, University Hospital of Aachen, Pauwelsstraße 30, 52074, Aachen, Germany
| | - Stefan Raith
- Department of Oral and Maxillofacial Surgery, University Hospital of Aachen, Pauwelsstraße 30, 52074, Aachen, Germany
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Martinez Choy SE, Lenz J, Schweizerhof K, Schmitter M, Schindler HJ. Realistic kinetic loading of the jaw system during single chewing cycles: a finite element study. J Oral Rehabil 2017; 44:375-384. [DOI: 10.1111/joor.12501] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/25/2017] [Indexed: 11/29/2022]
Affiliation(s)
- S. E. Martinez Choy
- Research Group Biomechanics; Institute for Mechanics; Karlsruhe Institute of Technology (KIT); Karlsruhe Germany
| | - J. Lenz
- Research Group Biomechanics; Institute for Mechanics; Karlsruhe Institute of Technology (KIT); Karlsruhe Germany
| | - K. Schweizerhof
- Research Group Biomechanics; Institute for Mechanics; Karlsruhe Institute of Technology (KIT); Karlsruhe Germany
| | - M. Schmitter
- Department of Prosthodontics; Dental School; University of Würzburg; Würzburg Germany
| | - H. J. Schindler
- Research Group Biomechanics; Institute for Mechanics; Karlsruhe Institute of Technology (KIT); Karlsruhe Germany
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Terebesi S, Giannakopoulos NN, Brüstle F, Hellmann D, Türp JC, Schindler HJ. Small vertical changes in jaw relation affect motor unit recruitment in the masseter. J Oral Rehabil 2015; 43:259-68. [PMID: 26707515 DOI: 10.1111/joor.12375] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/17/2015] [Indexed: 12/21/2022]
Abstract
Strategies for recruitment of masseter muscle motor units (MUs), provoked by constant bite force, for different vertical jaw relations have not previously been investigated. The objective of this study was to analyse the effect of small changes in vertical jaw relation on MU recruitment behaviour in different regions of the masseter during feedback-controlled submaximum biting tasks. Twenty healthy subjects (mean age: 24·6 ± 2·4 years) were involved in the investigation. Intra-muscular electromyographic (EMG) activity of the right masseter was recorded in different regions of the muscle. MUs were identified by the use of decomposition software, and root-mean-square (RMS) values were calculated for each experimental condition. Six hundred and eleven decomposed MUs with significantly (P < 0·001) different jaw relation-specific recruitment behaviour were organised into localised MU task groups. MUs with different task specificity in seven examined tasks were observed. The RMS EMG values obtained from the different recording sites were also significantly (P < 0·01) different between tasks. Overall MU recruitment was significantly (P < 0·05) greater in the deep masseter than in the superficial muscle. The number of recruited MUs and the RMS EMG values decreased significantly (P < 0·01) with increasing jaw separation. This investigation revealed differential MU recruitment behaviour in discrete subvolumes of the masseter in response to small changes in vertical jaw relations. These fine-motor skills might be responsible for its excellent functional adaptability and might also explain the successful management of temporomandibular disorder patients by somatic intervention, in particular by the use of oral splints.
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Affiliation(s)
- S Terebesi
- Department of Prosthodontics, Dental School, University of Heidelberg, Heidelberg, Germany
| | - N N Giannakopoulos
- Department of Prosthodontics, Dental School, University of Heidelberg, Heidelberg, Germany
| | - F Brüstle
- Department of Prosthodontics, Dental School, University of Heidelberg, Heidelberg, Germany
| | - D Hellmann
- Department of Prosthodontics, Dental School, University of Heidelberg, Heidelberg, Germany
| | - J C Türp
- Department of Reconstructive Dentistry and Temporomandibular Disorders, Dental School, University of Basel, Basel, Switzerland
| | - H J Schindler
- Research Group Biomechanics, Institute for Mechanics, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
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Kobayashi FY, Gavião MBD, Montes ABM, Marquezin MCS, Castelo PM. Evaluation of oro-facial function in young subjects with temporomandibular disorders. J Oral Rehabil 2014; 41:496-506. [DOI: 10.1111/joor.12163] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/22/2014] [Indexed: 12/30/2022]
Affiliation(s)
- F. Y. Kobayashi
- Department of Pediatric Dentistry; Piracicaba Dental School; University of Campinas-UNICAMP; Piracicaba Brazil
| | - M. B. D. Gavião
- Department of Pediatric Dentistry; Piracicaba Dental School; University of Campinas-UNICAMP; Piracicaba Brazil
| | - A. B. M. Montes
- Department of Pediatric Dentistry; Piracicaba Dental School; University of Campinas-UNICAMP; Piracicaba Brazil
| | - M. C. S. Marquezin
- Department of Pediatric Dentistry; Piracicaba Dental School; University of Campinas-UNICAMP; Piracicaba Brazil
| | - P. M. Castelo
- Department of Biological Sciences; Federal University of São Paulo; Diadema Brazil
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Shimada A, Hara S, Svensson P. Effect of experimental jaw muscle pain on EMG activity and bite force distribution at different level of clenching. J Oral Rehabil 2013; 40:826-33. [PMID: 23992609 DOI: 10.1111/joor.12096] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/09/2013] [Indexed: 11/30/2022]
Abstract
Bite force at different levels of clenching and the corresponding electromyographic (EMG) activity in jaw-closing muscles were recorded in 16 healthy women before, during and after painful stimulation of the left masseter muscle. Experimental pain was induced by infusion of 5·8% hypertonic saline (HS), and 0·9% isotonic saline (IS) was infused as a control. EMG activity was recorded bilaterally from the masseter and temporalis muscles, and static bite force was assessed by pressure-sensitive films (Dental Pre-scale) at 5, 50 and 100% of maximal voluntary contraction (MVC) during each session. Visual feedback was applied by showing EMG activity to help the subject perform clenching at 5, 50 and 100% MVC, respectively. EMG activity at 100% MVC in left and right masseter decreased significantly during painful HS infusion (1·7-44·6%; P < 0·05). EMG activity at 5% and 50% MVC was decreased during HS infusion in the painful masseter muscle (4·8-18·6%; P < 0·05); however, EMG activity in the other muscles increased significantly (18·5-128·3%; P < 0·05). There was a significant increase in bite force in the molar regions at 50% MVC during HS infusion and in the post-infusion condition (P < 0·05). However, there were no significant differences in the distribution of forces at 100% MVC. In conclusion, experimental pain in the masseter muscle has an inhibitory effect on jaw muscle activity at maximal voluntary contraction, and compensatory mechanisms may influence the recruitment pattern at submaximal efforts.
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Affiliation(s)
- A Shimada
- Section of Clinical Oral Physiology, Department of Dentistry, Aarhus University, Aarhus, Denmark
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14
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Ertem SY, Uckan S, Ozden UA. The comparison of angular and curvilinear marginal mandibulectomy on force distribution with three dimensional finite element analysis. J Craniomaxillofac Surg 2013; 41:e54-8. [DOI: 10.1016/j.jcms.2012.07.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Revised: 07/06/2012] [Accepted: 07/09/2012] [Indexed: 10/28/2022] Open
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KOBAYASHI FY, FURLAN NF, BARBOSA TS, CASTELO PM, GAVIÃO MBD. Evaluation of masticatory performance and bite force in children with sleep bruxism. J Oral Rehabil 2012; 39:776-84. [DOI: 10.1111/j.1365-2842.2012.02331.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Developing a musculoskeletal model of the primate skull: predicting muscle activations, bite force, and joint reaction forces using multibody dynamics analysis and advanced optimisation methods. J Theor Biol 2012; 310:21-30. [PMID: 22721994 DOI: 10.1016/j.jtbi.2012.06.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Revised: 06/01/2012] [Accepted: 06/05/2012] [Indexed: 11/22/2022]
Abstract
An accurate, dynamic, functional model of the skull that can be used to predict muscle forces, bite forces, and joint reaction forces would have many uses across a broad range of disciplines. One major issue however with musculoskeletal analyses is that of muscle activation pattern indeterminacy. A very large number of possible muscle force combinations will satisfy a particular functional task. This makes predicting physiological muscle recruitment patterns difficult. Here we describe in detail the process of development of a complex multibody computer model of a primate skull (Macaca fascicularis), that aims to predict muscle recruitment patterns during biting. Using optimisation criteria based on minimisation of muscle stress we predict working to balancing side muscle force ratios, peak bite forces, and joint reaction forces during unilateral biting. Validation of such models is problematic; however we have shown comparable working to balancing muscle activity and TMJ reaction ratios during biting to those observed in vivo and that peak predicted bite forces compare well to published experimental data. To our knowledge the complexity of the musculoskeletal model is greater than any previously reported for a primate. This complexity, when compared to more simple representations provides more nuanced insights into the functioning of masticatory muscles. Thus, we have shown muscle activity to vary throughout individual muscle groups, which enables them to function optimally during specific masticatory tasks. This model will be utilised in future studies into the functioning of the masticatory apparatus.
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Nieblerová J, Foltán R, Hanzelka T, Pavlíková G, Vlk M, Klíma K, Samsonyan L. Stability of the miniplate osteosynthesis used for sagittal split osteotomy for closing an anterior open bite: an experimental study in mini-pigs. Int J Oral Maxillofac Surg 2012; 41:482-8. [DOI: 10.1016/j.ijom.2011.11.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2010] [Revised: 08/04/2011] [Accepted: 11/08/2011] [Indexed: 01/08/2023]
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Shimada A, Yamabe Y, Torisu T, Baad-Hansen L, Murata H, Svensson P. Measurement of dynamic bite force during mastication. J Oral Rehabil 2012; 39:349-56. [PMID: 22288929 DOI: 10.1111/j.1365-2842.2011.02278.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Efficient mastication of different types and size of food depends on fast integration of sensory information from mechanoreceptors and central control mechanisms of jaw movements and applied bite force. The neural basis underlying mastication has been studied for decades but little progress in understanding the dynamics of bite force has been made mainly due to technical limitations of bite force recorders. The aims of this study were to develop a new intraoral bite force recorder which would allow the study of natural mastication without an increase in the occlusal vertical dimension and subsequently to analyze the relation between electromyographic (EMG) activity of jaw-closing muscles, jaw movements and bite force during mastication of five different types of food. Customized force recorders based on strain gauge sensors were fitted to the upper and lower molar teeth on the preferred chewing side in fourteen healthy and dentate subjects (21-39 years), and recordings were carried out during voluntary mastication of five different kinds of food. Intraoral force recordings were successively obtained from all subjects. anova showed that impulse of bite force as well as integrated EMG was significantly influenced by food (P<0·05), while time-related parameters were significantly affected by chewing cycles (P<0·001). This study demonstrates that intraoral force recordings are feasible and can provide new information on the dynamics of human mastication with direct implications for oral rehabilitation. We also propose that the control of bite force during mastication is achieved by anticipatory adjustment and encoding of bolus characteristics.
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Affiliation(s)
- A Shimada
- Department of Clinical Oral Physiology, School of Dentistry, Aarhus University, Aarhus, Denmark.
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Hannam AG. Current computational modelling trends in craniomandibular biomechanics and their clinical implications. J Oral Rehabil 2010; 38:217-34. [PMID: 20819138 DOI: 10.1111/j.1365-2842.2010.02149.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Computational models of interactions in the craniomandibular apparatus are used with increasing frequency to study biomechanics in normal and abnormal masticatory systems. Methods and assumptions in these models can be difficult to assess by those unfamiliar with current practices in this field; health professionals are often faced with evaluating the appropriateness, validity and significance of models which are perhaps more familiar to the engineering community. This selective review offers a foundation for assessing the strength and implications of a craniomandibular modelling study. It explores different models used in general science and engineering and focuses on current best practices in biomechanics. The problem of validation is considered at some length, because this is not always fully realisable in living subjects. Rigid-body, finite element and combined approaches are discussed, with examples of their application to basic and clinically relevant problems. Some advanced software platforms currently available for modelling craniomandibular systems are mentioned. Recent studies of the face, masticatory muscles, tongue, craniomandibular skeleton, temporomandibular joint, dentition and dental implants are reviewed, and the significance of non-linear and non-isotropic material properties is emphasised. The unique challenges in clinical application are discussed, and the review concludes by posing some questions which one might reasonably expect to find answered in plausible modelling studies of the masticatory apparatus.
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Affiliation(s)
- A G Hannam
- Faculty of Dentistry, Department of Oral Health Sciences, The University of British Columbia, Vancouver, BC, Canada.
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Rues S, Lenz J, Türp JC, Schweizerhof K, Schindler HJ. Muscle and joint forces under variable equilibrium states of the mandible. Clin Oral Investig 2010; 15:737-47. [PMID: 20585815 DOI: 10.1007/s00784-010-0436-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2009] [Accepted: 06/11/2010] [Indexed: 01/08/2023]
Abstract
It is well established that subjects without molars have reduced ability to comminute foods. However, epidemiological studies have indicated that the masticatory system is able to functionally adapt to the absence of posterior teeth. This supports the shortened dental arch concept which, as a prosthetic option, recommends no replacement of missing molars. Biomechanical modeling, however, indicates that using more anterior teeth will result in a larger temporomandibular joint load per unit of bite force. In contrast, changing bite from incisor to molar position increases the maximum possible bite force and reduces joint loads. There have been few attempts, however, to determine realistic joint loads and corresponding muscular effort during generation of occlusal forces similar to those used during chewing with intact or shortened dental arches. Therefore, joint and cumulative muscle loads generated by vertical bite forces of submaximum magnitude moving from canine to molar region, were calculated. Calculations were based on intraoral measurement of the feedback-controlled resultant bite force, simultaneous electromyograms, individual geometrical data of the skull, lines of action, and physiological cross-sectional areas of all jaw muscles. Compared to premolar and canine biting, bilateral and unilateral molar bites reduced cumulative muscle and joint loads in a range from 14% to 33% and 25% to 53%, respectively. During unilateral molar bites, the ipsilateral joints and contralateral muscles were about 20% less loaded than the opposing ones. In conclusion, unilateral or bilateral molar biting at chewing-like force ranges caused the least muscle and joint loading.
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Affiliation(s)
- Stefan Rues
- Research Group Biomechanics, Institute of Mechanics, Karlsruhe Institute of Technology, Karlsruhe, Germany.
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Schindler HJ, Lenz J, Türp JC, Schweizerhof K, Rues S. Influence of neck rotation and neck lateroflexion on mandibular equilibrium. J Oral Rehabil 2010; 37:329-35. [PMID: 20180896 DOI: 10.1111/j.1365-2842.2010.02064.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Neuromuscular interaction between neck and jaw muscles has been reported in several studies. However, the influence of experimentally modified posture of the neck on jaw muscle activity during isometric biting was not investigated so far. The aim of the present study was to test by the aid of simultaneous electromyographic and intraoral bite force measurements whether neck rotation and lateroflexion, in contrast to a straightforward neck position, change the isometric cocontraction patterns of masticatory muscles under identical submaximum bite forces of 50-200 N. Electric muscle activity of all masticatory muscles and changes of the reduction point (RP) of the resultant bite force vectors were examined. An anteroposterior displacement of the RPs could be observed for the rotated and lateroflexed neck position in comparison with the straightforward position. On the other hand, the results revealed no significant differences between bilateral muscle activation under the different test conditions. These findings suggest a force transmission between the neck and the masticatory system, but no essential activity changes in the masticatory muscles under short time posture modification of the neck.
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Affiliation(s)
- H J Schindler
- Research Group Biomechanics, Institute for Mechanics, University of Karlsruhe, Karlsruhe, Germany
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SCHINDLER HJ, LENZ J, TÜRP JC, SCHWEIZERHOF K, RUES S. Small unilateral jaw gap variations: equilibrium changes, co-contractions and joint forces. J Oral Rehabil 2009; 36:710-8. [DOI: 10.1111/j.1365-2842.2009.01985.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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