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Electromyographic activity of masticatory muscles in women with osteoporosis

SIÉSSERE, Selma; SOUSA, Luiz Gustavo de; LIMA, Naira de Albuquerque; SEMPRINI, Marisa; VASCONCELOS, Paulo Batista de; WATANABE, Plauto Christopher Aranha; RANCAN, Sandra Valéria; REGALO, Simone Cecilio Hallak
Fonte: Fundação Odontológica de Ribeirão Preto Publicador: Fundação Odontológica de Ribeirão Preto
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.53%
The purpose of this study was to analyze the electromyographic (EMG) activity and the maximal molar bite force in women diagnosed with osteoporosis in the maxillary and mandibular regions, considering the habits and conditions that lead to development of generalized skeletal bone loss, including on face bones, can disturb the functional harmony of the stomatognathic system. Twenty-seven women with mandibular and maxillary osteoporosis and 27 healthy controls volunteered to participate in the study. A 5-channel electromyographer was used. Muscle activity was evaluated by means of EMG recordings of the masticatory musculature (masseter and temporalis muscles, bilaterally) during the following clinical conditions: rest (5 s); right and left lateral excursions (5 s); protrusion (5 s); maximal dental clenching on Parafilm™ (4 s) and maximal voluntary contraction (4 s). This latter clinical condition was used as the normalization factor of the sample data. It was observed that individuals with osteoporosis presented greater EMG activity when maintaining mandible posture conditions and less activity during dental clenching and when obtaining maximal molar bite force. It may be concluded that facial osteoporosis can interfere on the patterns of masticatory muscle activation and maximal bite force of the stomatognathic system.; Este estudo teve como objetivo analisar a atividade eletromiográfica e a força de mordida molar máxima de indivíduos diagnosticados com osteoporose na região maxilar e mandibular...

Masticatory muscle function three years after surgical correction of class III dentofacial deformity

TRAWITZKI, L. V. V.; DANTAS, R. O.; MELLO-FILHO, F. V.; MARQUES JR., W.
Fonte: CHURCHILL LIVINGSTONE Publicador: CHURCHILL LIVINGSTONE
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
56.64%
Individuals with dentofacial deformities have masticatory muscle changes. The objective of the present study was to determine the effect of interdisciplinary treatment in patients with dentofacial deformities regarding electromyographic activity (EMG) of masticatory muscles three years after surgical correction. Thirteen patients with class III dentofacial deformities were studied, considered as group PI (before surgery) and group P3 (3 years to 3 years and 8 months after surgery). Fifteen individuals with no changes in facial morphology or dental occlusion were studied as controls. The participants underwent EMG examination of the temporal and masseter muscles during mastication and biting. Evaluation of the amplitude interval of EMG activity revealed a difference between P1 and P3 and no difference between P3 and the control group. In contrast, evaluation of root mean square revealed that, in general, P3 values were higher only when compared with PI and differed from the control group. There was an improvement in the EMG activity of the masticatory muscles, mainly observed in the masseter muscle, with values close to those of the control group in one of the analyses.

Association between rhythmic masticatory muscle activity during sleep and masticatory myofascial pain: A polysomnographic study

ROSSETTI, Leylha Maria Nunes; ARAUJO, Carlos Dos Reis Pereira de; ROSSETTI, Paulo Henrique Orlato; CONTI, Paulo Cesar Rodrigues
Fonte: QUINTESSENCE PUBLISHING CO INC Publicador: QUINTESSENCE PUBLISHING CO INC
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
56.52%
Aims: To test for an association between rhythmic masticatory muscle activity during sleep, as assessed according to polysomnographic criteria for sleep bruxism (RMMA-SB), and myofascial pain (MFP), as well as the chance of occurrence of MFP in patients with RMMA-SB. Methods: Thirty MFP patients (diagnosed according to the Research Diagnostic Criteria for Temporomandibular Disorders) and 30 age- and gender-matcbed asymptomatic controls underwent a polysomnographic examination. Also, any self-reporting of daytime clenching (DC) was registered in 58 of these subjects. Results: Most MFP patients reported mild or moderate pain (46.67% and 43.33%, respectively), and only 3 (10%) reported severe pain. Pain duration ranged from 2 to 120 months (mean 34.67 +/- 36.96 months). Significant associations were observed between RMMA-SB and MFP as well as between DC and MFP. Conclusions: (1) RMMA-SB is significantly associated with MFP; (2) although RMMA-SB represents a risk factor for MFP, this risk is low; and (3) DC probably constitutes a stronger risk factor for MFP than RMMA-SB.

Participação do estresse e ansiedade na alteração do limiar de dor à pressão (LDP) em pacientes com DTM miogênica: um estudo comparativo; Participation of stress/anxiety on the alteration of PPT values in myogenic TMD patients

Vedolin, Gabriela Modesti
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 29/03/2007 PT
Relevância na Pesquisa
46.53%
O objetivo deste trabalho foi analisar a influência da ansiedade e do estresse no limiar de dor à pressão (LDP) de músculos mastigatórios, numa amostra de estudantes universitários em diferentes períodos do ano letivo. Para este propósito, foram selecionados 45 indivíduos, sendo 29 estudantes, que apresentavam DTM de origem miogênica seguindo critérios de inclusão propostos pelo Research Diagnostic Criteria (RDC) e 16 que não apresentavam características de DTM, do gênero feminino, equilibrados em relação à idade. Utilizando um algômetro (KRATOS®) foram realizadas tomadas bilaterais dos limiares de dor à pressão (LDP) dos indivíduos da amostra nos músculos masseter, temporal anterior, médio e posterior. Além disso, os participantes foram solicitados a responder questionários multidimensionais, através do Inventário de Ansiedade de Beck (BAI) e o Inventário de Sintomas de Stress de Lipp (ISSL), para mensurar reações emocionais ou afetivas em situações que causem estresse e/ou ansiedade. Também, o nível de dor foi registrado pela Escala de Análise Visual (EAV). Todos os exames foram realizados em quatro momentos distintos (T1, T2, T3 e T4) tendo como parâmetro o período de avaliações acadêmicas da Faculdade de Odontologia de Bauru. Os dados obtidos foram submetidos à análise estatística (ANOVA...

Influência da idade e do gênero na força de mordida molar máxima e espessura dos músculos mastigatórios; Influence of age and gender on the maximum molar bite force and thickness of masticatory muscles

Palinkas, Marcelo
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 23/04/2010 PT
Relevância na Pesquisa
46.52%
O objetivo do presente estudo foi verificar a influência da idade e do gênero na obtenção da força de mordida molar máxima e traçar os critérios de normalidade do desenvolvimento muscular mastigatório em 177 indivíduos dentados com idade entre 7 a 80 anos divididos em cinco grupos etários. Grupo I (7 a 12 anos); II (13 a 20 anos); III (21 a 40 anos); IV (41 a 60 anos) com 20 homens e 20 mulheres em cada grupo; grupo V (61 a 80 anos) formado por nove mulheres e oito homens. Todos os participantes classificados como oclusão normal, respiradores nasais, sem hábitos parafuncionais e sintomas de disfunção temporomandibular. Os registros da força de mordida molar máxima foram realizados utilizando dinamômetro com capacidade até 100kgf, adaptado às condições bucais. O maior valor entre três registros executados foi considerado a força de mordida molar máxima do indivíduo. Os dados foram submetidos à análise estatística multivariada (SPSS 17.0). A espessura do músculo foi mensurada com ultrassom Sonosite Titan usando um transdutor linear 56 mm de 10 MHz de alta resolução. Foram adquiridas três imagens ultrassonográficas dos músculos masseter e porção anterior do músculo temporal, de ambos os lados...

Histoenzymology and morphometry of the masticatory muscles of tufted capuchin monkey (Cebus apella Linnaeus, 1758)

Andreo, J. C.; Oliveira, J. A.; Navarro, J. A. C.; Roque, D. D.; Roque, J. S.; Buchain, R. L.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 33-42
ENG
Relevância na Pesquisa
46.73%
Samples of the anterior and posterior regions of the masseter and temporal muscles and of the anterior belly of the digastric muscle of 4 adult male tufted capuchin monkeys (Cebus apella) were removed and stained with HE and submitted to the m-ATPase reaction (with alkaline and acid preincubation) and to the NADH-TR and SDH reactions. The results of the histoenzymologic reactions were similar, except for acid reversal which did not occur in fibers of the fast glycolytic (FG) type in the mandibular locomotor muscles. FG fibers had a larger area and were more frequent in all regions studied. No significant differences in frequency or area of each fiber type were detected, considering the anterior and posterior regions of the masseter and temporal muscles. The frequency of fibers of the fast oxidative glycolytic (FOG) and slow oxidative (SO) types and of FOG area differed significantly between the anterior belly of the digastric muscle and the mandibular locomotor muscle. The predominance of fast twitch (FG and FOG) fibers and the multipenniform and bipenniform internal architecture of the masseter and temporal muscles, respectively, are characteristics that permit the powerful bite typical of tufted capuchin monkeys.

The effect of manual therapy on masseter muscle pain and spasm

Albertin, A.; Kerppers, I. I.; Amorim, C. F.; Costa, R. V.; Corrêa, J. C. Ferrari; Oliveira, C. S.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 107-112
ENG
Relevância na Pesquisa
46.51%
Introduction: Orofacial pain and pain in the muscles of mastication are frequent symptoms of temporomandibular disorder. The masseter is the closet masticatory muscle to the surface and has the function of raising and retracting the mandible. This muscle has considerable strength and is one of the main muscles involved in the shredding of food It is therefore of utmost importance in the masticatory cycle and generally the most affected by pain and spasms. Objectives: The aim of the present study was to analyze the effect of manual therapy with transversal and circular movements on pain and spasm in the masseter muscle, using electromyography and a visual analogue pain scale (VAPS). Eight women who experienced pain upon palpation of the masseter greater than 6 on the VAPS were selected for participation in the study, which employed electromyography and a VAPS for assessment, followed by manual oral physiotherapy and reevaluation. Results: The statistical analysis revealed a reduction in pain, but there was no significant difference in electromyographic activity (p < 0.05). Conclusion: It was concluded that massage therapy was effective on pain symptoms, but was not capable of altering the electrical activity of the masseter muscle.

Facial pain associated with fibromyalgia can be marked by abnormal neuromuscular control: A cross-sectional study

Gui, Maísa Soares; Pedroni, Cristiane Rodrigues; Aquino, Luana M. Martins; Pimentel, Marcele Jardim; Alves, Marcelo Correa; Rossini, Sueli; Reimão, Rubens; Berzin, Fausto; Marques, Amélia Pasqual; Rizzatti-Barbosa, Célia Marisa
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 1092-1101
ENG
Relevância na Pesquisa
46.58%
Background. Temporomandibular disorder (TMD) development in fibromyalgia syndrome (FMS) is not yet fully understood, but altered neuromuscular control in FMS may play a role in triggering TMD. Objective. The purpose of this study was to verify the association between neuromuscular control and chronic facial pain in groups of patients with FMS and TMD. Design. A cross-sectional study was conducted. Methods. This study involved an analysis of facial pain and electromyographic activity of the masticatory muscles in patients with FMS (n=27) and TMD (n=28). All participants were evaluated according to Research Diagnostic Criteria for Temporomandibular Disorders and surface electromyography (SEMG). Myoelectric signal calculations were performed using the root mean square and median frequency of signals. Results. The data revealed premature interruption of masticatory muscle contraction in both patient groups, but a significant correlation also was found between higher median frequency values and increased facial pain. This correlation probably was related to FMS because it was not found in patients with TMD only. Facial pain and increased SEMG activity during mandibular rest also were positively correlated. Limitations. Temporal conclusions cannot be drawn from the study. Also...

Controvérsias do ensaio experimental clínico sobre DTM

Fernandes, Catarina Rodrigues
Fonte: Universidade Católica Portuguesa Publicador: Universidade Católica Portuguesa
Tipo: Dissertação de Mestrado
Publicado em /10/2012 POR
Relevância na Pesquisa
46.59%
Introdução: A disfunção temporomandibular é uma designação que abrange vários problemas clínicos envolvendo a musculatura mastigatória, a ATM e as estruturas associadas a ambos. Este trabalho pretende realizar uma abordagem histórica, definindo e clarificando definições, terminologias e índices mais utilizados, em investigação na Oclusão. Por fim, realizar uma revisão bibliográfica apoiada num grupo de casos sobre a investigação em si, ou seja, limitações dos estudos e dificuldades da investigação em Oclusão. Metodologia: Realizámos um estudo observacional longitudinal em que avaliámos uma amostra de 87 pacientes consultados na Clínica Universitária da UCP-Viseu e na Clínica Médica Corpus Dental, com idade entre os 20 e 70 anos. Cerca de 43,7% dos indivíduos pertenciam ao género masculino e 56,3% ao feminino. Estes foram sujeitos ao inquérito Índice RDC/TMD (“Research Diagnostic Criteria for Temporomandibular disorders”) eixo I. No final analisámos as dificuldades e limitações do estudo, produzindo uma lista que pode auxiliar futuros estudos. Resultados: A dor orofacial foi referida por 43,7% da amostra, sendo 32,2% indivíduos do género feminino. Dos pacientes com dor orofacial 73,7% apresentava dor á palpação muscular...

Electromyographic activity of masticatory muscles in women with osteoporosis

Siéssere,Selma; Sousa,Luiz Gustavo de; Lima,Naira de Albuquerque; Semprini,Marisa; Vasconcelos,Paulo Batista de; Watanabe,Plauto Christopher Aranha; Rancan,Sandra Valéria; Regalo,Simone Cecilio Hallak
Fonte: Fundação Odontológica de Ribeirão Preto Publicador: Fundação Odontológica de Ribeirão Preto
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2009 EN
Relevância na Pesquisa
46.53%
The purpose of this study was to analyze the electromyographic (EMG) activity and the maximal molar bite force in women diagnosed with osteoporosis in the maxillary and mandibular regions, considering the habits and conditions that lead to development of generalized skeletal bone loss, including on face bones, can disturb the functional harmony of the stomatognathic system. Twenty-seven women with mandibular and maxillary osteoporosis and 27 healthy controls volunteered to participate in the study. A 5-channel electromyographer was used. Muscle activity was evaluated by means of EMG recordings of the masticatory musculature (masseter and temporalis muscles, bilaterally) during the following clinical conditions: rest (5 s); right and left lateral excursions (5 s); protrusion (5 s); maximal dental clenching on Parafilm™ (4 s) and maximal voluntary contraction (4 s). This latter clinical condition was used as the normalization factor of the sample data. It was observed that individuals with osteoporosis presented greater EMG activity when maintaining mandible posture conditions and less activity during dental clenching and when obtaining maximal molar bite force. It may be concluded that facial osteoporosis can interfere on the patterns of masticatory muscle activation and maximal bite force of the stomatognathic system.

Psychological Stress Alters Ultrastructure and Energy Metabolism of Masticatory Muscle in Rats

Chen, Yong-Jin; Huang, Fei; Zhang, Min; Shang, Hai-Yan
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.69%
To investigate the effects of psychological stress on the masticatory muscles of rats, a communication box was applied to induce the psychological stress (PS) in rats. The successful establishment of psychological stimulation was confirmed by elevated serum levels of adrenocorticotropic hormone (ACTH) and changed behaviors in the elevated plusmaze apparatus. The energy metabolism of the bilateral masseter muscles was tested via chemocolorimetric analysis, whereas muscle ultrastructure was assessed by electron microscopy. In comparison to the control group, the PS group showed evidence of swollen mitochondria with cristae loss and reduced matrix density in the masticatory muscles after three weeks of stimulation; after five weeks of stimulation, severe vacuolar changes to the mitochondria were observed. Increased vascular permeability of the masticatory muscle capillaries was found in the five-week PS rats. In addition, there was decreased activity of Na+-K+ATPase and Ca2+-ATPase and a simultaneous increase in the activity of lactate dehydrogenase and lactic acid in the masticatory muscles of PS rats. Together, these results indicate that psychological stress induces alterations in the ultrastructure and energy metabolism of masticatory muscles in rats.

Psychological Stress Induces Temporary Masticatory Muscle Mechanical Sensitivity in Rats

Huang, Fei; Zhang, Min; Chen, Yong-Jin; Li, Qiang; Wu, An-Zhen
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.69%
To explore the relationship between psychological stress and masticatory muscle pain, we created a communication stress animal model to determine whether psychological stress could induce increased mechanical sensitivity in masticatory muscles and to study the changes of mechanical nociceptive thresholds after stress removal. Forty-eight male Sprague-Dawley rats were divided into a control group (CON), a foot-shocked group (FS, including 3 subgroups recorded as FS-1, FS-2, and FS-3), a psychological stress group (PS), and a drug treatment group (DT). PS and DT rats were confined in a communication box for one hour a day to observe the psychological responses of neighboring FS rats.Measurements of the mechanical nociceptive thresholds of the bilateral temporal and masseter muscles showed a stimulus-response relationship between psychological stress and muscle mechanical sensitivity. The DT rats, who received a diazepam injection, showed almost the same mechanical sensitivity of the masticatory muscles to that of the control in response to psychological stress. Fourteen days after the psychological stressor was removed, the mechanical nociceptive thresholds returned to normal. These findings suggest that psychological stress is directly related to masticatory muscle pain. Removal of the stressor could be a useful method for relieving mechanical sensitivity increase induced by psychological stress.

Chronic Low-Frequency Stimulation Transforms Cat Masticatory Muscle Fibers into Jaw-Slow Fibers

Kang, Lucia H.D.; Hoh, Joseph F.Y.
Fonte: SAGE Publications Publicador: SAGE Publications
Tipo: Artigo de Revista Científica
Publicado em /09/2011 EN
Relevância na Pesquisa
46.86%
Cat masticatory muscle during regeneration expresses masticatory-specific myofibrillar proteins upon innervation by a fast muscle nerve but acquires the jaw-slow phenotype when innervated by a slow muscle nerve. Here, we test the hypothesis that chronic low-frequency stimulation simulating impulses from the slow nerve can result in masticatory-to-slow fiber–type transformation. In six cats, the temporalis muscle was continuously stimulated directly at 10 Hz for up to 12 weeks using a stimulator affixed to the skull. Stimulated muscles were analyzed by immunohistochemistry using, among others, monoclonal antibodies against masticatory-specific myosin heavy chain (MyHC), myosin binding protein-C, and tropomyosins. Under the electrodes, stimulation induced muscle regeneration, which generated slow fibers. Deep to the electrodes, at two to three weeks, two distinct populations of masticatory fibers began to express slow MyHC: 1) evenly distributed fibers that completely suppressed masticatory-specific proteins but transiently co-expressed fetal MyHCs, and 2) incompletely transformed fibers that express slow and masticatory but not fetal MyHCs. SDS-PAGE confirmed de novo expression of slow MyHC and β-tropomyosin in the stimulated muscles. We conclude that chronic low-frequency stimulation induces masticatory-to-slow fiber–type conversion. The two populations of transforming masticatory fibers may differ in their mode of activation or lineage of their myogenic cells.

Painful Unilateral Temporalis Muscle Enlargement: Reactive Masticatory Muscle Hypertrophy

Katsetos, Christos D.; Bianchi, Michael A.; Jaffery, Fizza; Koutzaki, Sirma; Zarella, Mark; Slater, Robert
Fonte: Springer US Publicador: Springer US
Tipo: Artigo de Revista Científica
Publicado em 31/07/2013 EN
Relevância na Pesquisa
46.72%
An instance of isolated unilateral temporalis muscle hypertrophy (reactive masticatory muscle hypertrophy with fiber type 1 predominance) confirmed by muscle biopsy with histochemical fiber typing and image analysis in a 62 year-old man is reported. The patient presented with bruxism and a painful swelling of the temple. Absence of asymmetry or other abnormalities of the craniofacial skeleton was confirmed by magnetic resonance imaging and cephalometric analyses. The patient achieved symptomatic improvement only after undergoing botulinum toxin injections. Muscle biopsy is key in the diagnosis of reactive masticatory muscle hypertrophy and its distinction from masticatory muscle myopathy (hypertrophic branchial myopathy) and other non-reactive causes of painful asymmetric temporalis muscle enlargement.

Hypoxie transitoire en relation avec les activités rythmiques des muscles de la mastication chez les patients atteints du bruxisme du sommeil

Dumais, Isabelle
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
FR
Relevância na Pesquisa
46.56%
Study Objectives: Sleep bruxism (SB) is a repetitive jaw-muscle activity characterized by clenching or grinding of the teeth and/or by bracing or thrusting of the mandible occurring during sleep. SB is scored, from electromyographic traces, as rhythmic masticatory muscle activity (RMMA). Most RMMA occurred during sleep in association with sleep arousal. Since not all RMMA episodes were associated with sleep arousal we hypothesized that some event could be observed in relation to small fluctuations of the oxygen level resulting in mild desaturation/hypoxia. Methods: Sleep laboratory or home recordings from 22 SB (teeth grinding) patients were analyzed from our data bank. A total of 143 RMMA/SB episodes were classified in 4 categories: (i) no arousal & no body movement; (ii) arousal + & no body movement; (iii) no arousal & body movement +; (iv) arousal + & body movement +. Minimum blood oxygen levels were assessed from finger oxymetry signal: 1) during the baseline period before RMMA, i.e., an average of 7 s before RMMA onset (-20 s to -14 s); 2) during RMMA, i.e. a window of 15 s corresponding to -5 s before the onset until +10 s after the episode. For all episodes, the minimum oximetry values were compared for each patient. Results: There was a significant variation of blood oxygen level over time (p=0.001) with a statistically significant transient hypoxia during RMMA at time (+7)...

Rhythmic Masticatory Muscle Activity during Sleep: Etiology and Clinical Perspectives

Carra, Maria Clotilde
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
EN
Relevância na Pesquisa
46.52%
L’activité rythmique des muscles masticateurs (ARMM) pendant le sommeil se retrouve chez environ 60% de la population générale adulte. L'étiologie de ce mouvement n'est pas encore complètement élucidée. Il est cependant démontré que l’augmentation de la fréquence des ARMM peut avoir des conséquences négatives sur le système masticatoire. Dans ce cas, l'ARMM est considérée en tant que manifestation d'un trouble moteur du sommeil connue sous le nom de bruxisme. Selon la Classification Internationale des Troubles du Sommeil, le bruxisme est décrit comme le serrement et grincement des dents pendant le sommeil. La survenue des épisodes d’ARMM est associée à une augmentation du tonus du système nerveux sympathique, du rythme cardiaque, de la pression artérielle et elle est souvent en association avec une amplitude respiratoire accrue. Tous ces événements peuvent être décrits dans le contexte d’un micro-éveil du sommeil. Cette thèse comprend quatre articles de recherche visant à étudier i) l'étiologie de l’ARMM pendant le sommeil en relation aux micro-éveils, et à évaluer ii) les aspects cliniques du bruxisme du sommeil, du point de vue diagnostique et thérapeutique. Pour approfondir l'étiologie de l’ARMM et son association avec la fluctuation des micro-éveils...

Endocranial and masticatory muscle volumes in myostatin-deficient mice

Jeffery, Nathan; Mendias, Christopher
Fonte: The Royal Society Publishing Publicador: The Royal Society Publishing
Tipo: Artigo de Revista Científica
Publicado em 17/12/2014 EN
Relevância na Pesquisa
46.66%
Structural and functional trade-offs are integral to the evolution of the mammalian skull and its development. This paper examines the potential for enlargement of the masticatory musculature to limit the size of the endocranial cavity by studying a myostatin-deficient mouse model of hypermuscularity (MSTN−/−). The study tests the null prediction that the larger MSTN−/− mice have larger brains compared with wild-type (WT) mice in order to service the larger muscles. Eleven post-mortem MSTN−/− mice and 12 WT mice were imaged at high resolution using contrast enhanced micro-CT. Masticatory muscle volumes (temporalis, masseter, internal and external pterygoids) and endocranial volumes were measured on the basis of two-dimensional manual tracings and the Cavalieri principle. Volumes were compared using Kruskal–Wallis and Student's t-tests. Results showed that the masticatory muscles of the MSTN−/− mice were significantly larger than in the WT mice. Increases were in the region of 17–36% depending on the muscle. Muscles increased in proportion to each other, maintaining percentages in the region of 5, 10, 21 and 62% of total muscle volume for the external ptyergoid, internal pterygoid, temporalis and masseter, respectively. Kruskal–Wallis and t-tests demonstrated that the endocranial volume was significantly larger in the WT mice...

Occlusal force, electromyographic activity of masticatory muscles and mandibular flexure of subjects with different facial types

Custodio,William; Gomes,Simone Guimarães Farias; Faot,Fernanda; Garcia,Renata Cunha Matheus Rodrigues; Del Bel Cury,Altair Antoninha
Fonte: Faculdade De Odontologia De Bauru - USP Publicador: Faculdade De Odontologia De Bauru - USP
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2011 EN
Relevância na Pesquisa
46.53%
OBJECTIVE: The aim of this study was to evaluate whether vertical facial patterns influence maximal occlusal force (MOF), masticatory muscle electromyographic (EMG) activity, and medial mandibular flexure (MMF). MATERIAL AND METHODS: Seventy-eight dentate subjects were divided into 3 groups by Ricketts's analysis: brachyfacial, mesofacial and dolychofacial. Maximum occlusal force in the molar region was bilaterally measured with a force transducer. The electromyographic activities of the masseter and anterior temporal muscles were recorded during maximal voluntary clenching. Medial mandibular flexure was calculated by subtracting the intermolar distance of maximum opening or protrusion from the distance in the rest position. The data were analyzed using ANOVA followed by Tukey's HSD test. The significance level was set at 5%. RESULTS: Data on maximum occlusal force showed that shorter faces had higher occlusal forces (P<0.0001). Brachyfacial subjects presented higher levels of masseter electromyographic activity and medial mandibular flexure, followed by the mesofacial and dolychofacial groups. Additionally, dolychofacial subjects showed significantly lower electromyographic temporalis activities (P<0.05). CONCLUSION: Within the limitations of the study...

Changes in the thickness of the cervical flexor depending on the contraction level of the masticatory muscle during deep cervical flexor training

Moon, Hyun-Ju; Goo, Bong-Oh; Kwon, Hae-Yeon
Fonte: The Society of Physical Therapy Science Publicador: The Society of Physical Therapy Science
Tipo: Text
EN
Relevância na Pesquisa
46.77%
[Purpose] This study examined the changes in the thickness of the deep cervical flexor according to the contraction intensity of the masticatory muscle during deep cervical flexor training. [Subjects and Methods] Twenty healthy adults were randomly selected and the thicknesses of their longus colli and sternocleidomastoid were measured with ultrasound when the masticatory muscle contracted during deep cervical flexor training. [Results] The thickness of the longus colli tended to increase in proportion to the contraction intensity of the masticatory muscle, with a significant difference. However, the thickness of the sternocleidomastoid did not significantly differ with the contraction intensity of the masticatory muscle. [Conclusion] During deep cervical flexor training, when co-contraction of the masticatory muscle occures, changes in the thickness of the longus colli may be selectively increased. Deep cervical flexor training was most effective during contractions of a submaximal intensity.

Using overdenture on implants and complete dentures: Using overdenture on implants and complete dentures: Using overdenture on implants and complete dentures: effects on postural maintenance of masticatory effects on postural maintenance of masticatory musculature musculature;

Santos, Carla Moreto; Vitti, Mathias; Matsumoto, Wilson; Berro, Renato José; Semprini, Marisa; Hallak, Jaime Eduardo Cecílio; Galo, Rodrigo; Regalo, Simone Cecílio Hallak
Fonte: UNICAMP/FOP Publicador: UNICAMP/FOP
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; Formato: application/pdf
Publicado em 15/01/2016 ENG
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56.58%
Aims: Thanks to advances in osseointegration, oral rehabilitation specialists have had the option of using implants to improve retention and stability in treatments with complete dentures. This study compared the masticatory muscle electromyographic activity in implant-supported overdenture wearers, complete denture wearers and dentate individuals. The electromyographic activity of the right and left masseter muscles, and the right and left anterior temporalis muscles was analyzed in 10 implant-supported overdenture wearers (Group 1), 10 conventional complete denture wearers (Group 2), and 10 dentate individuals (Group 3), with mean age of 65 years, at rest and during postural position maintenance. The analysis was performed using the MyoSystem-Br1 electromyographer with differential active electrodes. Analysis of variance tests were carried out to compare the groups and muscles and revealed different electromyographic values that were statistically significant at 1% significance level. Duncan’s pos-hoc test showed that Group 3 presented the smallest values (pd”0.01). The electromyographic contraction pattern was similar between Groups 1 and 3 (p>0.01), and hyperactivity of anterior temporalis muscles was observed in Group 2 (pd”0.01). Conclusions: dentate individuals had smaller electromyographic values of masticatory muscles and the overdenture use caused electromyographic contraction patterns similar to those of dentate individuals in both positions.;