• 대한치과보철학회지
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• 제40권6호
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• pp.577-589
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• 2002

There are several variations in normal mastication. In them, unilateral mastication is chewing, predominantly on a preferred side of the dentition and hardly on e non-preferred side. Continual unilateral mastication may alter the coordination of masticatory muscles. Although they studied about these EMG of masticatory muscles, there were no information about characteristics of masticatory muscle activity in unilateral mastication. Therefore, In this study, we investigated the activity of the masseter and anterior temporal muscles during rest, clenching in maximum intercuspation and gum chewing in habitually unilateral mastication group compared with normal group and tried to know effects of continual unilateral mastication on activity of masticatory muscles. The results of this study were as follows 1. In electromyographic activity during rest, in bilateral mastication group pattern of muscle activity of right and left side was symmetrical. But, in unilateral mastication group, records of anterior part of temporal muscle was higher than that of bilateral mastication group (p<.01) and patterns of muscle activity of right and left side in both muscle were asymmetrical.(p<.05) 2. In electromyographic activity during clenching in maximum intercuspation, records of superficial part of masseter muscle were higher than anterior part of temporal muscle in both group. Muscle activity of temporal muscle in unilateral mastication group was a little higher han bilateral mastication group and asymmetry of activity pattern in temporal and masseter muscle was shown but these differences were not statistically significant. (p<.05) 3. In electromyographic activity during gum chewing, temporal muscle was activated earlier than masseter muscle and maximum bite force is derived from masseter muscle in both group. In unilateral mastication group, electromyographic activity of masseter and temporal muscle of preferred chewing side, regardless of right or left side chewing, was higher than that of bilateral mastication group and especially, difference in masseter muscle was statistically significant. (p<.01) Based on the above results, our study suggested that recording of masticatory muscle activity will be helpful in the effective diagnosis and treatment of some types of the parafunctional habits.

• 한국치위생학회지
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• 제14권3호
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• pp.293-302
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• 2014

Objectives : The objective of this study was to investigate the relationship between the status and necessity of dental prosthesis and mastication function in the Korean elderly. Methods : This study investigated 4,557 elderly people aged over 65 in the 5th Korea National Health and Nutrition Examination Survey(2010-2012). Frequency analysis, ${\chi}^2$ test, and logistic regression analysis were used. Results : Those aged over 75 complained of greater discomfort in mastication function than those from 65 to 74, and it was statistically significant(p<0.001). Mastication discomfort was not so significant in those with higher education and higher income(p<0.001). Those who did not use prosthesis tended to have better mastication function(p<0.001). Denture users complained of mastication discomfort when they used it(p<0.001). Conclusions : This study verified the relationship between the discomfort in mastication and related factors, and will provide the basic data for the access to dental clinic services.

• 보건의료기술평가
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• 제6권2호
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• pp.100-105
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• 2018

Objectives: The purpose of this research is to investigate regional variations of mastication difficulty rates in the elderly over 65 in 229 primary autonomous districts in Korea and explore relevant characteristics. For the research data, local community health survey conducted in 2015 and data from Ministry of the Interior and Safety, Ministry of Health & Welfare, National Health Insurance Service and Statistics Korea were used. Methods: Frequency analysis was conducted for general characteristics and mastication difficulty rates of each region, and distribution of mastication difficulty rates was displayed for each town, city and province by mapping them. Extremal quotient (EQ), coefficient of variation (CV) values were calculated for regional variations, and logistic regression analysis was performed to reveal the relationship between each independent variable and mastication difficulty rates. Results: The average of standardized mastication difficulty rate was 46.78%, and regional variations were significant with EQ 3.46, CV 0.18. Characteristic factors that have significant effects on mastication difficulty rate included sex ratio, elderly population and the number of dentists per 10000 people. Conclusion: As a result, there were variations among mastication difficulty rates in 229 primary local governments across the country, and the distribution of health care resources by the characteristics of the local environment by region affected mastication difficulty rates. Accordingly, it is required to provide political supports to overcome regional inequality of oral health levels and develop cooperative system between local governments and local dentists.

• Macromolecular Research
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• 제8권2호
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• pp.73-79
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• 2000

The influence of mastication of natural rubber (NR) on properties of carbon black-filled NR compounds was studied. Variations of viscosities of the masticated NR and the carbon black-filled NR compound by heating were also investigated. The viscosities of the compounds decreased by increasing the mastication time of the raw rubber. The viscosities of the masticated NR and the compounds increased by increasing the heating time. This was explained by the combination reaction between functional groups in the rubber. The viscosity increment of the masticated rubber and the compounds by heating became larger with increased mastication time. Cure rate of the compound became faster by increasing the mastication time. Modulus of the vulcanizate made of the rubber masticated for a long time was higher than that of the vulcanizate made of the rubber masticated for a short time while elongation at break of the former was shorter than that of the latter. This was explained by the content of bound rubber and chain length of the rubber molecules.

• 대한약리학회:학술대회논문집
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• 대한약리학회 2006년도 The 6th Congress of the Federation of Asian and Oceanian Physiological Societies
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• pp.122.1-122.1
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• 2006

• 융합정보논문지
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• 제10권7호
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• pp.215-222
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• 2020

본 연구는 한국 중·장년의 저작 문제와 삶의 질의 관련성을 알아보고자 실시하였다. 제6기 국민건강영양조사 자료에서 만 40세 이상 64세 이하의 중·장년 중 건강관련 삶의 질을 알아보는 EQ-5D 지수 및 구강건강 상태에 대한 설문에 응답한 7,125명이 최종 분석대상이 되었다. 대상자의 삶의 질의 평균은 0.96점이었으며 이를 기준으로 삶의 질이 낮은 그룹과 높은 그룹으로 분류하여 저작문제와의 관련성을 분석하였고, 분석은 SPSS 20.0 프로그램을 이용하였다. 저작문제가 있는 그룹에서 낮은 삶의 질의 비율은 41.9%로 저작문제가 없는 그룹(24.4%)보다 유의하게 높았다. 로지스틱 회귀분석을 이용하여 저작문제가 없는 그룹을 기준으로 문제가 있는 그룹에서의 낮은 삶의 질의 비율을 분석하였다. 일반적 특성과 구강건강상태를 보정했을 때 저작문제가 있는 그룹에서 낮은 삶의 질의 비율은 1.77배(95% CI: 1.53-2.06)로 분석되어 저작 문제는 삶의 질과 유의한 관련성이 있음이 확인되었다. 다양한 연령층을 대상으로 건강관련 삶의 질에 관련성이 있을 것으로 예측되는 구강의 요인들을 반영한 연구가 필요하다.

• 성인간호학회지
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• 제24권2호
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• pp.130-138
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• 2012

Purpose: The purpose of this study was to verify the effects of gum chewing temporalis muscle exercise on masticatory discomforts after craniotomy. Methods: Data collection was performed from July 10 to October 24, 2008. Forty participants who were treated with elective craniotomy were enrolled in this study. Twenty participants in the exercise group were given a gum chewing exercise protocol for five days and twenty participants in the control group received usual postoperative care only. All the participants were examined on the first, third and fifth postoperative day regarding the masticatory pain score, mouth opening range, and satisfaction with mastication. Collected data were analyzed using t-test, $x^2$-test and repeated measures ANOVA. Result: Masticatory pain of experimental group was significantly lower than the control group ($p$ <.001). Mouth opening range and satisfaction with mastication of experimental group were significantly improved in experimental group compared with the control group ($p$ <.001). Conclusion: The gum chewing temporalis muscle exercise after craniotomy is a useful intervention to reduce masticatory pain and to improve mouth opening range, recovery rate of mouth opening range and satisfaction with mastication.

• Elastomers and Composites
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• 제27권4호
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• pp.262-266
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• 1992

A number of tin-containing elastomers are produced commercially by Korea Kumho Petrochemical Co., Ltd. (KKPC) under the Kosyn Sol tradename. The effect of mastication of commercial and laboratory polymerized S-SBR has, been investigated using chemical mixer(ML-500), NMR, GPC and Mooney viscometer. Mastication of polymers containings coupling bonds is affected by the amount of stearic acid, the temperature of mixing and the time length of mixing.

• 대한치과보철학회지
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• 제33권3호
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• pp.440-452
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• 1995

A success of complete denture prosthesis can be determined by the satisfaction degree of the dentist and the patient. There are many factors influencing on the satisfaction of the complete denture patients. The purpose of this study is to analyze the correlation between the masticatory satisfaction and clinical evaluation, and the speech satisfaction and clinical evaluation in complete denture patients. 79 patients(total 119 complete dentures) were examined in this study who were treated in Seoul National University Dental Hospital. Through clinical evaluation, 2 examiners evaluated sex, age, edentulous period, the years of having used present complete denture, the number of the previous dentures, the state of the opposite arch, retention, stability, support, occlusion, vertical dimension of the complete denture and the condition of the residual alveolar ridge. Through questionnaires concerned with mastication and speech, examiners evaluate the satisfaction degree of the patients. This study led to the conclusion that : 1. The satisfaction degree of the mastication was lower in older patients(p<0.001) and in patients whose present complete denture period was shorter(p<0.05). The satisfaction degree of the mastication in male was higher than in female patients(p<0.01). 2. The satisfaction degree of the mastication was high when the retention of the complete denture was good(p<0.05), and when the condition of the residual alveolar ridge was good(p<0.05). 3. The satisfacion degree of the speech was high when the retention of the complete denture was good(p<0.01). 4. The satisfaction degree of the mastication was higher in patients with upper and lower complete denture than in patients with single complete denture whose oppsite arch was unilateral partial denture(p<0.05).

• 대한화학회지
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• 제19권5호
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• pp.386-393
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• 1975

Roll을 사용한 mastication에 의한 polystyrene(단독시와 SBR과의 blend시)의 기계적분열에 대하여 검토한 결과 다음과 같은 결론을 얻었다. 1. Polystyrene-SBR blend계에서 polystyrene 성분의 MWD는, original polystyrene속에 존재하는 고분자량의 polymer 분자가 기계적으로 절단되어 소멸하여 보다 낮은 분자량의 polymer 분자를 생성하며, 분포곡선의 정점은 분열이 진행함에 따라 저분자량역으로 이동하고 점차 높은 정점을 가지는 폭이 좁은 곡선으로 되어 최종적으로 비교적 균일한 polymer로 됨을 실증하였다. 2. Polystyrene chain의 절단수는 roll에 의한 mastication time이 길어짐에 따라 증가하였고, 140, 150 alc $160^{\circ}C$에서 각각 100분간 mastication시킨 처리물에서는 $2.36{\times}10^{20}개,\;1.76{\times}10^{20}개\;및\;1.52{\times}10^{20}$개의 분열 polymer가 생성하였다. 3. Polystyrene의 mechanical degradation의 분열속도는 온도가 상승함에 따라 감소되었고, -8.7kcal/mole이란 부(負)의 활성화에너지를 나타내었으며, 따라서 이 경우의 mechanical degradation은 활성화에너지를 기계적으로 공급받는 화학적 process임을 실증하였다.