Changes in the Human Masseteric Reflex Derived from Periodontal Mechanoreceptors Following Clenching

The purpose of this study was to investigate whether the masseteric reflex evoked by periodontal mechanoreceptors is involved in the positive-bias effects on the occlusal force .The masseteric reflex was evoked by applying pressure stimulation to the upper incisor teeth with a mechanical stimulato r.The mean amplitude of reflex responses obtained before and after clenching were compared .As a result, the amplitude ofmasseteric reflex recorded after clenching was 1 .16±0.49(mean±SEM) higher, but the difference was not statistically significant (p=0.05,Student's t-test).The results suggested that the role of the reflex arc derived from periodontal mechanoreceptors in the excitation of jaw-closing motoneurons after clenching is relatively small.