Masseter and temporalis muscle EMG levels and bite force in migraineurs

The purpose of this study was to compare absolute and proportional electrom yography (EMG) levels in the masseter and temporalis muscles during perform ance of a variety of oral functions for migraineurs and age- and sex-matche d controls, Both groups consisted of nine women and one man, with a mean ag e of 43 years (range, 29 to 51 years). Absolute resting EMG levels and thos e levels during swallowing and speech were not significantly different betw een the groups, but the levels of the group with migraine were significantl y higher during maximum voluntary effort contractions on the anterior teeth and on the posterior teeth for bath muscles. When expressed as a percentag e of those levels obtained at maximal posterior contraction (ie, proportion al levels), no difference in functional activity was demonstrated between g roups, It was concluded that the two groups studied had similar levels of E MG activity in the masseter and temporalis muscles during the normal oral f unctions investigated, but that the group with migraine had higher levels o f absolute EMG activity during anterior and posterior maximum voluntary con tractions. Furthermore, the group with migraine demonstrated higher levels of anterior and posterior bite force, although not correlated with EMG leve ls.