Electromyographic study of the temporal, masseter and suprahyoid muscles in the mandibular rest position

Abstract

The temporal muscles (anterior position), and the masseter and suprahyoid muscles were studied electromyographically in 15 subjects with ages ranging from 18 to 35 years, showing normal occlusion (Class I of angle), complete dentition and no dysfunction of the stomatognathic system. The volunteers sat comfortably in a chair, keeping the Frankfurt plane parallel to the floor; the muscles were analysed in the mandibular resting position through a number of stages: with minimum exteroceptive stimuli, relaxation with soft music, abolition of the intrabuccal negative pressure through a plastic tube, stress provoked by an electronic game, disocclusion of posterior teeth using the occlusal splint and finally withdrawal of this device. The electromyographic results were analysed statistically. The samples, were analysed for all of the frequencies of motor units, in a 1-min period. It was found that there were statistically significant difference between the relaxation stages as compared with the withdrawal of negative intraoral pressure and mainly with the stress phase, being this only on the suprahyoid muscles, with 5% significance.

Influence of temporomandibular disorder on temporal and masseter muscles and occlusal contacts in adolescents: an electromyographic study

“…The determination of EMG activity in the temporal and masseter muscles with the mandible at rest is of fundamental importance to comparisons between individuals, as muscle activity in the resting position is dependent on the lengthening reflex and is effectively maintained by the tonicity of the muscles that counterbalance the action of gravity and negative intra-oral pressure [34]. However, the physiological basis of the mandibular resting position is one of the most controversial areas in oral physiology [35,36].…”

Immediate effects of temporary bite-raising with light-cured orthodontic band cement on the electromyographic response of masticatory muscles

“…Surface EMGs were simultaneously recorded from the left and right superficial masseter and anterior temporalis muscles by a researcher using the ML866 PowerLab 4/35 (ADInstruments Pty Ltd., Bella Vista, Australia), following the protocol indicated by the manufacturer. The participants were seated upright on a chair with their trunk perpendicular to the floor, both feet on the floor, hands resting on their lap, and looking forward with their head unsupported in a quiet place listening to relaxing music 20 . We cleaned the skin with isopropyl alcohol (70%), and gently applied a small amount of abrasive gel (ADInstruments Pty Ltd.) on it, which lowered the electrode-skin impedance at the electrode site with minimal discomfort or irritation.…”

O uso da TCFC no diagnóstico de reabsorção radicular externa e perda óssea localizada em segundos molares adjacentes a terceiros molares impactados e avaliação da atividade dos músculos mastigatórios como fator de risco para reabsorção radicular externa

“…Recording the EMG activity of the temporal and masseter muscles with the mandible at rest is as fundamental as the evaluation in isometry and isotonic because it allows comparisons between individuals, since the rest is maintained even with the tonicity of the muscles that counterbalance the action of gravity. and negative intraoral pressure [45].…”