• 대한치과보철학회지
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• 제25권1호
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• pp.195-204
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• 1987

The purpose of this study was to investigate the effect of occlusal splints on the masseteric silent period and the changes of the masseteric silent period after experimental bruxism with occlusal splints. In nine subjects, anterior occlusal splints were fabricated. The jaw-jerk reflex was induced by tapping over mandibular symphysis area with solenoid driven hammer and electromyogram of left masseter muscle was recorded. In the recorded electromyogram of left masseter muscle the silent period duration was measured. This procedure was done before insertion of anterior occlusal splints, after insertion of anterior occlusal splints, after 30 min experimental bruxism with anterior occlusal splints, and 3hr after removal of anterior occlusal splints. The result were as follows; 1. The mean silent period duration was increased after insertion of occlusal splints compared with the mean silent period duration before insertion of occlusal splints. 2. There was no change of the mean silent period duration after 30 min experimental bruxism with occlusal splints compared with the mean silent period duration after insertion of occlusal splints. 3. 3hr after the removal of occlusal splints, the mean silent period duration showed no difference from the mean silent period duration before insertion of occlusal splints.

• 대한전기학회논문지:시스템및제어부문D
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• 제52권10호
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• pp.611-617
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• 2003

A mechanical or electrical stimulation to the mandibular symphysis during a maximal voluntary clenching of the teeth always produces a jaw jerk followed by a silent period (transient stops) in the masseteric EMG (electromyogram). Generally, a mechanical stimulation is followed by a single silent period, and an electrical stimulation is followed by multiple silent periods. In this paper, we propose a new algorithm for determining the duration of the masseter silent period. The decision approach in essentially based upon a segmentation algorithm consisted of variance filter, median filter and gaussian filter. The new adaptive digital notch filter using R-CLMS(reverse constrained least mean-squared) algorithm is proposed for the elimination of powerline(60Hz) noise. At the same time, we design a real time measurement system for the EMG silent period under Window base.

• 대한치과보철학회지
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• 제25권1호
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• pp.205-212
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• 1987

The purpose of this study was to investigate the duration of the silent period of the masseter muscle in normal subjects after experimental bruxism. The material for this study consisted of 9 male subjects with an age range of 22-24 years who showed normal occlusion clinically and were free from any history or symptoms of temporomandibular joint dysfunction. A jaw-jerk was stimulated by tapping the mandibular symphysis during maximal voluntary clenching with a solenoid-driven hammer. And three separate silent period records were made from the left masseter muscle at the following times: at normal state, after experimental bruxism, 1 week after bruxism. The following conclusions were obtained: 1. The average value of the duration of masseteric silent period during maximal voluntary clenching was $33.62{\pm}1.86msec$ when tap force of approximate 650g was applied at normal state. 2. After experimental tooth grinding for 30 minutes, the duration of masseteric silent period increased to $46.29{\pm}4.40msec$. 3. Comparing the duration of silent period measured at normal state with that measured after 1 week, the duration of silent period showed reproducibility.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.1005-1006
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• 2008

A mechanical or electrical stimulation to the muscle always produces special phenomena, as silent period. Generally, a mechanical stimulation is followed by a single silent period, and an electrical stimulation is followed by multiple silent periods. In this paper, we propose a new algorithm for determining the duration of the silent period.

• 대한치과교정학회지
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• 제22권3호
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• pp.617-626
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• 1992

This study was conducted for the assessment of the usefulness of masseteric silent period on electromyogram as a diagnostic method for temporomandibular disorder. Of students and dentists in Dental College of Yonsei University and patients, 36 experimental subjects with symptoms such as clicking bound, pain in the temporomandibular joint area and limitation of jaw movement, and 33 control subjects without such symptoms were selected for this study. On each subject electromyographic masseter muscle silent period followed by mention tap was recorded with surface electrodes and analysed with computerized system. The following results were obtained: 1. The mean silent period was $36.97{\pm}9.23$ msec in experimental group, and $25.62{\pm}5.24$ msec in control group respectively. 2. There were no statistically significant differences in silent period between male and female in either experimental and control group. 3. Silent periods in experimental group were more prolonged than those of control group. (P < 0.01) Taken all together, electromyographic masseter muscle silent period may be useful for diagnosis and evaluation of temporomandibular disorder.

• Journal of Oral Medicine and Pain
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• 제12권1호
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• pp.95-103
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• 1987

저자는 측두하악장애를 가진 환자 15명을 대상으로 교합안정장치 장착 전후의 Helkimo 장애지수 및 교근의 휴지기 지속시간을 측정한 결과 마음과 같은 결론을 얻었다. 측두하악장애를 가진 환자 15명의 실험전 평균 교근휴지기 지속시간은 좌측에서는 50.7msec 우측에서는 50.5msec였다. 교합안정장치를 이용한 4주간의 치료후 평균 교근 휴지기지속시간은 좌측에서는 25.4msec 우측에서는 26.5msec였다. 치료전 Helkimo 기능장애지수와 교근의 휴지기 지속시간과는 상관관계가 높았다.(r : 0.675, p<0.01). Helkimo 기능장애지수는 교합안정장치장착 4주후 현저히 감소하였다. (p<0.01). 교근의 휴지기 지속시간도 교합안정장치장착 4주후 현저히 감소하였다. (p<0.01).

• 대한치과교정학회지
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• 제17권1호
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• pp.15-21
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• 1987

The present study was carried out to investigate the relationships between the depth of overbite and the masseteric silent period. Normal subjects of 44 were selected, which consisted of 9 open bites, 24 normal overbites and 11 deep bites, all were 19-29 years of age. EMG activity was recorded on the bilateral masseteric muscles and craniofacial radiography was done. The following results were obtained. 1. The mean duration of masseteric silent period was $18.58{\pm}4.50$ msec in open bite, $17.37{\pm}7.05$ msec in normal overbite and $19.30{\pm}7.62$ msec in deep bite groups. 2. There were no significant differences on masseteric silent period among open bite, normal overbite and deep bite groups. 3. There were no significant correlations between masseteric silent period and craniofacial variables.

• Journal of Oral Medicine and Pain
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• 제10권1호
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• pp.105-112
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• 1985

The author has studied the duration of silent period of the masseter muscle using electromyography in order to obtain the information that is necessary to diagnose the patients with TMJ dysfunction syndrome objectively. The 55 normal subjects and the 40 patients with TMJ dysfunction syndrome were selected for this study. The results were as follows : Duration of silent period of the masseter muscles in normal subjects were 24.4 msec in males, 24.0 msec in females, and mean of $24.2\pm3.19$ msec. Duration of silent periods of the masseter muscles in patients with TMJ dysfunction syndrome were 39.4 msec in males, 41.3 msec in females, and mean of $40.5\pm7.01$ msec. There was no significant difference of the duration of silent periods between in the right and the left side of the masseter muscles, and between in the males and the females (p>0.05). Duration of silent periods of the masseter muscles in patients with TMJ dysfunction syndrome were significantly more prolonged than those in normal subjects (p<0.01). Borderline of silent periods of the masseter muscles between in normal and patients with TMJ dysfunction syndrome was 31.5 msec.

• 대한전기학회논문지:시스템및제어부문D
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• 제50권5호
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• pp.247-254
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• 2001

Silent period(SP) is transient stops of muscle activity that are induced by mechanical or electrical stimulus and the duration of silent period is a important parameter that have been associated with symptoms of masticatory dysfunction. Muscle fatigue is induced by sustained muscular contractions. It is associated with the external manifestations as the inability to maintain a desired force output, muscular tremor, and localized pain. Muscle fatigue is a parameter that have been measured or monitored the deterioration of a performance of muscles. On the study of relationship between SP and masticatory muscle fatigue, Nagasawa suggested that SP increases up to 3 min. from the beginning of clenching when the subjects performed sustained contractions at 50% maximum clenching level. In this paper, in order to evaluate a relationship between SP and muscle fatigue, 10 SPs per 1 minute are measured at 10%, 20%, 50% maximum clenching level. We used the median frequency in order to quantify the degree of muscle fatigue. However, the results shows that the duration of silent period was not significantly affected by differing levels of muscle fatigue. Therefore, we suggest that the SP is not increased or decreased as the results of muscle fatigue, also the origin of the SP generation mechanism is discussed.

• Annals of Clinical Neurophysiology
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• 제4권1호
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• pp.81-84
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• 2002

Tetanus is a disorder known to interfere with inhibitory modulation of the motor system in humans. In this report, we describe the characteristic neurophysiological findings in a 52-year-old patient with generalized tetanus. The cutaneous silent period was absent and the silent period evoked in distal upper limb muscles by transcranial magnetic stimulation was shortened. These findings can be interpreted as evidence of impaired inhibitory mechanisms at multiple levels of the nervous system.