2.The marginal accuracy of temporary crown with different matrix.
Tae Hun JU ; Hye Won CHO ; Jin Keun DONG
The Journal of Korean Academy of Prosthodontics 1991;29(2):59-66
No abstract available.
Crowns*
3.Comparison between Group I in Which Non-Supine Apnea-Hypopnea Index> or =5 and Group II in Which Non-Supine Apnea-Hypopnea Index<5 in Patients with Positional Sleep Apnea.
Won Il PARK ; Hye Won JUNG ; Joon Bum JOO ; Ju Eun CHO ; Jong Yang KIM
Sleep Medicine and Psychophysiology 2013;20(1):31-34
OBJECTIVES: The aim of this study was to evaluate the differences in patients with positional dependent sleep apnea according to their non-supine apnea-hypopnea index (AHI, > or =5 vs. <5). METHODS: 92 patients with positional sleep apnea were evaluated. The patients were divided into two groups : group I was non-supine AHI having > or =5 ; group II was non-supine AHI having less than 5. Statistical analysis was performed to find the difference between two groups. RESULTS: In 92 patients, the number of group I patients was 11 (12%) and the number of group II patients was 81 (88%). In the severe AHI group, percentage of group I was dominated (70%) and showing a significant difference compared with the mild and moderate AHI groups (p<.05). In the severe body mass index (BMI) group, percentage of group I was dominated (54.5%) and showing a significant difference compared with of the mild and moderate BMI groups (p<.05). The percentage of group I was significantly higher than group II (p<.05) in the AHI, supine AHI, non-supine AHI and snore time. CONCLUSIONS: In patients with positional sleep apnea, severe OSA and high BMI are more common in patients with non-supine AHI> or =5 than non-supine AHI<5.
Body Mass Index
;
Humans
;
Sleep Apnea Syndromes
;
Sleep Apnea, Obstructive
4.Traumatic Bowing of the Ulna with the Dislocation of the Radial Head: Report of a Case
Chang Ju LEE ; Won Ho CHO ; Sung Kee CHANG ; Won Jin CHA
The Journal of the Korean Orthopaedic Association 1988;23(4):1147-1150
Although traumatic bowing of one or both bones of the forearm in children following acute trauma was reported by some authors, traumatic bowing of the ulna with dislocation of the radial head was described by only a few reports. We experienced one case of traumatic bowing of ulna associated with dislocation of the radial head and it was managed with open reduction of the dislocation of radial head and closed management of the bowing of the ulna. The result 1 year 10 months after treatment was very good, so we report this a case with related literatures.
Child
;
Dislocations
;
Forearm
;
Head
;
Humans
;
Ulna
5.STRESS OF DENTAL IMPLANT ABUTMENT SCREW BY THE TIGHTENING TORQUE.
Won Joo LEE ; Ju Hwan LIM ; In Ho CHO
The Journal of Korean Academy of Prosthodontics 1998;36(5):721-737
Abutment screw loosening of implant restorations is a common problem in the treatment of dental implant. The purpose of this study was to calculate stress and preload from the elongation measurements and to determine maximum tightening torque without plastic deformation of the screw. The length of each gold alloy UCLA screw was measured after tightening to the manufacturer's recommended torque of 32 N-cm. Similarily, titanium UCLA screws were measured after tightening to the manufacturer's recommended torque of 20 N-cm. Loosening torque was also measured after tightening to 32 N-cm torque for gold alloy abutment screws and 20 N-cm for titanium abutment screws. The results were as follows ; 1. There was a regressive relationship between screw elongation and tightening torque (gold alloy : r2 = 0.987, titanium : r2 = 0.978), and the mean preload calculated from elongation measurements was 501.11 +/- 26.85 N (gold alloy) and 399.43 +/- 7.61 N (titanium). 2. Stress calculated for the gold alloy and titanium screws at maximum recommended tightening torque was less than 60% of their respective yield strengths and within the elastic range. Maximum tightening torque without plastic deformation was 61 N-cm(gold alloy) and 39 N-cm(titanium). 3. For titanium screws, there was a significant difference between loosening after trial 1 and loosening after trials 2 to 5 (p<0.05). No statistically significant difference was seen in mean loosening torques between the first and subsequent trials for gold alloy screws.
Alloys
;
Dental Implants*
;
Plastics
;
Titanium
;
Torque*
6.p53 Mutation and Expression of Rb Protein in Germ Cell Tumors.
Ju Han LEE ; Mee Yon CHO ; Hae Hyeog LEE ; Bom Woo YEOM ; Nam Hee WON
Korean Journal of Pathology 1998;32(12):1074-1080
We investigated the role of the tumor suppressor genes in the germ cell tumor. Immunohistochemistry (IHC) and polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) for p53 mutation were done in 46 cases of the germ cell tumor with paraffin embedded tissue. The immunohistochemical staining for Rb protein was also performed in the same specimens. The following results were obtained. The overexpression of the p53 protein was detected in 7 of 46 cases (15%). p53 mutation by PCR-SSCP was detected in 1 of 46 cases (2.2%). Expression of Rb protein was negative in 19 cases (41%). These results suggest that p53 mutation does not play an important role in the initiation and progression of germ cell tumors.
Genes, Tumor Suppressor
;
Germ Cells*
;
Immunohistochemistry
;
Neoplasms, Germ Cell and Embryonal*
;
Paraffin
;
Retinoblastoma Protein*
7.Immunohistochemical Analysis of Transforming Growth Factor (TGF)-beta1 and TGF-beta Receptor II and Quantitative Analysis of TGF-beta1 mRNA during Multistep Hepatocarcinogenesis Induced by Diethylnitrosamine in Sprague-Dawley Rats.
Mee Yon CHO ; Ju Han LEE ; Yong Koo KANG ; Nam Hee WON
Korean Journal of Pathology 1999;33(11):1009-1023
Transforming growth factor (TGF)-beta1 plays an important role in hepatocarcinogenesis and has been described as a useful tumor marker and one of the poor prognostic indicators in patients with hepatocellular carcinoma (HCC). To investigate the role and cellular localization of TGF-beta1 during multistep hepatocarcinogenesis we performed a quantitative analysis of TGF-beta1 mRNA and immunohistochemical expression of TGF-beta1 and TGF-beta receptor II (TGF-betarII) in female Sprague-Dawley rats. The experimental groups included neoplastic lesions produced by Solt-Farber's protocol, regenerating liver after partial hepatectomy, and normal control. Quantitative change of TGF-beta1 mRNA was analysed by competitive reverse-transcription polymerase chain reaction (RT-PCR). TGF-beta1 protein and TGF-betarII expression were evaluated by immunohistochemical stain. The discrete tumor nodules were detected on 14th day and then increased in number and size. Three HCCs were induced on 8th or 9th month. RT-PCR demonstrated TGF-beta1 mRNA band in all examples of the normal and regenerating liver, nodules and HCCs. Competitive RT-PCR displayed higher TGF-beta1 mRNA in nodules, HCCs and regenerating liver than in normal controls. Hepatocytes from control and regenerating livers showed weak immunoreactivity for TGF-beta1. In contrast, the cytoplasm of hepatocytes of nodules in 7th, 8th and 9th month and HCCs were intensely stained for TGF-beta1. Some sinusoidal cells showed immunoreactivity for TGF-beta1 in all experimental groups. In early phase of carcinogenesis, the cytoplasm of hepatocytes in liver of 12h, 1d and 3d showed transiently increased immunoreactivity for TGF-beta1 and The immunoreactivity decreased thereafter. TGF-beta1 mRNA was also detected in the neoplastic hepatocytes by in-situ hybridization. Although TGF-betarII expression was correlated with TGF-beta1 immunoreactivity during early phase of carcinogenesis, hepatocytes in most nodules in 7th, 8th, 9th month and carcinomas showed decreased or little immunoreactivity for TGF-betarII. Based on the above results, it is concluded that TGF-beta1 expression increases not only in precancerous nodules but also in HCCs and its increase seems to be correlated with decrease or loss of TGF-betarII expression although its mechanism remains unclear. Hepatocytes may be a major cellular source of TGF-beta1 during hepatocarcinogenesis.
Carcinogenesis
;
Carcinoma, Hepatocellular
;
Cytoplasm
;
Diethylnitrosamine*
;
Female
;
Hepatectomy
;
Hepatocytes
;
Humans
;
Liver
;
Polymerase Chain Reaction
;
Rats, Sprague-Dawley*
;
Receptors, Transforming Growth Factor beta*
;
RNA, Messenger*
;
Transforming Growth Factor beta*
;
Transforming Growth Factor beta1*
;
Transforming Growth Factors*
8.Reconstruction of the Soft Tissue Defect Using Thoracodorsal Artery Perforator Skin Flap.
Seog Keun YOO ; Ju Won CHO ; Jeong Jae LEE ; You Ree SOHN ; Young Chun YOO
Journal of the Korean Society of Plastic and Reconstructive Surgeons 1999;26(5):945-949
In the case of a soft tissue defect which requires thin & pliable tissues, the choice of donor site is limited due to flap bulkiness and donor site morbidity. To overcome these problems, a variety of perforator-based flaps such as paraspinous and parasacral perforator flap, deep inferior epigastric perforator flap, gluteal perforator flap, and thoracodorsal artery perforator flap have recently been introduced. We experienced 8 cases of soft tissue defects from December 1996 to March 1999 using the thoracodorsal artery perforator flap for reconstruction. We could elevate the cutaneous flap with preservation of the latissimus dorsi muscle flap only when it was based on one cutaneous perforator. Defatting procedure was possible for further thinning of skin flap. In one case, axillary defect after release of postburn scar contracture was repaired with island perforator flap and the other seven cases were repaired with free flap. The results were satisfactory. We believe the thoracodorsal artery perforator flap is useful for reconstruction of soft tissue defects which are large or under conditions requiring thin flap.
Arteries*
;
Cicatrix
;
Contracture
;
Free Tissue Flaps
;
Humans
;
Perforator Flap
;
Skin*
;
Superficial Back Muscles
;
Tissue Donors
9.Laboratory evaluation of blood coagulation system in FFP.
Sang Won CHO ; Gyeong Ran CHOI ; Tai Ju HWANG ; Dong Wook YANG
Korean Journal of Blood Transfusion 1992;3(1):35-40
No abstract available.
Blood Coagulation*
10.Fatigue fracture of different dental implant system under cyclic loading.
The Journal of Korean Academy of Prosthodontics 2009;47(4):424-434
STATEMENT OF PROBLEM: Problems such as loosening and fractures of retained screws and fracture of implant fixture have been frequently reported in implant prosthesis. PURPOSE: Implant has weak mechanical properties against lateral loading compared to vertical occlusal loading, and therefore, stress analysis of implant fixture depending on its material and geometric features is needed. MATERIAL AND METHODS: Total 28 of external hexed implants were divided into 7 of 4 groups; Group A (3i, FULL OSSEOTITE(R)Implant), Group B (Nobelbiocare, Branemark System(R)Mk III Groovy RP), Group C (Neobiotec, SinusQuick(TM) EB), Group D (Osstem, US-II). The type III gold alloy prostheses were fabricated using adequate UCLA gold abutments. Fixture, abutment screw, and abutment were connected and cross-sectioned vertically. Hardness test was conducted using MXT-alpha. For fatigue fracture test, with MTS 810, the specimens were loaded to the extent of 60 - 600 N until fracture occurred. The fracture pattern of abutment screw and fixture was observed under scanning electron microscope. A comparative study of stress distribution and fracture area of abutment screw and fixture was carried out through finite element analysis. RESULTS: 1. In Vicker's hardness test of abutment screw, the highest value was measured in group A and lowest value was measured in group D. 2. In all implant groups, implant fixture fractures occurred mainly at the 3 - 4th fixture thread valley where tensile stress was concentrated. When the fatigue life was compared, significant difference was found between the group A, B, C and D (P<.05). 3. The fracture patterns of group B and group D showed complex failure type, a fracture behavior including transverse and longitudinal failure patterns in both fixture and abutment screw. In Group A and C, however, the transverse failure of fixture was only observed. 4. The finite element analysis infers that a fatigue crack started at the fixture surface. CONCLUSION: The maximum tensile stress was found in the implant fixture at the level of cortical bone. The fatigue fracture occurred when the dead space of implant fixture coincides with jig surface where the maximum tensile stress was generated. To increase implant durability, prevention of surrounding bone resorption is important. However, if the bone resorption progresses to the level of dead space, the frequency of implant fracture would increase. Thus, proper management is needed.
Alloys
;
Bone Resorption
;
Dental Implants
;
Electrons
;
Fatigue
;
Finite Element Analysis
;
Fractures, Stress
;
Hardness
;
Hardness Tests
;
Prostheses and Implants