• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.4
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• pp.607-617
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• 2002

The purposes of this study were to evaluate the timing of tooth calcification and the change of tooth position with tooth developmental stage on the mandibular teeth. Seven hundred seventy two children(male:446, female:326), 3 to 12 years of age were examined radiographically with panoramic film. Dental development was determined by inspecting radiographs and assigning a rating according to consecutive stages defined by Moorrees, and tooth cusp position and root terminus position were measured from the lower border of mandibular body and calculated the position index to evaluate the movement of tooth with developmental stage. The results were as follows. 1. There were no significant differences between boys and girls in the timing of calcification until crown completion, but timing of calcification tend to be faster in girls than in boys after root initiation stage. 2. In terms of mean age, crown completion of central incisor in boys and girls occurred at the age of 3.71, 4.05 years, at 4.44, 4.60 years for the lateral incisor, at 5.35, 5.11 years for the canine, at 6.62, 6.36 years for the first premolar, at 7.36, 7.17 years of second premolar, at 3.51, 3.69 years of first molar, and at 7.90, 7.64 years for the second molar respectively. Apex 1/2 closed stage of central incisor occurred at the age of 8.70 in boys, 8.18 in girls, at 9.55, 8.99 years for the lateral incisor, at 12.48, 11.60 years for the canine, at 12.30, 12.01 years for the first premolar, at 12.19, 12.26 years of second premolar, at 9.12, 8.87 years of first molar, and at 12.59, 12.45 years for the second molar respectively. 3. There was no noticeable movement of cusp tip until crown completion (Crc), but showed rapid movement toward occlusion plane after root initiation(Ri) and again maintain stable position after root completion stage(Rc). 4. Root terminus position was stable until root 1/4 formation stage(R1/4), followed by rapid movement toward occlusal plane and was stable again after root 3/4 formation stage(R3/4). 5. Developmental stage at the time of alveolar bone penetration by cusp tip varied with each of the permanent teeth. 6. Canine tooth follicle was at the lowest position in the mandibular body during the early stage of calcification, followed by second premolar, first premolar, lateral incisor, second molar, first molar and central incisor in order.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.2
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• pp.205-215
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• 2008

The purpose of this study is to evaluate at which stage of tooth germ would develop into normal calcification and hence to increase the success rate of transplantation. Therefore, tooth germs on the 15th, 17th embryonic day and the 3rd day of birth were separated for allotransplantation into maxilla of adult rat of 11 weeks. Calcification processes were analyzed radiographically and histopathologically at 4 weeks and 8 weeks after allotransplantation. The results are as follows: 1. Allotransplanted tooth germ at 4 weeks and 8 weeks showed delayed calcification compared to that of normal odontogenesis. 2. At 4 weeks, abnormal calcified tissue, such as odontoma and ankylosis of osteodentin with surrounding alveolar bone were observed. 3. At 8 weeks, allotransplanted tooth germs of the 15th and 17th embryonic day showed calcification and osteodentin surrounded by periodontal ligament. 4. At 8 weeks, allotransplanted tooth germs of the 3rd day of birth showed calcification composed of cementum and osteodentin. In this study, we observed small sized and amorphous calcified tissue from allotropic allotransplantation of tooth germs. Since these calcified tissue were underdeveloped and shaped irregularly, for calcification into normal tooth form, further study needs consideration about the reduction of surgical trauma, developmental stage of transplanted tooth germ, blood supply from recipient site, fixation method in transplanted site and period of transplantation.

• Clinical and Experimental Pediatrics
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• v.46 no.1
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• pp.42-50
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• 2003

Purpose : The acute respiratory distress syndrome(ARDS), an acute form of severe alveolar-capillary injury evolving after a direct or indirect lung insult is thought to be a common cause of respiratory failure though not many clinical studies on the subject have been made yet. Methods : Between January 1992 and December 2001, we conducted a retrospective study on 33 children who fulfilled the definition of the ARDS recommended by the American-European Consensus Conference in 1994. Results : A total of 33 patients(20 boys and 13 girls) were selected. Their age ranged from 4 months to 12 years with seven children younger than 1 year. The overall mortality rate was 78.8% and no significant difference was noted based on age or sex. Concerning seasonal variation, incidence of the ARDS increased in spring, especially in May(21.2%). Pneumonia(66.7%) was found to be the most common risk factor of the ARDS followed by sepsis(24.2%) and aspiration(3.0%). In immune compromised children(six cases), including a recipient of bone marrow transplantation, the mortality rate was 100%. Compared with children with multiple organ failure recording a 83.3% mortality rate, those with isolated respiratory failure, showed a lower mortality rate of 33.3%, although stastistically insignificant. Between survivor and non-survivor groups, significant differences were shown in hematocrit, $PaO_2$, $PaCO_2$, PEEP, and $PaO_2/FiO_2$ on the seventh day after the onset of the ARDS. Conclusion : According to our study, respiratory failure proved to have a great effect on mortality rate in the ARDS. More aggressive intervention and further studies on this subject should be done to improve the survival rate.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.2
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• pp.206-214
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• 2009

Statement of problem: There are common clinical cases in which the mandibular first and second molars are missing unilaterally. Purpose: This study was designed to compare and evaluate the magnitude and distribution of stress produced by four kinds of mandibular unilateral free-end removable partial dentures that could be applied clinically in Kennedy class II cases. Material and methods: Four unilateral free-end removable partial dentures using clasp, Konus crown, resilient attachment, and flexible resin were fabricated on the photoelastic models of the Kennedy class II cases. The vertical load of 6㎏ was applied on the central fossa of the first molar of every removable partial denture in the stress freezing furnace and the photoelastic models were frozen according to the stress freezing cycle. After these models were sliced mesio-distally to a thickness of 6mm, the photoelastic isochromatic white and black lines of the sliced specimens were examined with the transparent photoelastic experiment device and photographs were taken with a digital camera. The fringe order numbers at eight measuring points in the photograph were measured with the naked eye. Results: The maximum fringe order number of each sliced specimen and the fringe order number at the residual ridge just below the loading point were in the decreasing order of the unilateral removable partial dentures using flexible resin followed by clasp, resilient attachment, and Konus crown. The fringe order number at the root apex of the second premolar was in the decreasing order of the unilateral removable partial dentures using clasp followed by flexible resin, Konus crown, and resilient attachment. Conclusion: The removable partial denture using Konus crown showed the most equalized stress distribution to the supporting alveolar bone of abutment teeth and residual ridge under the vertical loads. The removable partial denture using flexible resin can be applied to the case that has a better state of residual ridge than abutment teeth.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.1
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• pp.117-123
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• 2010

Tooth eruption is the movement of the tooth from the developing place in the alveolar bone to the functional position in the oral cavity. The permanent incisors originate from the dental lamina on the lingual side of preceding deciduous tooth and erupt to the level of the occlusion through the well developed gubernacular cord. Ectopic eruption is a developmental disturbance in the eruption pattern of the permanent dentition. Most of the ectopically erupted lower incisor has been found in lingual side. The ectopically erupted tooth could be repositioned by orthodontic force in the early mixed dentition, which could help preventing the problems of loss of space and the lingual tilting of the lower anterior teeth. An eight-year-old girl visited the department of pediatric dentistry, Yonsei Dental University Hospital, for the evaluation and the treatment of the lower right lateral incisor, which was horizontally erupted in the lingual side, parallel to the mouth floor. Her tongue was placed on the labial side of that tooth. There was no previous dental history of dental caries or trauma on the pre-occupied primary incisor. Clinical and radiographic examinations including the computed tomography(CT), showed no evidence of dilacerations on root. Therefore, we decided to start active orthodontic traction of the lower right lateral incisor. We designed the fixed type of buccal arch wire and the lip bumper with hook for the traction. Button was attached to the lingual side of the ectopically positioned tooth. Elastic was used between the appliance and the button on that tooth. After the tooth become upright over the tongue level, appliance was change to the removable type and periodic check-up with occlusal guidance was followed to monitor the position of the tooth. In this case using the fixed appliance with modified form of lip bumper and hook embedded in acrylic part instead of extraction was very efficient up-righting the ectopically erupted tooth toward the occlusal plane.

• Restorative Dentistry and Endodontics
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• v.36 no.1
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• pp.26-36
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• 2011

Objectives: In the present study, three kinds of tissues cells (pulp, gingiva, and periodontal ligament) were investigated if those cells express MMP and TIMP when they were stimulated with neuropeptides (substance P, CGRP) or proinflammatory cytokine, TNF-$\alpha$. Materials and Methods: The cells cultured from human dental pulp (PF), gingiva (GF) and periodontal ligament were (PDLF) stimulated with Mock, SP, TNF-$\alpha$, and CGRP for 24 hrs and 48 hrs. for an RNase protection assay and Enzyme Linked Immunosorbent Assay. Cells (PF, GF and PDLF) seeded in 100 mm culture dish were stimulated with SP ($10^{-5}$, $10^{-8}\;M$) or only with medium (Mock stimulation) for 4hrs and for 24 hrs for RNase Protection Assay, and they were stimulated with CGRP ($10^{-5}\;M$) and TNF-$\alpha$(2 ng/mL) for 24 hrs and with various concentraion of TNF-$\alpha$(2, 10, and 100 ng/mL) for Rnase Protection Assay with a human MMP-1 probe set including MMP 1, 2, 8, 7, 8, 9, 12, and TIMP 2, 3. In addition, cells (PF, GF and PDLF) were stimulated with Mock and various concentraion of TNF-$\alpha$(2, 10, and 100 ng/mL) for 24 hrs and with TNF-$\alpha$(10 ng/mL) for 48 hrs, and the supernatents from the cells were collected for Enzyme Linked Immunosorbent Assay (ELISA) for MMP-1 and MMP-13. Results: The expression of MMPs in PF, GF, PDLF after stimulation with SP and CGRP were not changed compared with Mock stimulation for 4 hrs and 24 hrs. The expression of MMP-1, -12, -13 24 hrs after stimulation with TNF-$\alpha$ were upregulated, however the expression of TIMP-3 in PF, GF, PDLF after stimulation with TNF-$\alpha$ were downregulated. TNF-$\alpha$(2 ng/mL, 10 ng/mL, 100 ng/mL) increased MMP-1 and MMP-12 expression in PF dose dependently for 24 hrs. Conclusions: TNF-$\alpha$ in the area of inflammation may play an important role in regulating the remodeling of dentin, cementum, and alveolar bone.

• Journal of Chest Surgery
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• v.39 no.2 s.259
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• pp.106-110
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• 2006

Background: Bronchioloalveolar carcinoma (BAC) is an uncommon primary malignancy of the lung, and it accounts for $2{\~}14\%$ of all pulmonary malignancies. According to World Health Organization (WHO) categorisation, BAC is a subtype of adenocarcinoma. The current definition of BAC includes the following: malignant neoplasms of the lung that have no evidence of extrathoracic primary adenocarcinoma, an absence of a central bronchogenic source, a peripheral parenchymal location, and neoplastic cells growing along the alveolar septa. Previous reports had demonstrated a better prognosis following surgery for patients affected by BAC than those affected by other type of non-small cell lung cancer (NSCLC). We aim to analyse Asan Medical Center experiences of BAC. Material and Method: Between 1990 and 2002, 31 patients were received operations for BAC. We analyse retrosepectively sex, age, disease location, preoperative clinical stage, postoperative pathologic stage & complications, survival according to medical record. Result: There were 12 men and 19 women, the average age was 61.09$\pm$10.63 ($31{\~}79$) years. Tumor locations were 7 in RUL, 1 in RML, 4 in RLL, 8 in LUL, 11 in LLL. Operations were 28 lobectomies, 2 pneumonectomies. Postoperative pathologic stage were 12 T1N0M0, 15 T2N0M0, 1 T1N1M0, 1 T1N2M0, 1 T2N2M0, 1 T1N0M1. Mortality were 4 cases ($12.9\%$) and there were no early mortality. Cancer free death was 1 cases, other 3 were cancer related deaths. All of them were affected by distal metastasis and received chemotherapy and each metastatic locations were right rib, brain, and both lung field. The average follow up periods were 50.87$\pm$24.77 months. The overall 3, 5-year survival rate among all patients was $97.1\%,\;83.7\%$, stage I patients overall 2, 5year survival rate was $96.3\%$. The overall disease free 1, 2, 5-year survival rate among all patients was $100\%,\;90\%,\;76\%$ and 2, 5-year survival rate in cases of stage I was $96.4\%,\;90.6\%$. 7 cases ($22.58\%$) were chemotherapies, 1 case ($3.22\%$) was radiation therapy, and 2 cases ($6.45\%$) were chemoradiation therapies. Metastatic locations were 3 cases in lung, 1 case in bone, 1 cases in brain. Conclusion: BAC has a favourable survival and low recurrence rate compare with reported other NSCLC after operative resections.