No abstract available.
Humans

No abstract available.
Finite Element Analysis*

No abstract available.
Ectoderm* ; Ectodermal Dysplasia* ; Prosthodontics*

INTRODECTION: In order to improve medical education through the introduction of a concept of comprehensive health care of a community, an area surrounding the University Campus was chosen for the Community Health Service Project. It has been on operation for last 4 years with its major emphasis on family planning services, and maternal and child health care. The major objectives of this survey at the area are to obtain: 1) The demographic data, 2) The health need and trend of medical care. 3) The attitude and practice in maternity care to be used for further improvement of the planning and the services of the project. Population and Survey Method: Out of three Dongs of the Community Health Service Area, only two Dongs namely Changchun and Yonhee were selected for the survey. Total number of households and population in the area studied was 3.683 and 21,857 respectively. An interview was performed with questionnaire schedule which was recorded by interviewers. This includes the degree of utilization of health services provided by the Community Health Service Program such as family planning, prenatal care during their last pregnancy, delivery history and complications of the delivery as well as the incidence of illnesses in general. Prior to the interview, all interviewers were trained for interviewing technique for two days. The survey was carried out during the period from October December 1967. RESUTLS: 1) Demographic Data : 41.3% of the population studied were children under age 15 and only 3.5% were over 60 years of age. Crude birth rate and crude death rate of this area studied during the period of November 1966-October 1967 were 20.5 and 7.7 respectively. Infant mortality rate during the same period was 35.9. 50.4% of the 2,832 households fell into the category of middle class, 39.8% to the lower class and 9.5% to the upper class in economic condition. 19.8% of 2,832 householders had no formal education, 22.7% primary school, and 57.5% middle or higher school education. 2) Health Status and Utilization of the Community Health Service: Those who suffered from many illnesses during the month of October, 1967 were 690(4.6% of 14,891 persons). Classification of these patients into the type of disease shown respiratory diseases 27.4%, gastrointestinal diseases 18.1%, tuberculosis 10.9%, skin and genitourethral diseases 4.5% and gynecologic patients 4.5%. Only 55.9% of the patients received medical care at hospital or doctor's clinic. But among TB and gynecologic patients, 70.7% and 72.4% were treated at medical facilities. 10.6% of 2,832 householders interviewed has ever utilized the Community Health Service Program provided by the Yonsei Medical School. Classifying these clients into the type of service, 35.9% utilized the wellbaby clinic, 31.0% the family planning clinic, 14.7% the home delivery care, and the rest utilized other services such as the premarital guidance clinic and the sanitary inspection service. 3) Maternity Care: 23.6% of 2,151 deliveries were done at medical facilities such as hospital, private clinic, while 76.4% were done at home. Acceptance rate of prenatal care was 32.6% as whole, but 49.6 of 774 women who had the prenatal care service had their deliveries at medical facility. 45.1% of total deliveries were attended by medical and or paramedical personnel. 75.8% of the deliveries of those received prenatal care were attended by medical and or paramedical personnel while only 27.8% of the deliveries of those who did not have prenatal care attended by medical and or paramedical personnel. 49.8% of deliveries of the upper class, 29.8% of the middle class and 9.9% of the lower class were attended by medical and or paramedical personnel. 6.2, 3.3% and 24.8% of mothers reported about their experience of edema, coma and fever during the period of trimester of pregnancy and puerperium. 4) Family Planning: The rate of practice of family planning was 27.9%. 31.7% of them were by IUD, 20.9% by oral pill, 15.2% by sterilization and the rest by traditional methods. Those women who had 3 to 4 children had highest(30.2%). Practice rate among the various methods of family planning, oral pill was the most popular method to whom had 2 or less children. In relation between the practicing rate of family planning and living standard, the upper, middle and lower class practiced 37.5, 29.4 and 19.9% respectively.
Allied Health Personnel ; Appointments and Schedules ; Birth Rate ; Child ; Child Health ; Classification ; Coma ; Community Health Services* ; Comprehensive Health Care ; Surveys and Questionnaires ; Edema ; Education ; Education, Medical ; Family Characteristics ; Family Planning Services ; Female ; Fever ; Gastrointestinal Diseases ; Health Services ; Health Surveys* ; Hospitals, Private ; Humans ; Incidence ; Infant ; Infant Mortality ; Mortality ; Mothers ; Postpartum Period ; Pregnancy ; Prenatal Care ; Surveys and Questionnaires ; Schools, Medical ; Seoul* ; Skin ; Socioeconomic Factors ; Sterilization ; Tuberculosis

OBJECTIVE: The aims of this study were to analyze the natural history of patients with pseudomyxoma peritonei originated from mucinous ovarian tumor, evaluate clinical and pathologic variables, and review our experience with available therapeutic modalities. METHODS: Six patients were treated for pseudomyxoma peritonei originating from mucinous ovarian tumor at Severance Hospital between 1990 and 1998. The data were collected retrospectively and all charts were reviewed RESULTS: The mean age at diagnosis was 51 years, and most common symptoms were abdominal distension. Pseudomyxoma peritonei was found in association with five mucinous ovarian tumors of borderline malignancy, and one ovarian mucinous adenoma. All patients underwent surgical staging and cytoreduction, three patients received postoperative adjuvant chemotherapy and, of these, two developed recurrence. With respect to survival, all patients were alive, four were alive and free of disease, two were alive with disease at the end point of study. CONCLUSION: Pseudomyxoma peritonei is commonly associated with borderline mucinous ovarian tumors, and is a frequently relapsing and protracted disease. But aggressive and repeated debulking surgery is recommended for long survival.
Adenoma ; Chemotherapy, Adjuvant ; Diagnosis ; Humans ; Mucins* ; Natural History ; Pseudomyxoma Peritonei* ; Recurrence ; Retrospective Studies

Platelet-rich plasma (PRP) has been known to increase the rate and degree of bone formation by virtue of growth factors in concentrated platelets. Although its great healing effect on bone defect or pre-implantation site preparation in conjunction with bone substitute has been reported, the effect associated with implant is unknown. The purpose of this study was to investigate the effect of PRP on rapid osseointegration of endosseous dental implants in the rabbit tibiae. Twenty two adult female New Zealand white rabbits, weighing approximately 2.7-3.3kg, were used for this study. Twelve of the 22 animals were used for histomorphometric analysis and ten of the 22 were for removal torque test. Each animal received two implants in each tibia (two treated with PRP and two as control) and was given fluorochrome intramuscularly. For histomorphometric analysis, rabbits were divided into four groups according to the healing period. At 1 week, 2 weeks, 4 weeks and 8 weeks postoperatively, each three animals were sacrificed serially and the amount and rate of bone formation around dental implant were examined on the undecalcified sections under fluorescent microscope, polarized microscope and light microscope connected to a personal computer equipped with image analysis system. For removal torque test, rabbits were divided into two groups and removal torque tests were performed at 4 weeks, 10 weeks after implant placement. In total, 88 screw shaped, commercially pure titanium implants (Neoplant, Neobiotech, Seoul, Korea) were used in this study. Labeling pattern reflected differences of two groups in bone formation rate at each period. Histomorphometrically, PRP group showed significantly higher bone volume within threads compared to control group at 2 weeks (70.30+/-4.96% vs. 50.68+/-6.33%; P<.01) and 4 weeks (82.59+/-5.94% vs. 72.94+/-4.57%; P<.05). PRP group at 1, 2 and 4 weeks revealed similar degree of bone volume formation comparable to control group at 2, 4 and 8 weeks, respectively. On the other hand, while PRP group showed higher bone-implant contact (47.37+/-8.09%) than control group (33.16+/-13.47%) at 2 weeks, there were no significant differences between PRP group and control group for any experimental period. Removal torque values also showed no significant differences between PRP group and control group at any experimental period (P>.05). These findings imply that PRP could induce rapid, more bone formation around implant during early healing period and get faster secondary stability for reducing healing period, though it has not induced bone maturation enough to resist functional loading.
Adult ; Animals ; Bone Substitutes ; Dental Implants* ; Female ; Hand ; Humans ; Intercellular Signaling Peptides and Proteins ; Microcomputers ; Osseointegration ; Osteogenesis* ; Platelet-Rich Plasma* ; Rabbits ; Seoul ; Tibia ; Titanium ; Torque* ; Virtues

It has been claimed that CNS lymphoma, a rare neoplasm accounting for only a small fraction of malignant brain tumors, occurs with increasing frequency in immunologically normal as well as immunocompromised individuals. We investigated the prognostic value of Ki-67 index, p53, and bcl-2 oncoprotein expression in relation to the clinicopathological parameters in the primary CNS lymphoma patients. The tumors were graded by Kiel classification and the Working formulation and included 33 high-grade, 4 intermediate-grade, and 5 low-grade lymphomas. The phenotype was determined in 38 cases: 30 were B cell type and 8 were T cell type. All cases displayed variable degrees of nuclear Ki-67 staining from 1.0% to 92.0% (mean 51.1%). A highly significant correlation was established between the proportion of Ki-67 positive cells and the classification into grades (p=0.0002) and phenotypes (p=0.0002). Overexpression of p53 and bcl-2 protein was found in 37.1% and 51.4% of 35 patients, respectively. And p53 expression was significantly increased in B cell type (p=0.02). On Kaplan-Meier survival curve, the phenotype, grade of tumors, and p53 and bcl-2 protein expression were not correlated with overall survival. On multivariate analyses, overall survival was independently influenced by Ki-67 index. In conclusion, it is suggested that Ki-67 proliferating index is the most important marker for predicting biologic behavior of the primary CNS lymphoma.
Brain Neoplasms ; Central Nervous System* ; Classification ; Humans ; Lymphoma* ; Lymphoma, Non-Hodgkin ; Multivariate Analysis ; Phenotype

PURPOSE: One of the major keys to achieve successful osseointegration of the implant is its surface properties. The aim of this study was to investigate the bone response to dental implants with different surface characteristics using the rabbit tibia model. Tricalcium phosphate (TCP) coated, anodic oxidized and turned (control) surfaces were compared. MATERIALS AND METHODS: Seventy two implants were placed in the tibia of eighteen rabbits. Nine rabbits were sacrificed at 3 weeks of healing and the remaining nine were sacrificed at 6 weeks of healing. The bone-to-implant contact (BIC) and the bone volume density (BVD) were assessed by light microscope after 3 and 6 weeks of healing. RESULTS: Statistical analysis showed that no significant differences in the BIC and BVD were observed between the different implant surfaces and the control group at 3 weeks and 6 weeks of healing. Data also suggested that the BVD of all the surfaces showed significant difference at 3 and 6 weeks. CONCLUSION: The present study has showed that osseointegration occurred in all investigated types of surface-treated implants. In the current study all of the threads of the implants were observed to calculate BIC and BVD values (instead of choosing some of the threads from the bone cortex for example), which didn't make BIC or BVD percentage values better than in the control group, therefore the clinical relevance of these results remains to be shown.
Calcium Phosphates ; Dental Implants ; Light ; Nitrogen Mustard Compounds ; Osseointegration ; Rabbits ; Surface Properties ; Tibia

All ceramic restorations have had a more limited life expectancy than metal ceramic crowns because of their lower strength. The relatively lower strength has limited the use of all-ceramic crowns to the areas where occlusal loads are lower. Therefore many researches have been done to increase the strength of all-ceramic crowns. IPS Empress 2 is a new type of lithium disilicate glass-ceramic with enhanced physical characteristics which has been in use clinically since 1998. Previous researches reported that the flexural strength of all-ceramic material was greater than 300MPa, and all-ceramic crowns can be used in staining or layering technique. The objective of this study was to investigate the influence of the thickness of IPS Empress 2 ceramic on fracture strength. Both staining technique and layering technique was investigated. Vita VMK was used as control. For all three groups, five specimens each of 0.8mm, 1.0mm, 1.4mm, 1.8mm, and 2.2mm thickness (a total of 75 specimens) were prepared. Control group: Vita VMK Porcelain specimens were prepared with dentine ceramic and liquid glazing was done. Group I: IPS Empress 2 were prepared with staining technique and stained twice and glazed once. Group II : IPS Empress 2 were prepared with layering technique and glazed after wash firing. The thickness and diameter of the specimen were measured and controlled after specimen preparation. Biaxial Flexure Test (ASTM Standard F394-78) was adopted as this test method produces results least affected by the edge condition of the specimens. Fracture strength was measured with Instron Universal Testing Machine. Conclusions are as follow : 1. The fracture strength was increase in order of control group, test group I, test group II. 2. Fracture strength of the group I(Empress 2 Staining) was 65.54 N in 0.8mm, 155.2 N in 1.0mm, 233.5 N in 1.44mm, 434.5 N in 1.8mm, and 600.1 N in 2.2mm. 3. Fracture strength of the group II (Empress 2 Layering) was 190.0 N in 0.8mm, 283.5 N in 1.0mm, 437.2 N in 1.4mm, 732.0 N in 1.8mm, and 1115.0 N in 2.2mm. 4. No statistical difference was found in flexural strengths according to thickness in a specified group(p>0.05).
Ceramics* ; Crowns ; Dental Porcelain ; Dentin ; Fires ; Life Expectancy ; Lithium

The ideal restorative material should mimic the properties of the tissues it replaces. Dental composite resins have been used widely as restorative materials due to its advantages such as excellent esthetics and ease of manipulation. But inadequate wear resistance has been a major factor limiting the use of composite restorative materials. Improved manufacturing techniques have allowed the development of hybrid composites, with a greater percentage volume filler loading, which have improved physical an mechanical properties. However they are lacking the study wear resistance. The purpose of this study was to evaluate the wear of human enamel against ceromer by the use of a pin-on-disk type wear testers. Discs of ceromer(Targis : Ivoclar, Vivadent, Amherst. NY) and discs of type III gold alloy as a control were used for test specimens. Intact cusp of premolar and molar were used for enamel specimens. The wear of enamel was determined by weighing the cusp before and after each test, and the weight converted to volumes by average density of enamel. Surface profilometer was used to quantify wear of the ceromer and gold specimens. Vicker's hardness tester was used to evaluate the surface hardness of test specimens. The SEM was used to evaluate the wear surfaces. The results were as follows; 1. Ceromer produced less enamel wear than gold(p<0.05). 2. The wear volume of ceromer was greater than that of gold(p<0.01). 3. The hardess of ceromer was lower than that of gold, but there was no correlation between the hardness and wear of the ceromer and gold. 4. SEM analysis revealed that there were many voids and microcracks in the wear tract of ceromer. in gold group, many minute V-shaped grooves were examined.
Alloys ; Bicuspid ; Composite Resins ; Dental Enamel* ; Esthetics ; Hardness ; Hardness Tests ; Humans* ; Molar