• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.448-453
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• 2017

The purpose of this study was to compare the marginal discrepancy of coping crowns according to manufacturing method and materials by using the CAD/CAM system to compare the optimum manufacturing method and materials. The coping crowns were fabricated by using manufacturing methods and materials, and marginal fit was measured using the replica technique. For comparative analysis of manufacturing methods and materials, analysis of variance was performed. One-way ANOVA was performed to compare and analyze different mean values. For the milling method of the alloy, 114.6 was obtained for the MM group, 111.4 for the MS group, 67.2 for the MSC group, and 50.9 for the MSS group, respectively, using the milling/sintering method. In the milling/sintering method of ceramic, 35.6 and 36.3, respectively, were obtained for the SLME group and SLMR group, respectively. However,there was a significant difference according to the material. The milling/sintering method of the ceramic material gave the lowest value, and it was verified by the optimal method. However, marginal discrepancy of coping crowns fabricated using the CAD/CAM system is applicable to the clinic since it corresponds to acceptable numerical values in clinical practice.

• Journal of Oral Medicine and Pain
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• v.17 no.2
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• pp.75-86
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• 1992

Of the many first-occuring major manifestations of Behcet's disease, the oral ulcer is most frequently observed, shows the highest mean recurrence rate, and the longest mean duration period. A study of the relationship between mechanical irritation buy local factors and the recurrence of oral ulcers was carried out to see if there is a correlation. The subjects chosen for the study were 81 patients who were referred to the Department of Oral Diagnosis at Yonsei University Dental Hospital from the Behcet clinic of Severace Hospital after being diagnosed as Behcet's disease patients. 1. By Shimuzu's classification, possible type was the most numerous with 55.55% ; while suspected type was 19.76% ; incomplete type, 17,28% ; and complete type, 7.41% were observed in that order. The male to female ration was 1 to 1.61, and the average age of onset was 17.63 years. 2. Oral ulcers developed most frequently on the tongue (48.28%), and lip(23.15%), buccal mucosa (20.69%), palate\pharynx(4.43%), and gingiva(3.45%) also showed ulceration. 3. 38.27% of the patients were HSV positive : 27.16% were CRP positive ; 12.34% were ASO positive ; 9.87% were RF positive ; and 3.7% were ANA positive. 4. According to the answers to the survey, fatigue(85.18%) was most frequently associated with Behcet's diseage. Trauma by tooth brushing (22.22%), un specified reasons (20.98%), hard food chewing (12.35%), and irritation by dentition and/or prosthesis (13.58%) were observed in association with Behcet's disease. 23.46% had a history of tonsilitis. 5. Oral ulcers on the anterior part of tongue and buccal mucosa were associated with local irritatants. 6. Oral ulcers on the lip and posterior portion of tongue were not associated with local irritants. Local irritation by dentition and oral ulcer on the anterior part of tongue and buccal mucosa was observed to coexit with one another : in other words, lo9cal factors can act to cause of recurrence of an oral ulcer and to delay the healing process in Behcet's disease. Therefore, elimination of local factors along with systemic therapy must be recommended when treating oral ulcers.

• Journal of Oral Medicine and Pain
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• v.26 no.4
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• pp.331-343
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• 2001

Advances in medical procedures and utilization of medication have resulted in expanding aged population, which leads to increased aged patients with salivary hypofunction and its associated symptoms in dental clinic. The purpose of this study was to investigate clinical characteristics of patients with dry mouth and its correlation with their salivary flow rate. Forty dry mouth patients (7 males, 33 females, mean age 42.0 years) whose flow rate of unstimulated whole saliva was less than 0.15 ml/min were included and their gender- and age-matched controls (7 males, 33 females, mean age 42.9 years) who did not report any complaints, suggestive of salivary gland dysfunction and had the flow rate of greater than 0.20 ml/min were included for comparison. The salivary flow rate was measured in both unstimulated and stimulated conditions. Dry mouth-related clinical information including history, dry mouth associated symptoms, exacerbating and relieving factors, drugs, systemic diseases, and family history was investigated using questionnaires. The differences in distribution of patients and control subjects to each question and their relation to the salivary flow rate were analyzed and we came to following conclusions. 1. There were statistically significant differences in the distribution of patients and controls to the following questions: the period and frequency of suffering from dry mouth; severity of dry feeling during a meal; severity of discomfort during swallowing; necessity of sipping liquids during swallowing dry foods, severity of discomfort in usual life due to dry feeling; self-assessment of residual salivary volume; taking medications. 2. The patients had more stress-related medical histories including indigestion, insomnia, and gastritis compared with controls. The patients took many kinds of medications to control their systemic diseases. 3. There were statistically significant differences in the salivary flow rate between different groups of patients to following questions: severity of dry feeling during a meal; severity of discomfort during swallowing; necessity of sipping liquids during swallowing dry foods. The difference was more significant in the case of stimulated salivary flow rate rather than unstimulated one. 4. The salivary flow rate of patients taking medications was significantly less than that of patients who did not take medications. The difference was more significant in the case of stimulated salivary flow rate rather than unstimulated one.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.2
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• pp.187-195
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• 2008

Purpose: This epidemiologic research was carried out to investigate the degree and aspects of symptoms of patients suffered from TMD using RDC/TMD. Subjects and Methods: Subjects were the patients who had visited to SNUBH dental clinic from Jan. 2005 to Dec. 2005, and total 117 patients were included (M: 22, F:95). The signs and symptoms of physical, psychological and behavioral factors were retrospectively evaluated by questionnaires in the RDC/TMD. The patients were examined through clinical and radiological method, and diagnosed by same investigator. They were divided into 3 groups such as osteoarthritis group (group 1), internal deragnement (group 2), myofascial pain dysfunction syndrome group (MPDS, group 3). In addition, in patient with complex diagnosis they were divided into subgroups in detail (ex. group 1+group 2). In the questionnaire, several items were selected to calculate the graded pain score (grade $0{\sim}IV$), depression and vegetative symptoms, nonspecific physical symptoms(pain items included) and nonspecific physical symptoms(pain items excluded) in each group. Results: As a result of classification by diagnostic criteria of this study, the patients were distributed to 45% of group 1, 47% of group 2, 8% of group 3 in this study. In younger patients (under 25-year old, n=40), group 2 was occupied 57% (n=23) and group 1 was 35%, group 3 was 8%, while group 1 was occupied 75% in elderly-patients (over 40-year old, n=28) in present study (group 2: 21%, group 3: 4%). In the analysis of depression and vegetative symptoms, majority of patients in Group 2 were included in 'normal', and in Group 3 it appeared to have larger proportion of 'moderate' & 'severe' than others. According to nonspecific physical symptoms, there have been tendencies of higher ratio of 'severe' in patients with MPDS. In graded pain score, more than half (58%) of subjects were included in grade 0 and low disability (Grade I and II), and 27% were revealed high disability (grade III, IV).

• Journal of Chest Surgery
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• v.13 no.1
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• pp.60-65
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• 1980

We have experienced 2 cases of the hunshot wound sof the chest involving cardiac injuries at department of the thoracic surgery, Capital Armed Forces General Hospital during I year from April I 1979 to Jan. 1980. In one case of two patients , he was a 22 years old man who was transported to this emergency room 4 hour 10 minutes after having gunshot wound of the left chest by helicopter. Physical examination showed small inlet in left 3rd ICS and left parasternal border, large outlet in left 8th ICS and left scapular line, no breath sound on left side and distant heart sound. chest roentgenography demonstrated marked pleural effusion in left side and mediastinum shifted to right. As soon as chest X-ray was taken, the bleeding through penetrating wound became profuse and cardiac arrest ensued. Closed chest cardiac massage was started and vigorous transfusion continued, but no effective cardiac activity could not be obtained. The patient was pronounced dead due to exsanguinating hemorrhage from wuwpected cardiac wounds. In this critically injured patient with evidence of intrathoracic hemorrhage and suspected cardiac penetration, only emergency thoracic exploration and immediate surgical control of bleeding points might offer the maximum possibility of survival. The other case was a 23 years old man who was transferred to the emergency room 4 hours 50 minutes after having kmultiple communicated fractures of sternum and linear fracture of right mandible by a missile. Examination revealed about 30% skin loss of the anterior chest wall, weak pulse of 96 beats/min., distant heart sound and decreased breath sounds bilaterally. finding on the chest X-ray films showed multiple sternal fractures, marked pericardial effusion indicating hemopericardium. So, the patient was moved immediately to the operation room where, after endotracheal tube inserted, a median sternotomy was performced. A hemorrhagic congestion of the right upper lobe and marked bulging pericardium were disclosed. The pericardium was opened anterior to right phrenic nerve and exsanguinating hemorrhage ensued from the 0.5cm lacerated wound in the auricle of right atrium. The rupture site of right atrium was occluded with non-crushing vascular clamps and then was over sewn with interrupted sutures. It was thought to be highly possible that he was alive long enough to have cardiorrhaphy because of cardiac tamponade, which prevented exsanguinating hemorrhage. He was taken closed reduction for linear fracture of right mandible 2 weeks after repair of ruptured right auricle in dental clinic. This patient's post-operative course was not eventful.

• Restorative Dentistry and Endodontics
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• v.30 no.3
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• pp.170-177
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• 2005

This study was conducted in order to assess whether the form of the shade guide affects in deciding the color of the teeth using the shade guide Eight shade light cured composite resins (Esthet-X, Dentsply, Milford, USA) were used in this study. Shade guides including the model of maxillary central incisors, teeth-form shade guide, doughnut form shade guide, and shade guide with perforated gray shield were prepared with eight shade composite resins and provided the codes randomly After arranging the models of teeth, 19 dentists working at the clinic of the Dentistry of Chonnam University Hospital and 65 students of college of dentistry, Chonnnam University selected the shade guides corresponding to the color of each tooth on the gray board under the D$_{65}$ standard illuminant. Bl shade showed highest accuracy of about 95% among all shade guides of 3 forms applied to the test and regardless of observer, tooth form shade guide showed the highest accuracy (p < 0.05) , and the doughnut form showed the lowest accuracy (p < 0.05). At the time of deciding on the color of the teeth using the shade guides as a result of above, the forms of the shade guides can affect the accuracy, and it suggests that the development of the diversified forms of shade guides, which may obtain more accurate results, is required.

• Journal of Oral Medicine and Pain
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• v.34 no.1
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• pp.81-90
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• 2009

This study is designed to assess Relationship between clinical diagnosis of Temporomandibular Joint Disorder and diagnostic finding of Cone Beam Computed Tomography(CBCT) The author performed clinical examination for TMD Patients who visited Orofacial pain clinic, Jin-ju ooo Dental office. CBCT(Cone beam computed tomography) was taken for 190 joints in 95 subjects. A Oral medicine and Oral radiologist evaluated CBCT each other. then we compared with that result, Condyle bony changes were classified by no bone change, flattening, erosion and osteophyte. The obtained results were as follow: 1. The Kappa index of the diagnosis between oral medicine and oral radiogist were high, the index of diagnosis by degenerative joint disease were more higher. 2. The Kappa index of panoramic view and CBCT was low, more condylar bone chages were observed by CBCT diagnosis 3. Condylar bone changes of the 54.2% of non-DJD group clinicaly was observed by CBCT diagnosis and no bone changes of the 15.3% of DJD group.was observed by CBCT 4. TMJ pain was associated with erosion of condyle bone change of TMJ. Crepitation and longest duration of TMD were associated with osteophytic bone change.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.1
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• pp.78-94
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• 2005

Purpose. The purpose of this study was to compare the effects of various surface treatments by measuring resonance frequency and histomorphometric analyses. Material and methods. In 5 adult dogs, the mandibular premolar were extracted. Six months later, 30 screw titanium implants (Dentium Co., Seoul, Korea) 6mm in length and 3.4mm in diameter, were placed in the mandibles of 5 dogs. Implants were divided into five groups following to surface treatment methods ; Group 1 is machined controls, Group 2 is sandblasted with large grit and acid-etched (SLA), Group 3 is anodized (Autoelectric Co., Korea, 660Hz, Duty10), Group 4 is hydroxyapatite(HA) coated by ion beam assisted deposition(E-beam), Group 5 is hydroxyapatite(HA) coated with Sol-gel coating process. Resonance frequency was measured implant placement immediately, and 3, 6 weeks and 10 weeks of healing perods. With the animal subject's sacrifice 10 weeks after implantation, implants were removed on bloc and histologic and computer-based histomorphometric analyses were performed. Histomorphometric analysis involved quantification of the entire bone to metal contact around the implants. Statistical analyses were performed using the SPSS for Windows (ver. 9.0 SPSS Inc.) Statistical differences were considered significant at P<0.05. Results. The results were as follows : 1) In five groups, mean value of resonance frequency analysis(RFA) were highest in group 5 (Sol-gel implant) at implantation and those of group 4 (E-beam)was highest at 10 weeks . but there was no correlation between surface treatments and RFA. 2) In all surface treatment groups, the RFA values of implants decreased until 3 weeks and increased to 10 weeks. 3) The percentage of direct bone-to-implant contact (BIC) had statistical significance between five groups in cancellous bone, (P<0.05) the percentage of bone density inside the thread had no statistical significance between five groups. (P>0.05) 4) There was a significant difference between cortical bone and cancellous bone in BIC. (P<0.05) and bone density. (P<0.05) 5) There was a correlation between the RFA value of implants at 10 weeks and BIC in cancellous bone, and between the RFA value of implants at 10 weeks and bone density in cortical bone. (P<0.05). Conclusions. These results indicate that surface treatment does not affect the implant stability in case of good bone quality.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.2
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• pp.180-188
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• 2002

Newly developed curing units(plasma arc curing units) operate at relatively high intensity and are claimed to result in optimum properties of composite resin in a short curing time. The purpose of this study was to evaluate the microhardness and microleakage at the resin-tooth interface of two types of composite resins polymerized with visible light and plasma arc curing units. The results from the present study can be summarized as follows 1. Microhardness in each depth was shown to be higher in group AHL than AP3 & AP6. Group ZHL was lower than AP6 at surface(p<0.05) and had no statistically significant difference at 1mm and 2mm(p>0.05). In other depths, group ZHL was higher than ZP3 and ZP6(p<0.05). 2. The incremental reduction in microhardness with depth was shown to be in all group except in surface-1mm of group AHL and $1{\sim}2mm$ of group ZHL(p<0.05). 3. Degree of microleakage in all oops were shown to be higher in gingival margin than occlusal margin but no statistically significant difference(p>0.05). 4. Differences between curing methods in microleakage were shown to be no statistically significant difference(p>0.05). 5. Differences between composite resins in microleakage were shown to be no statistically significant differ once(p>0.05).

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.1
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• pp.62-67
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• 2011

Early eruption refers to an accelerated eruption of a tooth beyond the normal eruption period. The clinical findings of an early erupted tooth with little formation of crown and/or root include severe mobility, pain on chewing, hypocalcification of the enamel, and inclination, displacement, and rotation of the tooth. The radiographic findings include underdeveloped root and insufficient bone support. Early eruption of a permanent tooth can cause several complications such as chronic trauma, pain, edema, an increased rate of premolar impaction and tooth displacement and/or rotation. Therefore, when a permanent tooth erupts earlier than its normal eruption period with accompanying symptoms, appropriate treatments should be done as soon as possible. A female patient of age 7 without any systemic disease was referred from a local dental clinic with chief complaint of severe mobilities and pain in both upper first premolars. According to the clinical and radiographic examinations, the permanent teeth erupted earlier with barely formed roots, severe mobilities, edema, and pain. This case is to report the successful accomplishment of root formations and stabilization of teeth after applying intraoral fixed appliances using bands and spurs for 14 months.