| 1092 Magnitude of Subjective Tooth Clenching Level | ||
|
H. SUZUKI1, O. KOMIYAMA2, T. ASANO2, T. KUROKI2, T. KOBAYASHI2, T. IIDA2, and M. KAWARA2, 1Nihon University, School of Dentistry at Matsudo, Chiba, Japan, 2Nihon University, Chiba, Japan Objective: The athletes subjectively show the status of tooth clenching as ”strong” or ”weak” during their exercise, however, there is no study to evaluate this magnitude of subjective tooth clenching level. In order to know the effect of tooth clenching to masticatory system during sports exercise, this study was conducted to measure the magnitude of subjective tooth clenching level using objective way.. Method: The subjects were 20 adults (12 males, 8 females; 18-24 years old) with normal occlusion and no dysfunction of stomatognathic systems. The anterior part of the left and right temporalis muscles and the middle region of the left and right superficial layers of the masseter muscles were measured. Electromyograms were obtained using a multi-telemeter system (WEB-5000, Nihon Koden). Each subject was asked to clench “weak” and “strong” as subjective levels and clenching at each level was performed 3 times for 3 seconds with 1 minute interval. The subject determined his/her clenching strength subjectively without visual feedback. RMS values were calculated from the electromyograms, and relative ratios to 100% maximum voluntary contraction (MVC) were determined. Results: During “strong” clenching, the temporalis and masseter muscles showed 61.1 ± 23.97% and 51.4 ± 23.18% of MVC, respectively. In contrast, during “weak” clenching, the temporalis muscles and masseter muscle showed 15.2 ± 7.45% and 9.3 ± 4.31% MVC, respectively. Significant difference activity were found between the “weak” and “strong” clenching levels in each muscles (ANOVA, p<0.01). Further, the temporalis muscles had significantly greater activity during both subjectively “strong” and “weak” clenching levels compared to the masseter muscle (ANOVA, p<0.05). Conclusion: The study clearly showed the different masticatory muscle activity between the subjectively “strong” and “weak” clenching levels, and may suggest the different role of masseter and temporalis muscle in subjective co-contraction level of masticatory muscle. | ||
| Seq #95 - Occlusion and Loading 3:30 PM-4:30 PM, Thursday, 29 June 2006 Brisbane Convention & Exhibition Centre Exhibit Hall 1 | ||
|
Back to the Prosthodontics Research Program
| ||