• Imaging Science in Dentistry
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• 제47권2호
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• pp.69-74
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• 2017

Purpose: The nasopalatine canal is a well-known, important anatomical structure in the anterior maxilla, but this region contains many accessory canals. The canalis sinuosus (CS) is one of these canals; it contains the anterior superior alveolar nerve, along with veins and arteries. The purpose of this study was to evaluate the CS using cone-beam computed tomography (CBCT) in patients with maxillary impacted canines. Materials and Methods: A total of 111 patients admitted to the Istanbul Medipol University School of Dentistry for the exposure, orthodontic treatment, and/or extraction of an impacted canine were included in this study. CBCT images were obtained for these patients under standard conditions. Axial, coronal, and sagittal sections were evaluated to assess the prevalence of CS, the direction and diameter of the canal, its relation with the impacted canine, and its distance from the alveolar crest. Further, possible correlations with patient gender and age were analyzed. Results: The CS could be detected bilaterally in all the evaluated tomography images. The mean canal diameter was significantly larger in males than in females(P=.001). The CS ran significantly closer to the impacted canine when the canal was located horizontally (P=.03). Variations of the canal, such as accessory canals, were identified in 6 patients. Conclusion: CS is an anatomical entity that may resemble periapical lesions and other anatomical structures. Evaluation with CBCT prior to surgical procedures in the anterior maxilla will help to prevent overlooking such anatomical structures and to decrease possible surgical complications.

• Journal of Korean Neurosurgical Society
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• 제61권2호
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• pp.180-185
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• 2018

Objective : Many lumbosacral fixation techniques have been described to offer a more screw-bone purchase. The forward anatomical fixation parallel to the endplate is still the most preferred method. Literature revealed little knowledge regarding the mechanical stability of lumbosacral trans-endplate fixation compared to the traditional trans-pedicular screw fixation method. The aim of this study is to assess the pull-out strength of lumbosacral screws penetrating the end plate and comparing it to the conventional trans-pedicular screw insertion method. Methods : Eight lumbar and eight sacral vertebrae, with average age 69.4 years, Left pedicles of the 5th lumbar vertebrae were used for trans-endplate screw fixation, group 1A, right pedicles were used for anatomical trans-pedicular screw fixation, group 1B. In the sacral vertebrae, the right side S1 pedicles were used for trans-endplate fixation, group 2A, left side pedicles were used for anatomical trans-pedicular screw fixation, group 2B. The biomechanical tests were performed using the axial compression testing machine. All tests were applied using 2 mm/min traction speed. Results : The average pull-out strength values of groups 1A and 1B were $403.78{\pm}11.71N$ and $306.26{\pm}17.55N$, respectively. A statistical significance was detected with p=0.012. The average pull-out strength values of groups 2A and 2B were $388.73{\pm}17.03N$ and $299.84{\pm}17.52N$, respectively. A statistical significance was detected with p=0.012. Conclusion : The trans-endplate lumbosacral fixation method is a trustable fixation method with a stronger screw-bone purchase and offer a good alternative for surgeons specially in patients with osteoporosis.

• Steel and Composite Structures
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• 제18권4호
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• pp.985-1000
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• 2015

The method of cross-section analysis for different sections in a structural frame has been widely investigated since the 1960s for determination of sectional capacities of beam-columns. Many hand-calculated equations and design graphs were proposed for the specific shape and type of sections in pre-computer age decades ago. In design of many practical sections, these equations may be uneconomical and inapplicable for sections with irregular shapes, leading to the high construction cost or inadequate safety. This paper not only proposes a versatile numerical procedure for sectional analysis of beam-columns, but also suggests a method to account for residual stress and geometric imperfections separately and the approach is applied to design of high strength steels requiring axial force-moment interaction for advanced analysis or direct analysis. A cross-section analysis technique that provides interaction curves of arbitrary welded sections with consideration of the effects of residual stress by meshing the entire section into small triangular fibers is formulated. In this study, two doubly symmetric sections (box-section and H-section) fabricated by high-strength steel is utilized to validate the accuracy and efficiency of the proposed method against a hand-calculation procedure. The effects of residual stress are mostly not considered explicitly in previous works and they are considered in an explicit manner in this paper which further discusses the basis of the yield surface theory for design of structures made of high strength steels.

• 한국임상약학회지
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• 제25권4호
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• pp.246-253
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• 2015

Background & Object: Ankylosing spondylitis (AS) is a chronic inflammatory disease that causes ankylosis and deformation of axial joints. Since current medicine cannot cure the disease yet, alleviating pain and preventing deformation with medications are the main therapy for patients with AS. The key medications for these purposes include nonsteroidal anti-inflammatory drugs (NSAIDs), and tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$) inhibitors. This study aims to analyze prescribing patterns of AS patients in South Korea. Method: National Patients Sample data compiled by the Health Insurance Review and Assessment Service from 2013 was analyzed. Patients with AS were identified with Korean Standard Classification of Diseases code-6, which was M45. The rates of prescription, discontinuation, and switching ingredients were calculated for each medication during 2013. Results: Total number of patients was 655, and most of them were male (n = 514, 78.5%). Of all age groups, the proportion of 30-40 year old patients was the greatest (35.1%). The most utilized drug class was NSAIDs (82.4%). Less than half of patients were prescribed $TNF-{\alpha}$ inhibitors (n = 212, 32.4%). Meloxicam, aceclofenac, and celecoxib were the most frequently prescribed NSAIDs. In case of $TNF-{\alpha}$ inhibitors, adalimumab, etanercept and infliximab were the top three most prescribed drugs. Although not recommended by the current practice guideline, significant proportions of patients were identified using disease modifying anti-rheumatic drugs (DMARDs). Conclusion: Considering the current practice guideline and previous studies about the efficacy, the use of DMARDs should be reduced and medical insurance term in South Korea should be re-examined.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.1207-1210
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• 2004

As many humans age, degenerative lumbar spinal stenosis (DLSS) becomes a major cause of lower limb discomfort and disability. By surgical treatment method of DLSS, the existing surgical treatment methods using internal fixation have showed degeneration changes of an adjacent vertebrae and loss of lumbar spine lordosis-kyphosis due to eliminating a motion. For solving the problems of internal fixation, a novel interspinous spacer has been developed to treat DLSS by surgical treatment method. In this study, we evaluated the biomechanical effects of the interspinous spacer on the kinematics of the porcine lumbar spine before and after insertion of the implant. For this purpose, a device that is capable of measuring 3-D motions were built based on direct linear transformation (DLT) algorithm written with MATLAB program. Results showed that in extension, a change of the mean angle between the intact and the implanted specimens at L4-L5 was 1.87 degree difference and the implant reduced the extension range of motion of the L4-L5 (p＆lt;0.05). But the range of motion in flexion, axial rotation and lateral bending at the adjacent segments was not statistically affected by the implant. In conclusion, we thought that interspinous spacer may have remedical value for DLSS by flexing human lumbar spine.

• Journal of Korean Neurosurgical Society
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• 제29권11호
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• pp.1461-1468
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• 2000

Objective : The aim of this study is to evaluate clinical outcome of anterior screw fixation for type II odontoid fractures for the prliematim of atlanatoaxial mobility. Methods : Between 1995 and 1999, we treated 15 cases of type II odontoid fractures by anterior screw fixation among 44 cases of odontoid fractures. Thece included 14 males and 1 female aged from 23 to 63 years, with a mean age of 39.7 years. The causes of trauma were traffic accident in 13 cases, slip down in 1 and fall down in 1. The fracture type was type II-P in 7 cases, type II-A in 3, type II-N in 2 and type II-A and P in 3. The fracture line was oblique downward and backward in 6 cases, oblique downward and forward in 3 and horizontally in 6. The range of follow up was 4 to 47 months(mean 26.5 months). Results : Adequate reduction and fixation were obtained in 12 cases. Three cases in which fracture type and line were type II-A and oblique downward forward were failed, so posterior transarticular screw fixation was performed. All except 3 failed cases had adequate cervical movement and stability. There were no operative mortality nor morbidity. Conclusion : Anterior screw fixation provides the best anatomical and functional results for type II odontoid fracture with intact transverse ligament when fracture line is horizontal or oblique downward and backward. But it is limited when fracture line is oblique downward and forward.

• Journal of Korean Neurosurgical Society
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• 제56권2호
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• pp.86-90
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• 2014

Objective : The spot sign is related with the risk of hematoma expansion in spontaneous intracerebral hemorrhage (ICH). However, not all spot sign positive patients undergo hematoma expansion. Thus, the present study investigates the specific factors enhancing the spot sign positivity in predicting hematoma expansion. Methods : We retrospectively studied 316 consecutive patients who presented between March 2009 to March 2011 with primary ICH and whose initial computed tomography brain angiography (CTA) was performed at our Emergency Department. Of these patients, 47 primary ICH patients presented spot signs in their CTA. We classified these 47 patients into two groups based on the presence of hematoma expansion then analyzed them with the following factors : gender, age, initial systolic blood pressure, history of anti-platelet therapy, volume and location of hematoma, time interval from symptom onset to initial CTA, spot sign number, axial dimension, and Hounsfield Unit (HU) of spot signs. Results : Of the 47 spot sign positive patients, hematoma expansion occurred in 26 patients (55.3%) while the remaining 21 (44.7%) showed no expansion. The time intervals from symptom onset to initial CTA were $2.42{\pm}1.24$ hours and $3.69{\pm}2.57$ hours for expansion and no expansion, respectively (p=0.031). The HU of spot signs were $192.12{\pm}45.97$ and $151.10{\pm}25.14$ for expansion and no expansion, respectively (p=0.001). Conclusions : The conditions of shorter time from symptom onset to initial CTA and higher HU of spot signs are the emphasizing factors for predicting hematoma expansion in spot sign positive patients.

• Journal of Trauma and Injury
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• 제32권4호
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• pp.195-201
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• 2019

Purpose: This study was conducted to investigate the usefulness of a polyester urethane dural substitute (Neuro-Patch^®, B. Braun, Boulogne, France) as an anti-adhesion agent in subsequent cranioplasty by analyzing the use of Neuro-Patch^® during decompressive craniectomy in traumatic brain injury patients. Methods: We retrospectively analyzed patients with traumatic brain injury who underwent decompressive craniectomy followed by cranioplasty from January 2015 to December 2018. Patients were analyzed according to whether they received treatment with Neuro-Patch^® or not (Neuro-Patch^® group, n=71; control group, n=55). Patients' baseline characteristics were analyzed to identify factors that could affect cranioplasty results, including age, sex, hypertension, diabetes mellitus, use of antiplatelet agents or anticoagulant medication, the interval between craniectomy and cranioplasty, and the type of bone used in cranioplasty. The cranioplasty results were analyzed according to the following factors: operation time, blood loss, postoperative hospitalization period, surgical site infection, and revision surgery due to extra-axial hematoma. Results: No significant difference was found between the two groups regarding patients' baseline characteristics. For the cranioplasty procedures, the operation time (155 vs. 190 minutes, p=0.003), intraoperative blood loss (350 vs. 450 mL, p=0.012), and number of surgical site infections (4 vs. 11 cases, p=0.024) were significantly lower in the Neuro-Patch^® group than in the control group. Conclusions: The use of Neuro-Patch^® was associated with a shorter operation time, less blood loss, and a lower number of surgical site infections in subsequent cranioplasties. These results may provide a rationale for prospective studies investigating the efficacy of Neuro-Patch^®.

• Journal of Korean Neurosurgical Society
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• 제58권6호
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• pp.534-538
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• 2015

Objective : To correct apical vertebral rotation for adolescent idiopathic scoliosis (AIS), direct vertebral derotation (DVD) or simple rod rotation (SRR) might be considered. The aim of the present study is to introduce the surgical experiences of AIS by a Korean neurosurgeon and to evaluate the effectiveness of SRR for apical vertebral rotation. Methods : A total of 9 patients (1 male and 8 females) underwent scoliosis surgery by a neurosurgeon of our hospital. The Lenke classifications of the patients were 1 of 1B, 2 of 1C, 1 of 2A, 1 of 2C, 3 of 5C and 1 of 6C. Surgery was done by manner of simple rod rotation on the concave side and in situ coronal bending. Coronal Cobb's angles, vertebral rotation angles and SRS-22 were measured on a plain standing X-ray and CT before and after surgery. Results : The mean follow up period was 25.7 months (range : 5-52). The mean number of screw positioning level was nine (6-12). The mean age was 16.4 years (range : 13-25) at surgery. The mean Risser grade was $3.7{\pm}0.9$. The apical vertebral rotation measured from the CT scans was $25.8{\pm}8.5^{\circ}$ vs. $9.3{\pm}6.7^{\circ}$ (p<0.001) and the Coronal Cobb's angle was $53.7{\pm}10.4^{\circ}$ vs. $15.4{\pm}6.5^{\circ}$ (p<0.001) preoperatively and postoperative, respectively. The SRS-22 improved from 71.9 preoperatively to 90.3 postoperatively. There were no complications related with the operations. Conclusion : SRR with pedicle screw instrumentation could be corrected successfully by axial rotation without complications. SRR might serve as a good option to correct AIS deformed curves of AIS.

• 치과방사선
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• 제27권1호
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• pp.179-188
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• 1997

This study was intended to compare the diagnostic ability between Waters' radiograph and CT in the diagnosis of midfacial fracture. The study group included 44 patients(male:32, female :12, age range :16-74 years old) with facial injury who underwent surgery. Waters' radiograph and both axial and coronal scanning were performed before surgery. Three oral radiologists and three non-oral radiologist interpreted 44 Waters' radiographs and 88 CT in three ways; 1) interpretation using Waters' radiograph only, 2) interpretation using CT only, 3) interpretation using Waters' radiograph and CT. The interpretation sites were confined to the walls of maxillary sinus; anterior, posterior, medial, lateral and superior wall. ROC curves were made with the findings during surgery as a gold standard except the posterior wall, where the joint evaluation of Waters' radiograph and CT by other three oral radiologists was used. ROC areas were compared according to the interpreting methods, the interpretation sites, and groups (R group ; oral radiologist group, N group ; non-oral radiologist group). The obtained results were as followed : 1. The diagnostic ability of CT only and Waters' radiograph and CT was higher than Waters' radiograph only in both groups(P<0.05). But there was no difference between CT only and Waters' radiograph and CT. 2. Generally, the diagnostic ability for the lateral antral wall was the highest and that for the posterior antral wall was the lowest in both groups(P<0.05). 3. In R group, for the anterior antral wall the diagnostic ability using CT only was increased but for the medial, lateral and superior antral walls the diagnostic ability was increased in only using Waters' radiograph and CT. 4. In N group, for the anterior and medial walls the diagnostic ability using CT only was increased. But for the posterior, lateral and superior antral walls there were no difference among three interpreting methods. 5. The diagnostic ability of R group was higher than N group in all interpreting methods.