Duração do ato e do ciclo mastigatorio em individuos com disfunção craniomandibular

AUTOR(ES)
DATA DE PUBLICAÇÃO

1996

RESUMO

The purpose of this study was to assess the eletromyographic parameters of the masticatory act duration, in the muscles temporal anterior and masseter of the 46 subjects with craniomandibular disorders (CMD), corresponding to the period of time between the start and the final of muscle contration; the duration of the masticatory cycle, or the period between the start of a muscle contraction and the start of the next one; the duration of the muscle relaxing period, relative to bioelectrical. potential absence between two masticatory acts and the maximum amplitude of bioelectrical potentials. The records were obtained during the voluntary teeth percussion and molar unilateral mastication (Ieft and right side) procedures. The control group was comprised of 22 normal subjects. The results showed a statistically significant decrease at 5% levei (ANOVA - Statgraphics 2,7) in ali parameters in CMD group, comparing to the normal subjects. The reduction in duration and amplitude of the masticatory act could be interpreted as a functional adaptation form, since the CMD group subjects have undergone a change in dietary behavior and a neuromuscular reprogramation, a likely neural readaptation of inhibitoi-y type, elicited by periodontal and/or muscle receptors stimuli. The reductions or decreases in the masticatÇ>ry cycle duration and of the muscle relaxing period observed in the CMD subjects, equally reflect the likely effect of the inhibitory reflex on the muscle activity and could possibly justify the presence of pain or discomfort, due to reduced relax periods, which would compromise the muscular blood flow. Concerning to the procedures, higher duration and amplitude masticatory act values were noted during the voluntary teeth percussion when compared to the unilateral molar mastication, right or left side, possibly due to the fact that voluntary percussion of the teeth is a voluntary and coordinated movement, without the participation of the occlusal interference, since the occlusal phase is immediately stopped after the teeth initial contact. In masticatory cycle duration and muscle relaxing period no statistically significant differences were observed between the procedures, indicating that the muscle activity and the muscle relaxing period are not compromised by the kind of movement, either voluntary or automatic, when considered as a whole. Another fact observed was the higher duration and amplitude for the masseters than the tempor.al anterior muscles, outlining the feature that the short muscles, as the masseters, would be primary strength producers, while the long muscles, as the temporal anterior, would be essencially producers of a grater rate of speed and freedom. Analysing the reductions in the duration and amplitude of the masticatory act, as well as in the duration of the masticatory cycle and in relaxing period of the CMD group patients, it was concluded that such reductions (decreases) can be interpreted as indicative signs of CMD

ASSUNTO(S)

musculo temporal eletromiografia face - musculos articulação temporomandibular - doenças

ACESSO AO ARTIGO

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