顎間距離の増大が咬筋活動に及ぼす影響 : 終日筋電図システムを活用して
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概要
- 論文の詳細を見る
A close relationship may be present between the masticatory muscle activities and the oral environment. The present study was carried out to evaluate the effect of the increase in the interarch distance on masticatory muscle activity. The subjects were 10 adult males with normal masticatory function. Using a whole day EMG recording and analysis system, 24-hour masticatory electromyograms were recorded with application of the plates to elevate the occlusal plane by 2, 4, and 8 mm as conditions 2, 4, and 8, respectively, with the plate designed not to elevate the occlusal plane as condition 0, or without any plate as condition N. The recorded EMG was smoothed as previously reported. The EMG at maximum clenching was also recorded before 24-hour EMG, and 4 reference levels, namely 1/16 (level 1), 1/4 (level 2), 1/2 (level 3), and 3/4 (level 4) of the maximum clenching, were specified to evaluate the 24-hour EMG. The duration and frequency of muscle activities over each of the 4 reference levels and between the reference levels were analyzed by two-way layout analysis of variance and t-test. The following results were obtained. 1. The standard deviation was large for the mean value for both the duration and frequency of muscle activities during awaking, during sleeping, and whole day. 2. Muscle activities decreased under bite-raised conditions as compared with condition N, and the decrease was the most notable under condition 8 than under other conditions during sleeping. 3. No significant differences in muscle activities were found among the conditions during awaking. 4. Muscle activities were apt to be smaller under condition 0 than under condition N. Those findings suggest that the masticatory muscle activities during sleeping are significantly reduced when the interarch distance is increased by application of the plates to elevate the occlusal plane widely above the rest position of the mandible and that the activities can also be reduced by the factors other than elevation of the occlusal plane.
- 九州歯科学会の論文
- 1997-02-25