脳電位分布からみた咬合干渉部位と大脳半球における脳波局在の関連

抄録

Purpose : The aim of this study was to examine the relationship between occlusal interference positions and localizing EEG potential in each hemisphere. Methods : Eight healthy dentates were selected as subjects. Electromyograms (EMG) from the bilateral masseter and posterior temporal muscles and electroencephalograms (EEG) were simultaneously recorded and analyzed before and after mastication of kamaboko. Twelve sessions were carried out : the control (Cont), just after (JA), 1∿7 days later after wearing the interference (1∿7 DL), just after removing the interference (JAR) and 1∿2 days after removing the interference (1∿2 DLAR). Results : The peak of decreasing masticatory muscle activity during non-interfering side mastication appeared later and continued to decrease, compared to interfering side mastication. EMG coordination pattern was affected by restraint of masseter activity during the interfering side mastication, and by restraint of posterior temporal activity during non-interfering side mastication. After mastication, %α in EEG decreased, and %β significantly increased compared to before mastication. %β increased later during non-interfering side mastication. %α after mastication showed no significant change in either hemisphere. However %β after mastication were significantly higher in the left hemisphere than the right regardless of the mastication side. In addition, hemispheric differences of %β appeared later in non-interfering side mastication compared to interfering side mastication. Conclusion : The experimental occlusal interference affected the %β of the left hemisphere, and fluctuation of %β agreed with EMG appearance. It suggests that impulses from occlusal interference projected to hemisphere activity opposite to the interfering side.