• 제목/요약/키워드: Computed-Assisted

검색결과 126건 처리시간 0.028초

In-vitro study on the accuracy of a simple-design CT-guided stent for dental implants

  • Huh, Young-June;Choi, Bo-Ram;Huh, Kyung-Hoe;Yi, Won-Jin;Heo, Min-Suk;Lee, Sam-Sun;Choi, Soon-Chul
    • Imaging Science in Dentistry
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    • 제42권3호
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    • pp.139-146
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    • 2012
  • Purpose: An individual surgical stent fabricated from computed tomography (CT) data, called a CT-guided stent, would be useful for accurate installation of implants. The purpose of the present study was to introduce a newly developed CT-guided stent with a simple design and evaluate the accuracy of the stent placement. Materials and Methods: A resin template was fabricated from a hog mandible and a specially designed plastic plate, with 4 metal balls inserted in it for radiographic recognition, was attached to the occlusal surface of the template. With the surgical stent applied, CT images were taken, and virtual implants were placed using software. The spatial positions of the virtually positioned implants were acquired and implant guiding holes were drilled into the surgical stent using a specially designed 5-axis drilling machine. The surgical stent was placed on the mandible and CT images were taken again. The discrepancy between the central axis of the drilled holes on the second CT images and the virtually installed implants on the first CT images was evaluated. Results: The deviation of the entry point and angulation of the central axis in the reference plane were $0.47{\pm}0.27$ mm, $0.57{\pm}0.23$ mm, and $0.64{\pm}0.16^{\circ}$, $0.57{\pm}0.15^{\circ}$, respectively. However, for the two different angulations in each group, the $20^{\circ}$ angulation showed a greater error in the deviation of the entry point than did the $10^{\circ}$ angulation. Conclusion: The CT-guided template proposed in this study was highly accurate. It could replace existing implant guide systems to reduce costs and effort.

Accuracy of a direct drill-guiding system with minimal tolerance of surgical instruments used for implant surgery: a prospective clinical study

  • Lee, Du-Hyeong;An, Seo-Young;Hong, Min-Ho;Jeon, Kyoung-Bae;Lee, Kyu-Bok
    • The Journal of Advanced Prosthodontics
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    • 제8권3호
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    • pp.207-213
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    • 2016
  • PURPOSE. A recently introduced direct drill-guiding implant surgery system features minimal tolerance of surgical instruments in the metal sleeve by using shank-modified drills and a sleeve-incorporated stereolithographic guide template. The purpose of this study was to evaluate the accuracy of this new guided surgery system in partially edentulous patients using geometric analyses. MATERIALS AND METHODS. For the study, 21 implants were placed in 11 consecutive patients using the direct drill-guiding implant surgery system. The stereolithographic surgical guide was fabricated using cone-beam computed tomography, digital scanning, computer-aided design and computer-assisted manufacturing, and additive manufacturing processes. After surgery, the positional and angular deviations between planned and placed implants were measured at the abutment level using implant-planning software. The Kruskal-Wallis test and Mann-Whitney U test were used to compare the deviations (${\alpha}=.05$). RESULTS. The mean horizontal deviations were 0.593 mm (SD 0.238) mesiodistally and 0.691 mm (SD 0.344) buccolingually. The mean vertical deviation was 0.925 mm (SD 0.376) occlusogingivally. The vertical deviation was significantly larger than the horizontal deviation (P=.018). The mean angular deviation was 2.024 degrees (SD 0.942) mesiodistally and 2.390 degrees (SD 1.142) buccolingually. CONCLUSION. The direct drill-guiding implant surgery system demonstrates high accuracy in placing implants. Use of the drill shank as the guiding component is an effective way for reducing tolerance.

Pulmonary Cryptococcosis That Mimicked Rheumatoid Nodule in Rheumatoid Arthritis Lesion

  • Jang, Dong Won;Jeong, Ina;Kim, Seon Jae;Kim, Seok Won;Park, Soo Yeon;Kwon, Yong Hwan;Jeong, Yeon Oh;Lee, Ji Yeon;Kim, Bo Sung;Kim, Woo-Shik;Joh, Joon-Sung
    • Tuberculosis and Respiratory Diseases
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    • 제77권6호
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    • pp.266-270
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    • 2014
  • Recently, the incidence of pulmonary cryptococcosis is gradually increasing in rheumatoid arthritis (RA) patients. Pulmonary rheumatoid nodules (PRN) are rare manifestations of RA. Eighteen months ago, a 65-year old woman was admitted to hospital due to multiple nodules ( $2.5{\times}2.1{\times}2cm$) with cavitations in the right lower lobe. She was diagnosed with RA three year ago. She had been taking methotrexate, leflunomide, and triamcinolone. A video-assisted thoracoscopic surgery biopsy was performed and PRN was diagnosed. However, a newly growing huge opacity with cavitation was detected in the same site. Pulmonary cryptococcal infection was diagnosed through a transthoracic computed tomograpy guided needle biopsy. Cryptococcus antigen was detected in serum but not in cerebrospinal fluid. The patient was treated with oral fluconazole which resulted clinical improvement and regression of the nodule on a series of radiography. Herein, we report the case of pulmonary cryptococcosis occurring in the same location as that of the PRN.

Clinical Characteristics and Management of Intrathoracic Bronchogenic Cysts: A Single Center Experience

  • Lee, Deok-Heon;Park, Chang-Kwon;Kum, Dong-Yoon;Kim, Jae-Bum;Hwang, Il-Seon
    • Journal of Chest Surgery
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    • 제44권4호
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    • pp.279-284
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    • 2011
  • Background: The aim of this study is to investigate the clinical characteristics and management of intrathoracic bronchogenic cysts. Materials and Methods: Twenty-four (n=24) patients with intrathoracic bronchogenic cysts were treated surgically between August 1990 and December 2009 at our institution. Patients were divided into two groups by bronchogenic cyst location: mediastinal or intrapulmonary. Symptoms at diagnosis, radiologic findings, locations, surgical methods, pathological findings, and surgical outcomes were investigated retrospectively from consecutive patient medical records. Results: There were 12 females (50.0%). The mean age was 26.8 (range, 5 to 64) years. The mean follow-up period was 27.3 (range, 1 to 121) months. There were 15 (62.5%) mediastinal and 9 (37.5%) intrapulmonary bronchogenic cysts. Symptoms occurred in 8 patients with mediastinal bronchogenic cysts (53.3%) and 5 patients with intrapulmonary bronchogenic cysts (55.6%) (p=1.000). On computed tomography (CT), 7 patients (46.7%) showed homogenous solid masses in mediastinal bronchogenic cysts and five (55.6%) patients exhibited heterogeneous cystic masses with air-fluid levels in intrapulmonary bronchogenic cystic masses. Open thoracotomy was performed in 17 (70.8%) patients, and video-assisted thoracic surgery was performed in 7 (29.2%) patients. On pathological findings, there were 16 (66.7%) complicated cysts, and in 13 symptomatic patients, 11 (84.6%) patients had complicated cysts. There was no operative death in this study. During the follow-up period, no recurrence was detected. Conclusion: Intrathoracic bronchogenic cysts have a wide variety of clinical characteristics and radiologic findings. Even though some patients do not experience symptoms and signs caused by bronchogenic cysts, serious symptoms and complications may develop with the passage of time.

지방흡입술을 이용한 양성 대칭성 지방종의 치험례 (Treatment of Beign Multiple Symmetrical Lipomatosis with Liposuction)

  • 허철;임소영;문구현;현원석;방사익;오갑성
    • Archives of Plastic Surgery
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    • 제33권6호
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    • pp.769-772
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    • 2006
  • Purpose: Benign symmetrical lipomatosis(Madelung's disease) is a disease of uncertain etiology that manifests as massive lipomatous deposits in specific area of the body. It is usually located on the neck, shoulder, proximal regions of the extremities and the abdomen. Madelung's disease is found many in middle-aged, Mediterranean man. Imaging using either computed tomography or magnetic resonance imaging is often recommended. Dietary restriction provides no relief of disease. Abstinence with alcohol may delay further progression but does not regression tumor mass. The objective of this study is to prove effectiveness of liposuction for treatment of benign lipomatosis. Methods: We conducted liposuction as a treatment for benign lipomatosis. After general anesthesia, We conducted power assisted liposuction and amount of suctioned volume was about 2500 cc. After surgery, we did compressive dressing and then followed by pressure garment. Results: Six months after surgery, patient was examined for follow up at outpatient department. Recurred lipoma was not observated. Patient was satisfied with result.Conclusion: The only effective therapy for Madelung's disease is surgical removal but recurrence could be occurring. Also multiple surgical scars will be visible. We report a patient with multiple large lipomatosis successfully treated with liposuction.

늑골의 양성 종양환자에서 흉강경을 이용한 늑골 절제술 (VATS Rib Resection in Benign Bone Tumor)

  • 박창률;김정원;이용직;주석;정종필;김대영
    • Journal of Chest Surgery
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    • 제43권4호
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    • pp.454-457
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    • 2010
  • 42세 남자 환자가 종합 검진상 발견된 좌측 6번 늑골의 후궁(posterior arc)의 종괴로 내원하였다. 흉부 컴퓨터 전산화 단층 촬영 및 뼈 스캔(bone scan)에서 뼈연골종(osteochondroma)으로 의심되었고, 흉강경하 늑골 절제술을 시행하였다. 수술 과정 중 혈관 및 신경 손상은 없었다. 환자는 수술 후 4일째 합병증 없이 퇴원 하였다. 조직학적 결과는 양성 섬유성 조직구종(benign fibrous histiocytoma)이었다. 본 증례를 통하여 흉강경을 이용한 늑골의 절제는 후측방 절개술을 통한 늑골 절제술에 비해 미용적인 면에서 장점이 있으며, 손쉽게 수행 가능함을 알 수 있었다.

Anatomical variations of trabecular bone structure in intraoral radiographs using fractal and particles count analyses

  • Amer, Maha Eshak;Heo, Min-Suk;Brooks, Sharon L.;Benavides, Erika
    • Imaging Science in Dentistry
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    • 제42권1호
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    • pp.5-12
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    • 2012
  • Purpose : This study was performed to evaluate possible variations in maxillary and mandibular bone texture of normal population using the fractal analysis, particles count, and area fraction in intraoral radiographs. Materials and Methods : Periapical radiographs of patients who had full mouth intraoral radiographs were collected. Regions of interest ($100{\times}100$ pixels) were located between the teeth of the maxillary anterior, premolar, and molar area, as well as the mandibular anterior, premolar, and molar areas. The fractal dimension (FD) was calculated by using the box counting method. The particle count (PC) and area fraction (AF) analyses were also performed. Results : There was no significant difference in the FD values among the different groups of age, gender, upper, and lower jaws. The mean FD value was $1.49{\pm}0.01$. The mean PC ranged from 44 to 54, and the mean AF ranged from 10.92 to 11.85. The values of FD, PC, and AF were significantly correlated with each other except for the upper molar area. Conclusion : According to the results, patients with normal trabecular pattern showed a FD of approximately 1.5. Based on these results, further investigation would be recommended if the FD value of patient significantly differenct from this number, since the alteration of this value indicates microstructural modification of trabecular pattern of the jaws. Additionally, with periapical radiographs, simple and cost-effective, PC and AF could be used to assess the deviation from the normal.

원인불명의 담즙흉 1예 (A Case of Cholethorax Developed by Unknown Cause)

  • 성문혁;김성무;유숙희;박우리;안진영;최강현;이기만;김시욱
    • Tuberculosis and Respiratory Diseases
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    • 제70권3호
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    • pp.261-265
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    • 2011
  • Cholethorax is a bilious pleural effusion caused by a pleurobiliary fistula or leakage of bile into the pleural space. Most cases of cholethorax arise from a complication of abdominal trauma, hepatobiliary infection, or invasive procedures or surgery of hepatobiliary system. However, we experienced a case of a patient with cholethorax of unknown origin. There was no evidence of pleurobiliary fistula or leakage of bile from the hepatobiliary system although we examined the patient with various diagnostic tools including chest and abdominal computed tomography, endoscopic retrograde cholangiopancreatography, tubography, bronchofiberscopy, hepatobiliary scintigraphy and video-assisted thoracoscopic surgery. Herein we report a case of cholethorax for which the specific cause was not identified. The patient was improved by percutaneous drainage of pleural bile.

Minute Pulmonary Meningothelial-Like Nodules Simulating Hematogenous Lung Metastasis: A Case Report

  • Lee, Sang Kook;Kim, Gi Jeong;Kim, Young Jae;Leem, Ah Young;Hwang, Eu Dong;Kim, Se Kyu;Chang, Joon;Kang, Young Ae;Kim, Song Yee
    • Tuberculosis and Respiratory Diseases
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    • 제75권2호
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    • pp.67-70
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    • 2013
  • A 52-year-old man was referred to our clinic for an 11.3 mm nodule in the left lower lobe that was discovered on a chest computed tomography (CT) scan. Eleven small nodules were subsequently found in both lungs. Initially, we performed a transthoracic needle aspiration using CT scan guidance. The pathologic report showed a few clusters of atypical cells that were suspicious for malignancy. The positron emission tomography images revealed multiple lung nodules scattered throughout both lungs. The largest nodule (11.3 mm) in the left lower lobe did not have any discernible fludeoxyglucose uptake. For pathologic confirmation, we consulted a thoracic surgeon to perform the video-assisted thoracoscopic surgery. The final diagnosis was minute pulmonary meningothelial-like nodules (MPMNs). MPMNs are benign in nature, and only a few cases require treatment. However, when clinicians are suspicious of potential malignancy, a pathological correlation is essential, even if the final diagnosis is MPMNs.

Image-guided navigation surgery for bilateral choanal atresia with a Tessier number 3 facial cleft in an adult

  • Sung, Ji Yoon;Cho, Kyu-Sup;Bae, Yong Chan;Bae, Seong Hwan
    • 대한두개안면성형외과학회지
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    • 제21권1호
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    • pp.64-68
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    • 2020
  • The coexistence of craniofacial cleft and bilateral choanal atresia has only been reported in three cases in the literature, and only one of those cases involved a Tessier number 3 facial cleft. It is also rare for bilateral choanal atresia to be found in adulthood, with 10 previous cases reported in the literature. This report presents the case of a 19-year-old woman with a Tessier number 3 facial cleft who was diagnosed with bilateral choanal atresia in adulthood. At first, the diagnosis of bilateral choanal atresia was missed and septoplasty was performed. After septoplasty, the patient's symptoms did not improve, and an endoscopic examination revealed previously unnoticed bilateral choanal atresia. Computed tomography showed left membranous atresia and right bony atresia. The patient underwent an operation for opening and widening of the left choana with an image-guided navigation system (IGNS), which enabled accurate localization of the lesion while ensuring patient safety. Postoperatively, the patient became able to engage in nasal breathing and reported that it was easier for her to breathe, and there were no signs of restenosis at a 26-month follow-up. The patient was successfully treated with an IGNS.