• 한국노년학
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• v.37 no.4
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• pp.909-924
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• 2017

The purpose of this study was to identify the impact of chewing ability on cognitive function of older people in Korea and the mediation effect of physical function and depression using the nationwide data from "Survey of the Living Conditions and Welfare Needs of Korean Older Persons in 2014", in Korea. This study was conducted on a total of 10,451 respondents in the "Survey of the Living Conditions and Welfare Needs of Korean Older Persons in 2014" and the data collection period was from June 11, to September 4, 2014. Chewing ability was used in the scale on level of daily life inconvenience in chewing ability (meat or hardness). Cognitive function was measured using MMSE-DS, physical function using K-IADL, and depression using SGDS-K. The data were analyzed using the SPSS 24.0 program and Process Macro. Total effects of chewing ability on cognitive function were not significant(p>.05). Direct effects of chewing ability on cognitive function were not significant(p>.05). There were the dual mediation effect(p<.05) of physical function and depression, a complete mediating effect by physical function(p<.05) or depression(p<.05) in the impact of chewing ability on cognitive function of older people in Korea. These results indicate that physical function and depression effect directly and indirectly in the impact of chewing ability on cognitive function of older people. In conclusion, it is suggested that to prevent the decline of cognitive function in older people, it is necessary to consider not only nursing strategies for strengthening chewing ability and physical function, but also nursing interventions for relieving or preventing depression in older people.

• The Journal of Advanced Prosthodontics
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• v.8 no.3
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• pp.187-193
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• 2016

PURPOSE. This pilot study was to find the influence of complete denture on the brain activity and cognitive function of edentulous patients measured through Electroencephalogram (EEG) signals. MATERIALS AND METHODS. The study recruited 20 patients aged from 50 to 60 years requiring complete dentures with inclusion and exclusion criteria. The brain function and cognitive function were analyzed with a mental state questionnaire and a 15-minute analysis of power spectral density of EEG alpha waves. The analysis included edentulous phase and post denture insertion adaptive phase, each done before and after chewing. The results obtained were statistically evaluated. RESULTS. Power Spectral Density (PSD) values increased from edentulous phase to post denture insertion adaption phase. The data were grouped as edentulous phase before chewing (EEG p1-0.0064), edentulous phase after chewing (EEG p2-0.0073), post denture insertion adaptive phase before chewing (EEG p3-0.0077), and post denture insertion adaptive phase after chewing (EEG p4-0.0096). The acquired values were statistically analyzed using paired t-test, which showed statistically significant results (P<.05). CONCLUSION. This pilot study showed functional improvement in brain function of edentulous patients with complete dentures rehabilitation.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.3
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• pp.269-276
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• 2012

Many researches have been published about the numerous factors related to the chewing ability of implant prosthesis. Most respective studies have concluded that the chewing ability of implant prosthesis is mostly fine compared to other type of prosthesis. However, some patients are not satisfied with their chewing ability of implant prosthesis. Therefore the neurologic factor, one of the factors related to dissatisfaction of chewing ability was reviewed in this study to understand the mechanism of action of mastication. Data was searched using the keywords; 'implant chewing ability, masticatory ability' in Pubmed database and reviewed. Definitions of chewing ability, factors of chewing ability are reviewed and the neurologic factor, one of the factors influencing on chewing ability, is reviewed. Mechanoreceptor of Periodontal ligament(PDL) is providing the mastication information to brainstem. Due to the absence of mechanoreceptions of PDL in implant, masticatory ability is decreased especially when chewing hard food. Masticatory muscles and mechanoreceptor in TMD may compensate the lack of mechanoreceptor of PDL in implants. Furthermore sensitivity of nerve fiber around peri-implant tissues may support the mechanoreception and sensory reaction in the implant mastication. However, further studies should be conducted to prove the relationships between neurologic factors and mastication.

• Journal of Korean society of Dental Hygiene
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• v.21 no.4
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• pp.383-391
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• 2021

Objectives: Based on the 7th National Health and Nutrition Examination Survey 1,135 adults aged 19 years were selected as the final study subjects to investigate the relationship between oral health and chewing difficulty in adults. Methods: Frequency analysis, chi-square test, and logistic regression analysis were performed for general characteristics, oral health behaviors, awareness symptoms, and oral health using SPSS Program 21.0. Results: Regarding factors related to chewing difficulty, the oral health was 0.44 times lower than the average level and 0.28 times lower than the good condition. In the case of oral examination, chewing difficulty was 0.85 times lower. The speaking problem was 0.11 times lower in usually than inconvenient and 0.06 times lower in not inconvenient. In the case of un-treatment, it was 0.40 times lower than that in the case of treatment. The chewing difficulty was significantly higher by 2.09 times in the case of experience of tooth pain and 1.36 times in the case of periodontal disease. Conclusions: Based on the above results, it is thought that prevention and treatment are actively needed to identify factors of oral health to improve oral health, to solve chewing difficulty and to improve chewing function.

• The Journal of Korean Academy of Prosthodontics
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• v.32 no.4
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• pp.565-572
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• 1994

According to the classification of dental arch form and the analysis of patterns of chewing movement, the patterns of chewing movement in each group were evaluated and compared with those of the normal group. Results were summarized as follows ; 1. Opening phase in chewing movement In the group which the maxillary second molar positionsbuccal side, the chewing patterns which have the Vertical Guide Openings in frontal plane, the Posterior Guide Openings in hjorizontal plane were observed. In the group which the maxillary premolars position lingual side, the chewing paterns which have the Protrusive Shift Openings in horizontal plane and sagittal plane were observed. 2. Closing phase in chewing movement. In each group except for the normal group, the chewing patterns which have the Concave Closure in frontal plane and in Horizontal plane were observed. In the group which the maxillary premolars position buccal side, the chewing patterns which have the Lateral Guide Closure in frontal plane and in horizontal plane, the Vertical Guide Closre in sagittal plane were observed: From the results, as the characteristics of the dental arch form have appeared in chewing movement, the close relationships were found between dental arch form and chewing movement. It is suggested that the evaluation of dental arch form is effective in the diagnosis of function of stomatognathic system.

• Journal of Korean society of Dental Hygiene
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• v.20 no.3
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• pp.281-290
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• 2020

Objectives: Stress is the cause of several illnesses, in older people, stress may also cause various social problems. The oral health of older adults is closely related to the quality of life, and chewing ability is particularly important for their general health. The purpose of this study was to investigate the relationship between stress, the number of teeth remaining, and the chewing ability, which reflects the oral health status among older adults. Methods: This study evaluated the stress level and chewing ability of adults older than 65 years using the 6th (2014-2015) Korea National Health and Nutrition Examination data. The total number of remaining teeth was determined based on the data of the teeth conditions. Results: There was an association between stress and chewing ability among older adults. The odds ratio of chewing function increased by 2.67 times (crude OR=2.67; 95% CI=1.88-3.79) with increased stress. After adjusting, the odds ratio increased to 2.74 times (adjusted OR=2.74; 95% CI=1.88-3.98). Conclusions: Reducing stress may facilitate effective oral health management and improve the overall quality of life in older adults. The findings of this study may help in the discovery of various approaches s to reducing stress in older adults and provide relevant information for oral health education.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1316-1319
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• 2003

The micromovements and stress distributions of cancellous bone in dental implant system play important roles in evaluating chewing function of an implant system. The micromovements and stress distributions in dental implant system generally depend on the chewing force and bone properties. Three dimensional nonlinear finite element analysis has been employed to investigate this issue quantitatively. Chewing forces and bone properties are classified into several groups and three types of implants involving one classical cylindrical type and two expandable implants are investigated in this paper.

• The Journal of Korean Academy of Prosthodontics
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• v.27 no.2
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• pp.37-52
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• 1989

The purpose of this study was to investigate the relationship between sternocleidomastoid (SCM) and masseter muscles during occlusal functions by means of EMG recordings of examined muscles. For the study, eighteen normal subjects were selected and the Bio-electric Processor EM2 (Myo-tronics Research, Inc., U.S.A.) with the surface electrodes was used to record the EMG activity from the right and left middle of masseter and insertion of SCM of each subject during right and left gum-chewing and isometric contraction by changing the biting force at right eccentric position of jaw. The amount of biting force ranged from 5 to 70kg during isometric contraction were measured by use of Jaw Force Meter. (Nihon Koden Kogyo, Japan.) The results were as follows: 1. The activity onset of SCM and masseter on the same side was almost at the same time, and integrated EMG values of two muscles on the chewing side were higher than the same named muscles on the non-chewing side during gum-chewing. (p<0.01) 2. The regression correlation was not present between both masseters (p>0.05), but between both SCM muscles or muscles of two kinds on the chewing or non-chewing side. ($p{\leqq}0.05$) 3. The integrated EMG value of SCM on chewing or non-chewing side were about 10 percent of that of ipsilateral masseter. 4. Mean voltage of each examined muscles were almost proportional to biting force during isometric contraction and the slope of voltage/biting force line was steepest at the ipsilateral masseter, followed by contalateral masseter, ipsi- and contra-lateral SCM muscles. 5. Mean voltage of ipsilateral masseter was highest during isometric contraction, followed by ipsilateral masseter, contra- and ipsi-lateral SCM muscles.

• The Journal of Korean Academy of Prosthodontics
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• v.33 no.4
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• pp.718-730
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• 1995

This study was performed to measure the mandibular movement and the changes of masicatory and sternocleidomastoid muscle activity reflected by occlusal disturbance during habitual chewing. For this study, 18 subjects(14 males and 4 females with an average age of 24.0) were selected. The impression of each subject were taken for measuring intermolar distance on lower dentition. The activities of masticatory and sternocleidomastoid muscle and the mandibular movement were recorded and analyzed during habitual chewing by means of E.M.G.(electromyograph), E.G.N.(electrognathograph), rotate program in BioPak analyzing system(BioResearch Inc.). The results were as follows : 1. In EMG of the mandibular rest position, the mean value of muscle activites were increased by nocleidomastoid muscle and anterior belly of digastric muscle(0.05

• Journal of Oral Medicine and Pain
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• v.30 no.1
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• pp.45-55
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• 2005

As people prefer to use right or left hand, some have preferred chewing side while others do not. Totally, 82 volunteers composed of students and staffs from Dental Hospital College of Dentistry Yonsei University participated in this study for the investigation of influence of preferred chewing habit, that has lasted for more than a year, on electromyographic(EMG) activity of masticatory muscles and bite force. Among the 82 volunteers, 46 had preferred chewing habit while the other 36 did not. Prior to the investigation, those with factors that could affect the study, such as, general disease, irregular dentition and malocclusion, were screened and excluded by questionnaire and clinical examination. The results were as follows: 1. There was no significant difference in EMG activities between chewing side and non-chewing side of preferred chewing subjects at rest as well as maximal voluntary contraction(MCV)(p>0.05). 2. Asymmetrical coefficient of temporal and masseter muscle EMG activities between preferred chewing subjects and non-preferred chewing subjects at rest was not significantly different(p>0.05). 3. Asymmetrical coefficient of masseter EMG activity was significantly higher(p<0.05) than that of non-preferred chewing subjects at MCV, whereas that of anterior temporal muscle showed no difference(p<0.05). 4. In preferred chewing subjects, there was no significant difference in average bite force and occlusal contact area between chewing side and non-chewing side(p>0.05). 5. There was no significant difference in Asymmetrical coefficients of average bite force and occlusal contact area between preferred chewing subjects and non-preferred chewing subjects (p>0.05). Consequently, preferred chewing habit can be considered as physiological asymmetry with normal function rather than to have influence on EMG muscle activity of masticatory muscles, average bite force and occlusal contact area. Objective standardization to differentiate preferred chewing subjects and non-preferred chewing subjects should be established in the further study.