The influence of occlusion on jaw and neck muscle activity: a surface EMG study in healthy young adults

Abstract

The electromyographic (EMG) characteristics of masseter, temporalis and sternocleidomastoid (SCM) muscles during maximum voluntary teeth clench were assessed in 27 male and 35 female healthy young adults. Subjects were divided into two groups: (i) 'complete' Angle Class I (bilateral, symmetric canine and molar Class I relationships), and (ii) 'partial' Angle Class I (one to three canine/molar Class I relationships, the remaining relationships were Class II or Class III). On average, standardized muscular symmetry ranged 80.7-87.9%. During maximum voluntary teeth clench, average co-contraction of SCM muscle was 13.7-23.5% of its maximum contraction. On average, all torque coefficients (potential lateral displacing component) were >90%, while all antero-posterior coefficients (relative activities of masseter and temporalis muscles) were >85%. The average integrated areas of the masseter and temporalis EMG potentials over time ranged 87.4-106.8 muV/muV s%. Standardized contractile muscular activities did not differ between 'complete' and 'partial' Angle Class I, and between sexes (two-way analysis of variance). A trend toward a larger intragroup variability in EMG indices was observed in the subjects with 'partial' Angle Class I than in those with 'complete' Angle Class I (significant difference for the temporalis muscle symmetry, P = 0.013, analysis of variance). In conclusion, the presence of a complete or partial Angle occlusal Class I did not seem to influence the standardized contractile activities of masseter, temporalis and SCM muscles during a maximum voluntary clench. Subjects with a 'complete' Angle Class I were somewhat a more homogenous group than subjects with 'partial' Angle Class I.

Effect of different dental articulating papers on SEMG activity during maximum clenching

“…This technique is regarded as an objective and reliable method for evaluating muscle function and efficiency by detecting electrical potentials; the analysis of the recordings allows the assessment of general muscle activity, the cooperation of different muscles, and the variability of their activity over time (Hugger et al , 2008;van der Bilt, 2011;Wozniak et al , 2013). In our study we followed the EMG protocol proposed by Ferrario et al which is based on a starting normalization record: an MVC is performed on cotton rolls just before the recording of the actual test, with the same electrodes and EMG apparatus (Ferrario et al , 2000;Ferrario et al , 2006). That protocol have been shown to be highly repeatable, allowing the standardization of EMG indices (like POC% and IMP µV/µS%) (Ferrario et al , 2000); moreover, it has been used successfully to discover EMG differences between healthy subjects, patients with temporo-mandibular disorders (TMD) or among patients belonging to different Research Diagnostic Criteria for TMD (Tartaglia et al , 2008).…”

Alterações no controle motor mandibular e cervical de crianças com paralisia cerebral

“…However, postural changes of the head are not necessarily more frequent in subjects with TMD 4 . There are also reports that the asymmetric electrical activity of masticatory muscles is higher in individuals with TMD 24,25 and this abnormal activity can be influenced by changes oclusais 15 . It was considered that CP children have a higher incidence of occlusal changes due to abnormalities of oromotor musculature, with a higher proportion of Angle class II and minor of Angle class III 10 .…”

“…Electromyography variables were analyzed: Symmetry Index of AT and MA muscle (ATS and MAS) and the Antero-Posterior Coefficient (APC) 15 during a chewing cycle for each of the three attempts. The symmetry index of muscle activity was calculated by temporal quantification between the normalized EMG waves of paired muscles and the common area between the two EMG waves was identified.…”

Estudo eletromiográfico da deglutição na musculatura supra-hióidea em sujeitos Classe Ie III de Angle

“…Electromyographic study of swallowing in suprahyoid musculature in Angle's Class I and III subjects Mirian Hideko Nagae (1) , Marcelo Corrêa Alves (2) RESUMO Objetivo: comparar a atividade elétrica do músculo supra-hióideo durante a deglutição em sujeitos com distintos padrões morfológicos e dentários. Métodos: foram realizados registros eletromiográfi-cos de superfície em 32 voluntários saudáveis e sem Disfunção Temporomandibular, subdivididos em dois grupos, 16 Uma ação conjunta e equilibrada das estruturas maxilo-mandibular com o sistema muscular é de suma importância para que funções, como: mastigação 7 , deglutição, fala e respiração, ocorram de forma eficiente 8 Em casos de desvios crânio-faciais e/ou oclusais é esperado que a plasticidade dos tecidos moles favoreça mecanismos de adaptação [9][10][11] , dentre os quais se destaca o das compensações musculares 12 que buscam o equilíbrio do sistema estomatogná-tico para a execução das tarefas.…”

“…As implicações de padrões morfológicos dentoesqueletais distintos têm sido vastamente estudadas sob vários aspectos, como área de contato oclusal 1,2 , ritmo mastigatório 3,4 , e posicionamento do bolo alimentar na cavidade bucal 5 . A musculatura, além de delimitadora das partes da cavidade bucal é agente determinante de sua mobilidade.…”