engleski

Silent period in individuals without periodontal receptors

Purpose: To study the latency and the duration of a silent period (SP) elicited in an open-close-clench cycle (OCC) in complete denture wearers (CDWs) and subjects with natural dentition (ND). Methods: SPs were registered in 32 individuals with ND and in 19 CDWs using the EMGA-1 device. Ten registrations of an OCC cycle were made to elicit SPs. Electromyographic signals from the right and the left anterior temporal (RAT, LAT) and the right and the left masseter muscles (RM, LM) were registered during 300 ms. Results: SPs had a latency of 12.5-12.9 ms after the occlusal contact and a single short inhibitory pause (20.1-21.1 ms) with complete inhibition of motoneuron activity in NDs. In CDWs various types of SPs emerged after the artificial teeth contact in OCC cycles: single or single prolonged SPs, double SPs, SPs with 3 inhibitory pauses, periods of depressed muscle activity following the first, or the second inhibitory pause, SPs of relative inhibition of motoneuron activity or even sometimes SP was missing. In cases with more than one inhibitory pause, complete duration of all inhibitory pauses together with a period of depressed muscle activity (if existed) (CDIP) was measured. In CDWs, latencies were significantly prolonged (16.8 ms, p<0.05), as well as the CDIP (40 ms, p<0, 05) in comparison with NDs. Conclusion: The latency and the duration of the SP were different between NDs and CDWs. Different mechanisms and pathways may be responsible for the reflex (periodontal receptors vs. receptors in oral mucosa).

silent period; mucosal receptors; complete dentures; EMG

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