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Kothari SF, Devendran A, Kumar A, de Caxias FP, Svensson P. Signal to noise ratio of masticatory muscle activity of functional and non-functional oral tasks. J Oral Rehabil 2024; 51:1599-1609. [PMID: 38837445 DOI: 10.1111/joor.13714] [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: 06/13/2023] [Revised: 03/02/2024] [Accepted: 04/15/2024] [Indexed: 06/07/2024]
Abstract
BACKGROUND Electromyographic activity (EMG) of masticatory muscles during wakefulness is understudied. It is unclear if single channel ambulatory EMG devices are sensitive enough to detect masticatory muscle activity (MMA) during wakefulness. OBJECTIVES To compare the MMA of various oral tasks recorded with a single channel EMG device ((Grindcare4-datalogger Prototype device) (GC4-β)) and a conventional EMG (cEMG) device. METHODS EMG activity of 30 standardised oral tasks was recorded unilaterally from the masseter and anterior temporalis muscle in 24 healthy volunteers using GC4-β and a cEMG device. To compare the EMG data, signal-to-noise ratios (SNR) were calculated as a way to normalise EMG activity across tasks. Analysis of variance was used to compare the SNR between the devices, muscles and oral tasks. RESULTS SNR measured from GC4-β was overall significantly higher than the cEMG device (p =.001). The SNR for maximum voluntary contraction (MVC) was significantly higher than all other tasks (p <.001). SNR for temporalis with GC4-β was significantly higher for MVC, hard food, soft food, gum chewing (dominant side), rhythmic clenching and upper lip biting compared to the cEMG device (p <.021). The SNR for masseter with GC4-β was significantly higher for hard food and gum chewing (dominant side), rhythmic clenching, rhythmic biting of an object and yawning compared to the cEMG device (p <.022). CONCLUSIONS This study provides novel insight into the EMG patterns of numerous oral tasks enhancing knowledge of physiological differences between the masticatory muscles. Further, single channel EMG devices can effectively measure the EMG activity of various oral tasks during wakefulness.
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Affiliation(s)
- Simple Futarmal Kothari
- Section for Orofacial Pain and Jaw Function, Department of Dentistry and Oral Health, Aarhus University, Aarhus, Denmark
- Scandinavian Center for Orofacial Neurosciences (SCON), Aarhus, Denmark
- Hammel Neurorehabilitation and University Research Clinic, Hammel, Denmark
| | - Anupriyadarshini Devendran
- Section for Orofacial Pain and Jaw Function, Department of Dentistry and Oral Health, Aarhus University, Aarhus, Denmark
| | - Abhishek Kumar
- Scandinavian Center for Orofacial Neurosciences (SCON), Aarhus, Denmark
- Department of Dental Medicine, Karolinska Institutet, Huddinge, Sweden
- Academic Centre for Geriatric Dentistry, Stockholm, Sweden
| | - Fernanda P de Caxias
- Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP), School of Dentistry, Araçatuba, Brazil
| | - Peter Svensson
- Section for Orofacial Pain and Jaw Function, Department of Dentistry and Oral Health, Aarhus University, Aarhus, Denmark
- Scandinavian Center for Orofacial Neurosciences (SCON), Aarhus, Denmark
- Department of Orofacial Pain and Jaw Function, Faculty of Odontology, Malmö University, Malmö, Sweden
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Zhou L, Li B, Zheng X, Guo S, Zhang Y, Chen C, Wang K, Wang M. Uptight responses between clenching and forearm raising with factors of visual feedback and maintenance effort in healthy young women: An experimental study on factorial design. BMC Oral Health 2023; 23:98. [PMID: 36788503 PMCID: PMC9926863 DOI: 10.1186/s12903-023-02767-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 01/25/2023] [Indexed: 02/16/2023] Open
Abstract
BACKGROUND To achieve different central preset force levels requires various fine-tuning efforts and may elicit different uptight responses. The mandibular lever system has a distinct regularity in the fine-tuning function of the upper limbs. The purpose of the present study was to detect whether the uptight responses elicited from motivating clenching differ from those induced by motivating forearm raising at different force levels. METHODS Twenty-five healthy females were enrolled in this study. The target was low, medium, and maximum force levels with or without visual feedback and/or maintenance effort. Surface electromyographic (SEMG) activity was recorded from the bilateral anterior temporalis and masseter or left biceps brachii muscle (BicL), and the T-Scan III System synchronously recorded the sensitive force values. The uptight responses and task difficulties were recorded for occlusal and left forearm lifting tasks using a unique visual analogue scale. RESULTS The highest uptight response value was achieved at a low clenching force level with visual feedback requiring no maintenance effort but at a maximum forearm-raising force level with visual feedback and maintenance effort. The SEMG activities of both jaw-closing muscles and BicL were associated with the central preset force level (P < 0.001). However, the maintenance effort only increased the jaw-closing muscles' SEMG activity at the maximal force level (P < 0.001). CONCLUSIONS Clenching at the central preset lower force level with visual feedback is prone to elicit a higher degree of uptight response. The constant need for a low-intensity bite can have a negative effect on an individual's mood.
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Affiliation(s)
- Lijuan Zhou
- grid.186775.a0000 0000 9490 772XDepartment of Orthodontics I, Hefei Stomatological Hospital, Clinical College of Stomatology, Anhui Medical University, Hefei, 230001 Anhui China ,grid.233520.50000 0004 1761 4404Department of Oral Anatomy and Physiology, School of Stomatology, The Fourth Military Medical University, Xi’an, 710032 Shaanxi China
| | - Baoyong Li
- grid.233520.50000 0004 1761 4404Department of Oral Anatomy and Physiology, School of Stomatology, The Fourth Military Medical University, Xi’an, 710032 Shaanxi China
| | - Xianyu Zheng
- grid.186775.a0000 0000 9490 772XStomatologic Hospital & College, Anhui Medical University, Key Lab. of Oral Diseases Research of Anhui Province, Hefei, 230032 China
| | - Shaoxiong Guo
- grid.233520.50000 0004 1761 4404Department of Oral Anatomy and Physiology, School of Stomatology, The Fourth Military Medical University, Xi’an, 710032 Shaanxi China
| | - Yuan Zhang
- grid.233520.50000 0004 1761 4404Department of Oral Anatomy and Physiology, School of Stomatology, The Fourth Military Medical University, Xi’an, 710032 Shaanxi China
| | - Changsheng Chen
- grid.233520.50000 0004 1761 4404Department of Health Statistics, The Fourth Military Medical University, Xi’an, 710032 Shaanxi China
| | - Kelun Wang
- grid.5117.20000 0001 0742 471XCenter for Sensory-Motor Interaction (SMI), Department of Health Science and Technology, Faculty of Medicine, Aalborg University, Fredrik BajersVej 7 D3, 9220 Aalborg, Denmark
| | - Meiqing Wang
- Shanghai Key Laboratory of Craniomaxillofacial Development and Diseases, Fudan University, Shanghai, China. .,Department of Oral Anatomy and Physiology, School of Stomatology, The Fourth Military Medical University, Xi'an, 710032, Shaanxi, China.
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Luderman LN, Michaels MT, Levic DS, Knapik EW. Zebrafish Erc1b mediates motor innervation and organization of craniofacial muscles in control of jaw movement. Dev Dyn 2023; 252:104-123. [PMID: 35708710 DOI: 10.1002/dvdy.511] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 05/31/2022] [Accepted: 06/03/2022] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Movement of the lower jaw, a common behavior observed among vertebrates, is required for eating and processing food. This movement is controlled by signals sent from the trigeminal motor nerve through neuromuscular junctions (NMJs) to the masticatory muscles. Dysfunctional jaw movements contribute to craniomandibular disorders, yet the pathophysiology of these disorders is not well understood, as limited studies have been conducted on the molecular mechanisms of jaw movement. RESULTS Using erc1b/kimm533 genetic loss of function mutant, we evaluated lower jaw muscle organization and innervation by the cranial motor nerves in developing zebrafish. Using time-lapse confocal imaging of the erc1b mutant in a transgenic fluorescent reporter line, we found delayed trigeminal nerve growth and disrupted nerve branching architecture during muscle innervation. By automated 3D image analysis of NMJ distribution, we identified an increased number of small, disorganized NMJ clusters in erc1b mutant larvae compared to WT siblings. Using genetic replacement experiments, we determined the Rab GTPase binding domain of Erc1b is required for cranial motor nerve branching, but not NMJ organization or muscle attachment. CONCLUSIONS We identified Erc1b/ERC1 as a novel component of a genetic pathway contributing to muscle organization, trigeminal nerve outgrowth, and NMJ spatial distribution during development that is required for jaw movement.
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Affiliation(s)
- Lauryn N Luderman
- Division of Genetic Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, USA
- Department of Cell Biology, Duke University Medical Center, Durham, North Carolina, USA
| | - Mackenzie T Michaels
- Division of Genetic Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Daniel S Levic
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, USA
- Department of Cell Biology, Duke University Medical Center, Durham, North Carolina, USA
- Neuroscience Graduate Program, Vanderbilt Brain Institute, Vanderbilt University, Nashville, Tennessee, USA
| | - Ela W Knapik
- Division of Genetic Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, USA
- Department of Cell Biology, Duke University Medical Center, Durham, North Carolina, USA
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Saini H, Klotz T, Röhrle O. Modelling motor units in 3D: influence on muscle contraction and joint force via a proof of concept simulation. Biomech Model Mechanobiol 2022; 22:593-610. [PMID: 36572787 PMCID: PMC10097764 DOI: 10.1007/s10237-022-01666-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 12/02/2022] [Indexed: 12/28/2022]
Abstract
AbstractFunctional heterogeneity is a skeletal muscle’s ability to generate diverse force vectors through localised motor unit (MU) recruitment. Existing 3D macroscopic continuum-mechanical finite element (FE) muscle models neglect MU anatomy and recruit muscle volume simultaneously, making them unsuitable for studying functional heterogeneity. Here, we develop a method to incorporate MU anatomy and information in 3D models. Virtual fibres in the muscle are grouped into MUs via a novel “virtual innervation” technique, which can control the units’ size, shape, position, and overlap. The discrete MU anatomy is then mapped to the FE mesh via statistical averaging, resulting in a volumetric MU distribution. Mesh dependency is investigated using a 2D idealised model and revealed that the amount of MU overlap is inversely proportional to mesh dependency. Simultaneous recruitment of a MU’s volume implies that action potentials (AP) propagate instantaneously. A 3D idealised model is used to verify this assumption, revealing that neglecting AP propagation results in a slightly less-steady force, advanced in time by approximately 20 ms, at the tendons. Lastly, the method is applied to a 3D, anatomically realistic model of the masticatory system to demonstrate the functional heterogeneity of masseter muscles in producing bite force. We found that the MU anatomy significantly affected bite force direction compared to bite force magnitude. MU position was much more efficacious in bringing about bite force changes than MU overlap. These results highlight the relevance of MU anatomy to muscle function and joint force, particularly for muscles with complex neuromuscular architecture.
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Affiliation(s)
- Harnoor Saini
- Institute of Modelling and Simulation of Biomechanical Systems, University of Stuttgart, Pfaffenwaldring 5a, 70569 Stuttgart, BW Germany
| | - Thomas Klotz
- Institute of Modelling and Simulation of Biomechanical Systems, University of Stuttgart, Pfaffenwaldring 5a, 70569 Stuttgart, BW Germany
| | - Oliver Röhrle
- Institute of Modelling and Simulation of Biomechanical Systems, University of Stuttgart, Pfaffenwaldring 5a, 70569 Stuttgart, BW Germany
- Stuttgart Center for Simulation Technology (SC SimTech), University of Stuttgart, Pfaffenwaldring 5a, 70569 Stuttgart, BW Germany
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5
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Kwon JS, Han SH, Im YG. Effect of passive jaw opening on the electromyographic activity of the temporalis, masseter, digastric, and infrahyoid muscles in healthy adults. Cranio 2022:1-9. [PMID: 35261336 DOI: 10.1080/08869634.2022.2048225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVE To investigate the surface electromyography (EMG) activity of the temporalis, masseter, digastric, and infrahyoid muscles during passive jaw opening in healthy adults. METHODS The EMG activity of the masseter, temporalis, digastric anterior belly, and infrahyoid muscles on the right side was recorded during the four jaw-opening tasks: active opening to 20 mm (AO20); active opening to 40 mm (AO40); passive opening to 40 mm with a rubber mouth prop on the right posterior teeth (POR40); and passive opening to 40 mm with a mouth prop on the left posterior teeth (POL40). RESULTS The EMG amplitude of the digastric anterior belly and infrahyoid muscles in either POL40 or POR40 was significantly less than that in AO20 or AO40, respectively. CONCLUSION Passive jaw opening reduces the EMG activity of the digastric and infrahyoid muscles significantly and could help reduce the load on these muscles during prolonged mouth-opening conditions.
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Affiliation(s)
- Jeong-Seung Kwon
- Department of Orofacial Pain & Oral Medicine, Yonsei Dental Hospital, Yonsei University College of Dentistry, Seoul, Republic of Korea
| | - Sang-Ho Han
- GnS International, Daejeon, Republic of Korea
| | - Yeong-Gwan Im
- Department of Oral Medicine, Dental Science Research Institute, School of Dentistry, Chonnam National University
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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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7
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Botzenhart UU, Keil C, Tsagkari E, Zeidler-Rentzsch I, Gredes T, Gedrange T. Influence of botulinum toxin A on craniofacial morphology after injection into the right masseter muscle of dystrophin deficient (mdx-) mice. Ann Anat 2021; 236:151715. [PMID: 33675949 DOI: 10.1016/j.aanat.2021.151715] [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: 01/08/2021] [Revised: 01/22/2021] [Accepted: 01/29/2021] [Indexed: 10/22/2022]
Abstract
BACKGROUND Severe craniofacial and dental abnormalities, typical for patients with progressive Duchenne muscular dystrophy (DMD), are an exellcent demonstration of Melvin L. Moss "functional matrix theory", highlighting the influence of muscle tissue on craniofacial growth and morphology. However, the currently best approved animal model for investigation of this interplay is the mdx-mouse, which offers only a limited time window for research, due to the ability of muscle regeneration, in contrast to the human course of the disease. The aim of this study was to evaluate craniofacial morphology after BTX-A induced muscle paralysis in C57Bl- and mdx-mice, to prove the suitability of BTX-A intervention to inhibit muscle regeneration in mdx-mice and thus, mimicking the human course of the DMD disease. METHODS Paralysis of the right masseter muscle was induced in 100 days old C57Bl- and mdx-mice by a single specific intramuscular BTX-A injection. Mice skulls were obtained at 21 days and 42 days after BTX-A injection and 3D radiological evaluation was performed in order to measure various craniofacial dimensions in the sagittal, transversal and vertical plane. Statstical analysis were performed using SigmaStat®Version 3.5. In case of normal distribution, unpaired t-test and otherwise the Mann-Whitney-U test was applied. A statistical significance was given in case of p ≤ 0.05. RESULTS In contrast to C57Bl-mice, in mdx-mice, three weeks after BTX-A treatment a significant decrease of skull dimensions was noted in most of the measurements followed by a significant increase at the second investigation period. CONCLUSIONS BTX-A can induce changes in craniofacial morphology and presumably partially inhibit muscle regeneration in mdx-mice, but cannot completely intensify craniofacial effects elicited by dystrophy. Further research is necessary in order to fully understand muscle-bone interplay after BTX-A injection into dystrophic muscles.
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Affiliation(s)
| | - Christiane Keil
- Medical Faculty Carl Gustav Carus Campus, TU Dresden, 01307, Dresden, Germany; Department of Orthodontics, Carl Gustav Carus Campus, TU Dresden, 01307, Dresden, Germany
| | - Eirini Tsagkari
- Department of Orthodontics, Faculty of Dentistry School of Health Sciences, Aristotle University of Thessaloniki, 54124, Thessaloniki, Greece
| | - Ines Zeidler-Rentzsch
- Department of Otorhinolaryngology, Head and Neck Surgery, Carl Gustav Carus Campus, TU Dresden, 01307, Dresden, Germany
| | - Tomasz Gredes
- Medical Faculty Carl Gustav Carus Campus, TU Dresden, 01307, Dresden, Germany; Department of Orthodontics, Carl Gustav Carus Campus, TU Dresden, 01307, Dresden, Germany
| | - Tomasz Gedrange
- Medical Faculty Carl Gustav Carus Campus, TU Dresden, 01307, Dresden, Germany
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Lim S, Brown JL, Washington TA, Greene NP. Development and progression of cancer cachexia: Perspectives from bench to bedside. SPORTS MEDICINE AND HEALTH SCIENCE 2020; 2:177-185. [PMID: 34447946 PMCID: PMC8386816 DOI: 10.1016/j.smhs.2020.10.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 10/24/2020] [Accepted: 10/28/2020] [Indexed: 02/06/2023] Open
Abstract
Cancer cachexia (CC) is a devastating syndrome characterized by weight loss, reduced fat mass and muscle mass that affects approximately 80% of cancer patients and is responsible for 22%-30% of cancer-associated deaths. Understanding underlying mechanisms for the development of CC are crucial to advance therapies to treat CC and improve cancer outcomes. CC is a multi-organ syndrome that results in extensive skeletal muscle and adipose tissue wasting; however, CC can impair other organs such as the liver, heart, brain, and bone as well. A considerable amount of CC research focuses on changes that occur within the muscle, but cancer-related impairments in other organ systems are understudied. Furthermore, metabolic changes in organ systems other than muscle may contribute to CC. Therefore, the purpose of this review is to address degenerative mechanisms which occur during CC from a whole-body perspective. Outlining the information known about metabolic changes that occur in response to cancer is necessary to develop and enhance therapies to treat CC. As much of the current evidences in CC are from pre-clinical models we should note the majority of the data reviewed here are from preclinical models.
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Affiliation(s)
- Seongkyun Lim
- Cachexia Research Laboratory, Exercise Science Research Center, Department of Human Health Performance and Recreation, University of Arkansas, 155 Stadium Dr, Fayetteville, AR, USA
| | - Jacob L. Brown
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, 825 NE 13th St, Oklahoma City, OK, USA
| | - Tyrone A. Washington
- Exercise Muscle Biology Laboratory, Exercise Science Research Center, Department of Human Health Performance and Recreation, University of Arkansas, 155 Stadium Dr, Fayetteville, AR, USA
| | - Nicholas P. Greene
- Cachexia Research Laboratory, Exercise Science Research Center, Department of Human Health Performance and Recreation, University of Arkansas, 155 Stadium Dr, Fayetteville, AR, USA
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Almotairy N, Kumar A, Grigoriadis A. Motor control strategies during unpredictable force control tasks in humans. J Oral Rehabil 2020; 47:1222-1232. [PMID: 32634248 DOI: 10.1111/joor.13052] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/15/2020] [Accepted: 06/30/2020] [Indexed: 01/08/2023]
Abstract
BACKGROUND There are fundamental similarities and differences between the jaw and hand motor systems. However, it is unclear how the two systems respond to unpredictable task demands. OBJECTIVE To investigate and compare the force control of the jaw motor system (OMS) and the hand motor system (HMS) during unpredictable load changes. METHODS Seventeen healthy adults (24.0 ± 4.3 years) performed two standardised force control tasks (OMS and HMS). During the OMS, the participants asked to bite and pull a force transducer with the front teeth. While during HMS they pinched and pulled the same force transducer with their index and thumb fingers. Series of loads were added to a string attached to the transducer in an unpredictable (sequential and non-sequential) manner. The entire force profile during the task was divided into "initial" and "latter" segments. The force control was analysed and compared between the OMS and HMS in terms of peak force during the initial segment and holding force and force variability during the latter segment. RESULTS The peak force, holding force and force variability were higher for the OMS than the HMS (P < .001). However, there were no differences in the peak force, holding force or force variability between the sequential and non-sequential load changes (P > .05). CONCLUSIONS The results showed that unpredictable load changes did not affect the force control during the motor control task. This study suggests that both the motor systems are optimised in performing simple motor control tasks and are rather resilient to motor unpredictability.
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Affiliation(s)
- Nabeel Almotairy
- Section of Oral Rehabilitation, Division of Oral Diagnostics and Rehabilitation, Department of Dental Medicine, Karolinska Institutet, Huddinge, Sweden.,Division of Orthodontics, Department of Preventive Dentistry, College of Dentistry, Qassim University, Buraidah, Saudi Arabia
| | - Abhishek Kumar
- Section of Oral Rehabilitation, Division of Oral Diagnostics and Rehabilitation, Department of Dental Medicine, Karolinska Institutet, Huddinge, Sweden
| | - Anastasios Grigoriadis
- Section of Oral Rehabilitation, Division of Oral Diagnostics and Rehabilitation, Department of Dental Medicine, Karolinska Institutet, Huddinge, Sweden
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10
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Laird MF, Granatosky MC, Taylor AB, Ross CF. Muscle architecture dynamics modulate performance of the superficial anterior temporalis muscle during chewing in capuchins. Sci Rep 2020; 10:6410. [PMID: 32286442 PMCID: PMC7156371 DOI: 10.1038/s41598-020-63376-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 03/30/2020] [Indexed: 11/09/2022] Open
Abstract
Jaw-muscle architecture is a key determinant of jaw movements and bite force. While static length-force and force-velocity relationships are well documented in mammals, architecture dynamics of the chewing muscles and their impact on muscle performance are largely unknown. We provide novel data on how fiber architecture of the superficial anterior temporalis (SAT) varies dynamically during naturalistic feeding in tufted capuchins (Sapajus apella). We collected data on architecture dynamics (changes in muscle shape or the architectural gear ratio) during the gape cycle while subjects fed on foods of different mechanical properties. Architecture of the SAT varied with phases of the gape cycle, but gape distance accounted for the majority of dynamic changes in architecture. In addition, lower gear ratios (low muscle velocity relative to fascicle velocity) were observed when animals chewed on more mechanically resistant foods. At lower gear ratios, fibers rotated less during shortening resulting in smaller pinnation angles, a configuration that favors increased force production. Our results suggest that architectural dynamics may influence jaw-muscle performance by enabling the production of higher bite forces during the occlusal phase of the gape cycle and while processing mechanically challenging foods.
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Affiliation(s)
- Myra F Laird
- Department of Integrative Anatomical Sciences, University of Southern California, Los Angeles, CA, USA.
| | | | - Andrea B Taylor
- Basic Science Department, Touro University, Vallejo, CA, USA
| | - Callum F Ross
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL, USA
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Laird MF, Ross CF, O'Higgins P. Jaw kinematics and mandibular morphology in humans. J Hum Evol 2020; 139:102639. [DOI: 10.1016/j.jhevol.2019.102639] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 07/05/2019] [Accepted: 07/08/2019] [Indexed: 10/25/2022]
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12
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Yilmaz G, Budan AS, Ungan P, Topkara B, Türker KS. Facial muscle activity contaminates EEG signal at rest: evidence from frontalis and temporalis motor units. J Neural Eng 2019; 16:066029. [DOI: 10.1088/1741-2552/ab3235] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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13
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Villaça Avoglio JL. Dental occlusion as one cause of tinnitus. Med Hypotheses 2019; 130:109280. [PMID: 31383322 DOI: 10.1016/j.mehy.2019.109280] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 06/11/2019] [Indexed: 11/26/2022]
Abstract
There is large support in literature linking tinnitus to dental occlusion and temporomandibular joint disorders (TMD). However, there is no model to explain such a link. This hypothesis explains how the fusimotor system of the muscles innervated by the trigeminal motor nucleus is affected by inadequacies in the occlusion of the teeth that cause changes in posture and movement of the mandible. Reptile to mammal evolution shows that stomatognathic structures underwent changes related to mastication. Among several changes, there was the appearance of a new articulation between the mandible and skull: the temporomandibular joint. The bones of the old reptile joint, quadrate-articular, have detached from the mandible and are part of the middle ear bone chain. The former becomes the incus and the latter the malleus. This bone change also carried the tensor tympani and its trigeminal motor innervation. Inadequate occlusal contacts give rise to an adapted function of the mandible and the most common compensatory muscular response is hypertonia involving all mandibular muscles, including the tensor tympani. A fundamental clinical feature that demonstrates the involvement of the trigeminal fusimotor system is the characteristic pain by palpation, but no pain on the mandibular movement. Muscle pain is always felt in the dermatome innervated by the mandibular branch of the trigeminal nerve, which carries the motor fibers, reported as tightening, similar to cramp, and has regular behavior in intensity, duration and frequency. In addition, the patient has increased musculature volume, detected by palpation of certain anatomical landmarks, but with loss of functional efficiency. The neuromotor control of the mandibular movements is poor and when asked to make lateral jaw movement touching the teeth, it is common to observe that the patient moves the lips, eyes, and even turns the head in the same direction as the movement. There is also difficulty eating hard foods and talking fast. Tongue biting while chewing is frequent, meaning that these non-physiological events surpass protective reflex circuits. The report of ear pain, tinnitus, blocked ear sensation and sudden hearing loss is common in such patients, compatible with the tonic contraction of the tensor tympani. The fusimotor system hypothesis is able to explain all events related to the symptoms and helps to establish a correct diagnosis for certain types of hearing disorders.
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Coclici A, Hedeşiu M, Bran S, Băciuţ M, Dinu C, Rotaru H, Roman R. Early and long-term changes in the muscles of the mandible following orthognathic surgery. Clin Oral Investig 2019; 23:3437-3444. [PMID: 31352516 DOI: 10.1007/s00784-019-03019-3] [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: 12/06/2018] [Accepted: 07/11/2019] [Indexed: 02/07/2023]
Abstract
OBJECTIVES The aim of the present study is to evaluate the early and long-term postoperative dimensional changes of the muscles of the mandible in patients with orthognathic surgery for class II and class III malocclusions by using ultrasonography (US). MATERIAL AND METHODS Twenty-six patients who underwent bimaxillary orthognathic surgery for class II or class III malocclusions (14 and 12 patients, respectively) were ultrasonographically examined. The length, width, and cross-sectional area of the masseter and suprahyoid muscles were measured at three different time points: T0 (preoperatively), T1 (early postoperatively at 1 month after the surgery), and T2 (late postoperatively at 9 months). A repeated measures ANOVA was used to calculate statistically significant dimensional changes of the mandibular muscles. RESULTS Statistically significant dimensional changes were found postoperatively in class II malocclusion patients only. The digastric muscle showed higher values for the length and lower values for the width (p < .05) at T1. The geniohyoid muscles were higher in length at T1 and lower in cross-sectional area (CSA) (p < .05) at T2. A decreased measured length and an increased measured width were found in case of the mylohyoid muscle (p < .05) at T2. The early and long-term postoperative dimensional changes of the masseter muscle were not statistically significant. CONCLUSIONS The mandibular muscles showed a variable adaptive response to the orthognathic surgery. US should be considered for the long-term follow-up of muscular dimensional changes in class II malocclusion patients. CLINICAL RELEVANCE From a clinical perspective, US is a reliable, non-invasive, and widely available method, which allows monitoring the postoperative muscular changes occurring in class II malocclusion patients.
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Affiliation(s)
- Alina Coclici
- Department of Oral Radiology, University of Medicine and Pharmacy, 31, Avram Iancu, 400083, Cluj Napoca, Romania
| | - Mihaela Hedeşiu
- Department of Oral Radiology, University of Medicine and Pharmacy, 31, Avram Iancu, 400083, Cluj Napoca, Romania.
| | - Simion Bran
- Department of Maxillofacial Surgery, University of Medicine and Pharmacy, Cluj Napoca, Romania
| | - Mihaela Băciuţ
- Department of Maxillofacial Surgery, University of Medicine and Pharmacy, Cluj Napoca, Romania
| | - Cristian Dinu
- Department of Maxillofacial Surgery, University of Medicine and Pharmacy, Cluj Napoca, Romania
| | - Horatiu Rotaru
- Department of Maxillofacial Surgery, University of Medicine and Pharmacy, Cluj Napoca, Romania
| | - Raluca Roman
- Department of Oral Radiology, University of Medicine and Pharmacy, 31, Avram Iancu, 400083, Cluj Napoca, Romania
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Lee HJ, Choi YJ, Lee KW, Hu KS, Kim ST, Kim HJ. Ultrasonography of the internal architecture of the superficial part of the masseter muscle in vivo. Clin Anat 2019; 32:446-452. [PMID: 30664275 DOI: 10.1002/ca.23337] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 12/28/2018] [Accepted: 01/06/2019] [Indexed: 12/11/2022]
Abstract
It is unclear whether the deep inferior tendon (DIT) is equally present in vivo, and little anatomical information is available regarding the existence and morphology of the DIT in healthy young subjects. The aim of this study was to characterize the DIT of the masseter muscle in healthy young subjects using ultrasonography and to compare the morphology of this tendon with previously reported data for healthy young subjects in order to provide the most-effective injection methods for botulinum neurotoxin treatments of masseteric hypertrophy. This study investigated two fresh cadavers and 30 healthy subjects. Ultrasonography scanning in both longitudinal and transverse directions was applied to the masseter muscle. The DIT within the superficial part of the masseter was observed in both the fresh cadavers and the living subjects. The posterior region of the masseter muscle was compartmentalized (entirely covered) by the DIT in 26.7% of the specimens. The superficial part of the masseter muscle was divided by the DIT transversely and longitudinally into the superficial and deep muscle bellies in 35% and 38.3% of the specimens, respectively. The present findings suggest applying a DIT-based injection technique under guidance by ultrasonography prior to treating masseteric hypertrophy. Clin. Anat. 32:446-452, 2019. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- Hyung-Jin Lee
- Division in Anatomy and Developmental Biology, Department of Oral Biology, Human Identification Research Institute, BK21 PLUS Project, Yonsei University College of Dentistry, Seoul, South Korea
| | - You-Jin Choi
- Department of Anatomy, Yonsei University College of Medicine, Seoul, South Korea
| | - Kang-Woo Lee
- Division in Anatomy and Developmental Biology, Department of Oral Biology, Human Identification Research Institute, BK21 PLUS Project, Yonsei University College of Dentistry, Seoul, South Korea
| | - Kyung-Seok Hu
- Division in Anatomy and Developmental Biology, Department of Oral Biology, Human Identification Research Institute, BK21 PLUS Project, Yonsei University College of Dentistry, Seoul, South Korea
| | - Seong Taek Kim
- Department of Orofacial Pain and Oral Medicine, Yonsei University College of Dentistry, Seoul, South Korea
| | - Hee-Jin Kim
- Division in Anatomy and Developmental Biology, Department of Oral Biology, Human Identification Research Institute, BK21 PLUS Project, Yonsei University College of Dentistry, Seoul, South Korea.,Department of Materials Science and Engineering, College of Engineering, Yonsei University Seoul, Seoul, South Korea
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Isola G, Anastasi GP, Matarese G, Williams RC, Cutroneo G, Bracco P, Piancino MG. Functional and molecular outcomes of the human masticatory muscles. Oral Dis 2018; 24:1428-1441. [PMID: 29156093 DOI: 10.1111/odi.12806] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 10/30/2017] [Accepted: 11/14/2017] [Indexed: 02/05/2023]
Abstract
The masticatory muscles achieve a broad range of different activities such as chewing, sucking, swallowing, and speech. In order to accomplish these duties, masticatory muscles have a unique and heterogeneous structure and fiber composition, enabling them to produce their strength and contraction speed largely dependent on their motor units and myosin proteins that can change in response to genetic and environmental factors. Human masticatory muscles express unique myosin isoforms, including a combination of thick fibers, expressing myosin light chains (MyLC) and myosin class I and II heavy chains (MyHC) -IIA, -IIX, α-cardiac, embryonic and neonatal and thin fibers, respectively. In this review, we discuss the current knowledge regarding the importance of fiber-type diversity in masticatory muscles versus supra- and infrahyoid muscles, and versus limb and trunk muscles. We also highlight new information regarding the adaptive response and specific genetic variations of muscle fibers on the functional significance of the masticatory muscles, which influences craniofacial characteristics, malocclusions, or asymmetry. These findings may offer future possibilities for the prevention of craniofacial growth disturbances.
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Affiliation(s)
- G Isola
- Department of Biomedical, Odontostomatological Sciences and of Morphological and Functional Images, School of Dentistry, University of Messina, Messina, Italy
| | - G P Anastasi
- Department of Biomedical, Odontostomatological Sciences and of Morphological and Functional Images, School of Dentistry, University of Messina, Messina, Italy
| | - G Matarese
- Department of Biomedical, Odontostomatological Sciences and of Morphological and Functional Images, School of Dentistry, University of Messina, Messina, Italy
| | - R C Williams
- Department of Periodontology, UNC School of Dentistry, Chapel Hill, NC, USA
| | - G Cutroneo
- Department of Biomedical, Odontostomatological Sciences and of Morphological and Functional Images, School of Dentistry, University of Messina, Messina, Italy
| | - P Bracco
- Department of Orthodontics and Gnathology-Masticatory Function, University of Turin, Turin, Italy
| | - M G Piancino
- Department of Orthodontics and Gnathology-Masticatory Function, University of Turin, Turin, Italy
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Guzmán-Venegas RA, Palma FH, Biotti P JL, de la Rosa FJB. Spectral components in electromyograms from four regions of the human masseter, in natural dentate and edentulous subjects with removable prostheses and implants. Arch Oral Biol 2018; 90:130-137. [PMID: 29609053 DOI: 10.1016/j.archoralbio.2018.03.010] [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: 09/20/2017] [Revised: 03/20/2018] [Accepted: 03/22/2018] [Indexed: 01/22/2023]
Abstract
OBJECTIVE To compare the frequency or spectral components between different regions of the superficial masseter in young natural dentate and total edentulous older adults rehabilitated with removable prostheses and fixed-implant support. A secondary objective was to compare these components between the three groups. DESIGN 21 young natural dentate and 28 edentulous (14 with removable prostheses and 14 with fixed-implant support) were assessed. High-density surface electromyography (sEMG) was recorded in four portions of the superficial masseter during submaximal isometric bites. Spectral components were obtained through a spectral analysis of the sEMG signals. An analysis of mixed models was used to compare the spectral components. RESULTS In all groups, the spectral components of the anterior portion were lower than in the posterior region (p < 0.05). Both edentulous groups showed lower spectral components and median frequency slope than the natural dentate group (p < 0.05). The removable prostheses group showed the greatest differences with natural dentate group. CONCLUSIONS There were significant differences in the spectral components recorded in the different regions of the superficial masseter. The lower spectral components and fatigability of older adults rehabilitated with prostheses could be a cause of a greater loss of type II fibers, especially in the removable prostheses group.
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Affiliation(s)
- Rodrigo A Guzmán-Venegas
- Laboratorio Integrativo de Biomecánica y Fisiología del Esfuerzo (LIBFE), Escuela de Kinesiología, Facultad de Medicina, Universidad de los Andes, Monseñor Álvaro del Portillo 12455, Santiago, Chile.
| | - Felipe H Palma
- Laboratorio Integrativo de Biomecánica y Fisiología del Esfuerzo (LIBFE), Escuela de Kinesiología, Facultad de Medicina, Universidad de los Andes, Monseñor Álvaro del Portillo 12455, Santiago, Chile
| | - Jorge L Biotti P
- Facultad de Odontología, Universidad de los Andes, Monseñor Álvaro del Portillo 12455, Santiago, Chile
| | - Francisco J Berral de la Rosa
- Laboratorio de Biomecánica, Kinesiología y Cineantropometría, Universidad Pablo de Olavide, Carretera de Utrera km 1, Seville, Spain
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Yilmaz G, Ungan P, Türker KS. EEG-like signals can be synthesized from surface representations of single motor units of facial muscles. Exp Brain Res 2018; 236:1007-1017. [DOI: 10.1007/s00221-018-5194-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 02/01/2018] [Indexed: 11/30/2022]
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Muzalev K, Lobbezoo F, Janal MN, Raphael KG. Interepisode Sleep Bruxism Intervals and Myofascial Face Pain. Sleep 2017; 40:3800074. [PMID: 28482089 DOI: 10.1093/sleep/zsx078] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Study Objectives Sleep bruxism (SB) is considered as a possible etiological factor for temporomandibular disorder (TMD) pain. However, polysomnographic (PSG) studies, which are current "gold standard" diagnostic approach to SB, failed to prove an association between SB and TMD. A possible explanation could be that PSG studies have considered only limited characteristics of SB activity: the number of SB events per hour and, sometimes, the total duration of SB per night. According to the sports sciences literature, lack of adequate rest time between muscle activities leads to muscle overloading and pain. Therefore, the aim of this study was to determine whether the intervals between bruxism events differ between patients with and without TMD pain. Methods Two groups of female volunteers were recruited: myofascial TMD pain group (n=124) and non-TMD control group (n=46). From these groups, we selected 86 (69%) case participants and 37 (80%) controls who had at least two SB episodes per night based on PSG recordings. A linear mixed model was used to compare case and control groups over the repeated observations of interepisode intervals. Results The duration of interepisode intervals was statistically similar in the case (mean [standard deviation {SD}] 1137.7 [1975.8] seconds)] and control (mean [SD] 1192.0 [1972.0] seconds) groups. There were also a similar number of SB episodes per hour and a total duration of SB episodes in both groups. Conclusions The current data fail to support the idea that TMD pain can be explained by increasing number of SB episodes per hour of sleep or decreasing the time between SB events.
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Affiliation(s)
- Konstantin Muzalev
- Department of Oral Kinesiology, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Frank Lobbezoo
- Department of Oral Kinesiology, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.,Department of Oral and Maxillofacial Pathology, Radiology, and Medicine, New York University College of Dentistry, New York, NY
| | - Malvin N Janal
- Department of Epidemiology and Health Promotion, New York University College of Dentistry, New York, NY
| | - Karen G Raphael
- Department of Oral and Maxillofacial Pathology, Radiology, and Medicine, New York University College of Dentistry, New York, NY
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Korfage JAM, Koolstra JH, Langenbach GEJ, van Eijden TMGJ. Fiber-type Composition of the Human Jaw Muscles—(Part 1) Origin and Functional Significance of Fiber-type Diversity. J Dent Res 2016; 84:774-83. [PMID: 16109984 DOI: 10.1177/154405910508400901] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
This is the first of two articles on the fiber-type composition of the human jaw muscles. The present article discusses the origin of fiber-type composition and its consequences. This discussion is presented in the context of the requirements for functional performance and adaptation that are imposed upon the jaw muscles. The human masticatory system must perform a much larger variety of motor tasks than the average limb or trunk motor system. An important advantage of fiber-type diversity, as observed in the jaw muscles, is that it optimizes the required function while minimizing energy use. The capacity for adaptation is reflected by the large variability in fiber-type composition among muscle groups, individual muscles, and muscle regions. Adaptive changes are related, for example, to the amount of daily activation and/or stretch of fibers. Generally, the number of slow, fatigue-resistant fibers is relatively large in muscles and muscle regions that are subjected to considerable activity and/or stretch.
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Affiliation(s)
- J A M Korfage
- Department of Functional Anatomy, Academic Center for Dentistry Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
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21
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Schindler HJ, Rues S, Türp JC, Schweizerhof K, Lenz J. Jaw Clenching: Muscle and Joint Forces, Optimization Strategies. J Dent Res 2016; 86:843-7. [PMID: 17720852 DOI: 10.1177/154405910708600907] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Realistic masticatory muscle and temporomandibular joint forces generated during bilateral jaw clenching are largely unknown. To determine which clenching directions load masticatory muscles and temporomandibular joints most heavily, we investigated muscle and joint forces based on feedback-controlled electromyograms of all jaw muscles, lines of action, geometrical data from the skull, and physiological cross-sectional areas acquired from the same individuals. To identify possible motor control strategies, we applied objective functions. The medial pterygoid turned out to be the most heavily loaded muscle for all bite directions. Biting with accentuated horizontal force components provoked the highest loading within the medial and lateral pterygoids. The largest joint forces were also found for these bite directions. Conversely, the lowest joint forces were detected during vertical biting. Additionally, joint forces with a clear posterior orientation were found. Optimization strategies with the elastic energy as objective function revealed the best fit with the calculated results.
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Affiliation(s)
- H J Schindler
- Research Group Biomechanics, Faculty for Mathematics, University of Karlsruhe, D-76128, Karlsruhe, Germany.
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Influence of Botulinumtoxin A on the Expression of Adult MyHC Isoforms in the Masticatory Muscles in Dystrophin-Deficient Mice (Mdx-Mice). BIOMED RESEARCH INTERNATIONAL 2016; 2016:7063093. [PMID: 27689088 PMCID: PMC5023834 DOI: 10.1155/2016/7063093] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 06/27/2016] [Accepted: 07/10/2016] [Indexed: 11/17/2022]
Abstract
The most widespread animal model to investigate Duchenne muscular dystrophy is the mdx-mouse. In contrast to humans, phases of muscle degeneration are replaced by regeneration processes; hence there is only a restricted time slot for research. The aim of the study was to investigate if an intramuscular injection of BTX-A is able to break down muscle regeneration and has direct implications on the gene expression of myosin heavy chains in the corresponding treated and untreated muscles. Therefore, paralysis of the right masseter muscle was induced in adult healthy and dystrophic mice by a specific intramuscular injection of BTX-A. After 21 days the mRNA expression and protein content of MyHC isoforms of the right and left masseter, temporal, and the tongue muscle were determined using quantitative RT-PCR and Western blot technique. MyHC-IIa and MyHC-I-mRNA expression significantly increased in the paralyzed masseter muscle of control-mice, whereas MyHC-IIb and MyHC-IIx/d-mRNA were decreased. In dystrophic muscles no effect of BTX-A could be detected at the level of MyHC. This study suggests that BTX-A injection is a suitable method to simulate DMD-pathogenesis in healthy mice but further investigations are necessary to fully analyse the BTX-A effect and to generate sustained muscular atrophy in mdx-mice.
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23
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Scarr G, Harrison H. Resolving the problems and controversies surrounding temporo-mandibular mechanics. J Appl Biomed 2016. [DOI: 10.1016/j.jab.2016.03.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
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Giannakopoulos NN, Katsikogianni EN, Hellmann D, Eberhard L, Leckel M, Schindler HJ, Schmitter M. Comparison of three different options for immediate treatment of painful temporomandibular disorders: a randomized, controlled pilot trial. Acta Odontol Scand 2016; 74:480-6. [PMID: 27410169 DOI: 10.1080/00016357.2016.1204558] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVE The purpose of this study was to compare the short-term effectiveness of three different types of immediate, non-pharmacological intervention for alleviation of the painful symptoms of temporomandibular disorders (TMD). MATERIAL AND METHODS Thirty-six patients (mean age 41.6 ± 16.7 years, 25 females) diagnosed with non-dysfunctional painful TMD received counselling and subsequently were randomly allocated to three treatment groups: patients in Group A received prefabricated oral splints with water-filled elastic pads (Aqualizer(®)), those in Group B were provided with vacuum-formed co-polyester oral splints and those in Group C were given appointments to receive Michigan-type hard splints. Clinical examination was conducted, at baseline and after 2 weeks, by use of the RDC/TMD. Current pain intensity was determined by evaluation of graded chronic pain status (GCPS) on a numerical rating scale (NRS). Active maximum mouth opening without pain (AMMOP) was also measured. Paired sample t-tests and one-way analysis of variance with a significance level of p ≤ 0.05 were conducted. RESULTS After 2 weeks, overall mean current pain was reduced by 41.95% (p < 0.001). Current pain reduction was significant for Group B (66.6%, p < 0.001) but not for Groups A (37.88%, p = 0.56) and C (22.29%, p = 0.26). After 2 weeks, current pain level for Group B was significantly lower than that for Group C (p = 0.041). Overall, there was a statistically significant increase of AMMOP (p = 0.01). CONCLUSION All therapeutic options were pain-reducing. The results from this study suggest that cost-effective and time-effective intervention of counselling combined with use of a vacuum-formed splint is a favourable option for initial, short-term treatment of painful TMD.
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25
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Costa YM, Porporatti AL, Hilgenberg-Sydney PB, Bonjardim LR, Conti PCR. Deep pain sensitivity is correlated with oral-health-related quality of life but not with prosthetic factors in complete denture wearers. J Appl Oral Sci 2016; 23:555-61. [PMID: 26814457 PMCID: PMC4716693 DOI: 10.1590/1678-775720150174] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 07/31/2015] [Indexed: 11/22/2022] Open
Abstract
Low pressure Pain Threshold (PPT) is considered a risk factor for Temporomandibular Disorders (TMD) and is influenced by psychological variables. Objectives To correlate deep pain sensitivity of masticatory muscles with prosthetic factors and Oral-Health-Related Quality of Life (OHRQoL) in completely edentulous subjects. Material and Methods A total of 29 complete denture wearers were recruited. The variables were: a) Pressure Pain Threshold (PPT) of the masseter and temporalis; b) retention, stability, and tooth wear of dentures; c) Vertical Dimension of Occlusion (VDO); d) Oral Health Impact Profile (OHIP) adapted to orofacial pain. The Kolmogorov-Smirnov test, the Pearson Product-Moment correlation coefficient, the Spearman Rank correlation coefficient, the Point-Biserial correlation coefficient, and the Bonferroni correction (α=1%) were applied to the data. Results The mean age (standard deviation) of the participants was of 70.1 years (9.5) and 82% of them were females. There were no significant correlations with prosthetic factors, but significant negative correlations were found between the OHIP and the PPT of the anterior temporalis (r=-0.50, 95% CI-0.73 to 0.17, p=0.005). Discussion The deep pain sensitivity of masticatory muscles in complete dentures wearers is associated with OHRQoL, but not with prosthetic factors.
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Affiliation(s)
- Yuri Martins Costa
- Departamento de Prótese, Faculdade de Odontologia de Bauru, Universidade de São Paulo, Bauru, SP, Brasil
| | - André Luís Porporatti
- Departamento de Prótese, Faculdade de Odontologia de Bauru, Universidade de São Paulo, Bauru, SP, Brasil
| | | | - Leonardo Rigoldi Bonjardim
- Departamento de Ciências Biologicas, Faculdade de Odontologia de Bauru, Universidade de São Paulo, Bauru, SP, Brasil
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Aiello BR, Iriarte-Diaz J, Blob RW, Butcher MT, Carrano MT, Espinoza NR, Main RP, Ross CF. Bone strain magnitude is correlated with bone strain rate in tetrapods: implications for models of mechanotransduction. Proc Biol Sci 2015; 282:20150321. [PMID: 26063842 PMCID: PMC4590470 DOI: 10.1098/rspb.2015.0321] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 05/13/2015] [Indexed: 11/12/2022] Open
Abstract
Hypotheses suggest that structural integrity of vertebrate bones is maintained by controlling bone strain magnitude via adaptive modelling in response to mechanical stimuli. Increased tissue-level strain magnitude and rate have both been identified as potent stimuli leading to increased bone formation. Mechanotransduction models hypothesize that osteocytes sense bone deformation by detecting fluid flow-induced drag in the bone's lacunar-canalicular porosity. This model suggests that the osteocyte's intracellular response depends on fluid-flow rate, a product of bone strain rate and gradient, but does not provide a mechanism for detection of strain magnitude. Such a mechanism is necessary for bone modelling to adapt to loads, because strain magnitude is an important determinant of skeletal fracture. Using strain gauge data from the limb bones of amphibians, reptiles, birds and mammals, we identified strong correlations between strain rate and magnitude across clades employing diverse locomotor styles and degrees of rhythmicity. The breadth of our sample suggests that this pattern is likely to be a common feature of tetrapod bone loading. Moreover, finding that bone strain magnitude is encoded in strain rate at the tissue level is consistent with the hypothesis that it might be encoded in fluid-flow rate at the cellular level, facilitating bone adaptation via mechanotransduction.
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Affiliation(s)
- B R Aiello
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637, USA
| | - J Iriarte-Diaz
- Department of Oral Biology, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - R W Blob
- Department of Biological Sciences, Clemson University, Clemson, SC 29634, USA
| | - M T Butcher
- Department of Biological Sciences, Youngstown State University, Youngstown, OH 44555, USA
| | - M T Carrano
- Department of Paleobiology, Smithsonian Institution, Washington, DC 20013, USA
| | - N R Espinoza
- Department of Biological Sciences, Clemson University, Clemson, SC 29634, USA
| | - R P Main
- Department of Basic Medical Sciences, College of Veterinary Medicine and Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - C F Ross
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637, USA
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D'Amico JM, Yavuz ŞU, Saraçoglu A, Atiş ES, Gorassini MA, Türker KS. Activation properties of trigeminal motoneurons in participants with and without bruxism. J Neurophysiol 2013; 110:2863-72. [PMID: 24068753 DOI: 10.1152/jn.00536.2013] [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] [Indexed: 11/22/2022] Open
Abstract
In animals, sodium- and calcium-mediated persistent inward currents (PICs), which produce long-lasting periods of depolarization under conditions of low synaptic drive, can be activated in trigeminal motoneurons following the application of the monoamine serotonin. Here we examined if PICs are activated in human trigeminal motoneurons during voluntary contractions and under physiological levels of monoaminergic drive (e.g., serotonin and norepinephrine) using a paired motor unit analysis technique. We also examined if PICs activated during voluntary contractions are larger in participants who demonstrate involuntary chewing during sleep (bruxism), which is accompanied by periods of high monoaminergic drive. In control participants, during a slowly increasing and then decreasing isometric contraction, the firing rate of an earlier-recruited masseter motor unit, which served as a measure of synaptic input to a later-recruited test unit, was consistently lower during derecruitment of the test unit compared with at recruitment (ΔF = 4.6 ± 1.5 imp/s). The ΔF, therefore, is a measure of the reduction in synaptic input needed to counteract the depolarization from the PIC to provide an indirect estimate of PIC amplitude. The range of ΔF values measured in the bruxer participants during similar voluntary contractions was the same as in controls, suggesting that abnormally high levels of monoaminergic drive are not continually present in the absence of involuntary motor activity. We also observed a consistent "onion skin effect" during the moderately sized contractions (<20% of maximal), whereby the firing rate of higher threshold motor units discharged at slower rates (by 4-7 imp/s) compared with motor units with relatively lower thresholds. The presence of lower firing rates in the more fatigue-prone, higher threshold trigeminal motoneurons, in addition to the activation of PICs, likely facilitates the activation of the masseter muscle during motor activities such as eating, nonnutritive chewing, clenching, and yawning.
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Affiliation(s)
- Jessica M D'Amico
- Department of Biomedical Engineering, Centre for Neuroscience, University of Alberta, Canada
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Fitton LC, Shi JF, Fagan MJ, O'Higgins P. Masticatory loadings and cranial deformation in Macaca fascicularis: a finite element analysis sensitivity study. J Anat 2012; 221:55-68. [PMID: 22690885 DOI: 10.1111/j.1469-7580.2012.01516.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Biomechanical analyses are commonly conducted to investigate how craniofacial form relates to function, particularly in relation to dietary adaptations. However, in the absence of corresponding muscle activation patterns, incomplete muscle data recorded experimentally for different individuals during different feeding tasks are frequently substituted. This study uses finite element analysis (FEA) to examine the sensitivity of the mechanical response of a Macaca fascicularis cranium to varying muscle activation patterns predicted via multibody dynamic analysis. Relative to the effects of varying bite location, the consequences of simulated variations in muscle activation patterns and of the inclusion/exclusion of whole muscle groups were investigated. The resulting cranial deformations were compared using two approaches; strain maps and geometric morphometric analyses. The results indicate that, with bite force magnitude controlled, the variations among the mechanical responses of the cranium to bite location far outweigh those observed as a consequence of varying muscle activations. However, zygomatic deformation was an exception, with the activation levels of superficial masseter being most influential in this regard. The anterior portion of temporalis deforms the cranial vault, but the remaining muscles have less profound effects. This study for the first time systematically quantifies the sensitivity of an FEA model of a primate skull to widely varying masticatory muscle activations and finds that, with the exception of the zygomatic arch, reasonable variants of muscle loading for a second molar bite have considerably less effect on cranial deformation and the resulting strain map than does varying molar bite point. The implication is that FEA models of biting crania will generally produce acceptable estimates of deformation under load as long as muscle activations and forces are reasonably approximated. In any one FEA study, the biological significance of the error in applied muscle forces is best judged against the magnitude of the effect that is being investigated.
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Affiliation(s)
- L C Fitton
- Centre for Anatomical and Human Sciences, Hull York Medical School, University of York, UK.
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Cvetko E, Karen P, Janáček J, Kubínová L, Plasencia AL, Eržen I. Human masseter muscle fibers from the elderly express less neonatal Myosin than those of young adults. Anat Rec (Hoboken) 2012; 295:1364-72. [PMID: 22707480 DOI: 10.1002/ar.22512] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Revised: 05/08/2012] [Accepted: 05/10/2012] [Indexed: 11/08/2022]
Abstract
In contrast to limb muscles where neonatal myosin (MyHC-neo) is present only shortly after birth, adult masseter muscles contain a substantial portion of MyHC-neo, which is coexpressed with mature MyHC isoforms. Changes in the numerical and area proportion of muscle fibers containing MyHC-neo in masseter muscle with aging could be expected, based on previously reported findings that (i) developmental MyHC-containing muscle fibers exhibit lower shortening velocities compared to fibers with exclusively fast MyHC isoforms and (ii) transformation toward faster phenotype occurs in elderly compared to young masseter muscle. In this study, we detected MyHC isoforms in the anterior superficial part of the human masseter muscle in a sufficiently large sample of young, middle-aged, and elderly subjects to reveal age-related changes in the coexpression of MyHC-neo with adult MyHC isoforms. MyHC isoforms were visualized with immunoperoxidase method and the results were presented by (i) the area proportion of fibers containing particular MyHC isoforms and (ii) the numerical proportion of fiber types defined by MyHC-1, -2a, -2x, and -neonatal isoform expression from a successive transverse sections. We found a lower numerical and area proportion of fibers expressing MyHC-neo as well as a lower area proportion of fibers containing MyHC-1 in elderly than in young subjects. We conclude that the diminished expression of MyHC-neo with age could point to a lower regeneration capacity of masseter muscle in the elderly.
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Affiliation(s)
- Erika Cvetko
- Institute of Anatomy, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.
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30
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Myosin heavy chain composition of the human sternocleidomastoid muscle. Ann Anat 2012; 194:467-72. [PMID: 22658700 DOI: 10.1016/j.aanat.2012.05.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Revised: 04/17/2012] [Accepted: 05/02/2012] [Indexed: 11/24/2022]
Abstract
The sternocleidomastoid (SCM) muscle is one of the neck muscles responsible for head posture and control of head movement. It functions in rotation, inclination, protraction, extension and flexion of the head, whilst chewing and in exerting increased respiratory efforts. This study is the first one describing the myosin heavy chain (MyHC) isoform composition of the SCM muscle of presumably healthy young males for the purpose of better understanding the contractile properties of the muscle as well as to help in evaluation of pathologically altered structure of the muscle. Autopsy samples were processed immunohistochemically to reveal the MyHC isoform composition. The muscle fibres expressed MyHC-1 (31.5%), -2a (29.7%) and -2x (4.3%) or co-expressed MyHC-2a with MyHC-2x (26.8%), MyHC-1 with MyHC-2a (4.1%) and/or MyHC-1, -2a with -2x (1.1%). In addition to the MyHC isoforms, characteristic of adult limb muscles, a very low percentage of muscle fibres (0.2-2.7%) expressed MyHC-neo, which is normally not found in adult limb muscles. Only two samples exhibited MyHC-neo at a rather higher percentage (6.3% and 7.5%) of muscle fibres. The high share of hybrid fibres and the presence of MyHC-neo in the SCM muscle differ from that of adult limb muscles where hybrid fibres are rare and the expression of immature MyHC isoforms occurs only in pathological or experimental conditions. Since the SCM muscle shares the same embryogenic potential as limb muscles, its distinct MyHC expression appears to be associated with twin innervation and with the intrinsic specialisation to perform multiple functions.
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31
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Firing duration of masseter motor units during prolonged low-level contractions. Clin Neurophysiol 2011; 122:2433-40. [DOI: 10.1016/j.clinph.2011.05.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2010] [Revised: 05/13/2011] [Accepted: 05/14/2011] [Indexed: 11/20/2022]
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32
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Cioffi I, Gallo LM, Palla S, Erni S, Farella M. Macroscopic Analysis of Human Masseter Compartments Assessed by Magnetic Resonance Imaging. Cells Tissues Organs 2011; 195:465-72. [DOI: 10.1159/000329503] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/17/2011] [Indexed: 12/18/2022] Open
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Kent RD, Robbins J. Introduction to the special issue, Integrative neural systems underlying vital aerodigestive tract functions. Madison, Wisconsin, June 17–19, 2010. Head Neck 2011; 33 Suppl 1:S1-4. [PMID: 21901778 DOI: 10.1002/hed.21900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/05/2011] [Indexed: 11/10/2022] Open
Affiliation(s)
- Ray D Kent
- Department of Communicative Disorders, Waisman Center, University of Wisconsin, Madison, Wisconsin, USA
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Abstract
In the masticatory system, activities of muscles are the main source of force. The daily activity of the jaw muscle is a measure of the total daily loading of the tissues involved. This article gives an overview on the recent assessments of the physiology and ontogeny of the daily use of the jaw muscles. Variations in the characteristics of daily activity could be linked to differences in the types of fibers composing the muscles as well as to the properties of the underlying bone, although these relationships are not absolute. Experimental decrease of the hardness of foods eaten by rats and rabbits showed a significant decrease in the number of daily bursts of feeding. These reductions in daily muscular activity were accompanied by higher mineralization of bone and by a transition toward "faster" fiber types in the muscles. It was revealed in rabbits that the characteristics of the daily activities of muscles (total duration of activity, number and lengths of bursts) were not altered during the transition from suckling to chewing and remained largely unaffected during further postnatal development. These results suggest that, despite large anatomical and functional changes, the average daily load on the jaw muscles by the masticatory system appears to be established before chewing develops and remains largely unchanged all the way through development. Whenever the daily muscular activity changes, this seems to have a significant effect on the properties of the tissues involved.
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Affiliation(s)
- Geerling E J Langenbach
- Department of Functional Anatomy, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, Research Institute MOVE, Gustav Mahlerlaan, LA, Netherlands.
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Türker KS, Koutris M, Sümer NC, Atış ES, Linke IR, Lobbezoo F, Naeije M. Provocation of delayed-onset muscle soreness in the human jaw-closing muscles. Arch Oral Biol 2010; 55:621-6. [DOI: 10.1016/j.archoralbio.2010.05.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2009] [Revised: 04/19/2010] [Accepted: 05/29/2010] [Indexed: 10/19/2022]
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Crompton AW, Owerkowicz T, Skinner J. Masticatory motor pattern in the koala (Phascolarctos cinereus): a comparison of jaw movements in marsupial and placental herbivores. ACTA ACUST UNITED AC 2010; 313:564-78. [DOI: 10.1002/jez.628] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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37
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Koutris M, Naeije M, Lobbezoo F, Wang K, Arendt-Nielsen L, Svensson P, Farina D. Normalization reduces the spatial dependency of the jaw-stretch reflex activity in the human masseter muscle. Muscle Nerve 2010; 41:78-84. [DOI: 10.1002/mus.21436] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Grünheid T, Langenbach GEJ, Korfage JAM, Zentner A, van Eijden TMGJ. The adaptive response of jaw muscles to varying functional demands. Eur J Orthod 2009; 31:596-612. [PMID: 19656804 DOI: 10.1093/ejo/cjp093] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Jaw muscles are versatile entities that are able to adapt their anatomical characteristics, such as size, cross-sectional area, and fibre properties, to altered functional demands. The dynamic nature of muscle fibres allows them to change their phenotype to optimize the required contractile function while minimizing energy use. Changes in these anatomical parameters are associated with changes in neuromuscular activity as the pattern of muscle activation by the central nervous system plays an important role in the modulation of muscle properties. This review summarizes the adaptive response of jaw muscles to various stimuli or perturbations in the orofacial system and addresses general changes in muscles as they adapt, specific adaptive changes in jaw muscles under various physiologic and pathologic conditions, and their adaptive response to non-surgical and surgical therapeutic interventions. Although the jaw muscles are used concertedly in the masticatory system, their adaptive changes are not always uniform and vary with the nature, intensity, and duration of the stimulus. In general, stretch, increases neuromuscular activity, and resistance training result in hypertrophy, elicits increases in mitochondrial content and cross-sectional area of the fibres, and may change the fibre-type composition of the muscle towards a larger percentage of slow-type fibres. In contrast, changes in the opposite direction occur when neuromuscular activity is reduced, the muscle is immobilized in a shortened position, or paralysed. The broad range of stimuli that affect the properties of jaw muscles might help explain the large variability in the anatomical and physiological characteristics found among individuals, muscles, and muscle portions.
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Affiliation(s)
- Thorsten Grünheid
- Department of General and Specialised Dentistry, Section of Orthodontics, Academic Centre for Dentistry Amsterdam (ACTA), The Netherlands.
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39
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Taylor AB, Eng CM, Anapol FC, Vinyard CJ. The functional correlates of jaw‐muscle fiber architecture in tree‐gouging and nongouging callitrichid monkeys. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2009; 139:353-67. [DOI: 10.1002/ajpa.20991] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Andrea B. Taylor
- Doctor of Physical Therapy Division, Department of Community and Family Medicine, Duke University School of Medicine, Durham, NC 27708
- Department of Evolutionary Anthropology, Duke University, Durham, NC 27708
| | - Carolyn M. Eng
- Department of Anthropology, The Biological Anthropology Program, Harvard University, Cambridge, MA
| | - Fred C. Anapol
- Department of Anthropology, University of Wisconsin, Milwaukee, Milwaukee, WI 53201
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40
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Bhutada MK, Phanachet I, Whittle T, Peck CC, Murray GM. Regional properties of the superior head of human lateral pterygoid muscle. Eur J Oral Sci 2008; 116:518-24. [DOI: 10.1111/j.1600-0722.2008.00582.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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41
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Rues S, Lenz J, Türp JC, Schweizerhof K, Schindler HJ. Forces and motor control mechanisms during biting in a realistically balanced experimental occlusion. Arch Oral Biol 2008; 53:1119-28. [DOI: 10.1016/j.archoralbio.2008.06.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2007] [Revised: 06/18/2008] [Accepted: 06/25/2008] [Indexed: 11/25/2022]
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Farella M, Palla S, Erni S, Michelotti A, Gallo LM. Masticatory muscle activity during deliberately performed oral tasks. Physiol Meas 2008; 29:1397-410. [PMID: 18974440 DOI: 10.1088/0967-3334/29/12/004] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The aim of this study was to investigate masticatory muscle activity during deliberately performed functional and non-functional oral tasks. Electromyographic (EMG) surface activity was recorded unilaterally from the masseter, anterior temporalis and suprahyoid muscles in 11 subjects (5 men, 6 women; age = 34.6 +/- 10.8 years), who were accurately instructed to perform 30 different oral tasks under computer guidance using task markers. Data were analyzed by descriptive statistics, repeated measurements analysis of variance (ANOVA) and hierarchical cluster analysis. The maximum EMG amplitude of the masseter and anterior temporalis muscles was more often found during hard chewing tasks than during maximum clenching tasks. The relative contribution of masseter and anterior temporalis changed across the tasks examined (F 5.2; p < or = 0.001). The masseter muscle was significantly (p < or = 0.05) more active than the anterior temporalis muscle during tasks involving incisal biting, jaw protrusion, laterotrusion and jaw cupping, the difference being statistically significant (p < or = 0.05). The anterior temporalis muscle was significantly (p < or = 0.01) more active than the masseter muscle during tasks performed in intercuspal position, during tooth grinding, and during hard chewing on the working side. Based upon the relative contribution of the masseter, anterior temporalis, and suprahyoid muscles, the investigated oral tasks could be grouped into six separate clusters. The findings provided further insight into muscle- and task-specific EMG patterns during functional and non-functional oral behaviors.
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Affiliation(s)
- M Farella
- Clinic for Masticatory Disorders, Removable Prosthodontics, and Special Care Dentistry, University of Zurich, Plattenstrasse, 11, 8032 Zurich, Switzerland.
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Vinyard CJ, Wall CE, Williams SH, Hylander WL. Patterns of variation across primates in jaw-muscle electromyography during mastication. Integr Comp Biol 2008; 48:294-311. [PMID: 21669792 DOI: 10.1093/icb/icn071] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Christopher J Vinyard
- *Department of Anatomy and Neurobiology, NEOUCOM, Rootstown, OH, USA; Department of Evolutionary Anthropology, Duke University, Durham, NC, USA; Department of Biomedical Sciences, Ohio University College of Osteopathic Medicine, Athens, OH, USA
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44
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Simony E, Saraf-Sinik I, Golomb D, Ahissar E. Sensation-targeted motor control: every spike counts? Focus on: "whisker movements evoked by stimulation of single motor neurons in the facial nucleus of the rat". J Neurophysiol 2008; 99:2757-9. [PMID: 18400953 DOI: 10.1152/jn.90432.2008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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45
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Moazen M, Curtis N, Evans SE, O'Higgins P, Fagan MJ. Rigid-body analysis of a lizard skull: modelling the skull of Uromastyx hardwickii. J Biomech 2008; 41:1274-80. [PMID: 18308322 DOI: 10.1016/j.jbiomech.2008.01.012] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2007] [Revised: 01/15/2008] [Accepted: 01/17/2008] [Indexed: 10/22/2022]
Abstract
Lizard skulls vary greatly in their detailed morphology. Theoretical models and practical studies have posited a definite relationship between skull morphology and bite performance, but this can be difficult to demonstrate in vivo. Computer modelling provides an alternative approach, as long as hard and soft tissue components can be integrated and the model can be validated. An anatomically accurate three-dimensional computer model of an Uromastyx hardwickii skull was developed for rigid-body dynamic analysis. The Uromastyx jaw was first opened under motion control, and then muscle forces were applied to produce biting simulations where bite forces and joint forces were calculated. Bite forces comparable to those reported in the literature were predicted, and detailed muscular force information was produced along with additional information on the stabilizing role of temporal ligaments in late jaw closing.
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Affiliation(s)
- M Moazen
- Centre for Medical Engineering and Technology, University of Hull, Hull, East Yorkshire HU6 7RX, UK.
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46
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Langenbach GEJ, van Wessel T, Brugman P, Korfage JAM, van Eijden TMGJ. Is fiber-type composition related to daily jaw muscle activity during postnatal development? Cells Tissues Organs 2007; 187:307-15. [PMID: 18089936 DOI: 10.1159/000112791] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/09/2007] [Indexed: 11/19/2022] Open
Abstract
AIM Muscles containing large numbers of slow-contracting fibers are generally more active than muscles largely composed of fast fibers. This relationship between muscle activity and phenotype suggests that (1) changes in fiber-type composition during postnatal development are accompanied by changes in daily activity and (2) individual variations in fiber-type composition are related to similar variations in daily muscle activity. METHODS The masseter and digastric muscles of 23 New Zealand White rabbits (young, juvenile and adult) were examined for their phenotype (myosin heavy chain content) and their daily activity (total daily number of activity bursts). RESULTS During development, the masseter showed a strong increase in the number of fast-type fibers compared to the number of slow-type fibers. During development, also the number of powerful bursts in the masseter increased. The digastric showed no significant changes in fiber types or burst numbers. Within each muscle, across individual animals, no significant correlations (R < 0.70) were found between any of the fiber types and daily burst numbers in any of the age groups. CONCLUSIONS The results suggest that activity-related influences are of relatively minor importance during development and that other factors are dominant in determining fiber-type composition.
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Affiliation(s)
- G E J Langenbach
- Department of Functional Anatomy, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, The Netherlands.
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48
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Dean MN, Azizi E, Summers AP. Uniform strain in broad muscles: active and passive effects of the twisted tendon of the spotted ratfish Hydrolagus colliei. J Exp Biol 2007; 210:3395-406. [PMID: 17872993 DOI: 10.1242/jeb.007062] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
A muscle's force output depends on the range of lengths over which its fibers operate. Regional variation in fiber shortening during muscle contraction may translate into suboptimal force production if a subset of muscle fibers operates outside the plateau of the length–tension curve. Muscles with broad insertions and substantial shortening are particularly prone to heterogeneous strain patterns since fibers from different regions of the muscle vary in their moment arms, with fibers further from the joint exhibiting greater strains. In the present study, we describe a musculotendon morphology that serves to counteract the variation in moment arm and fiber strains that are inherent in broad muscles. The tendon of the anterior jaw adductor of the spotted ratfish Hydrolagus colliei is twisted such that the distal face of the muscle inserts more proximally than the proximal face. Using quantitative geometric models based on this natural morphology, we show that this inversion of insertion points serves to equalize strains across the muscle such that at any gape angle all fibers in the muscle are operating at similar positions on their length–tension curves. Manipulations of this geometric model show that the natural morphology is `ideal' compared to other hypothetical morphologies for limiting fiber strain heterogeneity. The uniform strain patterns predicted for this morphology could increase active force production during jaw closing and also decrease passive resistance to jaw opening. This divergence from `typical' tendon morphology in the jaw adductors of H. colliei may be particularly important given the demands for high force production in durophagy.
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Affiliation(s)
- Mason N Dean
- Ecology and Evolutionary Biology, University of California Irvine, 321 Steinhaus Hall, Irvine, CA 92697-2525, USA.
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49
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Ross CF, Dharia R, Herring SW, Hylander WL, Liu ZJ, Rafferty KL, Ravosa MJ, Williams SH. Modulation of mandibular loading and bite force in mammals during mastication. ACTA ACUST UNITED AC 2007; 210:1046-63. [PMID: 17337717 DOI: 10.1242/jeb.02733] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Modulation of force during mammalian mastication provides insight into force modulation in rhythmic, cyclic behaviors. This study uses in vivo bone strain data from the mandibular corpus to test two hypotheses regarding bite force modulation during rhythmic mastication in mammals: (1) that bite force is modulated by varying the duration of force production, or (2) that bite force is modulated by varying the rate at which force is produced. The data sample consists of rosette strain data from 40 experiments on 11 species of mammals, including six primate genera and four nonprimate species: goats, pigs, horses and alpacas. Bivariate correlation and multiple regression methods are used to assess relationships between maximum (epsilon(1)) and minimum (epsilon(2)) principal strain magnitudes and the following variables: loading time and mean loading rate from 5% of peak to peak strain, unloading time and mean unloading rate from peak to 5% of peak strain, chew cycle duration, and chew duty factor. Bivariate correlations reveal that in the majority of experiments strain magnitudes are significantly (P<0.001) correlated with strain loading and unloading rates and not with strain loading and unloading times. In those cases when strain magnitudes are also correlated with loading times, strain magnitudes are more highly correlated with loading rate than loading time. Multiple regression analyses reveal that variation in strain magnitude is best explained by variation in loading rate. Loading time and related temporal variables (such as overall chew cycle time and chew duty factor) do not explain significant amounts of additional variance. Few and only weak correlations were found between strain magnitude and chew cycle time and chew duty factor. These data suggest that bite force modulation during rhythmic mastication in mammals is mainly achieved by modulating the rate at which force is generated within a chew cycle, and less so by varying temporal parameters. Rate modulation rather than time modulation may allow rhythmic mastication to proceed at a relatively constant frequency, simplifying motor control computation.
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Affiliation(s)
- Callum F Ross
- Organismal Biology and Anatomy, University of Chicago, 1027 E. 57th Street, Chicago, IL 60637, USA.
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50
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van Wessel T, Langenbach GEJ, Korfage JAM, Brugman P, Kawai N, Tanaka E, van Eijden TMGJ. Fibre-type composition of rabbit jaw muscles is related to their daily activity. Eur J Neurosci 2005; 22:2783-91. [PMID: 16324112 DOI: 10.1111/j.1460-9568.2005.04466.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Skeletal muscles contain a mixture of fibres with different contractile properties, such as maximum force, contraction velocity and fatigability. Muscles adapt to altered functional demands, for example, by changing their fibre-type composition. This fibre-type composition can be changed by the frequency, duration and presumably the intensity of activation. The aim of this study was to analyse the relationship between the spontaneous daily muscle activation and fibre-type composition in rabbit jaw muscles. Using radio-telemetry combined with electromyography, the daily activity of five jaw muscles was characterized in terms of the total duration of muscle activity (duty time) and the number of activity bursts. Fibre-type composition of the muscles was classified by analysing the myosin heavy chain content of the fibres. The amount of slow-type fibres was positively correlated to the duty time and the number of bursts only for activations exceeding 20-30% of the maximum activity per day. Furthermore, cross-sectional areas of the slow-type fibres were positively correlated to the duty time for activations exceeding 30% of the maximum activity. The present data indicate that the amount of activation above a threshold (> 30% peak activity) is important for determining the fibre-type composition and cross-sectional area of slow-type fibres of a muscle. Activation above this threshold occurred only around 2% of the time in the jaw muscles, suggesting that contractile properties of muscle fibres are maintained by a relatively small number of powerful contractions per day.
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Affiliation(s)
- T van Wessel
- Department of Functional Anatomy, Academic Centre for Dentistry Amsterdam, Universiteit van Amsterdam and Vrije Universiteit, Meibergdreef 15, 1105 AZ, Amsterdam, Netherlands.
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