PURPOSE: The purpose of this study was to investigate the perceived sources of stress among dental students. The relationships of these stresses to the year of study and gender were also examined. METHODS: The responses from the first to fourth year dental students to 30 items adapted from Dental Environment Stress (DES) questionnaire were subjected to confirmatory factor analysis. The Likert scale, ranging from 0 (not applicable) to 4 (very stressful), was applied to these items. A total of 341 students (male=196, female=145) participated, their average age being 24.7. Multivariate analysis of variance (MANOVA) was conducted to analyze the effects of the year of study and gender on stressors. RESULTS: Confirmatory factor analysis established a five-factor model including 1) clinical practice, 2) academic load and pressure, 3) personal problems, 4) low self-esteem, and 5) school administration or climate. Subscales for each factor show good internal consistency with Cronbach's alpha ranging from .71 to .88. Mean score for factor II (academic load and pressure) was the highest among all factors for all of 4 years, which meant that primary stressors were amount of classwork, shortage of time, and competition among classmates regardless of the year of study. MANOVA result showed that the amount of stress from clinical practice and school climate generally increased through the years (p < .01), and that female students were more stressed than male students (p < .01). CONCLUSION: Students' stress is related to the features of the curricula and the learning environment. In reducing this stress, it would be helpful to modify the curriculum as well as to introduce mentor or counselor programs.
Climate ; Counseling ; Curriculum ; Education, Dental ; Female ; Humans ; Learning ; Male ; Mentors ; Multivariate Analysis ; Prothrombin ; Students, Dental* ; Surveys and Questionnaires

It was reported that low dose doxycycline(LDD) regimen could inhibit pathologically elevated collagenase activity in the gingival crevicular fluid of petients with adult periodontitis without producing typical antibiotic side effects. The purpose of this study was to evaluate the effects of LDD regimen(20mg) administered during non-surgical therapy on clinical index and gingival crevicular fluid enzyme activity in diabetics who are at high risk for periodontal disease. Fortynine subjects having at least two sites with probing pocket depths greater than 4mm were selected. In this double-blind, placebo-controlled study, the patients were administered 20 mg doxycycline capsule or placebo capsule b.i.d. for 2 weeks. Clinical parameters of dental plaque, gingival inflammation, probing pocket depth and probing attachment level were assessed at week 0, 2, 4, and 8. Gingival crevicular fluid samples were collected at the same time to evaluate the activities of collagenase and elastase. Clinical parameters and elastase activity were significantly reduced in all groups compared to the baseline value after treatment. Significantly greater reduction in pocket depth and gain in attachment level was shown in the LDD-administered group compared to placebo group in both adult periodontitis and diabetic patients. Total collagenase activity was also reduced significantly in all groups after treatment, but the greater reduction was seen in the LDD-administered diabetics group compared to relevant placebo group(at 4, 8week). Significantly greater reduction in active collagenase activity was also seen in the LDDadministered group compared to placebo group in diabetic patients(at 2, 4, 8week). These results indicated that use of low dose doxycycline could be aueseful adjunct to instrumentation therapy in the management of diabetic patient with periodontitis as well as adult periodontitis patient.
Adult* ; Chronic Periodontitis* ; Collagenases ; Dental Plaque ; Doxycycline* ; Gingival Crevicular Fluid* ; Humans ; Inflammation ; Pancreatic Elastase ; Periodontal Diseases ; Periodontitis* ; Root Planing

Oral melanin pigmentation is common in some races and ethnic groups. The gingivae are the most frequently pigmented intra-oral tissues. Melanin pigmentation is the result of melanin granules, produced by melanoblasts intertwined between epithelial cells at the basal layer of the epithelium. We present one case of melanin pigmentation of the gingiva of 26-year old female. Melanin depigmentation method is applying a 90% phenol solution to deepithelize pigmented areas, gingivectomy, epithelial abrasion, bone denudation, and split thickess flap. We chose epithelial abrasion using round diamond bur. The patient satisfies the result and have almost no pain and discomfort. But repigmentation potential must be noticed to patient.
Adult ; Continental Population Groups ; Dental Instruments ; Epithelial Cells ; Epithelium ; Ethnic Groups ; Female ; Gingiva* ; Gingivectomy ; Humans ; Melanins* ; Phenol ; Pigmentation*

No abstract available.
Adult* ; Chronic Periodontitis* ; Doxycycline* ; Humans

The purpose of this study was to evaluate the effects of bioactive glass and natural coral on the human periodontal ligament fibroblast(HPLF) behaviors during the regeneration process of peridontium. To determine the cellular events occuring in the presence of the particles of bioactive glass and natural coral, HPLF were isolated from healthy premolar teeth extracted for orthodontic treatment. Cells were cultured in alphaMEM at 37degrees C, 5% CO2, 95% humidity incubator. Bioactive glass and natural coral were powdered, and each particled(<40micrometer) were placed on the cultured cells at the concentration of 0.3mg/ml, and l,0mg/ml for experimental group. In control group no particles were added. And each group was evaluated by examining the cell morphology under phase-contrast micrograph at 4 day and transmission electron micrograph(TEM) and scanning electron micrograph(SEM) at 14 day, alkaline phosphatase activity at 5 and 9 day, protain synthesis at 4 day, DNA synthesis at 1, 2, 3 and 4 day, cell proliferation at 1, 3, 5,7 and 9 day and the formation of bone nodule at 30 day after culturing all groups in mineralizing supplemented mediun. No significant changes in cell morphology by adding these two matirials were found under phase contrast microscopy and TEM, HPLF phagocytocized each particles suggesting that HPLF is involved in the process of resorbing each particles and that bioactive glass were more biocompatible than natural coral. The ALPase activity of bioactive glass 0.3 mg/ml was similar with control groups and all the rests of control groups were significantly low(P<0.01) indicating a transient dedifferentiation of HPLF in the presence of bioactive glass and natural coral particles. There were no significant differences of protein synthesis between all groups. The DNA synthesis in experimental groups were significantly lower than control groups at 1, 2 and 3 day (P<0.01) but became similar to control groups at 4 day. Between control groups, the DNA synthesis in bioactive glass 0.3mg/ml group was significantly higher than other groups(P (0.01). Cell proliferation in natural coral 1.0mg/ml and bioactive glass l.0mg/ml groups were significantly lower than control group at 3 day(P(0.05) and there were no differences at 5, 7, 9 day. There were more bone nodule formation in experimental groups than in control groups. In conclusion, these results indicated that bioactive glass and natural coral have some effects of a transient dedifferentiation on HPLF and regeneration of periodontal tissues, however any significant cytotoxic effect on HPLF by these two particles were not found.
Alkaline Phosphatase ; Anthozoa* ; Bicuspid ; Cell Proliferation ; Cells, Cultured ; DNA ; Glass* ; Humans ; Humidity ; Incubators ; Microscopy, Phase-Contrast ; Periodontal Ligament* ; Regeneration ; Tooth

This study analyzed a hospital-based study to investigate the incidence and clinical features of ocular traumatic emergencies in Korea. Over a 6-year period, 1809 patients with ocular traumatic emergency each individually underwent clinical study including subject characteristics, type of ocular emergency, disease severity, etiology of ocular trauma, injury location, cause of decreased visual acuity, management of ocular injury, and final visual acuity. The homogeneity of each finding of the clinical features of ocular traumatic emergency was tested by an X2 test at a 95% level of certainty. During follow-up periods ranging from 3 days to 23 months (mean 2.0 months), the 1809 patients with ocular traumatic emergency, 1183 males (65.4%) and 626 females (34.6%), were studied. The incidence of ocular emergencies peaked in the third decade of life, irrespective of gender (P< 0.05). Corneal abrasion was the most common etiology among 1, 552 (85.8%) closed injuries, and corneal laceration among 257 (14.2%) open injuries (P< 0.05). There were 542 cases (30%) of severe ocular injury, such as penetrating ocular injury, blow out fracture, and intraocular foreign body (IOF), and 1267 (70%) of less severe ocular injury, such as superficial ocular injury or contusion. The most common etiology of severe ocular injury was penetrating ocular injury, and that of less severe injury was corneal injury (P< 0.05). The main causative activity of ocular injuries was work in 631 cases (34.9%), assault in 398 (22.0%), play in 278 (15.4%), traffic accidents in 145 (8.0%) and sports in 128 (7.1%). Five hundred and fifty-four cases (32.5%) underwent surgical intervention. There was an improvement of visual acuity in 502 cases (70.1%), no change in 122 (17.0%), and worsening in 92 (12.9%). We suggest that preventive educational measures be instigated at workplaces to reduce the incidence of ocular traumatic emergency, especially severe ocular injury.
Adolescent ; Adult ; Age Distribution ; Aged ; Aged, 80 and over ; Child ; Child, Preschool ; Emergency Medical Services/*statistics & numerical data ; Eye Injuries/*epidemiology ; Female ; Humans ; Incidence ; Infant ; Korea/epidemiology ; Male ; Middle Aged ; Research Support, Non-U.S. Gov't ; Retrospective Studies ; Sex Distribution ; Visual Acuity

The oral cavity is easily accessible for direct exposure of a malignant disease. 1 percent of the oral malignant tumors are of metastatic origin and approximately 10 percent to 25 percent of the 1 percent fraction originate from the lungs. A case of metastatic lung carcinoma to the gingiva in a 88-year-old male is reported. He complained of pain and swelling between right maxillary 1st premolar and 2nd molar. Although surgical excision of the lesion has been done, the gingival lesion developed as a quickly growing mass and recurred 2 weeks after surgical excision. The gingival mass was histopathologically diagnosed as an undifferentiated carcinoma. Epithelial layer was continuous without ulceration and it seems that the cancer cells are originated from primary tumor. Infiltrated cancer cells were pleomorphic and dyskeratotic. The cells had 2 or more nuclei, not showing squamous or glandular differentiation. Immunohistochemical study revealed the cells originated from the epithelial cells. The prognosis is poor, because prognosis depends on surgical elimination of the primary tumor.
Aged, 80 and over ; Bicuspid ; Carcinoma ; Epithelial Cells ; Gingiva ; Humans ; Lung Neoplasms ; Lung* ; Male ; Molar ; Mouth ; Neoplasm Metastasis ; Periodontium* ; Prognosis ; Ulcer

No abstract available.
Chlorhexidine* ; Guided Tissue Regeneration*

Many factors may affect periodontal changes during the physiologic conditions of woman(e.g. puberty, menstrual cycle, pregnancy, menopause). Recently many research has focused on the immunological changes of host, but the exact mechanism is not clear. Collagen is a major constituent of periodontium, and collagenase specifically digests the collagen and plays a role in destruction of periodontal tissue. So, I suppose that it participates with the cytokines in the inflammation of gingiva and vascular response during the changes of female sex hormones. Because there are some evidences of the existence of the receptors of estrogen and progesterone in the gingiva, it may be a target tissue of female sex hormones. In this experiment, gingival fibroblast and periodontal ligament cell were cultured in the presence of various concentrations of estrogen or progesterone corresponding to the menstrual cycle and pregnancy. Collagenase activity of the supernatant of culture media was determined by Spectrophotometric collagenase assay. The enzyme activity was calculated by the % decrease of the coated collagen. 1. The estrogen at both concentrations had no effect on the activity of collagenase of the gingival fibroblast. 2. The progesterone had some effect on the collagenase activity of the gingival fibroblast at low and high concentration of menstrual cycle, and elevated the enzyme activity at all range of pregnancy concentrations. 3. In periodontal ligament cells, estrogen elevated the enzyme activity at the early pregnancy concentration and progesterone elevated at the concentration just before menstruation. In this experiment, progesterone elevated the collagenase activity of gingival fibroblast and periodontal ligament cells. But the mechanism of the up-regulation of the enzyme activity was not confirmed. The more experiments of direct effect of progesterone on gingival at the molecular level(e.g. northern blot analysis) can reveal the exact mechanism.
Adolescent ; Blotting, Northern ; Collagen ; Collagenases* ; Culture Media ; Cytokines ; Estrogens ; Female* ; Fibroblasts* ; Gingiva ; Gonadal Steroid Hormones* ; Humans ; Inflammation ; Menstrual Cycle ; Menstruation ; Periodontal Ligament* ; Periodontium ; Pregnancy ; Progesterone ; Puberty ; Up-Regulation

The purposes of this study were to investigate the relationship between cigarette smoking levels and periodontal status. 199 subjects, consisting of male 127 and female 72, classified by smoking levels and duration were selected: Patients who had smoked for more than 20 cigarettes/day were considered heavy smokers, 10 to 19, moderate smokers ; 1- 9, light smokers; 0, non-smoker. And smokers were divided into ones who had smoked for more than 20 years, 10-19 years, less than 10 years and non-smokers. Heavy smokers and moderate smokers showed significantly greater pocket depths, less clinical attachment levels, more molar furcation involvements, greater alveolar bone loss and higher scores of plaque index than light smokers and non-smokers, (p < 0.05). When the duration of smoking was considered as a factor, scores of clinical parameters were worse and alveolar bone loss were significantly greater in long-term smokers, who had smoked for more than 20 years. In conclusion, cigarette smoking is associated with periodontal status.
Alveolar Bone Loss ; Female ; Humans ; Male ; Molar ; Smoke ; Smoking* ; Tobacco Products*