• Korean Journal of Radiology
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• v.19 no.6
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• pp.1077-1088
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• 2018

Objective: To correlate CT parameters on detector-based dual-energy CT enterography (DECTE) with Crohn's disease activity index (CDAI) and externally validate quantitative CT parameters. Materials and Methods: Thirty-nine patients with CD were retrospectively enrolled. Two radiologists reviewed DECTE images by consensus for qualitative and quantitative CT features. CT attenuation and iodine concentration for the diseased bowel were also measured. Univariate statistical tests were used to evaluate whether there was a significant difference in CTE features between remission and active groups, on the basis of the CDAI score. Pearson's correlation test and multiple linear regression analyses were used to assess the correlation between quantitative CT parameters and CDAI. For external validation, an additional 33 consecutive patients were recruited. The correlation and concordance rate were calculated between real and estimated CDAI. Results: There were significant differences between remission and active groups in the bowel enhancement pattern, subjective degree of enhancement, mesenteric fat infiltration, comb sign, and obstruction (p < 0.05). Significant correlations were found between CDAI and quantitative CT parameters, including number of lesions (correlation coefficient, r = 0.573), bowel wall thickness (r = 0.477), iodine concentration (r = 0.744), and relative degree of enhancement (r = 0.541; p < 0.05). Iodine concentration remained the sole independent variable associated with CDAI in multivariate analysis (p = 0.001). The linear regression equation for CDAI (y) and iodine concentration (x) was y = 53.549x + 55.111. For validation patients, a significant correlation (r = 0.925; p < 0.001) and high concordance rate (87.9%, 29/33) were observed between real and estimated CDAIs. Conclusion: Iodine concentration, measured on detector-based DECTE, represents a convenient and reproducible biomarker to monitor disease activity in CD.

• Clinics in Shoulder and Elbow
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• v.22 no.1
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• pp.16-23
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• 2019

Background: We aimed to evaluate whether the use of our novel patient-specific guide (PSG) with 3-dimensional reconstruction in reverse total shoulder arthroplasty (RTSA) would allow accurate and reliable implantation of the glenoid and humeral components. Methods: 20 fresh-frozen cadaveric shoulders were used. The PSG group (n=10) and conventional group (n=10) was evaluated the accuracy and reproducibility of implant positioning between before and after surgery on the computed tomography image. Results: The superoinferior and anteroposterior offset in the glenoid component were $0.42{\pm}0.07$, $0.50{\pm}0.08$ in the conventional group and $0.45{\pm}0.03$, $0.46{\pm}0.02$ in the PSG group. The inclination and version angles were $-1.93^{\circ}{\pm}4.31^{\circ}$, $2.27^{\circ}{\pm}5.91^{\circ}$ and $0.46^{\circ}{\pm}0.02^{\circ}$, $3.38^{\circ}{\pm}2.79^{\circ}$. The standard deviation showed a smaller difference in the PSG group. The anteroposterior and lateromedial humeral canal center offset in the humeral component were $0.45{\pm}0.12$, $0.48{\pm}0.15$ in the conventional group and $0.46{\pm}0.59$ (p=0.794), $0.46{\pm}0.06$ (p=0.702) in the PSG group. The PSG showed significantly better humeral stem alignment. Conclusions: The use of PSGs with 3-dimensional reconstruction reduces variabilities in glenoid and humerus component positions and prevents extreme positioning errors in RTSA.

• Clinics in Shoulder and Elbow
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• v.21 no.4
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• pp.227-233
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• 2018

Background: The purpose of this study was to compare the radiologic results of patients who underwent surgery with a hook plate and a locking plate in distal clavicle fractures. Methods: Sixty patients underwent surgical treatment for Neer type IIa, IIb, III, and V distal clavicle fracture. Twenty-eight patients underwent fracture fixation with a hook plate and 32 with a locking plate. Coracoclavicular distance was measured on standard anteroposterior radiographs before and after the surgery, and union was confirmed by radiograph or computed tomography taken at 6 months postoperatively. Other radiologic complications like osteolysis was also checked. Results: Bony union was confirmed in 59 patients out of 60 patients, and 1 patient in the hook plate group showed delayed union. Coracoclavicular distance was decreased more in the hook plate group after surgery (p<0.01). After 6 weeks of the hook plate removal, the coracoclavicular distance was increased a little compared to before metal removal, but there was no difference compared to the contralateral shoulder. Eleven out of 28 patients (39.3%) showed osteolysis on the acromial undersurface in the hook plate group. Conclusions: Both the hook plate group and the locking plate group showed satisfactory radiologic results in distal clavicle fractures. Both hook plate and locking plate could be a good treatment option if it is used in proper indication in distal clavicle fracture with acromioclavicular subluxation or dislocation.

• Restorative Dentistry and Endodontics
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• v.43 no.4
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• pp.42.1-42.7
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• 2018

Objectives: The purpose of this study was to investigate the C-shaped root canal anatomy of mandibular second molars in a Korean population. Materials and Methods: A total of 542 teeth were evaluated using cone-beam computed tomography (CBCT). The canal shapes were classified according to a modified version of Melton's method at the level where the pulp chamber floor became discernible. Results: Of the 542 mandibular second molars, 215 (39.8%) had C-shaped canals, 330 (53%) had 3 canals, 17 (3.3%) had 2 canals, 12 (2.2%) had 4 canals, and 8 (1.7%) had 1 canal. The prevalence of C-shaped canals was 47.8% in females and 28.4% in males. Seventy-seven percent of the C-shaped canals showed a bilateral appearance. The prevalence of C-shaped canals showed no difference according to age or tooth position. Most teeth with a C-shaped canal system presented Melton's type II (45.6%) and type III (32.1%) configurations. Conclusions: There was a high prevalence of C-shaped canals in the mandibular second molars of the Korean population studied. CBCT is expected to be useful for endodontic diagnosis and treatment planning of mandibular second molars.

• The korean journal of orthodontics
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• v.49 no.5
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• pp.279-285
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• 2019

Objective: This study evaluated the efficiency of anchorage provided by temporary anchorage devices (TADs) in maxillary bicuspid extraction cases during retraction of the anterior teeth using a fixed appliance. Methods: Patients aged 12 to 50 years with malocclusion for which bilateral first or second maxillary bicuspid extractions were indicated were included in the study and randomly allocated to the TAD or control groups. Retraction of the anterior teeth was achieved using skeletal anchorage in the TAD group and conventional dental anchorage in the control group. A computed tomography (CT) scan was performed after alignment of teeth, and a second CT scan was performed at the end of extraction space closure in both groups. A three-dimensional superimposition was performed to visualize and quantify the maxillary first molar movement during the retraction phase, which was the primary outcome, and the stability of TAD movement, which served as the secondary outcome. Results: Thirty-four patients (17 in each group) underwent the final analysis. The two groups showed a significant difference in the movement of the first maxillary molars, with less significant anchorage loss in the TAD group than that in the control group. In addition, TAD movement showed only a slight mesial movement on the labial side. On the palatal side, the mesial TAD movement was greater. Conclusions: In comparison with conventional dental anchorage, TADs can be considered an efficient source of anchorage during retraction of maxillary anterior teeth. TADs remain stable when correctly placed in the bone during the anterior tooth retraction phase.

• Journal of Periodontal and Implant Science
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• v.49 no.5
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• pp.330-343
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• 2019

Purpose: The aim of this study was to evaluate the use of dehydrated human amnion/chorion membrane (dHACM) to repair perforated sinus membranes in rabbits. Methods: Bilateral surgical windows (7.5-mm diameter) were prepared on the nasal bones of 14 rabbits. Standardized circular perforations (5-mm diameter) were made in the sinus membrane by manipulating implant twist drills. The perforated sinus membranes were repaired using dHACM or a resorbable collagen membrane (CM). The negative control (NC) group did not undergo perforated sinus membrane repair, while the positive control (PC) group underwent sinus augmentation without perforations. The same amount of deproteinized porcine bone mineral was grafted in all 4 groups. After 6 weeks, micro-computed tomography (micro-CT) and histomorphometric evaluations were conducted. Results: The micro-CT analysis revealed that the total augmented volume was not significantly different among the groups. In the dHACM group, newly formed bone filled the augmented area with remaining biomaterials; however, non-ciliated flat epithelium and inflammatory cells were observed on the healed sinus membrane. Histometric analysis showed that the percentage of newly formed bone area in the dHACM group did not differ significantly from that in the CM group. The dHACM group showed a significantly higher percentage of newly formed bone area than the NC group, but there was no significant difference between the dHACM and PC groups. Conclusions: dHACM could be a feasible solution for repairing sinus membrane perforations that occur during sinus floor augmentation.

• Progress in Medical Physics
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• v.32 no.2
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• pp.40-49
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• 2021

Purpose: This study aimed to develop a surface-guided radiosurgery system customized for a neurosurgery clinic that could be used as an auxiliary system for improving the accuracy, monitoring the movements of patients while performing hypofractionated radiosurgery, and minimizing the geometric misses. Methods: RGB-D cameras were installed in the treatment room and a monitoring system was constructed to perform a three-dimensional (3D) scan of the body surface of the patient and to express it as a point cloud. This could be used to confirm the exact position of the body of the patient and monitor their movements during radiosurgery. The image from the system was matched with the computed tomography (CT) image, and the positional accuracy was compared and analyzed in relation to the existing system to evaluate the accuracy of the setup. Results: The user interface was configured to register the patient and display the setup image to position the setup location by matching the 3D points on the body of the patient with the CT image. The error rate for the position difference was within 1-mm distance (min, -0.21 mm; max, 0.63 mm). Compared with the existing system, the differences were found to be as follows: x=0.08 mm, y=0.13 mm, and z=0.26 mm. Conclusions: We developed a surface-guided repositioning and monitoring system that can be customized and applied in a radiation surgery environment with an existing linear accelerator. It was confirmed that this system could be easily applied for accurate patient repositioning and inter-treatment motion monitoring.

• Imaging Science in Dentistry
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• v.51 no.2
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• pp.167-174
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• 2021

Purpose: Sex determination can be done by morphological analysis of different parts of the body. The mastoid region, with its anatomical location at the skull base, is ideal for sex identification. Statistical shape analysis provides a simultaneous comparison of geometric information on different shapes in terms of size and shape features. This study aimed to investigate the geometric morphometry of the inter-mastoid triangle as a tool for sex determination in the Iranian population. Materials and Methods: The coordinates of 5 landmarks on the mastoid process on the 80 cone-beam computed tomographic images(from individuals aged 17-70 years, 52.5% female) were registered and digitalized. The Cartesian x-y coordinates were acquired for all landmarks, and the shape information was extracted from the principal component scores of generalized Procrustes fit. The t-test was used to compare centroid size. Cross-validated discriminant analysis was used for sex determination. The significance level for all tests was set at 0.05. Results: There was a significant difference in the mastoid size and shape between males and females(P<0.05). The first 2 components of the Procrustes shape coordinates explained 91.3% of the shape variation between the sexes. The accuracy of the discriminant model for sex determination was 88.8%. Conclusion: The application of morphometric geometric techniques will significantly impact forensic studies by providing a comprehensive analysis of differences in biological forms. The results demonstrated that statistical shape analysis can be used as a powerful tool for sex determination based on a morphometric analysis of the inter-mastoid triangle.

• Journal of Chest Surgery
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• v.54 no.3
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• pp.179-185
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• 2021

Background: The use of ProGlide as a percutaneous vascular closure device in cardiac surgery remains inconclusive. This study investigated the clinical outcomes of using ProGlide in the percutaneous cannulation of femoral vessels in adult cardiac surgery. Methods: From September 2017 to July 2018, 131 consecutive patients underwent femoral vessel cannulation during cardiac surgery. The ProGlide (Abbott Vascular Inc., Santa Clara, CA, USA) with percutaneous cannulation was used in 118 patients (mean age, 55.7±15.5 years). The accessibility of femoral cannulation was evaluated through preoperative computed tomography. For cannulation, sonography was routinely used. The postoperative ankle-brachial index (ABI) was used to evaluate femoral artery stenosis. Results: Of the 118 patients, 112 (94.9%) and 6 (5.1%) underwent minimally invasive cardiac surgery and median sternotomy, respectively. Most femoral cannulations were performed on the right side (98.3%) using 15F to 19F arterial cannulas. The technical success rate of cannulation with ProGlide was 99.2%, with no delayed bleeding or cannulation site-related complications during hospitalization. During follow-up, only 1 patient showed femoral artery stenosis with claudication and was treated with interventional balloon angioplasty. The postoperative ABI revealed no significant difference in functional stenosis between the cannulation and non-cannulation sides (n=86; cannulation vs. non-cannulation, 1.2±0.1 vs. 1.1±0). Conclusion: Percutaneous femoral cannulation with ProGlide was safe and feasible in adult cardiac surgery. This technique may be a good alternative option in patients requiring femoral vessel cannulation for cardiac surgery.

• Archives of Craniofacial Surgery
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• v.23 no.3
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• pp.119-124
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• 2022

Background: Many severe nasal bone fractures present with septal fractures, causing postoperative septal deviation and negatively affecting the patients' quality of life. However, when a septal fracture is absent, it is difficult to predict whether surgical correction can help minimize nasal septal deviation postoperatively. This study determined whether performing closed reduction on even mildly displaced nasal bone fracture could deter the outcome of septal deviation. Methods: We retrospectively reviewed the data of 116 patients aged 21-72 years who presented at the outpatient clinic and emergency room with fractures of nasal bones only without any involvement of the septum from January 2014 to December 2020. Patients were classified into three fracture type groups: A (unilateral), B (bilateral), and C (comminuted with depression). The degree of septal deviation was calculated by measuring the angle between the apex of the most prominent point and the crista galli in the coronal view on computed tomography images. The difference between the angles of the initial septal deviation and that of the follow-up was calculated and expressed as delta (Δ). Results: Closed reduction tended to decrease the postoperative septal deviation in all fracture types, but the values were significantly meaningful only in type A and B fractures. In the surgical group, with type A as the baseline, type B showed a significantly larger Δ value, but type C was not significantly different, although type C showed a smaller Δ value. In the conservative group, with type A as the baseline, the other fracture types presented significantly lower Δ values. Conclusion: For all fracture types, closed reduction significantly decreased the extent to which the nasal septum likely deviated. Therefore, when a patient is reluctant to undergo closed reduction, physicians should address the possible outcomes and prognosis of untreated nasal bone fractures.