• Restorative Dentistry and Endodontics
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• 제32권1호
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• pp.61-68
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• 2007

이 연구의 목적은 네 종류 file systems의 중심유지능과 근관성형 전후의 상아질 삭제량을 비교하는 것이다. 10-20도의 만곡을 갖는 발거된 20개의 하악 제1대구치의 근심근관(총 40개의 근관)을 근관성형 전에 X선 미세단층촬영 스캐너를 이용하여 스캔하였다. 제 1군은 근관부를 넓힌 후 stainless steel K-Flexofile을 사용하여 step-back technique으로 근관성형하였고, 나머지 군들은 각 제조사의 추천대로 ProFile system (2군), ProTaper system (3군), K3 system (4군)을 사용하여 crown-down technique으로 근관성형하였다. 모든 근관의 근단부 기구조작은 #25 크기까지 시행하였고 근관성형 후 스캔하였다. 3차원 영상 소프트웨어로 근관성형 전후의 스캔된 이미지들을 재구성하여 근관의 전체적 부피 변화를 측정하였다. 또한, 근단공으로부티 1, 3, 5, 7 mm되는 지점의 근관 횡단면을 비교하여 근관성형 전후의 단면적 변화와 중심변위율을 산출하였다. 그 결과, ProTaper와 K3가 다른 file systems보다 상아질을 더 많이 삭제하는 경향을 보였고 모든 실험군에서 중심 변위율은 근단공으로부터 3 mm 지점에서 가장 낮은 수치를 나타냈으며, 3 mm 지점을 제외하고는 ProTaper가 다른 file systems보다 중심유지능이 떨어지는 결과를 얻을 수 있었다 (P < 0.05).

• 대한골절학회지
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• 제30권4호
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• pp.186-191
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• 2017

목적: 이번 연구의 목적은 고령 인구의 골반 부전 골절에 대한 방사선적, 역학적 특징과 임상 경과를 알아보는 것이다. 대상 및 방법: 2010년 3월부터 2017년 5월까지 골반 부전 골절 환자를 대상으로 후향적 조사를 시행하였다. 환자의 인구학적 정보, 골밀도, 골표지자를 조사하였다. 단순 방사선 촬영과 컴퓨터 단층촬영을 비교하였다. 임상 경과 평가를 위해 이환된 합병증과 골절 6개월 이후 보행 능력을 비교하였다. 결과: 연구 대상 총 42명의 평균 나이는 76.5세였고, 1명을 제외하고는 모두 여성이었다. 초진 병원이 타 병원인 5예 중 골절 진단을 받지 못한 경우가 3예였다. 단순 방사선 사진에서 발견된 골절 외 컴퓨터 단층촬영에서 추가로 골절이 발견된 경우가 81.0%였다. 모두에서 보존적 치료를 시행하였다. 골절 후 보행 시작까지 걸린 시기는 평균 2.8주였으며 42명 중 1예를 제외한 전체 예(97.6%)에서 수상 전 보행 상태로 회복이 가능하였다. 결론: 골반 부전 골절을 진단하는 경우 단순 방사선 사진으로는 제한점이 있는 것을 확인하였다. 골반 부전 골절은 보존적 치료로 좋은 결과를 얻을 수 있었으며, 치명적인 합병증이 비교적 적게 발생하였다.

• 대한두개안면성형외과학회지
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• 제18권1호
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• pp.21-24
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• 2017

Background: In evaluation of craniosynostosis patients in terms of neurodevelopmental delay, positron emission tomography computed tomography (PET-CT) scan can be used to assess brain abnormalities through glucose metabolism. We aimed to determine the unnecessity of PET-CT in this study. Methods: Thirty-eight patients diagnosed with craniosynostosis who underwent distraction osteogenesis from October, 2010 to November, 2013 were reviewed. Magnetic resonance imaging (MRI) and PET-CT scan were carried out for evaluation of the brain structure and function, whereas X-ray and CT scan were taken for evaluation of the skull. Results: Nine patients reported abnormal MRI findings which were not significant, and five patients showed local problem on brain on PET-CT scan. No correlation was found among them. Conclusion: PET-CT evaluation of possible abnormal brain findings do not affect surgical planning or require additional therapy. Preoperative PET-CT scan is not the essential study to get any etiologic information of the disease consequences or to establish the treatment plan.

• 대한족부족관절학회지
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• 제18권4호
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• pp.165-172
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• 2014

Purpose: We evaluated the correlation of postoperative clinical outcomes and radiologic findings using computed tomography and simple X-ray in intra-articular calcaneal fractures. Materials and Methods: The current study is based on 41 feet, 38 patients with displaced intra-articular fracture who underwent surgical treatment with at least one year of follow-up. Evaluation of clinical outcome included American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, visual analogue scale (VAS) score, and subjective satisfaction. A simple X-ray was used in evaluation of preoperative and postoperative Gissane angle, B${\ddot{O}}$hler angle, and calcaneal fracture width. Computed tomography scan was performed for evaluation of preoperative and postoperative articular step-off and articular gap in all cases. Finally, we evaluated the correlation of the postoperative clinical outcomes and radiologic findings based on the measurement. Results: The average postoperative AOFAS score and VAS score was $84.1{\pm}8.5$ and $2.2{\pm}2.2$. Subjective satisfaction was excellent in 15 cases, good in 19 cases, and fair in seven cases. The average B${\ddot{O}}$hler angle was restored from $11.1^{\circ}$ to $24.7^{\circ}$(p<0.05), Gissane angle was changed from $121.0^{\circ}$ to $119.0^{\circ}$ (p>0.05), and the average width was restored from 45.8 to 35.0 mm (p<0.05). The average articular step-off and gap were decreased from 6.3 to 2.0 mm and from 11.1 to 4.6 mm, respectively (p<0.05). No significant correlations were observed between the clinical outcome and Gissane angle, B${\ddot{O}}$hler angle, and width, and there was no significant correlation between the clinical outcome and Sanders classification. However, postoperative articular step-off showed correlation with VAS and AOFAS score and articular gap showed correlation with VAS score. Conclusion: The clinical outcome did not show correlation with B${\ddot{O}}$hler angle and Gissane angle but did show correlation with anatomical reduction of the posterior facet joint.

• Imaging Science in Dentistry
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• 제41권2호
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• pp.79-84
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• 2011

Purpose : The aim of the present study was to investigate the disagreement of cephalometric analysis depending on the reference determination of midsagittal plane on three-dimensional computed tomography. Materials and Methods : A total of 102 young women with class III dentofacial deformity were evaluated using three-dimensional computed tomography. The cranial and facial midsagittal planes were defined and the amounts of jaw deviation were calculated. The amounts of jaw deviation were compared with paired t-test (2-tailed) and Bland-Altman plot was drawn. Results : The landmark tracing were reproducible ($r{\ge}.978$). The jaws relative to the cranial midsagittal plane were 10-17 times more significantly deviated than to the facial midsagittal plane (P<.001). Bland-Altman plot demonstrated that the differences between the amounts of jaw deviation from two midsagittal planes were not normally distributed versus the average of the amounts of jaw deviation from two midsagittal planes. Conclusion : The cephalometric analyses of facial asymmetry were significantly inconsistent depending on the reference determination of midsagittal plane. The reference for midsagittal plane should be carefully determined in three-dimensional cephalometric analysis of facial asymmetry of patients with class III dentofacial deformity.

• 한국임상수의학회지
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• 제32권4호
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• pp.313-318
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• 2015

The lung opacity on radiography is influenced by various factors. The physical density of the lung and the attenuation ensured on computed tomography (CT) scans is determined by three components : lung tissue, blood, and air. Temporary right lateral recumbency may responsible for the increase of opacity on ventrodorsal projection view. Thus, our aim is to demonstrate that the effect of right lateral recumbency posture on right lung opacity using radiograph and CT scan. In this study, 62 dogs without clinical or radiologic signs of cardiopulmonary disease are selected. Thorax radiographs per 30 seconds for 2 minutes (30s, 60s, 90s, 120s) were performed for 62 dogs. After discussion of the radiographic findings of lung field by two radiologists and a student at Chungbuk national university veterinary medical center a consensus opinion was recorded. Computed tomography per a minute (1 min, 2 min) for 2 minutes were performed for 2 dogs. Mean x-ray attenuation of lung was measured quantitatively using software at two levels (aortic arch and basal level). Among 62 dogs with radiograph comparison, 9.3% of dogs showed influence by postural effect. However, all 2 dogs with computed tomography comparison, showed influence by postural effect. In conclusion, position dependent changes of lung density in CT exam are not consistent with thoracic radiograph.

• Imaging Science in Dentistry
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• 제51권1호
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• pp.27-34
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• 2021

Purpose: This study was performed to compare the ability of limited- and large-volume cone-beam computed tomography (CBCT) to display isthmuses in the apical root canals of mandibular molars. Materials and Methods: Forty human mandibular first molars with isthmuses in the apical 3 mm of mesial roots were scanned by micro-computed tomography (micro-CT), and their thickness, area, and length were recorded. The samples were examined using 2 CBCT systems, using the smallest voxels and field of view available for each device. The Mann-Whitney, Friedman, and Dunn multiple comparison tests were performed (α=0.05). Results: The 3D Accuitomo 170 and i-Cat devices detected 77.5% and 75.0% of isthmuses, respectively (P>0.05). For length measurements, there were significant differences between micro-CT and both 3D Accuitomo 170 and i-Cat(P<0.05). Conclusion: Both CBCT systems performed similarly and did not detect isthmuses in the apical third in some cases. CBCT still does not equal the performance of micro-CT in isthmus detection, but it is nonetheless a valuable tool in endodontic practice.

• Imaging Science in Dentistry
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• 제52권3호
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• pp.303-308
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• 2022

Purpose: This technical report aims to describe and detail the use of micro-computed tomography for a reliable evaluation of the bulk-fill composite/tooth interface. Materials and Methods: Bulk-fill composite restorations in tooth cavities were scanned using micro-computed tomography to obtain qualitatively and quantitatively valuable information. Two-dimensional information was processed using specific algorithms, and ultimately a 3-dimensional (3D) specimen reconstruction was generated. The 3D rendering allowed the visualization of voids inside bulk-fill composite materials and provided quantitative measurements. The 3D analysis software VG Studio MAX was used to perform image analysis and assess gap formation within the tooth-restoration interface. In particular, to evaluate internal adaptation, the Defect Analysis addon module of VG Studio Max was used. Results: The data, obtained with the processing software, highlighted the presence and the shape of gaps in different colours, representing the volume of porosity within a chromatic scale in which each colour quantitatively represents a well-defined volume. Conclusion: Micro-computed tomography makes it possible to obtain several quantitative parameters, providing fundamental information on defect shape and complexity. However, this technique has the limit of not discriminating materials without radiopacity and with low or no filler content, such as dental adhesives, and hence, they are difficult to visualise through software reconstruction.

• Anatomy and Cell Biology
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• 제56권2호
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• pp.185-190
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• 2023

The root canal morphology undergoes aging-related changes, and relevant quantitative analyses have not yet been reported. We compared the cone beam computed tomography (CBCT) and micro-computed tomography (microCT) scans of extracted mandibular incisors to check the accuracy of morphological measurements. Thereafter, the root canal morphology and aging-related changes in the mandibular incisors of Japanese individuals were assessed using CBCT. Six extracted teeth were fixed in a phantom head and imaged using CBCT and micro-CT. The correlation between the findings of the two imaging modalities was examined. Further, CBCT reconstructed images of the mandibular incisors of 81 individuals were observed. Age-related changes of the root canals were compared between participants aged <30 years and those aged ≥30 years. The CBCT and micro-CT findings regarding the root canals of the extracted teeth coincided in 94.4% of the cases. Mandibular incisors exhibiting two root canals in either cross-section accounted for 9.9% of central incisors and 12.4% of lateral incisors. Mandibular central incisors with two root canals were observed in two (6.3%) individuals aged <30 years and six (12.2%) aged ≥30 years. Mandibular lateral incisors with two root canals were observed in one (3.1%) individual aged <30 years and nine (18.4%) aged ≥30 years. CBCT allows accurate evaluation of complex root canal morphologies and is useful for endodontic preoperative assessment. Mandibular incisors have more frequent occurrence of two root canals with aging.

• Journal of the Korean Wood Science and Technology
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• 제42권5호
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• pp.516-522
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• 2014

Old architectural wood materials damaged by a fire were evaluated on the basis of wood species and scanning electron microscopy (SEM) observation of wood tissues in combination with energy dispersive X-ray spectroscopy (EDXS) analysis. Results of SEM observation showed that tracheid wall thickness of burned parts was very thin compared with undamaged and sound wood, and tylosoid in the resin canals disappeared after the exposure to fire. SEM-EDXS analysis indicated that carbon and oxygen peaks occurred in the original energy band, and the carbon peak was higher than that of the oxygen in the burned part. A computerized tomography was also undertaken to investigate the carbonization layer formed by fire and possible internal defects.