• The korean journal of orthodontics
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• v.39 no.2
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• pp.72-82
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• 2009

Objective: The purpose of this study was to investigate the structural changes of the hyoid bone and upper airway after orthognathic surgery for skeletal class III anterior open bite patients, and make comparisons with normal occlusion. Methods: Pre- and post-operative computed tomography (CT) examinations were performed on 12 skeletal class III anterior open bite patients who were treated with mandibular setback osteotomy. Using the V-works $4.0^{TM}$ program, 3-dimensional images of the total skull, mandible, hyoid bone, and upper airway were evaluated. Results: In the Class III open bite group, the hyoid bone were all positioned anteriorly, compared to the Normal group (p < 0.05). The angle between the hyoid plane and mandibular plane in the Class III openbite group before surgery was greater than in the Normal group (p < 0.05), and the difference increased after surgery (p < 0.01). In the Class III openbite group, the volume of the upper airway decreased after surgery (p < 0.001) and the volume of the upper airway was smaller than the Normal group before and after surgery (p < 0.001). Conclusions: The narrow upper airway space in skeletal Class III openbite patients decreased after mandibular setback osteotomy. This may affect the post-surgical stability.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.3
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• pp.300-305
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• 2008

Purpose: The purpose of our study was to evaluate the volume of pre- and post operative masseter muscle and bite force in mandibular prognathic patients treated with SSRO with the use of the 3D CT imaging technique and occlusal force meter. Materials and methods: The study group consisted of 12 patients with mandibular prognathism (5 males and 7 females) who underwent mandibular setback surgery (BSSRO) in the Department of Oral and Maxillofacial Surgery, Samsung medical center. Bite force was measured at pre op, post op 3, 6 and 12 months by occlusal force meter(GM10, Nagano Keiki, Japan) The preoperative CT examination of subjects was performed between one month prior to operation and one year after to operation. And muscle volume was measured. Result: As compared to preoperative measurements at 1 year postoperatively the masseter & internal pterygoid muscle volume were diminished (p<0.05) The bite force steadily recovered, so at postoperatively 6 months reached the preoperative level. And at 1 year after operation, the maximum bite force was significantly greater than preoperative levels. No significant correlation was presented between masseter muscle and bite force (p>0.05), internal pterygoid muscle and bite force (p>0.05). Conclusion: In this study, the results showed that volume and bite force of the masticatory muscles decreased significantly immediate after orthognathic surgery for mandibular set-back. However, reduction of maximum bite force disappears within 6 months after surgery.

• Imaging Science in Dentistry
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• v.30 no.2
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• pp.109-116
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• 2000

Purpose : To compare the size and bone wall thickness of the maxillary sinus in normal, preoperative and postoperative maxillary sinusitis patients. Materials and Methods : The author analyzed CT images of both left and right maxillary sinuses in 357 patients who visited Chonbuk National University Hospital between January 1997 and December 1998. The size and bone wall thickness of the maxillary sinus of normal, inflammatory and post-Caldwell-Luc groups were compared. Results: The significant differences of transverse, maximum medio-lateral, maximum supero-inferior dimensions and medio-lateral dimension at nasal floor level between normal and post-Caldwell-Luc groups were found (P<0.05). And the significant differences of antero-posterior dimensions between inflammatory and post-Caldwell-Luc group were found (P<0.05). But, no significant differences of vertical height dimensions between groups was found (P>0.05). The significant differences of postero-lateral, infero-lateral and medial wall thickness between normal and post-Caldwell-Luc groups were found (P<0.05). Conclusion : The results of this study will aid in the diagnosis and treatment of maxillary sinus diseases and post operative treatment planning.

• Radiation Oncology Journal
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• v.16 no.1
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• pp.63-69
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• 1998

Purpose : This study is to evaluate the efficacy of small bowel displacement system(SBDS) in post-operative pelvic radiation therapy(RT) of rectal cancer patients by measurement of small bowel volume included in the radiation fields receiving therapeutic dose. Materials and Method : Ten consecutive new rectal cancer patients referred to the department of Radiation Oncology of Samsung Medical Center in May of 1997 were included in this study. All patients were asked to drink $Castrographin^(R)$ before simulation and were laid prone for conventional simulation and CT scans with and without SBDS. The volume of opacified small bowel on CT scans, which was to be included in the radiation fields receiving therapeutic dose, was measured using Picture archiving and communication system (PACS). Results : The average small bowel volumes with and without SBDS were 176.0ml(5.2-415.6ml) and 185.1ml(54.5-434.2ml), respectively The changes of small bowel volume with SBDS compared to those without SBDS were more than $10\%$ decrease in three, less than 10% decrease in two, less than $10\%$ increase in three, and more than $10\%$ increase in two patients. Conclusion : No significant advantage of using SBDS in post-operative pelvic RT for rectal cancer patients has been shown by small bowel volume measurement using CT scan considering additional effort and time needed for simulation and treatment setup.

• Journal of the Korean Society of Radiology
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• v.15 no.3
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• pp.273-279
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• 2021

Metal material inserted into the body have a large difference in density from human tissues or bones around the Metal during CT scans.. Therefore, the Metal material inserted into the body produces Artifact. Metal Artifact, which occurs around Metals, can degrade the quality of CT images, causing confusion when medical team diagnose lesions. Through this experiment, we confirm that the occurrence of Artifacts decrease by using Dual energy CT and MAR algorithm in Single source Dual energy CT. We also want to present basic data on clinical application methods by comparing and analyzing the characteristics of images obtained by each method. Using GE 750HD CT, artificial implants were scanned using general method and Dual energy. Then we apply the MAR algorithm to each image obtained. And all previously acquired images were compared and analyzed the characteristics of the examination, such as image quality evaluation and dose evaluation. Images with MAR algorithm and Dual Energy confirmed a decrease in Metal Artifact. Images with MAR algorithm have reduced Metal Artifact, but have the disadvantage of distorting the details of artificial joint implants. On the other hand images teseted with Dual Energy have the advantage of being able to implement details than those applied with MAR algorithms, it takes longer to reconstruct the image and the exposure dose was about four times higher than those applied with MAR algorithm. In order to locate Metals, such as the post-operative follow-up period, it is useful to apply MAR algorithm to obtain images. And it is more useful to examine with Dual Energy when micro lesion identification, such as cardiac examination, and surgical planning or when tests are performed in diagnostic way.

• The korean journal of orthodontics
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• v.35 no.4 s.111
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• pp.320-329
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• 2005

The three-dimensional (3D) changes of bone, soft tissue and the ratio of soft tissue to bony movement was investigated in 8 skeletal Class III patients treated by mandibular setback surgery. CT scans of each patient at pre- and post-operative states were taken. Each scan was segmented by a threshold value and registered to a universal three-dimensional coordinate system, consisting of an FH plane, a mid-sagittal plane, and a coronal plane defined by PNS. In the study, the grid parallel to the coronal plane was proposed for the comparison of the changes. The bone or soft tissue was intersected by the projected line from each point on the gird. The coordinate values of intersected point were measured and compared between the pre- and post-operative models. The facial surface changes after setback surgery occurred not only in the mandible, but also in the mouth corner region. The soft tissue changes of the mandibular area were measured relatively by the proportional ratios to the bone changes. The ratios at the mid-sagittal plane were $77\~102\%(p<0.05)$. The ratios at all other sagittal planes had similar patterns to the mid-sagittal plane, but with decreased values. And, the changes in the maxillary region were calculated as a ratio, relative to the movement of a point representing a mandibular movement. When B point was used as a representative point, the ratios were $14\~29\%$, and when Pog was used, the ratios were $17\~37\%(9<0.05)$. In case of the 83rd point of the grid, the ratios were $11\~22\%(p<0.05)$.

• Annals of Hepato-Biliary-Pancreatic Surgery
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• v.26 no.2
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• pp.184-189
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• 2022

Backgrounds/Aims: The soft texture of the pancreas parenchyma may influence the incidence of pancreatic leakage after pancreaticcoduodenectomy (PD). One possible method to assess pancreatic texture and atrophy, is via computed tomography (CT) scan of the abdomen. The purpose of our study was to evaluate the relation between the preoperative CT scan and the incidence of pancreatic fistula after PD. Methods: A retrospective single-center study including patients who underwent PD for a benign and malignant tumor of the periampullary region between the years 2000 and 2016. Demographic and imaging data were analysed and a correlation with the post-operative leak was evaluated. Results: Pancreatic leak was documented in 34 out of 154 (22.1%) patients. All the leakage cases occurred in the preserved pancreas group (33.1% of the total preserved pancreas group alone). No leak was documented in the atrophic pancreas group. This difference between the two groups was found to be statistically significant (p ≤ 0.00001). Conclusions: Atrophic pancreas in the preoperative CT scan may be protective against leakage after PD. These findings may help the surgeon to risk stratify patients accordingly. In addition, the findings suggest that patients with a preserved pancreas may require more protective methods to prevent leakage.

• Journal of Trauma and Injury
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• v.22 no.1
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• pp.57-64
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• 2009

Purpose: Computed tomography (CT) is an accurate test for evaluating hemodynamically stable patients with blunt abdominal trauma. Until now, there have been few studies concentrating on the diagnostic and prognostic significance of the intravenous contrast extravasation (CE) site. We investigated the site of CE on abdominopelvic CT (APCT) and its effect on treating trauma patients and predicting the clinical outcome. Methods: The 50 patients admitted to our emergency department with blunt abdominal trauma showing CE on APCT from January 2004 to September 2006 were included in this study. Patients were prospectively collected, and medical records were reviewed and analyzed. The patients'clinical and lab findings, Focused Assessment with Sonography for Trauma (FAST) findings, CT findings were analyzed. CE sites were classified as intraperitoneal, retroperitoneal, and pelvic cavity and were correlated with post-treatment complications, mortality, and morbidity. Results: Of the 50 patients (mean age : $45{\pm}18years$, 29 males, 21 females) included in our study, 33 patients died (66%). There was no correlation between CE site and ICU or total hospitalization duration (p=0.553, p=0.523). During the first 24 hours of resuscitation, the pelvic cavity group required a mean of 20 units more of packed red blood cell (pRBC) transfusion compared to other groups (p=0.003). In the intraperitoneal group, more patients received operative invasive intervention - either laparotomy or embolization (p=0.025). The intraperitoneal group had the highest mortality, with 13 deaths (11/33, 39%), and the highest early mortality rate (10/13, 76%) in the first 24 hours (p=0.001). Conclusion: Intraperitoneal CE on the CT scan in cases of blunt abdominal trauma is regarded as an indication of a need for invasive intervention (either angiography or laparotomy) and of a higher mortality rate in the first 24 hours. A pelvic cavity CE rquires more aggressive transfusion with pRBC. However, the CT findings themselves showed no significant correlation with overall mortality, morbidity, or hospitalization.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.2
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• pp.114-121
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• 2011

Introduction: The aim of this study was to demonstrate that the simulation surgery on rapid prototype (RP) model, which is based on the 3-dimensional computed tomography (3D CT) data taken before surgery, has the same accuracy as traditional orthograthic surgery with an intermediate splint, using an optoelectronic tracking navigation system. Materials and Methods: Simulation surgery with the same treatment plan as the Le Fort I osteotomy on the patient was done on a RP model based on the 3D CT data of 12 patients who had undergone a Le Fort I osteotomy in the department of oral and maxillofacial surgery, Seoul National University Dental Hospital. The 12 distances between 4 points on the skull, such as both infraorbital foramen and both supraorbital foramen, and 3 points on maxilla, such as the contact point of both maxillary central incisors and mesiobuccal cuspal tip of both maxillary first molars, were tracked using an optoelectronic tracking navigation system. The distances before surgery were compared to evaluate the accuracy of the RP model and the distance changes of 3D CT image after surgery were compared with those of the RP model after simulation surgery. Results: A paired t-test revealed a significant difference between the distances in the 3D CT image and RP model before surgery.(P<0.0001) On the other hand, Pearson's correlation coefficient, 0.995, revealed a significant positive correlation between the distances.(P<0.0001) There was a significant difference between the change in the distance of the 3D CT image and RP model in before and after surgery.(P<0.05) The Pearson's correlation coefficient was 0.13844, indicating positive correlation.(P<0.1) Conclusion: Theses results suggest that the simulation surgery of a Le Fort I osteotomy using an optoelectronic tracking navigation system I s relatively accurate in comparing the pre-, and post-operative 3D CT data. Furthermore, the application of an optoelectronic tracking navigation system may be a predictable and efficient method in Le Fort I orthognathic surgery.

• The Journal of Internal Korean Medicine
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• v.41 no.1
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• pp.88-96
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• 2020

Objectives: Osteonecrosis of the femoral head (ONFH) is caused by a circulatory disorder. If symptoms are not present, the patient's progress is observed, but if symptoms are present, non-surgical methods or total hip replacement are performed. Several case reports have described the effects of Korean Medicine treatment on ONFH, but the number of cases is still small, and few studies have used blood stasis-based herbal medicines like Hwaeo-jeon (HEJ). This study reports the effectiveness of Korean Medicine treatments, including HEJ, on a case of ONFH. Methods: A patient diagnosed with ONFH by CT and MRI was treated with Korean Medicine treatments consisting of herbal medicine including HEJ, bee venom pharmacopuncture, acupuncture, cupping, and physical therapy. The improvement of pain was assessed using a numerical rating scale. Inflammation levels were determined by blood tests conducted during hospitalization. Results: Korean Medicine treatment, including herbal medicine, resulted in good clinical improvement responses, including reduced pain, improved mobility, and reduced inflammatory levels in the blood tests. Conclusions: Korean Medicine treatments, including HEJ, may be effective for ONFH patients. Further studies are needed to determine the recovery of osteonecrosis and the improvement of post-operative aftereffects using Korean Medicine treatments, as well as the reduction of pre-operative pain.