[The reflex behavior of the masseter muscle under standardized stimuli]

Both reflex phenomena of the masticatory musculature (jaw-jerk-reflex and silent period) were studied in the masseter muscle under standardized reflexogenic conditions in terms of the strength of the stimulus and initial muscle tension. The measurements were carried out with loading forceps. The reflex time for the selfregulating reflex of the masseter for 11 subjects ranged from 7.4 to 9.4 ms; the latency time for the silent period, from 13.9 to 18.1 ms; the duration of the latency period, from 11 to 23 ms. On the basis of our data, no dependency could be established between these values and the strength of the stimulus or initial muscle tension. The silent period, in accordance with its neurophysiologic mode of development, was further differentiated into a monosynaptic, muscle-conditioned and a polysynaptic form. The experimental conception was analyzed critically in terms of its applicability for ongoing studies of the reflex activity of masticatory musculature.