Correlation between Dental calcification stages and Skeletal Maturity in Korean Children

이 연구의 목적은 한국 아동의 골 성숙 단계와 여러 치아들의 석회화 단계 간의 상관관계를 알아보고, 치아 성숙도의 평가를 통해 골 성숙 단계를 예측할 수 있는지를 알아보고자 하는 것이다. 만 6 - 14세의 남아 359명, 여아 384명의 수완부 방사선사진, 측방두부규격 방사선사진, 파노라마 방사선사진을 분석하여 평가하였다. 하악 좌측의 7개 영구치의 치아 석회화 단계는 Demirjian이 제시한 방법에 의해 평가되었다. 골 성숙도 단계를 평가하기 위하여 수완부 방사선사진은 Fishman이 제시한 skeletal maturity indicators (SMI)에 따라 평가되었고, 측방두부규격 방사선사진은 Baccetti가 제시한 cervical vertebral maturation (CVM) 방법에 따라 평가되었다. Spearman의 순위상관분석을 시행한 결과 치아 석회화 단계와 골 성숙도 간에 유의미하게 높은 상관관계가 나타났다(r = 0.40-0.84, p < 0.001). 7개의 영구치 중에서 하악 제2대구치가 골 성숙도와 가장 높은 상관관계를 보인 반면 중절치가 가장 낮은 상관관계를 나타내었다. 남녀 모두에서 하악 견치의 stage G와 하악 제2대구치의 stage F가 SMI 6단계와 CS 3단계에서 나타날 확률이 가장 높았다. 이 연구의 결과에 따르면 치아 성숙도와 골 성숙도 사이에 높은 상관관계가 있으므로, 파노라마 방사선사진에서의 치아 성숙도 평가는 성장기 아동의 골 성숙도를 평가하는 보조적 수단으로 활용될 수 있다. The aim of this study was to investigate the relationships between the stages of calcification of various teeth and skeletal maturity stages among Korean subjects. The samples were derived from hand-wrist, panoramicradiographs, and lateral cephalograms of 743 subjects (359 males and 384 females) with ages ranging from 6 to 14 years. Calcification of seven permanent mandibular teeth on the left side were rated according to the system of Demirjian. To evaluate the stage of skeletal maturation, handwrist radiographs were analyzed by skeletal maturity indicators (SMI) system of Fishman and lateral cephalograms by cervical vertebral maturation (CVM) method of Baccetti. Statistically significant relationships were found between dental calcification and skeletal maturity stages according to Spearman rank-order correlation coefficients (r = 0.40-0.84, p < 0.001). The second molar showed the highest correlation and central incisor showed the lowest correlation for female and male subjects. For both sexes, canine stage G and second molar stage F were related to SMI 6 and CS 3. Because of the high correlation coefficients, this study suggests that tooth calcification stages from panoramic radiographs might be clinically useful as a maturity indicator of the pubertal growth period in Korean patients.open석

Help not Wanted: Effect of Pure Altruism Beliefs on Reactions to Being Helped

학위논문(석사)--서울대학교 대학원 :사회과학대학 심리학과,2019. 8. 최인철.The present research investigated the effects of pure altruism beliefs, beliefs regarding how purely selfless an action must be in order to be called altruistic, on reactions to being helped. Although the possibility of purely altruistic behaviors has been studied extensively by philosophers and psychologists alike, relatively less attention has been paid to lay theories about what altruism really means. Three studies examined the relationship between lay peoples pure altruism beliefs and their reactions to being helped. The results revealed that participants with high pure altruism beliefs were less likely to show positive reactions to being helped and that the effect of pure altruism beliefs was most pronounced when the helper was described as an altruistic person.Introduction ............................................................................... 1 Study 1 .................................................................................... 14 Study 2 .................................................................................... 25 Study 3 .................................................................................... 31 General Discussion ................................................................. 42 References .............................................................................. 48 Appendices ............................................................................. 56Maste

A Basic Study on Operation Effectiveness of Vessel Traffic Services(VTS)

The number of vessels has increased in the world. And vessels have become bigger and speed up. Because of this, marine traffic volume is increasing especially in the vicinity of ports. Increasing amount of traffic causes marine accidents which could cause a large amount of damages to the marine environment, loss of lives and social losses. VTS(Vessel Traffic Service) is used in most of the ports and coastal waters to prevent marine accident and increase efficiency of port operation. VTS plays a positive role in preventing the marine accidents and assisting port operation. This study focused on comparative of marine accident rate before and after establishment of the VTS. The statistics indicate that marine accidents in vicinity of ports are on the decrease after the establishment of VTS. The volume of marine traffic density in the coast of Korea was researched to draw a conclusion of high risk areas. Eligibility and necessity analysis was carried out to establish the VTS in the high risk area. Firstly, marine accident rate draw a comparison between before and after establishment of VTS. Following the establishment of VTS in the vicinity of ports, marine accidents have decreased by 39.9%. This comparison indicates that VTS contributes greatly to prevent marine accidents. Secondly, in the last 5 years, marine accidents rate in the vicinity of Korea was analyzed. Marine accidents are occurring in all areas. Coastal waters of Korea shall be divided to Eastern, Southern, Western. Marine accidents occurred 900 cases in each Western and Southern, 310 cases in Eastern coastal water. Thirdly, coastal waters of Korea shall be divided into ten(10) parts based on VTS control areas to research volume of marine traffic density. The volume of marine traffic was researched one week during 08:00~08:20 to find out for traffic volume distribution. This result was compared with marine accident rate to determine establishment of VTS. As a result of research, VTS to be operated preferentially in Gyeong-In area to reduce marine accidents rate. Lastly, the result of the precedent study on accident prevention index of VTS was compared with actual data of Jin-Do VTS. The precedent result of accident prevention index was 45.7%, actual data of Jin-Do VTS was 62.7%. Marine accident rate was reduced from average 67 cases per year to average 25 cases after establishment of VTS at Jin-Do area. According to above result, VTS plays a positive role in preventing the marine accidents with similar results.표 목 차 iii 그림 목차 iv Abstract v 제 1 장 서 론 1 1.1 연구의 배경 및 목적 1 1.2 연구의 방법 및 범위 2 제 2 장 VTS의 현황 조사 분석 3 2.1 VTS의 현황 및 기능 조사 3 2.1.1 VTS의 현황 3 2.1.2 VTS의 기능 5 2.1.3 우리나라의 VTS 현황 8 2.2 VTS의 장비현황 조사 9 2.2.1 VTS의 구성요소 9 2.2.2 VTS 주요 장비 10 2.3 VTS로 예방가능한 해양사고 종류 조사 12 2.3.1 해양사고의 정의 12 2.3.2 해양사고의 종류 13 2.3.3 선박피해의 종류 14 2.3.4 VTS로 예방가능한 해양사고의 종류 14 제 3 장 VTS 설치 후 해양사고 저감율 분석 15 3.1 VTS 설치년도 및 설치 전・후 해양사고 저감율 15 3.1.1 VTS 설치년도 조사 15 3.1.2 VTS 설치 전・후 20년간 해양사고 발생현황 16 3.1.3 항만 VTS 설치 전・후 해양사고 저감율 18 3.2 항만 VTS 설치 이후 해양사고 발생현황 및 분석 20 3.2.1 우리나라 항만의 교통량 증가 조사 분석 20 3.2.2 최근 5년간 해양사고 조사 22 3.2.3 구역별 통항선박 밀집도 및 해양사고 조사 24 3.2.4 구역별 통항선박 밀집도 및 해양사고 비교분석 33 3.4 VTS 설치 효과 필요성 제시 35 3.4.1 해양사고 피해액 대비 설치효과 사례연구 35 3.4.2 기타 연구와의 VTS 설치 효과 비교 분석 37 제 4 장 결 론 38 참 고 문 헌 4

High-Dose Chemotherapy and Autologous Stem Cell Rescue Therapy for High-Risk Neuroblastoma Patients

학위논문 (석사)-- 서울대학교 대학원 : 의학과, 2014. 2. 신희영.Background: Neuroblastoma (NBL) accounts for 8% to 10% of all childhood cancers, and more than half of these cases are advanced stages. Vigorous research on single, tandem or triple high-dose chemotherapy (HDCT) and autologous stem cell rescue therapy have improved the survival of many high-risk NBL patients, however, patients remain to have a dismal prognosis. In 2002, the Korean National Health Insurance policy extended coverage to include children over 1 year of age diagnosed with stage IV that showed partial response to surgery or chemotherapy and stage III in which complete resection was infeasible. As the burden of medical expenses was lifted, high-risk NBL patients were able to receive tandem HDCT more readily. The objective of this study was to conduct a historical analysis of patient outcome after the implementation of the Korean health care reform. Methods: During the period between October 1997 and December 2010, a retrospective analysis was performed of 60 patients with stage III or IV NBL who received single or tandem HDCT with stem cell rescue therapy at Seoul National University Childrens Hospital (SNUCH). The overall survival (OS) and event-free survival (EFS) were analyzed. Results: Sixty patients diagnosed with NBL received single or tandem HDCT and autologous stem cell rescue therapy. Five-year OS of the single and tandem group were 82.9% (95% CI, 69.4%-96.4%) and 85.6% (95% CI, 72.5%-98.7%), respectively (P=0.590). Five-year EFS of the single and tandem group were 52.9% (95% CI, 30.9%-67.4%) and 71.4% (95% CI, 43.3%-81.0%) (P=0.234). An event was more likely attributed to relapse, rather than treatment related mortality (TRM). Conclusion: With the change of the Korean National Health Insurance policy, an improvement of outcome in NBL patients receiving autologous stem cell rescue was observed. However, relapse remains to be an issue. As subclinical disease activity is correlated with disease relapse, monitoring disease activity before relapse is crucial and identifying molecular targets for future therapies are warranted.Abstract i Contents iii List of Tables and Figures iv List of Abbreviations v Introduction 1 Patients and Methods 3 Results 12 Discussion 23 References 30 Abstract in Korean 36Maste

Morphologic evaluation of the incisive canal and its proximity to the maxillary central incisors using computed tomography images.

OBJECTIVE: To evaluate the morphologic features and the relative position of the incisive canal with regard to the maxillary incisor roots using computed tomography (CT). MATERIALS AND METHODS: Morphologic evaluation of the incisive canal and its proximity to the maxillary central incisors were measured using CT images of 38 adults with skeletal and dental class I normal occlusion. Linear measurements were performed on the axial cross-sectional images corresponding to three vertical levels, the palatal opening of the incisive canal (L1), midlevel between the opening level and the root apex of the maxillary central incisors (L2), and the root apex of the maxillary central incisors (L3). RESULTS: The percentage of subjects with an incisive canal width greater than the interroot distance of the central incisors was 86.8% and 63.2% at levels L1 and L2, respectively. The anteroposterior distance between the maxillary incisor roots and the boarder of the incisive canal was approximately 5-6 mm at levels L1 and L2. CONCLUSION: The anteroposterior distance between the maxillary central incisor roots and the incisive canal was approximately 5-6 mm. More than 60% of the subjects had an incisive canal width greater than the interroot distance. Evaluation of the proximity of the incisive canal to the maxillary incisors, along with its dimensional characteristics, may be helpful when a considerable amount of maxillary retraction is planned.ope

Distalization pattern of whole maxillary dentition according to force application points

OBJECTIVE: The purpose of this study was to observe stress distribution and displacement patterns of the entire maxillary arch with regard to distalizing force vectors applied from interdental miniscrews. METHODS: A standard three-dimensional finite element model was constructed to simulate the maxillary teeth, periodontal ligament, and alveolar process. The displacement of each tooth was calculated on x, y, and z axes, and the von Mises stress distribution was visualized using color-coded scales. RESULTS: A single distalizing force at the archwire level induced lingual inclination of the anterior segment, and slight intrusive distal tipping of the posterior segment. In contrast, force at the high level of the retraction hook resulted in lingual root movement of the anterior segment, and extrusive distal translation of the posterior segment. As the force application point was located posteriorly along the archwire, the likelihood of extrusive lingual inclination of the anterior segment increased, and the vertical component of the force led to intrusion and buccal tipping of the posterior segment. Rotation of the occlusal plane was dependent on the relationship between the line of force and the possible center of resistance of the entire arch. CONCLUSIONS: Displacement of the entire arch may be dictated by a direct relationship between the center of resistance of the whole arch and the line of action generated between the miniscrews and force application points at the archwire, which makes the total arch movement highly predictable.ope

Repeated injections of botulinum toxin into the masseter muscle induce bony changes in human adults: A longitudinal study

Objective: To evaluate soft- and hard-tissue changes in the mandibular angle area after the administration of botulinum toxin type A (BoNT-A) injection to patients with masseteric hypertrophy by using three-dimensional cone-beam computed tomography (3D-CBCT). Methods: Twenty volunteers were randomly divided into two groups of 10 patients. Patients in group I received a single BoNT-A injection in both masseter muscles, while those in group II received two BoNT-A injections in each masseter muscle, with the second injection being administered 4 months after the first one. In both groups, 3D-CBCT was performed before the first injection and 6 months after the first injection. Results: Masseter muscle thicknesses and cross-sectional areas were significantly reduced in both groups, but the reductions were significantly more substantial in group II than in group I. The intergonial width of the mandibular angle area did not change significantly in either group. However, the bone volume of the mandibular gonial angle area was more significantly reduced in group II than in group I. Conclusions: The repeated administration of BoNT-A injections may induce bone volume changes in the mandibular angle area.ope

Neural regulation of energy and bone homeostasis by the synaptic adhesion molecule Calsyntenin-3

Neuronal regulation of energy and bone metabolism is important for body homeostasis. Many studies have emphasized the importance of synaptic adhesion molecules in the formation of synapses, but their roles in physiology still await further characterization. Here, we found that the synaptic adhesion molecule Calsyntenin-3 (CLSTN3) regulates energy and bone homeostasis. Clstn3 global knockout mice show reduced body mass with improved leptin sensitivity and increased energy expenditure compared to their wild-type littermates. In addition, Clstn3 knockout mice show reduced marrow volume and cortical bone mass without alteration of trabecular bone microarchitecture. This reduced bone mass is not bone cell-autonomous because neither osteoblast- nor osteoclast-specific Clstn3 knockout mice show bone defects; similarly, in vitro cultures of both Clstn3 knockout osteoblasts and osteoclasts do not show any defects. These reduced body and bone mass phenotypes can be attributed instead to neuronal CLSTN3 because they are recapitulated by pan-neuronal but not sympathetic neuron-specific deletion of Clstn3. This study reveals novel physiological functions of neuronal Clstn3 as a key regulator of energy and bone homeostasis.ope

Volumetric Difference Analysis in Accordance with Time Elapsing of the Latissimus Dorsi Flap

학위논문 (석사)-- 서울대학교 치의학대학원 : 치의학과, 2015. 2. 이종호.배경: 편평세포암과 같은 악성 종양으로 진단된 구강암환자의 경우, 종양에 이환된 부위를 제거하고, 환부 위치와 크기에 따라 다양한 방법의 피판을 이용한 재건술이 활용된다. 큰 조직 결손부의 경우에는 광배근을 사용한 피판이 많이 사용되는데, 광배근피판은 시간경과에 따라 신경의 부재에 따른 근위축이나 섬유화로 피판 수축 현상이 나타나게 된다. 본 연구에서는 광배근피판으로 재건수술을 받은 구강암 환자에서 술 후 이식체의 부피 변화량을 3차원적인 방법으로 측정하고, 부피 변화량에 방사선치료 여부, 환자의 연령 혹은 성별에 따라서 차이성이 있는 지 알아보고자 하였다. 방법: 2008년부터 2012년까지 서울대학교 치과병원에서 광배근피판을 이용해 재건 수술을 받은 환자들을 대상으로 하였으며 (n=18), 환자의 술 후 24개월 동안 촬영된 컴퓨터단층영상이나 자기공명영상을 이용하여 가장 술 후 즉시 채득된 영상을 기준으로 다른 영상들에 대해서 컴퓨터 방사선 정합과정을 수행하였다. 정합된 사진들로부터 2차원 단층 영상들의 차이 영상을 구하고, 일련의 2차원 차이 영상들을 바탕으로 한 3차원 부피로의 보간을 통해서 원하는 광배근피판의 최종 부피 차를 구하였다. 방사선치료여부, 연령, 성별에 따른 부피 변화량의 차이를 구하기 위해 student t-test를 사용하여 통계적 분석을 하였다. 결과: 전체 환자군에서 광배근피판의 술 후 2년동안 부피 감소량은 평균 약 17.55 ± 8.98% 로 나타났으며, 시간이 지날수록 단위 시간당 부피의 감소량은 점차 줄어드는 양상을 보였다. 재건술 후 방사선치료를 받은 환자군 (n=14)의 평균 부피 감소량은 약 20.41 ± 9.06%, 술 후 방사선치료를 받지 않은 환자군 (n=4)에서는 10.12 ± 0.81%로 나타나, 두 군 사이에 통계적으로 유의한 차이가 있었다 (t=4.05, p=0.001). 연령에 따른 피판의 부피 감소량은 저연령군 (53, n=7)에서 15.02 ± 4.47%로 나타나 통계적 차이는 없었다 (t=1.211, p=0.244). 남성 (n=14)의 평균 부피 감소량은 17.00 ± 7.46%, 여성 (n=4)은 18.96 ± 13.12%로 두 군 사이에도 통계적 차이는 없었다 (t=-0.314, p=0.766). 결론: 광배근피판의 술 후 2년간 부피 감소량의 평균은 18% 정도였으며, 재건술 후 방사선치료 여부에 따라서 부피 감소는 유의하게 차이가 있었고, 방사선치료를 받은 환자군이 비방사선치료 군에 비하여 약 2배의 부피 감소를 나타냈다. 반면, 부피변화에 있어 성별과 연령은 영향을 미치지 않는 것으로 파악되었다.목차 I 서론 ...................................................................................... 1 I.1 연구 배경 및 목적 ................................................................... 1 II 환자 및 방법 ......................................................................... 2 II.1 환자군 선정 ............................................................................. 2 II.2 측정 방법 ................................................................................ 3 II.2.1 영상으로부터 3차원적 부피의 차를 구하기 ...................... 3 II.2.1 영상 채득 ....................................................................... 3 II.2.2 변환 및 정합 .................................................................. 4 II.2.3 삼차원 부피로의 복원 및 부피 차이 구하기 ..................... 6 II.2.4 전체 과정 정리 ............................................................... 7 III 대표증례 및 결과 ................................................................... 8 III.1 대표증례 ................................................................................. 8 III.2 결과 ....................................................................................... 14 IV 토의 .................................................................................... 18 V 결론 .................................................................................... 20 참고문헌 .................................................................................... 21Maste