1.A STUDY OF THE STRESS DISTRIBUTION OF THE ABUTMENT AND SUPPORTING TISSUES ACCORDING TO THE SLOPES AND TYPES OF GUIDING PLANES OF THE LAST ABUTMENT IN DISTAL EXTENSION REMOVABLE PARTIAL DENTURE USING THREE DIMENSIONAL FINITE ELEMENTANALYSIS METHOD.
Yang Kyo KIM ; Cheong Hee LEE ; Kwang Hun JO
The Journal of Korean Academy of Prosthodontics 1999;37(5):581-596
The purpose of this study was to investigate the stress distribution of the abutment and supporting tissues according tot he slopes and types of the guiding plane of distal extension removable partial dentures. The 3-dimensional finite element method was used and the finite element models were prepared as follows. Model I : Kratochvil type guiding plane with 90degree to residual ridge Model II : Kratochvil type guiding plane with 95degree to residual ridge Model III : Kratochvil type guiding plane with 100degree to residual ridge Model IV : Krol type guiding plane with 90degree to residual ridge Distal extension partial denture which right mandibular first and second molar were lost was used and the second premolar was prepared as primary abutment with RPI type retainer. Then 150N of compressive force was applied to central fossae of the first and second molars and von Mises stress and displacement were measured. The results were as follows : 1. Model I and Model IV showed a similar stress distribution pattern and the stress was concentrated on the apex of the root of the abutment. 2. The stress was increased and concentrated on mesial side of the root of the abutment in Model II. The stress was concentrated on buccal and mesiobuccal side of the root of the abutment in Model III. 3. In Model I, the root of the abutment displaced and twisted a little in clockwise. In Model IV, the root of the abutment displaced to distolingually at apical region of the root and mesiobucally at cervical region of the root. 4. In Model II, the root of the abutment displaced to mesiolingually at apical region of the root and more displaced and twisted in counterclockwise at cervical region of the root. In Model III, the root of the abutment displaced to mesiobucally at apical region of the root and more displaced and twisted in clockwise at cervical region of the root.
Bicuspid
;
Denture, Partial
;
Denture, Partial, Removable*
;
Molar
2.SHEAR BOND STRENGTH OF PRETREATED DENTIN SURFACE WITH RESIN-REINFORCED GLASS IONOMER CEMENT.
Hye Souk CHOI ; Cheong Hee LEE ; Kwang hun JO
The Journal of Korean Academy of Prosthodontics 2001;39(5):502-513
The purpose of this study was to evaluate the effect of dentin pretreatment with Dentin Conditioner,Ultra-Etch,conditioner of Fuji Plus cement on the shear bond strength of resin-reinforced glass ionomer cements to dentin and analyze the fractured surfaces. To evaluate the bond strengh, the extracted human teeth which had uniform area of exposed dentin were cemented with conventional glass ionomer cement. 3M RelyX TM Luting (Vitremer luting cement). Fuji Plus cement after dentin pretreatment. The shear bond strengh was measured using the Universal testing machine(Instron Co., USA) with a crosshead speed of 1mm/m. The effect of dentin pretreatment was evaluated by observing pretreated dentin surfaces under the scanning electron microscope,measuring the shear bond strength and observing the fractured surfaces under the scanning electron microscope. The results were as follows: On the SEM observation of surface morphology, the specimens treated with Dentin Conditioner, Ultra-Etch and conditioner of Fuji Plus cement were removed the smear layer and funneled dentinal tubules in dentin surfaces. In RelyX TM Luting cement group, shear bond strengh of pretreated group was significantly higher than control group. In Fuji Plus cement group and Fuji I group, regardless of the type of pretreatment agents, there was tendency of increase in the shear bond strength. On the SEM observation of fractured surfaces, as the shear bond strength increase, it were shown thicker cement layers and were not shown dentinal tubules. According to these results, it were shown that dentin pretreatment have much effect on bonding states.
Dentin*
;
Glass Ionomer Cements*
;
Glass*
;
Humans
;
Smear Layer
;
Tooth
3.FITNESS TEST USING THE PHASE-SHIFTING PROFILOMETRY ACCORDING TO THE DENTURE CURING METHODS.
Cheong Hee LEE ; Kwang Hun JO ; Boo Byung CHOI
The Journal of Korean Academy of Prosthodontics 1999;37(4):474-493
According to repeated measurements and correction procedures, the accuracy of the phase-shifting profilometry was developed. At first, after 20 final models for maxillary complete denture were duplicated, the mucosa surfaces of models were measured with the phase-shifting profilometry and each mirror view of these was calibrated. Maxillary cats were divided into 4 groups of 5 casts per each, and wax dentures with 2 sheets of baseplate wax and artificial teeth were made and then cured according to the curing method of each group. Group I ; quick curing with QC-20 acrylic resin Group II ; 9 hour curing with QC-20 acrylic resin Group III ; SR-Ivocap system Group IV ; metal base and quick curing with QC-20 acrylic resin After curing, polishing, and storing at 37degrees C n saline for 30 days, the forms of the impression surface of the dentures were measured with the phase-shifting profilometry. Then, the impression surface form of each denture was placed in the optimal position of comparison with the mirror view of the same final cast. The amount and direction of distortion of each denture was analyzed and the effects of polishing and storage in each denture were compared. The obtained results were as follows : 1. In Group I, the denture was observed as the appearance distorted in the opposite direction of the mucosa and the postero-lateral part of palatal portion of the denture was observed as the appearance separated from the mucosa. Also, the buccal flanges of the denture were observed as the appearance distorted in the direction of the mucosa. 2. In Group II, the postero-lateral part of palatal portion of the denture was observed as the appearance separated slightly from the mucosa. The bilateral buccal flanges of denture were observed as the appearance distorted severely in the direction of the mucosa. 3. In Group III, the bilateral part of the residual ridge crest portions and the buccal flanges of the denture were observed as the appearance distorted in the direction of the mucosa, and specially, the buccal flanges of the maxillary tuberosities were distorted severely. 4. In Group IV, the acrylic resin base of the buccal portion of the denture was observed as the appearance distorted in the opposite direction of the mucosa. 5. The phase-shifting profilometry, done with repeated measurements and correction procedures, was effective in comparing the amount and direction of distortion at every position after the laboratory work and the delivery of maxillary complete denture.
Animals
;
Cats
;
Denture, Complete
;
Dentures*
;
Mucous Membrane
;
Tooth, Artificial
4.Two Cases of Right Homonymous Hemianopsia and Total Blindness due to Cerebral Paragonimiasis.
Jae Wook PYUN ; Wan Hun KOO ; Jung Jo HUANG
Journal of the Korean Ophthalmological Society 1966;7(1):27-30
We present two cases of cerebral paragonimiasis in a 23-year-old Korean army soldier and in a 18-year-old Korean girl, respectively. The diagnosis was made on the basis of clinical, laboratory and x-ray findings, and was confirmed by the histopathological examination of the excised cyst. P.W. skin test showed positive reaction, whereas C.S. test negative. X-ray study on skull revealed multiple globulated round cystic formations in occipital region. Two months after surgical removal of cysts, visual field were not improved. Pertinent literatures are reviewed.
Adolescent
;
Adult
;
Blindness*
;
Choroid*
;
Coloboma*
;
Diagnosis
;
Female
;
Hemianopsia*
;
Heredity
;
Humans
;
Iris*
;
Membranes
;
Military Personnel
;
Optic Nerve*
;
Paragonimiasis*
;
Skin Tests
;
Skull
;
Visual Fields
;
Young Adult
5.Surgical Treatment of the Congenital Esophageal Atresia.
Pil Jo CHOI ; Hee Jae JUN ; Yong Hun LEE ; Kwang Jo JO ; Si Chan SUNG ; Chong Su WOO
The Korean Journal of Thoracic and Cardiovascular Surgery 1999;32(6):567-572
BACKGROUND: Surgical correction of the full spectrum of esophageal atresia with tracheoesophageal fistula has improved over the years, but the mortality and morbidity assoiated with repair of these anomalies still remains high. MATERIAL AND METHOD: We retrospectively analyzes 27 surgically treated patients with esophageal atresia and tracheoesophageal fistula at Dong-A University Hospital between January 1992 and March 1997. RESULT: There were 21 male and 6 female patients. Mean birth weight was 2.62+/-.385 kg(2.0~3.4 kg). Twenty- four(88.9%) had esophageal atresia with distal tracheoesophageal fistula, and 3(11.1%) had pure esophageal atresia. Four(14.8%) infants were allocated to Waterston risk group A, 18(66.7%) to group B, and 5(18.5%) to group C. In eighteen(66.7%) infants with associated anomalies, cardiovascular anomalies were the most common. Three had a gap length of 3.5 cm or greater(ultra-long gap) between esophageal segments, 7 had 2.0 to 3.5 cm(long gap), 8 had 1.0 to 2.0 cm(medium gap), and 9 had 1 cm or less(short gap) gap length. Among 27 neonates, 3 cases underwent staged operation, late colon interposition was done in 2, and all other 24 cases underwent primary esophageal anastomosis. Oerative mortality was 2/27(7.4%). Causes of death included acute renal failure(n=1), empyema from anastomotic leak(n=1), necrotizing enterocolitis(n=1), sepsis(n=1), insulin-dependent diabetus mellitus(n=1 . There were 4 anastomosis- related complications including stricture in 3, leakage in 1. Mortality was related to the gap length(p<.05). CONCLUSION: Although the complication rate associated with surgical repair of these anomalies is high, this does not always implicate the operative mortality. The overall survival can be improved by effective treatment for combined anomalies and intensive postoperatve care.
Birth Weight
;
Cause of Death
;
Colon
;
Constriction, Pathologic
;
Empyema
;
Esophageal Atresia*
;
Female
;
Humans
;
Infant
;
Infant, Newborn
;
Male
;
Mortality
;
Retrospective Studies
;
Tracheoesophageal Fistula
6.The Effects of Intravenous Administration of Nimodipine on Cerebral Pial Vessels Following the Injection of Autogenous Hemolytic Blood into Cisterna Magna in Rabbits.
Journal of Korean Neurosurgical Society 1995;24(3):278-289
The reactions of cerebral pial vessels following the injection of normal saline(0.05cc, at 37 degrees C, pH7.4) and autogenous hemolytic blood(0.05cc, 0.1cc 0.2cc) into the cisterna magna of rabbits were tested in vivo. This experiment was performed in order to observe the effect of intravenous nimodipine(30 microgram/kg) injection at the maximally constricted time of the pial vessels, about 6 hours after intracisternal injection of autogenous hemolytic blood. The diameter changes of the pial vessels were measured under operating microscope through a cranial window on craniectomized area. Pial vessels were not significantly changed after an intracisternal injection of normal saline. But after intracisternal injection of autogenous hemolytic blood(0.05cc, 0.1cc, 0.2cc), pial vessels were maximally constricted at 6 hours and the constriction was continued during the experiments. Percentile constriction was increased as the amount of subarachnoid hemolytic blood increased. According to the results, pial vessels, especially small pial artery, were constricted by autogenous hemolytic blood containing oxyhemoglobin. Nimodipine, calcium antagonist, showed dilating effect on vasospasm after experimental subarachnoid hemorrhage with autogenous hemolytic blood in rabbits.
Administration, Intravenous*
;
Arteries
;
Calcium
;
Cisterna Magna*
;
Constriction
;
Nimodipine*
;
Oxyhemoglobins
;
Rabbits*
;
Subarachnoid Hemorrhage
7.A Case of Ocular Cysticercus in Severe Systemic Cysticerosis.
Jae Wook PYUN ; Wan Hun KOO ; Jung Jo HWANG
Journal of the Korean Ophthalmological Society 1965;6(1):73-77
A case of iridocyclitis due to cysticercus cyst in the anterior chamber and exophthalmos due to in the orbit. A case of iridocycleitis due to cysticercus cyst in the anterior chamber of the left eye, bilateral exophthalmos due to in the orbit and generalized multiple cysticercus cyst in the subcutaneous tissue, brain and the internal organs is reported in a twenty one year old Korean male. To watch characteristic heaving and undulatory movements of the live cysticercus cyst in the anterior chamber of the eye is fascinating. Iridocyclitis was improved fairly after subconjunctival injection of hydrocortisone acetate 5mg and with general treatment for iridocyclitis. Regarding to literature, ocular cysticercosis is known as a very rare case in Korea. A brief review of the related literatures is presented.
Anterior Chamber
;
Brain
;
Cysticercosis
;
Cysticercus*
;
Exophthalmos
;
Humans
;
Hydrocortisone
;
Iridocyclitis
;
Korea
;
Male
;
Orbit
;
Subcutaneous Tissue
8.Effect of Cobalt-Chromium Alloy Surface Treatment When Bonding With 4-Meta/mma-Tbb Resin.
Jae Sik JIN ; Kyo Han KIM ; Cheong Hee LEE ; Kwang Hun JO
The Journal of Korean Academy of Prosthodontics 2000;38(4):510-525
The effects of pretreatment of Co-Cr alloy, including two adhesive primers that contain either MDP or MAC-10, and silicoating on the bond. The results obtained as follows : Strength of 4-META/MMA-TBB resin were investigated using FT-IR SEM, and EDAX. in the SEM observation of surface morphologies, the sandblasted specimen exibited a very rough surface, whereas the surfaces of the two groups primed with either MDR or MAC-10 were covered with a layer of primer, and the surface morphology of the silicoated specimen remained almost the same after sandblasting. Before the thermocycling tests, the group treated with MDP demonstrated the highest mean tensile bond strength and the sandblasted group showed the lowest bond strength. After 20,000 themocyling, the mean tensile bond strength of the sandblasted group exhibited a 50% reduction in bond strength, while the other showed a 20~30% reduction. Observation of the metal-resin interface revealed that in all groups the resin permeated the rough surface formed by sandblasting thereby producing a mechnical bond between the metal and the resin, It was also found that thermocycling resulted in a gap formation at the metal-resin interface of the specimens, and the sandblasted group exhibited a larger gap width than the other groups. in fracture mode, all specimens indicated a cohesive fracture within the resin before thermocycling. However, thermocyling produced adhesive failure at the edge of the resin-metal interface in most specimens, The sandblasted group, which exhibited the lowest bond strength after thermocycling, also demonstrated the largest area of adhexive failure.
Adhesives
;
Alloys*
9.A Case of Reticulate Acropigmentation of Kitamura.
Kwang Hoon LEE ; Kyung Hun CHANG ; Soo Il CHUN ; Chang Jo KOH
Korean Journal of Dermatology 1983;21(3):321-325
Reticulate acropigmentation of Kitamura, described first by Kitamura and Akam atsu in 1943, is a pigmentary disorder that may be determined by an autasomal dominant gene. Skin lesions are characterized clinically by depressed brownisL pigmented spots, in a reticulated pattern, on the extensor surface of the acral parts of the extremities. Most reported cases are confined to Japanese. We report herein a case of reticulate acropigmentation of Kitarnura in a 28- year-old woman, with a depressed brownish pigmented spots, in a reticulate pattern, on the dorsum of hands and left foot. The authors make the diagnosis of this case a reticulate acropigmentation of Kitamura for the clinical symptoms and histopathologic findings.
Asian Continental Ancestry Group
;
Diagnosis
;
Extremities
;
Female
;
Foot
;
Genes, Dominant
;
Hand
;
Humans
;
Skin
10.Speckled Lentiginous Nevus.
Choong Seop HAHN ; Jung Bock LEE ; Seung Hun LEE ; Yoon Kee PARK ; Chang Jo KOH
Korean Journal of Dermatology 1981;19(3):353-358
Speckled lentiginous nevus is a clinical variant of nevus-cell nevus first described by Stewart et al. in 1978. It is characterized by small, dark hyperpigmentated speckles superimposed on a tannish-brown background. The speckled areas show varying histologic patterns ranging from nevus incipiens to junctional or compound nevus. The back ground shows histologic features of Ientigo simplex. Recently, we observed clinical and histological features of 5 cases of speckled lentiginous nevi. The age of onset ranges from birth to infancy, The locations are face, thigh, back and scapula. One has zosteriform distribution in upper extrernity, chest and back. Histologic features of speckles are junctional or compound nevus. We suggest that the origin of dark speckles may be from the tannish-brown background, lentigo simplex.
Age of Onset
;
Lentigo
;
Nevus*
;
Parturition
;
Scapula
;
Thigh
;
Thorax