• Journal of the Korean Society for Precision Engineering
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• v.22 no.10 s.175
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• pp.210-217
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• 2005

This study examined the effect of cancellous bone microstructure on stress distribution within a premolar tooth and a dental implant against mastication force by the micro-finite element method (FEM). The mandibular specimen including a premolar was obtained from a cadaver and scanned with micro-CT to obtain CT images. FE models were reconstructed from CT images at mid-sagittal plane of the tooth. Six models were generated and analyzed for different structure and density in cancellous bone. Stress distributions fur each implant (or tooth) and the surrounding bone were compared. The study indicated that the microstructure of cancellous bone should be considered in finite element analysis to produce reasonable results and thus implant systems with high success rate.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.21 no.4
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• pp.388-394
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• 1999

To compare the effect of hyaluronate and dexamethasone on the temporomandibular joint arthrocentesis the author investigated 22 temporomandibular joint disorder(TMD) patients with pain and limitation of mouth opening who visited at the Department of Oral and Maxillofacial Surgery. Chosun Dental Hospital and were made a diagnosis as Wilkes stage III or IV of TMJ internal derangement clinically and radiographically. The two groups consisted of 10 patients with injection of sodium hyaluronate 10mg$(Artz^{(R)})$(hyaluronate group) on the upper joint space of the affected temporomandibular joint 5 times at intervals of a week after arthrocentesis, and 12 patients with injection of dexamethasone$(Oradexon^{(R)})$ at a time(dexamethasone group). Maximum mouth opening, pain value and satisfaction value during mastication were assessed on a visual analog scale before arthrocentesis and after 6 months. Then the within-group and between-group differences were evaluated in the obtained data and the clinical success rate of each group was calculated according to our success criteria. The results were as follows. 1. the mean of maximum mouth opening before arthrocentesis and after 6 months in the hyaluronate group were 24.9mm and 39.0mm respectively, and those before arthrocentesis and after 6 months in the dexamethasone group were 25.7mm and 41.3mm respectively. 2. The mean of pain value on a visual analog scale in the hyaluronate group before arthrocentesis and after 6 months were 6.7 and 1.8 respectively, and those in the dexamethasone group before arthrocentesis and after 6 months were 7.0 and 1.8 respectively. 3. The mean of satisfaction value during mastication on a visual analog scale in the hyaluronate group before arthrocentesis and after 6 months were 2.8 and 7.7 respectively, and those in the dexamethasone group before arthrocentesis and after 6 months were 3.1 and 7.8 respectively. 4. There were statistically significant differences between all measurements before arthrocentesis and after 6 months(P<0.001), but no difference between all measurements in the hyaluronate group and those in the dexamethasone group. 5. The over all success rate of the hyaluronate group and the dexamethasone group were 60.0% and 63.6% respectively. In summary, there was significant difference between the effect of hyaluronate and dexamethasone on the temporomandibular joint arthrocentesis but hyaluronate is better than corticosteroid as the injection drug in consideration of the side effect related with repeated injection.

• Korean Journal of Breeding Science
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• v.43 no.4
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• pp.311-317
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• 2011

This experiment was conducted to give basic information to sprout-soybean breeding and automated sprout production by investigating the effect of seed size on the sprout growth and texture. Twenty cultivars and lines including large and medium soybean, small interspecific cultivars and extra-small wild soybean lines were used. Seeds were cultured for 4 days using small sprout-culturing kits. Hypocotyl length of large Hwanggeumkong, small Pungsannamulkong and Soyoung were longer and wild soybean lines were shorter than other cultivars. Fresh sprout weight and growth rate per unit dry seed weight of wild soybean lines ware increased dramatically and more than other cultivars between 48 to 72 hours after culture. Not only the increasing rate but sprout yield ratio to used dry seed weight showed the negative relationship pattern with seed size. The hardness of hypocotyl in Jangyeubkong, mastication in Taekwang, and cutting force in Eunhakong were the highest as 3,505 g, 1,650 g, and 133 g respectively, and texture values of these traits in wild soybean YWS516 were the lowest. Cutting force of soybean hypocotyl showed the positive relationship pattern with seed size. Breaking force of hypocotyl in large Jangyeobkong was the highest as 83.5g and wild soybean lines were the lowest showing the same pattern as other textural characters.

• Journal of Korean Academy of Nursing
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• v.7 no.1
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• pp.63-72
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• 1977

The Purposes of this study are to determine differences of body temperature between Right arid left subligual areas itself and differences depending upon the utilization rate of mastication according to time intervals and to determine the length of time necessary for temperature taking. This Experiment was conducted from Oct 6 through Oct 11, 1975. in which accurately tested clinical Centigrade Thermometers have been utilized. Two thermometers were inserted simultaneously under the right and left sublingual areas and the mouth kept closed while thermometers were in Place. Temperature readings were dr no at three minutes, five minutes and ten minutes. These procedures were repeated one hundred times to different subjects and the data were analyzed statistically by means of the t-test and the F-ratio. Under the 10 hypotheses designed for this study, The findings obtained are as follows; 1. The body temperatures taken at 3, 5, 10minutes intervals in the left sublingual areas were significantly higher than in the right sublingual areas , The average differences of body temperature between the right and left sublingual areas were 0.09$^{\circ}C$, 0.05$^{\circ}C$ and 0.03$^{\circ}C$ in the oder of time interval of 3, 5, and 10 minutes. 2. The body temperatures taken in the right sublingual areas among three different temperature readings, 3, 5 and 10 minutes were significantly different in 57 subjects who have been utilizing evenly both sides of the Teeth. The average readings in a group taking for 3 minutes was 37.04$^{\circ}C$, for 5 minutes 37.15$^{\circ}C$ and for 10minutes 37.28$^{\circ}C$. 3. The body temperatures taken in the left sublingual areas among three different temperature readings, 3, 5 and 10 minutes were significantly different in 57 subjects who have been utilizing evenly both sides of the tenth. The average reading in a group taking for 3 minutes was 37.13$^{\circ}C$, for 5 minutes 37.2$^{\circ}C$ and for 10 minutes 37.31$^{\circ}C$. 4., Oral temperatures taken at 3, 5, 10 minutes intervals at the side of mouth utilized for more frequent mastication were Significantly higher than the other side. The average differences of body temperature between more frequently utilized side and Less frequently utilized side were 0.08f, 0.08f and 0.09f in the order of time interval of 3, 5 and 10 minutes. 5. Oral temperature taken at the side of mouth more frequently utilized for mastication among three different temperature readings, 3, 5 and 10 minutes were significantly different in 43 subjects who have been unequally utilizing either side of teeth. The average reading in a group taking for 3 minutes was 37.09$^{\circ}C$, for 5 minutes 37.17$^{\circ}C$ and for 10 minutes 37.3$^{\circ}C$. 6. Oral temperature taken at the side of mouth less frequently utilized for mastication among three different temperature readings 3, 5 and 10 minutes were significantly different in 43 subjects who have been unequally utilizing either side of teeth. The average reading in a group taking for 3 minutes was 37.01$^{\circ}C$, for S minutes 37.09$^{\circ}C$ and for minutes 37.21$^{\circ}C$. As a result of this study, these differences among time intervals were statistically significant, but there were not so much differences as to be considered important in the clinical practice. Therefore, there would be clinically little difference between two groups who are taking for 3 minutes and for 10 minutes.

• Journal of Animal Science and Technology
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• v.63 no.5
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• pp.1018-1033
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• 2021

In this study, we aimed to assess the effect of flaking on the nutrient digestibility of corn grain in ruminants. In this regard, in vitro rumen fermentation, in situ rumen degradability, and in vivo metabolic experiments were performed. The automated gas production technique was used for the in vitro fermentation experiments. Six types of corn flakes with various degrees of gelatinization (32%, 41%, 48%, 66%, 86%, and 89%) were ground and incubated in rumen fluid to measure rumen fermentation characteristics and digestion rate. The in situ degradability of ground corn, whole corn, and corn flakes with 62% and 66% gelatinization was measured by incubation in the rumen of two cannulated Holstein cows. In vivo metabolic experiments were performed using 12 crossbred goats (29.8 ± 4.37 kg) using a 3 × 3 Latin square design. The dietary treatments consisted of ground corn and flaked corn with 48% or 62% gelatinization. In vitro experiments showed that as the degree of gelatinization increased, the digestion rate increased linearly, while the discrete lag time decreased linearly (p < 0.05). The effective rumen dry matter degradability, determined by in situ fermentation, was 37%p lower in corn flakes than ground corn, assuming a passage rate of 6%/h (p < 0.01), and there was no difference between the two flakes. In the in vivo experiment, there was no difference in dry matter intake, average daily gain, feed efficiency, and nitrogen utilization among the treatment groups (p > 0.05); however, the crude fat digestibility was lower for corn flakes than for ground corn (p < 0.05). To summarize, the rate of fermentation of corn flakes increased as the degree of gelatinization increased. However, non-ground corn flakes had lower rumen digestibility and did not improve in vivo apparent nutrient digestibility, compared with ground corn. In contrast to the assumption that flaked corn provides more energy to ruminant animals than ground corn, we conclude that the digestibility and energy value of corn flakes are lower than those of ground corn if mastication does not sufficiently reduce the particle size of corn flakes.

• Journal of Technologic Dentistry
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• v.23 no.2
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• pp.61-74
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• 2002

This experiment was to find out the complacency of wearing dentures and the linkage to the quality of life style of oldsters 60 years old and over. 122 numbers of oldsters who came to aid to the health center were put to survey. This was taken place within the areas of Deajun, Koonsan, Mooju and Jinahn, thus procured the following result. 1. The length of edentulous period of 1-6years of oldsters aged around 60s showed 26.0%. The oldsters with edentulous period of over 7years aged in the 70s showed 26.1 % and 56.0% on oldsters aged in the 80s. This shows that as the age increases the edentulous period lengthens. (P<0.05) The length of time of using the denture shows. llyears or over on women 41.9%, less than 6years on men 71.4% as the highest rate. 11 years or over on towns/subcounty show 57.5%, small and medium cities more than 1 year 63.6%, less than six years also 63.6% and Kwangyuk city 47.6%. 2. The complacency on medical treatment of dentures was highest in Kwangyuk city of 61.3%, compared to towns/subcounty of 50.8% and small and medium cities of 33.3%. (P<0.05) 3. The complacency on mastication and pronunciation appears, 2.74% in Kwangyuk city, 3.10% in towns/ subcounty which is higher than the small and medium cities showing 1.09% on average. Satisfaction rate tends to be higher as the length of time of using the denture is longer. 4. Inconvenience on eating habits caused by dentures were felt by women. Wanting to get a new denture was 25.6% by women showing much higher rate than that of men which is 2.8% by men. (P<0.05) 5. The complacency of change in their life style after wearing the dentures were higher in Kwangyuk city of 64.5% whereas it showed 27.0% in towns! subcounty and 16.7%in small and medium cities. (P<0.05)

• Journal of Technologic Dentistry
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• v.41 no.4
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• pp.305-317
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• 2019

Purpose: The purpose of this study is to provide basic data for the improvement of dental care service for patient care. Methods: The survey period was from December 10, 2018 to June 10, 2019. The subjects were 180 patients who were treated with dental implant in 20 dental hospitals and clinics in Daejeon and Gyeonggi province. A total of 145 questionnaires were analyzed except for 35 copies which were unreliable or difficult to analyze. Results: The most important care method for prolonging the life time of dental implant prosthesis was the highest rate of correct brushing (39.4%), and a majority in the subjects used oral hygiene products (91.0%). With regard to discomfort after dental implant prosthesis, food particles between the teeth showed the highest response (49.7%), and discomfort with gum infections and bleeding and reduced mastication increased significantly with age (p<0.05), whereas feeling of irritation decreased significantly with age (p<0.05). Conclusion: This study is meaningful in that it approached the perception and discomfort of prosthesis from the patients' point of view. It needs to establish the basic data to improve dental treatment service for patient care.

• Journal of the korean academy of Pediatric Dentistry
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• v.21 no.2
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• pp.577-585
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• 1994

The Twin Blocks technique was developed by Dr. William Clark of Scotland during the early 1980's. Twin Blocks are an uncomplicated system that incorporates the use of upper and lower bite blocks. These blocks reposition the mandible and redirect occlusal forces to achieve rapid correction of malocclusions. They are also comfortable and the patients wear them full-time-inducing eating time. Occlusal forces transmitted through the dentition provide a constant proprioceptive stimulus to influence the rate of growth and the trabecular structure of the supporting bone. The features of Twin Blocks mean easier and quicker treatment. The occlusal inclined plane is the fundamental functional mechanism of the natural dentition. Twin blocks are bite blocks that effectively modify the occlusal inclined plane to induce favorably directed occlusal forces by causing a functional mandibular displacement. Upper and lower bite blocks interlock at a $45^{\circ}$ angle and are designed for full-time wear to take advantage of all functional forces applied to the dentition including the forces of mastication. The patients who were treated with modified Twin Blocks, and following results were observed: 1. Large overjet and deep overbite were corrected. 2. Class II molar relationship was changed into Class I. 3. Labial inclination of upper incisors was corrected by adjustment of labial bow of upper bite block. 4. The profiles of two patients were improved by anterior displacement of mandible.

• Journal of dental hygiene science
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• v.16 no.6
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• pp.481-487
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• 2016

The elderly population with dementia is rapidly growing in South Korea. The aim of this study was to investigate the relationship between dementia and oral health in 197 subjects aged ${\geq}65$ years. The questionnaire included questions on subjective health status, subjective health concern, subjective oral health status and behavior, mastication ability, Oral Health Impact Profile-14 (OHIP-14), and Korean Dementia Screening Questionnaires (KDSQ). Oral examination was conducted by a single dentist to evaluate upper or lower denture use, and determine the numbers of remaining and functioning teeth, including implant and fixed prosthesis. The subjects who required a dementia test (KDSQ-C [cognition] of ${\geq}6$) had significant differences in systemic disease prevalence rate, subjective health status, subjective health concern, KDSQ-V (vascular disease) score, KDSQ-D (depression) score, subjective oral treatment need, key food mastication ability and OHIP-14 score compared to the healthy subjects. The proportion of denture wearers, total remaining teeth, total functioning teeth, toothbrushing frequency, oral pain severity, symptoms of periodontal disease, subjective oral health status, and subjective oral health concern showed no significant differences between the two groups. KDSQ-C and OHIP-14 scores showed a strong positive relationship, while KDSQ-C score and total remaining teeth or key food mastication ability showed a weak negative relationship. In the multiple regression analysis, the KDSQ-D, KDSQ-V, and OHIP-14 scores influenced the KDSQ-C scores. We suggest a relationship between oral health and cognitive impairment.

• The Journal of Korean Academy of Prosthodontics
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• v.55 no.4
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• pp.458-466
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• 2017

After the resection of oral tumor, defected maxillofacial structure caused functional difficulties including phonetics, mastication and esthetic aspects. In this cases, implant retained prosthesis can contribute to the functional enhancement. Regardless of the success rate in grafted bone, however, the soft tissue usually had a shape which was susceptible to inflammation. Moreover, infected graft bone presented rapid destruction. For success of the prosthetic treatment, adequate soft tissue treatment and frequent recall check are the essential factors to the successful implant prognosis.