• 제목/요약/키워드: Detector placement

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The preliminary study for three-dimensional alveolar bone morphologic characteristics for alveolar bone restoration

  • Cho, Hyun-Jae;Jeon, Jae-Yun;Ahn, Sung-Jin;Lee, Sung-Won;Chung, Joo-Ryun;Park, Chang-Joo;Hwang, Kyung-Gyun
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제41권
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    • pp.33.1-33.7
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    • 2019
  • Background: The concept of the ideal morphology for the alveolar bone form is an important element to reconstruct or restore the in maximizing esthetic profile and functional alveolar bone restoration. The purpose of this preliminary study is to evaluate the normal alveolar bone structure to provide the standard reference and guide template for use in diagnosing for implant placement, determining the correct amount of bone augmentation in actual clinical practice and producing prostheses based on three-dimensional imaging assessment of alveolar bone. Methods: This study was included 11 men and 11 women (average age, 22.6 and 24.5 years, respectively) selected from among 127 patients. The horizontal widths of alveolar bone of maxilla and mandible were measured at the crestal, mid-root, and root apex level on MDCT (multi-detector computed tomography) images reconstructed by medical imaging software. In addition, tooth dimensions of the central incisors, canines, second premolars, and first molars of maxilla and mandible, including the horizontal width of the interdental alveolar bone crest, were also measured and statistically analyzed. Results: The horizontal alveolar bone width of the palatal side of maxilla showed a distinct increment from the alveolar bone crest to the apical region in both anterior and posterior areas. The average widths of the maxillary alveolar ridge were as follows: central incisor, 7.43 mm; canine, 8.91 mm; second premolar, 9.57 mm; and first molar, 12.38 mm. The average widths of the mandibular alveolar ridge were as follows: central incisor, 6.21 mm; canine, 8.55 mm; second premolar, 8.45 mm; and first molar, 10.02 mm. In the buccal side, the alveolar bone width was not increased from the crest to the apical region. The horizontal alveolar bone width of an apical and mandibular border region was thinner than at the mid-root level. Conclusions: The results of the preliminary study are useful as a clinical guideline when determining dental implant diameter and position. And also, these measurements can also be useful during the production of prefabricated membranes and customized alveolar bone scaffolds.

Monte Carlo 시물레이션에 기초한 포획모드 중성자-감마 스펙트럼 존데 설계 및 반응 분석 (Neutron Induced Capture Gamma Spectroscopy Sonde Design and Response Analysis Based on Monte Carlo Simulation)

  • 원병호;황세호;신제현;김종만;김기석;박창제
    • 지구물리와물리탐사
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    • 제18권3호
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    • pp.154-161
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    • 2015
  • 본 연구에서는 중성자-감마 스펙트럼검층 존데 설계를 목적으로 Monte Carlo 시물레이션을 이용하여 열중성자 반응의 우세한 영역 파악 및 포획감마 스펙트럼의 에너지피크 값에 기초한 지층 구성 원소 구분을 수행하였다. 14 MeV 에너지준위의 중성자를 방출하는 중성자발생장치를 선원으로 이용하여 선원으로부터 10 cm 간격으로 12개의 중성자 검출기들을 배열함으로써 거리에 따른 열중성자 양을 측정하였다. 시추공 영향 저감을 위해 존데모형에 차폐재를 적용하여 보다 정확한 열중성자 측정을 수행하여 열중성자 반응이 우세한 위치를 분석한 뒤, 이 위치에서 검출된 포획감마 에너지 스펙트럼을 분석하여 지층을 구성하는 주요 원소 및 그 양을 확인하였다. 본 연구 결과는 중성자-감마 스펙트럼검층 존데의 신호대잡음 비 향상과 포획감마 검출기 최적 위치 선정에 도움이 될 것으로 판단된다.

자연치열에 설치한 pivot의 전후방 일치변화에 따른 하악의 moment에 관한 연구 (A STUDY ON THE MANDIBULAR MOMENTS ACCORDING TO ANTERO-POSTERIOR PLACEMENT OF PIVOT ON LOWER NATURAL DENTITION)

  • 이현식;박남수;최대균
    • 대한치과보철학회지
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    • 제31권3호
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    • pp.394-410
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    • 1993
  • This study was accomplished for appreciation of the mandibular moments according to antero- posterior movement of pivot placed on the lower natural dentition. For this study, 20 subjects(male, $21\sim30$ yrs., average age 24) in the category of normal occlusion were selected, and the intraoral Vitallium clutches were cast and fabricated for each subjects. A 2-dimension PSD(Position Sensitive Detector, Hamamatsu Photonics Co., Japan) was attached to maxillary clutch in a mode of three dimensional control and LED (Light Emit Diode, Hamamatsu Photonics Co., Japan) was set up on mandibular clutch. Both clutches were set into oral cavity of each subjects and adjusted. Then the subjects were allowed to intercuspated with maximal bite force while the pivoting ball in the mid-line moving from anterior toward posterior position. The displacement scales were recorded by CCD camera(Sony, CCD-TR-705) and VCR, The conclusions were as follows : 1. When the subject was allowed to bite the metal pivoting ball in the midline of lower dentition with maximal bite force voluntarily while moving from lower central incisor to canine, 1st premolar, End premolar, 1st molar and 2nd molar. The lever actions on the pivot were revealed in all subjects. The equilibrium of moment were revealed on the pivots of 1st premolar(14 subjects), End premolar(4 subjects), and canine(2 subjects) areas. 2. The changes of loading on the TMJ according to antero-posterior positional changes of metal pivoting ball were able to recognize as follow. Compression on the TMJ was increased when the pivot moves anteriorly from the equilibrium point, and tension on the TMJ was increased when posteriorly. 3. 13 subjects were recognized their habitual chewing sides(Rights, Left8), and 7 subjects were not. During maximal biting, mandible was displaced toward their habitual chewing sides on the metal pivoting ball in the frontal plane. 4. In cephalometric analysis, the average genial angle of 20 subjects was $116.75^{\circ}$ and the average mandibular body length was 79.77mm. The equilibrium points of mandibular moment were positioned more posteriorly in the subjects having larger Genial angle than in the smaller(p<0.05). Relationships among the angle between FH plane and occlusal plane, the angle between occlusal plane and mandibular plane , and mandibular body length were not significant(p>0.05).

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May-Thurner 증후군과 동반된 하지 심부정맥혈전환자에서 혈전제거술과 스텐트삽입술 (Pharmaco-mechanical Thrombectomy and Stent Placement in Patients with May-Thurner Syndrome and Lower Extremity Deep Venous Thrombosis)

  • 전용선;김영삼;조정수;윤용한;백완기;김광호;김정택
    • Journal of Chest Surgery
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    • 제42권6호
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    • pp.757-762
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    • 2009
  • 배경: May-Thurner 증후군은 좌측장골정맥이 우측장골동맥에 의해 눌리어 정맥 환류장해에 의해 혈전증을 일으키는 것을 말한다. 저자들은 심부 정맥혈전중의 치료를 위해 시행한 혈전 제거-용해술 및 스탠트 삽입술의 결과를 분석하고자 한다. 대상 및 방법: May-Thurner 증후군과 동반된 하지 심부정맥혈전증으로 진단받고 좌측 장골정맥에 스탠트를 삽입한 34명(평균연령 $64.6{\pm}13.7$세, 여자 25(74%)명)을 대상으로 하였다. 시술은 흡인성 혈전제거와 혈전용해 후 분지성 협착이 있는 곳에 Wall stent를 삽입하고 풍선 확장을 하였다. Multi side hole 카테타를 혈전이 있는 부위에 위치시키고 Urokinase를 시간당 8만에서 12만 International Unit을 1일 또는 2일 동안 주입하였다. 시술 중 폐동맥혈전색전증을 방지 하기 위하여 대부분 환자에서 시술 전 일시적 하대정맥 여과기(IVC Filter)를 삽입하였다. 퇴원 후 3개월간 경구용 와파린을 투여 하였으며 퇴원 전과 퇴원 후 6개월에 Multi Detector Computerized Tomography (MDCT) 혈관촬영을 이용하여 혈전의 유무를 판단하였다. 결과: 시술 48시간 이내 부종과 동통이 완전하게 소실된 환자가 2 (6%)명이었으며 증상의 완화가 있는 환자가 28 (82%)명, 증상의 호전이 없는 환자가 4 (12%)명이었다. 퇴원 시 MDCT혈관촬영에서 9 (26%)명에서 혈전없음, 21 (62%)명에서 부분 혈전, 그리고 4명(12%)에서 폐쇄소견을 보였다. 퇴원 6개월 후에 2명을 제외한 32명이 추적 MDCT혈관촬영을 하였는데 23 (72%)명에서 혈전없음을 9 (26%)명에서는 부분혈전이 관찰 되었다. 평균 5.6개월 관찰기간 동안 2 (6%)명에서 심부정맥혈전이 재발되어 재입원하였으며 하지 부종과 통증을 동반한 혈전 후 증후군은 9예(26%)에서 발생하였다. 결론: May-Thurner 증후군과 동반된 하지 심부정맥혈전환자에서 심부정맥혈전의 제거와 혈전용해술과 함께 시술된 스탠트 삽입은 효과적인 치료 방법으로 생각된다.