• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.4
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• pp.693-702
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• 2005

Accurate timing and sequence of eruption of permanent teeth are indicies of growth and essential for pediatric dentistry and pediatric clinical orthodontics. From the children brought to the Yonsei Dental Hospital during 2001 to 2003, 654 boys and 542 girls, ranging in age from five to fourteen years, were selected and analysed. The following was concluded. 1. Eruption time of maxillary teeth is 6.81 years in boys, 6.78 years in girls for central incisor, 8.30 years in boys, 7.98 years in girls for lateral incisor, 10.28 years in boys, 10.04 years in girls for canine, 9.74 years in boys, 9.90 years in girls for first premolar, 10.87 years in boys, 10.41 years in girls for second premolar, 6.25 years in boys, 6.54 years in girls for first permanent molar, 12.21 years in boys, 12.03 years in girls for second permanent molar 2. Eruption time of mandibular teeth is 6.00 years in boys, 6.06 years in girls for central incisor, 6.99 years in boys, 6.74 years in girls for lateral incisor, 9.83 years in boys, 9.17 years in girls for canine, 9.92 years in boys, 9.75 years in girls for first premolar, 10.66 years in boys, 10.39 years in girls for second premolar, 5.99 years in boys, 5.75 years in girls for first permanent molar, 11.92 years in boys, 12.17 years in girls or second permanent molar. 3. The following eruption sequence was observed the first permanent molar erupted first, followed by the central incisor, the lateral incisor, the first premolar, the canine, the second premolar and the second permanent molar in the maxilla. The first permanent molar erupted first, followed by the central incisor, the lateral incisor, the canine, the first premolar, the second premolar and the second permanent molar in the mandible.

• Clinical and Experimental Reproductive Medicine
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• v.27 no.1
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• pp.31-37
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• 2000

This study was designed to identify the ultrastructural changes of mouse endometrium during peri-implantation period and obtain the fundamental information for the establishment of 3-dimensional culture system of mouse endometrial cells in vitro. The used female ICR mice ($6{\sim}8$ wks) were conducted on pregnant. The biopsies were obtained from whole uterus at cycle day 1 (D1) and day 5 (D5) after hCG injection and mating. The biopsies materials were fixed 2.5% glutaraldehyde and 1% osmium tetroxide. Subsequently, for observation using light and transmission electron microscopy (LM and TEM), they were dehydrated and embedded in Epon and the embedded biopsies were sectioned and stained. For scanning electron microscopy (SEM), the fixed specimens were dehydrated, dried and coated with gold. 1) For LM, the biopsied materials at D5 (late secretory phase) were appeared the extended stromal layer by increased connective tissues and the fully developed endometrial glands and vessels compared with D1 (early secretory phase). 2) For TEM, the mouse endometrium was consisted of 3-layers, a simple polarized columnar epithelial cells, basement membrane and stromal cells. At D5, the distribution of microvilli, endoplasmic reticulum, Golgi body, lipid and glycogen deposits, secretory granules and surface area of basement membrane were increased. 3) For SEM, the degree of folding and microvilli of surface of mouse epithelial cells was became more and more according to the process of secretory phase, and at D5, implantation time of mouse, the appearance of pinopodes as a specific marker of uterine receptivity was found. The uterine pinopodes of mouse were found in narrow sites at the luminal surface, irregularity and appeared the different stages in the same sample. Therefore, these results indicated that the mouse endometrium was experienced dramatic morphological changes during peri-implantation period.

• Journal of Korean Academy of Nursing
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• v.24 no.2
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• pp.264-277
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• 1994

In Korea the concept of social support was first used as a research concept in nursing and has not had much application in the clinical field. Another problem is that research on social support has used a direct translation of the words “social support” into Korean as “sawhejuk jiji”. Three questions were posed to direct the re-search. 1) Is there a concept of social support in Korean society? 2) if so, what words or expressions are used to de-scribe it? 3) further, if so, how is social support structured and how does it function? In order to answer the research questions a three-step research methodology was used : The first step consisted of a literature review on re-search related to social support and on information on the background of, and the way of thinking re-lated to interpersonal relations among Korean people. The second step, which was done to identify whether there is a concept of social support in korean society, involved interviewing a sample of the population. The third step involved a panel discussion that included the members of the research team and three consultants, a sociologist, a philosopher and a scholor in korean literature. A review of the literature on interpersonal relationships in traditional korean society identified a four cirole structure that explains interpersonal relationships. The first circle with “me” at the center is the family but here “me” disappears into the “we” that is essential for a cooperative agricultural society. In the second circle are those close to “me” but outside the family. The third circle includes those with whom “I ” have infrequent but regular contact and with whom correct conduct is important. The last circle is all the people with whom “I” have nothing in common. They are excluded in interpersonal relationships. The literature on interpersonal relationships showed that within the traditional Korean society people lived in villages where most people were very familiar with each other. “Yun”, the social network established the connection and “Jung”, the feeling of affection increased with time as the connection was strengthened. In the traditional village psychological support was provided through “Mallaniki”, “Pumashi” and “Kae” with the latter two also providing material support. In modern Korea there are more informal and formal social networks, like social services and community activities on the formal level and cultural and leisure groups along with “kae’s on the informal level. But even with this modern variety of groups, most social support comes from informal networks that resemble the traditiorlal “Pumashi”, “Kai” md “Mallaniki”. The six member research team interviewed 65 people in order to identify whether there is a concept of social support and then analysed their responses. There were 20 different words describing the reception of the social support and these could be grouped into seven major categories : virtuous, fortunate, helped, supported, blessed, attached(receiving affection) and receiving (grace) benevolence. there were 27 words describing the act of social support which could be categorized into seven major categories : love, looking after, affection(attachment), kindness(goodness), faith, psychological help and material help. for the meaning of social support translated as “sawhe juk jiji” there were a total of 14 different answers which could be categorized into 3 major categories : help, agreement, and faith. In third step, the results of the literature review and the answers to the questions were discussed in a pannel. The results of the discussion led to the following definition of social support in Korea which is shaped like a the four sided pyramid on a base. Social support is the apex of the pyramid and four sides are made up of : “do-oom” (both emotional and material help), “jung” (connectedness, or relationship bound by affection, regard or shared common experience ), “midum” (faith or belief in), “eunhae” (kindness or benevolence). The research team identified “Yun”( the basic network of relationships) as the base of the pyramid and as such the foundation for the components of social support in Korean culture. On “Yun” rest the other four components of social support : “Jung”, “Midum”, “Do-oom”, and “Eunhae”, For social support to take place there must be “Yun”. This is an important factor in social support. In private social network “Jung” is an essential factor in social support. But not in the public social network. “Yun” is a condition for “Jung” and “Jung” is the manifestation of support.

• The korean journal of orthodontics
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• v.34 no.5 s.106
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• pp.371-379
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• 2004

The purpose of this study was to investigate the changes and types of statistical methods used in the Korean Journal of Orthodontics (KJO) and the American Journal of Orthodontics and Dentofacial Orthopedics (AJODO) from )999 to 2003. The frequency of use, transitions, assumption check of statistical methods and types of advanced statistical methods were examined from each journal. The study consisted of 247 articles published in the KJO and randomly chosen 50 articles per year which were original articles and used statistical methods T-test, analysis of variance(ANOVA), correlation analysis, nonparametric analysis. regression analysis chi-square test. factor analysis, were the order of statistical methods most frequently used in the KJO, while t-test. ANOVA, nonparametric analysis, correlation analysis, regression analysis, chi-square test. factor analysis. were the order of statistical methods used in the AJODO The changes of statistical methods observed in the KJO were not significant $(X^2=17.4\;p=0.5881)$ but the changes observed in the AJODO was seen to be significant $(x^2=42.4,\;p=0.0397)$ Some of the studies examined had overlooked the assumptions of the statistical methods employed. Data investigation such as outlier should be performed before analysis and alternative statistical approaches are applied for a small sample size. Types of advanced statistical methods were factor analysis and discriminant analysis in the KJO and Intention-To-Treat (ITT) analysis in clinical trials through multi-center, survival analysis and Generalized Estimating Equations (GEE) in the AJODO. Appropriate analysis approaches and interpretations should be applied for the correlated and repeated measurements of the orthodontic data set.

• The korean journal of orthodontics
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• v.27 no.1
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• pp.1-20
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• 1997

Skeletal Class III malocclusions are growth-related discrepancies, and the problems are more severe until growth is complete. Causes of skeletal Class III malocclusion are classified into mandibular overgrowth, maxillary deficiency, and combination of the two. Face mask has been recommended for treatment of Class III malocclusion with maxillary deficiency in the early time of growth. Numerous experiments were performed and clinical studies have been reported on face mask ; nevertheless, studies on profile changes and stability after treatment of face mask are considered to be somewhat insufficient. The author selected 50 patients who can be checked for follow-up. They had been diagnosed as skeletal Class III malocclusion with maxillary deficiency and then treated with face mask ; the sample group was divided according to sex, treatment beginning age, palatal suture opening (intraoral appliance). For each group, changing pattern of facial profile and stability of treatment observed, and comparison with 20 Korean normal children(Angle's Class I). The following results were obtained. 1. skeletal, dental, and soft tissue measurements indicated more changes in the amounts of maxillary forward movement during face mask treatment. 2. R.P.E. group showed more significant maxillofacial changes and La-Li group showed more dental changes. 3. Growth changes of maxilla induced in the treatment group during wearing face mask were much more than those of normal group. 4. Growth changes of maxilla in the treatment group after treatment of face mask were less than those of normal group. From the obtained aata, it can be concluded that there was a stimulative effect on forward growth of maxilla during the use of face mask ; however, on removal of face mask, the stimulative effect was eliminated and undergrowth tendency of maxilla resumed.

• Tuberculosis and Respiratory Diseases
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• v.42 no.6
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• pp.838-845
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• 1995

The determination of ADA(adenosine deaminase) activity in pleural fluid is useful in differental diagnosis of pleural effusion. The conventional method of determining ADA activity used by Giusti was influenced by contamination of ammonia. Additionally, because Giusti's method was mannual method a determining the ADA activities in sample, was not easily automated. In 1993, Oosthuizen HM with collegues developed simple kinetic method for determining ADA activity. It was reliable and suiable method for automation. In this study, we have measured ADA activity in 162 patients with various pleural effusion by Hitachi 747 autoanalyser using the Oosthuizen kinetic method for the purpuse of determination of new diagnostic cut-off value for the tuberculous effusion and evaluation of the correlation between the conventional method and new automated method. This new method of an enzymatic reaction involves 2, 6-dichlorophenolindophenol dye(DICP), adenosine, xanthine oxidase(XO), and nucleoside phosphorylase(NP). The results were as follows: 1) The mean pleural ADA activity of the tuberculous effusion was $52.53{\pm}16.43\;U/L$ and significantly higher than that of other groups(p<0.001). If the diagnostic cut-off value of pleural ADA activity for tuberculous effusion is above 30 U/L, the sensitivity is 96% and the specificity is 90%. 2) The mean pleural to serum ADA activity ratio of the tuberculous effusion was $2.29{\pm}0.96$ and it was also significantly higher than that of other pleural groups(p<0.001). If the diagnostic cut-off value of pleural to serum ADA activity ratio is 1.5, the sensitivity is 80% and the specificity is 88% in the diagnosis of tuberculous pleural effusion. 3) The new kinetic method is correlates well to Giuisti's conventional method(r=0.971). In conclusion, the new kinetic method described is easily automated and seems to be suitable for the routine determination of ADA activity.

• Tuberculosis and Respiratory Diseases
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• v.52 no.1
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• pp.46-53
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• 2002

Background: Pulmonary aspergilloma is relatively common in korea. It arises from the colonization and proliferation of Aspergillus in preexisting lung parenchymal cavities, in particular tuberculosis. The most common symptom in this disorder is hemoptysis, which mayor may not be massive and life threatening. A routine chest radiography and computed tomography (CT) are the most important diagnostic procedures. A surgical resection of the aspergilloma has recently been recommended, because of the relatively low incidence of postoperative complications than in the past. A more concentrated sample of patients with aspergilloma, who either underwent a thoracotomy or tested positive for aspergillus antibodies, were reviewed. Method : The medical records of twenty-two patients with aspergilloma, who had a proven thoracotomy (9 cases), or who tested positive for the diagnostic procedure and/or aspergillus antibodies (13 cases) from January 1995 to December 2000, were reviewed retrospectively. Results : The most common underlying lung disease was a current or old healed tuberculosis, and 3 patients had cultures of mycobacterium other than tuberculosis (MOTT). The mean time until the aspergilloma was detected 5.91 years in the healed tuberculosis cases. The others cases involved a lung abscess, bronchiectasis and without lung disease. The extrapulmonary disease was alcoholism and diabetes. Hemoptysis was most common in 72.7%. A computed tomography (CT) is useful for diagnosis. The right upper lobe, especially the posterior segment, is the most common location. Bronchial artery embolization is ineffective for a long term follow-up. A lobectomy is most common in a thoracotomy, and intra-operative and post-operative complications are rare. During follow-up, the mortality rate, not from the aspergilloma but from respiratory failure, was 13.6%. Conclusion : Aspergilloma is a common cavitary lung disease, It mainly arises from tuberculosis, either current or healed, but extra-pulmonary disease including alcoholism or diabetes are other possible risk factors. Their most common problem in aspergilloma is hemoptysis. Surgery has a low risk of post-operative complications and is recommended in relatively preserved lung function or healthy patients. Medical maneuvers including embolization, and the local insertion of certain materials needs to be studied more closely.

• Journal of Periodontal and Implant Science
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• v.36 no.2
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• pp.555-565
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• 2006

The purpose of the present study is to evaluate the biological stability of the zirconia/alumina composite abutment by histologic and radiographic examination in clinical cases. 17 partially edentulous patients (5 men and 12 women, mean age 47) were treated with 37 implants. The implants were placed following the standard two-stage protocol. After a healing period of 3 to 6 months, zirconia/alumina composite abutments were connected. All radiographs were taken using paralleling technique with individually fabricated impression bite block, following insertion of the prosthesis and at the 3-, 6-, 12 month re-examinations. After processing the obtained images, the osseous level was calculated using the digital image in the mesial and distal aspect in each implant. An ANOVA and t-test were used to test for difference between the baseline and 3-, 6-, 12 months re-examinations, and for difference between maxilla and mandible. Differences at P <0.05 were considered statistically significant. For histologic examination, sample was obtained from the palatal gingiva which implant functioned for 12 months. Sections were examined under a light microscope under various magnifications. Clinically, no abutment fracture or crack as well as periimplantitis was observed during the period of study. The mean bone level reduction(${\pm}standard$ deviation) was 0.34 rom(${\pm}\;0.26$) at 3-months, 0.4 2mm(${\pm}\;0.30$) at 6-months, 0.62 mm(${\pm}\;0.28$) at 12-months respectively. No statistically significant difference was found between baseline and 3-, 6-, 12-months re-examinations (p > 0.05). The mean bone level reduction in maxilla was 0.33(${\pm}0.25$) at 3-months, 0.36(${\pm}0.33$) at 6-months, 0.56(${\pm}0.26$) at 12-months. And the mean bone level reduction in mandible was 0.35(${\pm}0.27$) at 3-months, 0,49(${\pm}0.27$) at 6-months, 0.68(${\pm}0.30$) at 12-months. No statistical difference in bone level reduction between implants placed in the maxilla and mandible. Histologically, the height of the junctional epithelium was about 2.09 mm. And the width was about 0.51 mm. Scattered fibroblasts and inflammatory cells, and dense collagen network with few vascular structures characterized the portion of connective tissue. The inflammatory cell infiltration was observed just beneath the apical end of junctional epithelium and the area of direct in contact with zirconia/alumina abutment. These results suggest the zirconia/alumina composite abutment can be used in variable intraoral condition, in posterior segment as well as anterior segment without adverse effects.

• The Journal of Korean Academy of Prosthodontics
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• v.48 no.1
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• pp.69-74
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• 2010

Purpose: The purpose of this study was to analyze the influence of palatal height on Korean vowels and speech intelligibility in Korean adults and to produce baseline data for future prosthodontic treatment. Material and methods: Forty one healthy Korean men and women who had no problem in pronunciation, hearing, and communication and had no history of airway disease participated in this study. Subjects were classified into H, M, and L groups after clinical determination of palatal height with study casts. Seven Korean vowels were used as sample vowels and subjects'clear speech sounds were recorded using Multispeech software program on computer. The F1 and the F2 of 3 groups were produced and they were compared. In addition, the vowel working spaces of 3 groups by /a/, /i/, and /u/ corner vowels were obtained and their areas were compared. Kruskal-Wallis test and Mann-Whiteny U test were used as statistical methods and P < .05 was considered statistically significant. Results: There were no significant differences in formant frequencies among 3 groups except for the F2 formant frequency between H and L group (P = .003). In the analysis of vowel working space areas of 3 groups, the vowel working spaces of 3 groups were similar in shape and no significant differences of their areas were found. Conclusion: The palatal height did not affect vowel frequencies in most of the vowels and speech intelligibility. The dynamics of tongue activity seems to compensate the morphological difference.

• Journal of Dental Rehabilitation and Applied Science
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• v.36 no.3
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• pp.183-195
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• 2020

Purpose: The purpose of this study is to compare the flexural strength of CAD/CAM denture base resins with conventional denture base resins based on their thicknesses. Materials and Methods: For the conventional denture base resins, Lucitone 199^® (C-LC) was used. DIOnavi - Denture (P-DO) and DENTCA Denture Base II (P-DC) were taken for the 3D printing denture base resins. For the prepolymerized PMMA resins, Vipi Block Gum (M-VP) and M-IVoBase^® CAD (M-IV) were used. The final dimensions of the specimens were 65.0 mm x 12.7 mm x 1.6 mm / 2.0 mm / 2.5 mm. The 3-point bend test was implemented to measure the flexural strength and flexural modulus. Microscopic evaluation of surface of fractured specimen was conducted by using a scanning electron microscope (SEM). After testing the normality of the data, one-way ANOVA was adopted to evaluate the differences among sample groups with a significance level of P = 0.05. The Tukey HSD test was performed for post hoc analysis. Results: Under the same thicknesses, there are significant differences in flexural strength between CAD/CAM denture base resins and conventional denture base resins except for P-DO and C-LC. M-VP showed higher flexural strength than conventional denture base resins, P-DC and M-IV displayed lower flexural strength than conventional denture base resins. Flexural modulus was highest in M-VP, followed by C-LC, P-DO, P-DC, M-IV, significant differences were found between all materials. In the comparison of flexural strength according to thickness, flexural strength of 2.5 mm was significantly higher than that of 1.6 mm in C-LC. Flexural strength of 2.5 mm and 2.0 mm was significantly higher than that of 1.6 mm in P-DC and M-VP. In M-IV, as the thickness increases, significant increase in flexural strength appeared. SEM analysis illustrates different fracture surfaces of the specimens. Conclusion: The flexural strength of different CAD/CAM denture base resins used in this study varied according to the composition and properties of each material. The flexural strength of CAD/CAM denture base resins was higher than the standard suggested by ISO 20795-1:2013 at a thickness of 1.6 mm or more though the thickness decreased. However, for clinical use of dentures with lower thickness, further researches should be done regarding other properties at lower thickness of denture base resins.