• Journal of Animal Science and Technology
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• v.49 no.5
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• pp.639-646
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• 2007

To evaluate the effect of fiber sources on chewing activity, five sheep were consecutively fed diets containing 45% of a fiber source selected from 7 tested fiber sources of alfalfa hay cube(AHC), corn cob (CC), corn silage(CS), cotton seed hull(CSH), peanut hull(PHL), rice straw(RS) and sugarcane bagasse (SCB). Number of chew showed significantly higher value in CC(p<0.001) then other sources. RS and CC had highest(p<0.01) rumination times of 352 and 367 min/d, respectively. CC also showed the highest number of chew per kg NDF intake(p<0.01), but rumination time per kg NDF intake showed no difference except CSH(p<0.001). These results suggest that chewing activities were greatly affected by the fiber sources, and therefore it should be accounted in the formulation for ruminant feed.

• The Journal of Korean Academy of Prosthodontics
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• v.27 no.1
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• pp.103-121
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• 1989

The purpose of this study was to investigate the influence of balancing interference on the activity of masticatory muscles and condylar path. Eight dental students of Won Kwang University without any symptoms of temporomandibular disorder and occlusal interferences, were selected for this study, The balancing interference was provided by construction and cementation of cast metal crowns on the upper and lower first molars. For the measurement of muscle activity, bioelectric processor (EM2, Myotronic Res., Inc., U.S.A.) was used and for the condular path, computerized electronic pantograph (Pantronics, Denar Corp., U.S.A.) was used and the myographic recordings were taken bilaterally from the anterior temporal, masseter and digastric muscles on rest position and on functions. These experimental procedures were done before cementation of experimental crown, three days after cementation of experimental crown, one week after, two weeks after and then one week after removal of experimental crown. The results are as follows: 1. The PRI score was increased at three days after application of balancing interference, and decreased at two weeks after. 2. Three subjects showed mild symptom of temporomandibular disorder at three or four days after application of interference, but the symptom was subsided in one or two weeks after application of interference. 3. One week after application of balancing interference, the activity of ipsilateral anterior temporal muscle in four subjects was decreased on gum chewing at experimental site. 4. Three days after application of balancing interference, the activity of ipsilateral anterior temporal muscle in three subjects was increased on gum chewing at non-experimental site. 5. The influence of balancing interference on the activity of anterior temporal, masseter and gigastric muscle was not prominent.

• Journal of the Korean Dietetic Association
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• v.30 no.2
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• pp.112-124
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• 2024

This study investigated the factors associated with HINT-8 (Korean health-related quality of life instrument with eight items), including health habits, hand grip strength, chronic disease, chewing function, mental health, and nutrient intake. In this study, the health-related quality of life (HRQoL; HINT-8) was assessed using the data from the 2019 Korea National Health and Nutrition Examination Survey (KNHANES VIII) among Koreans aged over 65, with HINT-8 being evaluated based on the general characteristics. Of the participants from KNHANES VIII, 1,455 subjects were analyzed using SPSS statistics complex samples (Windows ver. 27.0). The HINT-8 score was significantly lower in females and in those aged 75 years or older, lowest educational level, lowest income level, and single households. Logistic regression analysis, adjusted for the general characteristics, revealed a significant association between a lower HINT-8 group and various factors: low aerobic physical activity (OR=1.71, 95% CI=1.25~2.35), low hand grip strength (OR=1.34, 95% CI=1.02~1.78), chewing difficulties (OR=2.17, 95% CI=1.62~2.92), poor self-rated health status (OR=6.11, 95% CI=4.42~8.45), stressful mental status (OR=3.57, 95% CI=2.27~5.63) and poor calcium status (OR=1.45, 95% CI=1.11~1.88). On the other hand, this study could not reveal a significant association between a lower HINT-8 group and factors such as smoking, drinking, chronic disease, and nutrient intake status, except for calcium intake. This study suggests that HINT-8 is associated with aerobic physical activity, hand grip strength, chewing function, mental health, and calcium intake, but not with smoking, drinking, chronic disease, and nutrient intake.

• The korean journal of orthodontics
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• v.22 no.1
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• pp.253-271
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• 1992

The purpose of this study was to investigate the difference of EMG activity of the Orbicularis oris and Mentalis muscle between normal occlusion and class III malocclusion group during various lip position and to find out whether any correlations exist between the muscular activity and craniofacial morphology. In this study, 50 subjects with a mean age of 22.9 Years (range 20.0-26.0) were investigated (25 subjects were normal occlusion, and 25 subjects were class III malocclusion). EMG data were recorded from the Orbicularis oris and Mentalis muscle during rest lip posture, lip position at maximum biting, lip position at maximum sealing effort, lip position at chewing, swallowing and phonation with the Medelec MS-25 electromyographic machine. Lateral cephalometric radiographs was taken with the mandible in intercuspal position on all subjects. All data were recorded and statistically processed. The findings of this study can be summerized as follows: 1. In normal occlusion, the maximal mean amplitude of upper lip during the lip position at chewing was lower than that of lower lip and mentalis muscle. But the maximal mean amplitude of orbicularis oris and mentalis muscle during the other lip position was not statistically different. 2. In Class III malocclusion, the maximal mean amplitude of upper lip during the lip position at chewing, swallowing and phonation was lower than that of lower lip and mentalis muscle. But the maximal mean amplitude of orbicularis oris and mentalis muscle during the other lip position was not statistically different. 3. Compare to normal occlusion, the Class III malocclusion was showed low maximal mean amplitude of upper lip during rest lip posture and the lip position at swallowing of saliva, and showed great maximal mean amplitude of lower lip and meantalis muscle during the lip position at chewing and phonation. 4. In normal occlusion, the maximal mean amplitude of upper lip during various lip position was not correlated with the length and thickness of upper lip, but the maximal mean amplitude of lower lip during the lip position at chewing and swallowing was positively correlated with the thickness of lower lip. 5. In Class III malocclusion, the maximal mean amplitude of upper lip during rest lip posture was negatively correlated with the thickness of upper lip, and the maximal mean amplitude of lower lip and mentalis muscle during the lip position at chewing and swallowing was positively correlated with the thickness of lower lip and mentalis muscle. But the maximal mean amplitude of orbicularis oris and mentalis muscle during the other lip position was not correlated with the cephalometric measurements of soft tissue. 6. The correlation between the maximal mean amplitude of orbicularis oris and mentalis muscle and cephalometric measurements of incisors was not nearly present. 7. In normal occlusion, the maximal mean amplitude of lower lip and mentalis muscle during the lip position at maximum biting was negatively correlated with the angle between palatal plane and mandibular plane. In Class III malocclusion, the maximal mean amplitude of upper lip, lower lip and mentalis muscle during function was negatively correlated with the length of maxilla, the maximal mean amplitude of upper lip and lower lip during function was negatively correlated with the SNA and SNPo, and the maximal mean amplitude of lower lip during the lip position at chewing was negatively correlated with the ANB.

• Korean Journal of Food Science and Technology
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• v.24 no.2
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• pp.122-126
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• 1992

The shelf-life of wrapped chewing gum(7 sticks) under the climate condition of Seoul was predicted by using moisture gain equation to reach safe moisture limits of 3.16% (dry basis). The overall water vapor permeability of multilayer packaging material was about 0.00045g water/pack day mmHg. The water activity of chewing gum at any temperature was predictable using Clausius-Clapeyron equation. The most significant loss of shelf-life was occurred between June and July, and most products reached the end of shelf-life at July and August. The product which were made in October and November had the longest shelf-life as seven months.

• The korean journal of orthodontics
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• v.44 no.3
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• pp.143-153
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• 2014

An 8-years old boy with facial asymmetry and unilateral posterior crossbite on the left side received orthopedic and orthodontic treatment. During the first phase of treatment, the narrow maxillary arch was expanded using an acrylic plate. Then, the acrylic plate was used as a bite block with occlusal indentations from the construction bite that was obtained with the incisors in a coincident dental midline. After the position of the mandible was stabilized, the second phase of orthodontic treatment was initiated using fixed appliances for detailing of the occlusion. Skeletal symmetry, ideal occlusion, and coincident dental midlines were thus achieved. Functionally, occlusal force balance and masticatory muscle activity were improved, and the chewing patterns were normalized.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.2
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• pp.159-168
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• 2004

The effect of xylitol and sorbitol chewing gums on dental caries levels among 5-year old kindergarteners was investigated. Three kindergartens the operations of which were partly subsidized by municipal government of Daegu city, Korea, were chosen as the study sites. The child base of the kindergartens were considered demographically and ethnically similar, representing middle-income families. The subjects were examined at their own kindergarten by the two dentists. Participation in the program was voluntary. Over 12 months, 123 participants chewed xylitol chewing gums(X group; 42 subjects), sorbitol chewing gum(S group; 42 subjects), or did not receive chewing gum as a control group(C group; 39 subjects). Consumption of xylitol and sorbitol was 4.5 to 5.0 g/day/subject, consumed in five daily chewing episodes of 5 min. Oral examination, Dentocult-SM test and interproximal dental plaque collection were completed at baseline and 12 months later. The dmfs of group C increased 59.2%, but group S increased 33.4% and group X increased only 31.3% during 12 months study period. The caries prevention ratio was 47.1% at group X and 43.6% at group S. There also appeared the reduction of caries activity at group X(1.39), group S(1.50) than control group(1.79). Compared with groups S and C, there was a statistically significant reduction of S. mutans in interproximal plaque in group X. The results suggest that xylitol chewing gum can prevent dental caries of deciduous dentition, and may be a little more effective than a sorbitol-containing product in controlling some caries-associated parameters in kindergarten-age subjects.

• The korean journal of orthodontics
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• v.49 no.4
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• pp.254-264
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• 2019

Objective: To evaluate the short-term changes in masticatory muscle activity and mandibular movement patterns after orthognathic surgery in skeletal Class III patients with facial asymmetry. Methods: Twenty-seven skeletal Class III adult patients were divided into two groups based on the degree of facial asymmetry: the experimental group (n = 17 [11 male and 6 female]; menton deviation ${\geq}4mm$) and control group (n = 10 [4 male and 6 female]; menton deviation < 1.6 mm). Cephalography, electromyography (EMG) for the anterior temporalis (TA) and masseter muscles (MM), and mandibular movement (range of motion [ROM] and average chewing pattern [ACP]) were evaluated before (T0) and 7 to 8 months (T1) after the surgery. Results: There were no significant postoperative changes in the EMG potentials of the TA and MM in both groups, except in the anterior cotton roll biting test, in which the masticatory muscle activity had changed into an MM-dominant pattern postoperatively in both groups. In the experimental group, the amount of maximum opening, protrusion, and lateral excursion to the non-deviated side were significantly decreased. The turning point tended to be shorter and significantly moved medially during chewing in the non-deviated side in the experimental group. Conclusions: In skeletal Class III patients with facial asymmetry, the EMG activity characteristics recovered to presurgical levels within 7 to 8 months after the surgery. Correction of the asymmetry caused limitation in jaw movement in terms of both ROM and ACP on the non-deviated side.

• Journal of dental hygiene science
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• v.10 no.2
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• pp.123-129
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• 2010

To examine whether the effects of chewing gum containing xylitol are purely based on xylitol itself rather than the preventive effects on dental caries based on other constituents or factors, gargling was done using xylitol solution which was diluted in a distilled water. Then, attempts were made to perform an experiment for the bacterial activity of S. mutans depending on the amount of xylitol. Gargling was done using solutions containing xylitol at an amount of 30, 50, 60, 70, 80 and 90% with the same methods after 48 hours. When gargling was done using a solution containing xylitol at a volume of 60% in those who experienced dental caries, the bacterial activity of S. mutans was decreased by 35% as compared with the control group. When gargling was done using a solution containing xylitol at a volume of 70%, the bacterial activity of S. mutans was decreased by 80% as compared with the control group. These results indicate that there was a significant difference between the two groups (p<0.05). Besides, similar result appeared in those who did not experience dental caries(p<0.05). Based on the above results, under the hypothesis that the effects of xylitol contained in a chewing gum were not associated with other constituents, it is presumed that the amount of xylitol at a ratio of > 70% is effective in reducing the bacterial activity of S. mutans with no respect to experiences of dental caries. But we need an another experiment to confirm whether this result is due to xylitol's effect or not.

• Journal of Oral Medicine and Pain
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• v.15 no.1
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• pp.37-44
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• 1991

The author has synchronously recorded average electromyographic activities of temporalis anteriors and masseter muscles and the maximum bite force on the mandibular first molar on the prferred chewing side. These activities were recorded in order to study the EMG activity pattern of the working side and the balancing side to maximum bete force and functioning state of muscle in 30 patients with TMD and in 30 healthy subjects as controls. The results were as follows : 1. The maximum bite force on the mandibular first molar on the preferred chewing side was 20.63kg in TMD patients and 53.30kg in the healthy subjects(p<0.01). The maximum bite force in TMD patients was 38.7% of the healthy subjects. 2. The average electromyographic activities of temporalis anterioris and masseter muscles on the working side and the balancing side during maximum bite force were lower in TMD patients than in the healthy subjects(p<0.01). The average electromyographic activities of each muscle in TMD patients were 61.0%-62.8% of the healthy subjects. 3. The proportionalities of average electromyographic activities of temporalis anteriors and masseter muscles on the working side and the balancing side to maximum bite force were greater in TMD patients than in the healthy subjects(p<0.01). 4. Between the working side and the balancing side, the proportionality of average electromyographic activity of temporalis anterior to maximum bite force on the working healthy subjects (p<0.01). The proportionality of average electromyographic activity of working side and the balancing side in both groups (p<0.05).