• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.23 no.1
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• pp.1-5
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• 1987

The authors carried out an experiment to determine the vertical opening of the midwater trawl, which is the same used in the former experiment in this series of studies. To determine the vertical opening of otter board and front weight, three fish finders were used. A 200 KHz fish finder set on board the research vessel was used to sound the depth of water. A transmitter of 50 KHz fish finder was set through the shoe plate of otter board to determine the height of otter board from the sea bed, and a transmitter of another 50 KHz fish finder was set downwardly on the net pendant right before the front weight to determine the height of weight from the sea bed. The depth of otter board and weight were calculated by subtract the height of those from the depth of water, respectively. To determine the vertical opening of mouth, a transmitter of net recorder was set on the head rope and the vertical opening of that to ground rope was directly read on the recording paper. The results obtained can be summarized as follows: 1. The rate of the depth of otter board to the length of warp was in the range of 0.44 to 0.25, and the depth was linearly shoaled about 5m per 0.1m/sec of the towing speed or per 20rpm of the main engine. The rate of the observed depth to the calculated depth of otter board was in the range of 0.92 to 0.080 with a decreasing tendancy in accordance with the increase of towing speed. 2. The depth of head rope was 2 to 3m deeper than that of otter board, and the vertical opening of net mouth was in the range of 22 to 19m, with a decreasing tendancy in accordance with the increase of towing speed, 3. The difference of depth between front weight and otter board was about 20m and 22m respectively in the length of warp 100m and 150m without distinct change in accordance with the towing speed. The depth of front weight was 2 to 3m shallower than that of ground rope. 4. The changing range of depth of head rope according to the revolution of main engine was about 4m per 20rpm.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.1
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• pp.96-102
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• 1990

Cracks found in pressure vessels have been reported to be mostly semi-elliptic surface cracks. The fatigue crack growth behaviour of the surface cracks on pressure vessel materials, SPV 50Q and API 5A-K55, was studied with the consideration of the crack opening character. To determine the crack opening loads for the surface cracks, the displacement/strain were measured at three positions; the center and the side of the surface crack, the back face of the specimen using CMOD gauge and strain gauges. The experimental results showed that the crack opening load levels measured at the side of the surface crack were generally a little higher than those measured at the back face. As for the crack growth rates at the different parts of the surface crack, the experiments also showed that, if .DELTA.K$_{eff}$ is used, the exponent n of the Paris' law obtained were the same for the rear and the side parts of the surface cracks.

• Imaging Science in Dentistry
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• v.41 no.4
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• pp.161-165
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• 2011

It is difficult to take intraoral radiographs in some patients who are intolerable to place the film in their mouth. For these patients, Newman and Friedman recommended a new technique of extraoral film placement. Here we report various cases that diagnostic imaging was performed in patients using the extraoral periapical technique. This technique was used to obtain the radiographs for the patients with severe gag reflex, pediatric dental patients, and patients with restricted mouth opening. This technique can be recommended as an alternative to conventional intraoral periapical technique in cases where intraoral film placement is difficult to achieve.

• Journal of Oral Medicine and Pain
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• v.43 no.1
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• pp.16-20
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• 2018

Graft-versus-host disease (GVHD) is frequent complications of hematopoietic stem cell transplantation. In the chronic GVHD (cGVHD), the oral cavity is the most commonly affected region. The clinical manifestations include erythema, ulceration, lichenoid-hyperkeratotic change in oral mucosa, dry mouth, and limitation of mouth opening. The initial treatment strategy of oral cGVHD patients is topical corticosteroid therapy in various formulation. However, corticosteroid resistance appears in some patients. We report a case of a 25-year-old male patient with oral cGVHD, who has resistance to topical corticosteroid medication, treated with 0.03% tacrolimus ointment and low-dose doxycycline. The patient showed subjective and objective improvement without side effect.

• The Journal of the Korea Contents Association
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• v.11 no.10
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• pp.388-395
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• 2011

This study was performed to grasp the relation between the effect and the satisfaction of a mouth gymnastics program on the promotion of oral function of old persons. The experimental group of 47 old persons conducted a mouth gymnastics exercise two times every week for 12 weeks, while the control group of 39 old persons carrying out physical examinations. The mean salivary secretion in the experimental group was 0.075 ml and more than 0.046 ml in the control group. Maximum mouth opening in the experimental group, 4.12 cm, was higher than 3.92 cm in the control. Oral diadochokinesis in experimental and control group was 1.69 times per second and 1.65, respectively. The result of principal component analysis by Quartimax method with Kaiser normalization showed that program prevalence prediction of mouth-gymnastics exercise was high, and it is estimated that this exercise program would be more popular for health promotion of old persons. From the correlation analysis, mouth gymnastics exercise made salivary flow increase(r=.592), this exercise should be recommended actively for improving mouth health of old persons. Also more modification is required for old persons with difficulty in mouth gymnastics exercise. Some movements of the mouth gymnastics exercise need be modified, and then the exercise should be publicized as one of the ways to improve holistic health of the aged.

• Journal of Korea Multimedia Society
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• v.23 no.12
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• pp.1454-1463
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• 2020

An important factor in eye-tracking PC interface for general paralyzed patients is the implementation of the mouse interface, for manipulating the GUI. With a successfully implemented mouse interface, users can generate mouse events exactly at the point of their choosing. However, it is difficult to define this interaction in the eye-tracking interface. This problem has been defined as the Midas touch problem and has been a major focus of eye-tracking research. There have been many attempts to solve this problem using blink, voice input, etc. However, it was not suitable for general paralyzed patients because some of them cannot wink or speak. In this paper, we propose a mouth-pop-up, eye-tracking mouse interface that solves the Midas touch problem as well as becoming a suitable interface for general paralyzed patients using a common RGB camera. The interface presented in this paper implements a mouse interface that detects the opening and closing of the mouth to activate a pop-up menu that the user can select the mouse event. After implementation, a performance experiment was conducted. As a result, we found that the number of malfunctions and the time to perform tasks were reduced compared to the existing method.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.17 no.1
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• pp.60-72
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• 1995

Temporomandibular joint ankylosis is the movemental obstacle of mandible which depend on proliferation of bony or fibrous tissue in temporomandibular joint structure by various causes. In order to treat this, various surgical methods have been performed, but no operative methods have been produced consistently successful results. This research has been performed to the patients who had been operated due to temporomandibular joint ankylosis by studying classification, cause, onset, duration, anesthesia and treatment method, symptom, change of mouth opening, complication through medical record, X-ray, follow-up for being a help to proper selection of treatment method and evaluation of prognosis. The author obtained the following results by analyzing 44 cases among patients who had been operated due to temporomandibular joint ankylosis during 8 year hospitalization from 1986 to 1993 in Dept. of Oral & Maxillofacial Surgery of Seoul National University Hospital. 1. The occurrence was in the order of below 10, 20's, 10's, 30's. The average of occurrence was 12.95. Illness period was 50.0% within 10 years and 50% beyond 10 years. The average period of illness was 13.33 years. 2. Trauma occupied 54.5% of causes and inflammation occupied 45.5%. Men had more occurrences due to trauma and there was no difference in case of inflammation. 3. In nasotracheal intubations for general anesthesia, the cases of using fiberoptic laryngoscope occupied 40.9%, direct or blind nasotracheal intubation occupied 40.9% and the cases of using tracheostomy occupied 18.2%. 4. In operative approaching methods, submandibular & preauricular approach were mainly applied, and in operative methods, high condylectomy(Group I) occupied 11.4%, arthroplasty without interpositional material following condylectomy or gap ostectomy(Group II) occupied 11.4%, with interpositional material following high condylectomy (Group III) occupied 40.9%, and using condylar reconstruction following condylectomy or gap ostectomy(Group IV) occupied 36.6%. 5. In change of mouth opening reformed after surgery, Group III showed the best result of average 23.5mm, Group IV showed 16.3mm, Group I showed 14.9mm and Group II showed 10.2mm of reformation. Summarizing the results as written above, it is considered that early treatment is important as soon as possible in Temporomandibular joint ankylosis. It is recommended in surgical method what can lead to postoperative early movement maintaining anatomaical & functional form, and then the development of various surgical methods will be requested.

• 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.

• Journal of Oral Medicine and Pain
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• v.31 no.4
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• pp.365-373
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• 2006

This study suggested correction of excessive mouth opening or maximum occlusal contact to analyse occlusal contact time, occlusal contact number and force through evaluation of occlusal pattern in policemen with temporomandibular disorders. The community of policemen influence on temporomandibular disorder's development and progress due to other condition of mouth opening and maximal occlusal contact. Repeated training or changes of usual life style may cause imbalance of stomatognathic system including the masticatory muscle, then develop or aggravate pain of temporomandibular joints and associated structures. This study uses T-scan II system(Tekscan Co., USA) for evaluation on occlusal pattern may influence temporomandibular disorders, and then the subjects take a sensor at 20 mm opening for maximal occlusal contact force. The policemen with temporomandibualr disorders get more long time on maximum contact timing, more short on end contact timing, and more force on end contact force than general society's. So they get closure of mouth with more short time and more force, then transfer remaining load to temporomandibular joint. There are no statistically significances between affected side and occlusal pattern of occlusal contact time and force. There are Left -right dental arch imbalances seems on Rt. dental arch if affected side is right and Lt. dental arch if affected side is left. In above results, It's worth due consideration that policemen with temporomandibular disorders get more smooth mandibualr movement and less force on maximal occlusal contact position.

• Journal of Oral Medicine and Pain
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• v.37 no.3
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• pp.183-188
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• 2012

Previous studies of the relationship of TMJ signs and symptoms in elderly people have provided inconsistent findings. The objective of this study was to retrospectively analyze the prevalence of signs and symptoms of temporomandibular disorders(TMD). Additionally, young subjects were examined as a control group. Forty old patients (28 female, 12 male, mean age: $65.2{\pm}2.5$ years) and forty young patients (30 female, 10 male, mean age: $23.3{\pm}2.6$ years) clinically diagnosed with TMD were screened. Patient records were analyzed regarding: pain on chief complain, amount of range of mouth opening, TMJ noises(clicking sounds, crepitus), pain on palpation of the TMJ and masticatory muscles and neck and upper back muscles. Differences between the groups were assessed using t-test and the chi-squared test. (SPSS v.17) P value <0.05 was considered statistically significant. Geriatric subjects more often exhibited crepitus on mouth opening (25%), muscular palpation pain of masseter muscles (82.5%) and temporal muscles(60%). In contrast, young subjects more frequently exhibited joint sounds (62.5%), more amount of range of passive mouth opening (p=0.043). It was found that the younger subjects (82.5%) and the older subjects (87.5%) suffered from subjective sign (orofacial pain on chief complain). There were not statistically significant relationships between orofacial pain (VAS) and the groups. Differences between the groups with respect to joint sounds, muscular palpation pain and mandibular range of motion were significant. Although older subjects more frequently exhibited objective signs (crepitus on opening, pain on muscular palpation) of TMD, younger subjects more frequently objective signs (clicking sound on mouth opening, amount of mandibular range of motion).