TY - JOUR
T1 - Remote noxious stimuli modulate jaw reflexes evoked by activation of periodontal ligament mechanoreceptors in man
AU - Mason, Andrew G.
AU - Scott, Brendan J. J.
AU - Van der Glas, Hilbert W.
AU - Linden, Roger W. A.
AU - Cadden, Samuel W.
N1 - dc.publisher: The Physiological Society
This paper follows up the main line of our research group and reports that jaw reflexes evoked by mechanical stimuli inside the mouth are also dependent on sensory events elsewhere on the body. The paper is the result of our collaboration with internationally renowned colleagues from London and the Netherlands.
PY - 2002
Y1 - 2002
N2 - The purpose of the study was to investigate whether jaw reflexes evoked by selective stimulation of periodontal ligament mechanoreceptors are susceptible to modulation by remote noxious stimulation. Experiments were performed on 10 volunteer subjects. Skin surface recordings were made from the jaw-closing masseter muscle. The subjects activated the muscle to approximately 10% of maximum by biting on a rubber impression of their molar teeth while they received visual feedback of the electromyogram (EMG) of the muscle. Reflexes were produced by the application of gentle mechanical stimuli to an upper central incisor tooth. The stimuli were in the form of ‘ramp and hold’ forces with a 5 ms rise-time and a 1.5 N plateau which lasted 350ms. The resulting reflexes were recorded both under control conditions and while the subjects received a remote noxious stimulus (immersion of a hand in water at 3°C). In all 10 subjects, the stimuli produced a single period of inhibition of masseteric activity (latency, 12.8 ± 0.4 ms; duration, 18.1 ± 1.3 ms; means ± S.E.M.), which was usually followed by a period of increased masseteric activity. The period of inhibition constituted a downward wave in full-wave rectified, averaged signals. The integrals of such waves were significantly smaller (by 17 ± 6.5 %; P = 0.027; Student’s t test) when the reflex was evoked during remote noxious stimulation rather than under control conditions. As such reflexes are believed to play a modulatory role during normal oral function, this finding may be relevant to disorders of mastication associated with pain.
AB - The purpose of the study was to investigate whether jaw reflexes evoked by selective stimulation of periodontal ligament mechanoreceptors are susceptible to modulation by remote noxious stimulation. Experiments were performed on 10 volunteer subjects. Skin surface recordings were made from the jaw-closing masseter muscle. The subjects activated the muscle to approximately 10% of maximum by biting on a rubber impression of their molar teeth while they received visual feedback of the electromyogram (EMG) of the muscle. Reflexes were produced by the application of gentle mechanical stimuli to an upper central incisor tooth. The stimuli were in the form of ‘ramp and hold’ forces with a 5 ms rise-time and a 1.5 N plateau which lasted 350ms. The resulting reflexes were recorded both under control conditions and while the subjects received a remote noxious stimulus (immersion of a hand in water at 3°C). In all 10 subjects, the stimuli produced a single period of inhibition of masseteric activity (latency, 12.8 ± 0.4 ms; duration, 18.1 ± 1.3 ms; means ± S.E.M.), which was usually followed by a period of increased masseteric activity. The period of inhibition constituted a downward wave in full-wave rectified, averaged signals. The integrals of such waves were significantly smaller (by 17 ± 6.5 %; P = 0.027; Student’s t test) when the reflex was evoked during remote noxious stimulation rather than under control conditions. As such reflexes are believed to play a modulatory role during normal oral function, this finding may be relevant to disorders of mastication associated with pain.
M3 - Article
SN - 0958-0670
VL - 87
SP - 699
EP - 706
JO - Experimental Physiology
JF - Experimental Physiology
IS - 6
ER -