• Journal of the HCI Society of Korea
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• v.2 no.1
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• pp.33-39
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• 2007

Because of the cognitive overload which is caused by the complicated information structure, Digital Convergence product interferes with the effective retrieval of the information from the menu. Two methods have been used to alleviate that cognitive overload by making an effective menu structure; physical menu structure method which is related with the width and depth of the menu, semantic menu structure method which is related with the menu title. In this research, we tried to demonstrate the effectiveness of the menu structure designing method by suggesting a new semantic methodology which uses the Fixation and Fixation duration which are accompanied by the visual search. Because the Fixation is automatically processed by the human cognitive model, we could easily recognize whether the information structure is correspond to the cognitive model or not. From this fact we established the hypothesis that the number of cognitively well established menu structures are fewer than that of the wrongly designed menu structures in terms of the Fixation number and Duration. To verify this hypothesis, we compared the Fixation number and Duration of the modified menu structures with those of the original menu structures by using the Eye-Tracking experiment. As a result, we could find the significant decrease of the Fixation number and Duration after modification. Therefore we could recognize that the modified menu structure was more effective than the original menu structure. In sum, the newly suggested menu structure designing methodology which uses the Fixation and Fixation Duration accompanied by the visual search was proved to be a very effective method.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.1
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• pp.32-38
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• 2005

The efficacy of bioresorbable fixation has recently been described in the osseosynthesis of the oral & maxillofacial region. However, a liitle data exist regarding the use of biodegradable plates and screws for the internal fixation of human mandible fractures. The purpose of this study is to analyze and compare the treatment of mandibular fractures by using a bioresorbable fixation system with conventional titanium system in human mandible fractures. eighteen patients constituted the bioresorbable fixation group and twenty-five patients constituted the titanium fixation group. Both groups underwent open reduction and internal fixation by use of a bioresorbable system or a titanium fixation system. Panoramic radiograph were obtained preoperatively, immediately postoperatively after reduction, at 6 months and at 12 months postoperatively. In the bioresorbable fixation group, complication(infection) occurred in 1 patient(5.6%) and was resolved by incision & drainage, plate removal and antibiotics without untoward sequelae. 2 patients(8.0%) experienced complications in the titanium fixation group and were treated using conservative treatment. There was no statistical difference in complication rates between two groups. Our data supported the use of bioresorbale plate fixation in mandibular fractures as a means of avoiding the potential and well documented problems with rigid titanium fixation systems. In conclusion, the bioresorbable fixation system provide a reliable and sufficient alternative to conventional titanium plate system.

• Archives of Plastic Surgery
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• v.44 no.1
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• pp.53-58
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• 2017

Background Adequate fixation of replanted digits is essential not only for short-term healing but for long-term function. Various bony fixation methods using Kirschner (K-) and intraosseous wire are available in replantation. We examined clinical and radiographic outcomes of fixation methods on bone union after digital replantation. Methods A single institutional retrospective review identified 992 patients who had undergone 1,247 successful replantations between July 2009 and September 2015. Exclusion criteria included amputations of the distal phalanx, comminuted fractures, and intra-articular fractures. Patients were classified according to 5 categories of fixation methods: single K-wire, double longitudinal K-wires, cross K-wires, wire with, and wire without K-wire support. Bone union was evaluated by 5-month postoperative X-ray and fixation outcomes were compared across the 5 groups. Results The exclusion criteria were applied, and 88 patients with 103 replanted digits remained for analysis. Single K-wire fixation was used in 40 digits, double longitudinal K-wires in 30, and cross fixation in 14. Wire with and without K-wire support was required in 15 and 4 digits. Nonunion was observed in 32 digits (31.1%), of which 13 required additional operations such as bone graft or corrective osteotomy. The highest percent of nonunion was observed after cross fixation (35.7%) and the lowest after wire alone (25.0%). Conclusions In this study, contrary to general knowledge, we found that single K-wire fixation was not associated with poorer outcomes. Successful bone union outcomes may be achieved by careful selection of bone fixation methods. This study provides useful information for planning bone fixation in digital replantation.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.4
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• pp.539-550
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• 2014

Purpose: This research was designed to figure out if there are changes based on types of vergence fixation disparity curve after optical correction and vision training to for people with steep slope of forced vergence fixation disparity curve and symptoms. Methods: For 30 subjects out of 91 subjects, who have steep slopes of fixation disparity curve examined with Wesson Fixation Disparity Card and symptoms about steep slope of fixation disparity curve, proper vision training was offered for 5 weeks. Results: After Vision training for 30 people with the symptoms of type I, II, III, IV for 5 weeks, slope of fixation disparity curve was significantly changed (p=0.013), and the results of binocular vision test and subjective symptoms were also significantly improved. Conclusions: Vision training can not only affect the change of fixation disparity curve, but also relieve the symptoms. Fixation disparity curve has lots of visual function information of the subject and can be suggested as a guideline for prescribing.

• Archives of Plastic Surgery
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• v.39 no.4
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• pp.284-290
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• 2012

Open reduction and anatomic reduction can create better function for the temporomandibular joint, compared with closed treatment in mandible fracture surgery. Therefore, the double miniplate fixation technique via mini-retromandibular incision was used in order to make the most stable fixation when performing subcondylar fracture surgery. Those approaches provide good visualization of the subcondyle from the posterior edge of the ramus, allow the surgeon to work perpendicularly to the fracture, and enable direct fracture management. Understanding the biomechanical load in the fixation of subcondylar fractures is also necessary in order to optimize fixation methods. Therefore, we measured the biomechanical loads of four different plate fixation techniques in the experimental model regarding mandibular subcondylar fractures. It was found that the loads measured in the two-plate fixation group with one dynamic compression plate (DCP) and one adaption plate showed the highest deformation and failure loads among the four fixation groups. The loads measured in the one DCP plate fixation group showed higher deformation and failure loads than the loads measured in the two adaption plate fixation group. Therefore, we conclude that the selection of the high profile plate (DCP) is also important in order to create a stable load in the subcondylar fracture.

• Journal of Korean Neurosurgical Society
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• v.61 no.2
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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.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.25 no.4
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• pp.361-366
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• 1999

Intermaxillary fixation is routine procedure to oral and maxillofacial area in jaw bone fracture, surgical correction of jaw deformity, osseus reconstruction of jaw. After transoral surgery, accompanied by intermaxillary fixation, dysphagia or airway obstruction may be followed due to blood clot, vomitus, or laryngeal spasm resulting from irritation by blood or secretions. Lingual or pharyngeal edema is other contributing factors of airway obstruction. In addition, intermaxillary fixation itself may cause obstruction of airway. In this study, pulmonary function test and arterial blood gas analysis were evaluated before and after intermaxillary fixation in 30 patients suffered from mandibular fractures. Comparative analysis was performed by estimated values. The results were as followed. 1. The spirometric values of FEV1, FEV1/FVC and FEF25-75% without intermaxillary fixation were reduced from 97.57%, 85.1%, 98.3,% to 71.7%, 66.5%, 61.2% with intermaxillary fixation, indicating the presence of obstructive pulmonary impairment. 2. Spirometric value of MVV, as the most influencing value of sensitive to extrapulmonary factors, was changed from 84.5% to 46.48%. 3. After intermaxillary fixation, the spirometric value of FVC, as indicator of restrictive pattern of pulmonary function, was not reduced significantly as measured from 94.47% to 89.97%. 4. $O_2$ saturation of arterial blood gas analysis without intermaxillary fixation was 97.86%. While intermaxillary fixation, $O_2$ saturation was 97.47%. The results indicate that careful airway management is mandatory undergoing intermaxillary fixation of various oral and maxillofacial surgery.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.2
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• pp.127-135
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• 2009

Objectives : The titanium fixation system has been used in orthognathic surgery for fixation of bone segments usually, but the biodegradable fixation system was developed and also being used. The strongest point in the biodegradable system is that no extra operation should be needed to remove fixation materials. In spite of this merit, oral & maxillofacial surgeons hesitate to use this system in fracture or orthognathic surgery. In this study, as we got some clinical experiences, we'd like to report the result of clinical study using the biodegradable fixation system in orthognathic surgery. Patients and Methods : A total of 35 patients composed of 17 males and 18 females with 25 osteotomies in maxilla and 34 osteotomies in mandible were fixated with the biodegradable fixation system(Inion $CPS^{(R)}$). We investigated methods of stabilization, fixation time, and complications on the basis of the method as above. Results : Four 2mm thick L shaped plates with 7 holes of which 1 hole was removed were fixed in maxilla with six $2.0{\times}7mm$ screws. Three $2.5{\times}16{\sim}18mm$ screws were used to fix superior ramus area and one mandibular angle area in mandible. It took about 27.4 minutes in maxilla, 25.3 minutes in mandible to perform the fixation which took longer time than the titanium system(9.5 minutes in maxilla, 8 minutes in mandible). Generally, there was no problem except 9 cases in which there were some complications. Conclusions : In most cases, the biodegradable fixation system can be used without problem in usual orthognathic surgery. But, this system is inferior to the titanium fixation one in some respects such as fixation time, size, and physical property. Some supplementations for such weak points as aforementioned should be needed for the universal use of biodegradable materials.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.3
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• pp.175-181
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• 2002

Intermaxillary fixation and occusal splint are routine procedure for maxillofacial fracture and orthognathic surgery. When these methods could obstruct oral airway the patients who kept intermaxillary fixation and occusal splint in their mouth, are very difficult to breath after surgery. Nasal bleeding and pharyngeal edema due to nasotracheal intubation, residual effect of muscle relaxants, and anesthetic agent could be contributing factor of airway obstruction. In this study, pulmonary function test was evaluated before and after intermaxillary fixation, and intermaxillary fixation with occusal splint in 22 volunteers. The results were as follows 1. FVC, %FVC, $FEV_1$, $FEV_1%$, PEF, $PEF_{50}$, MVV without intermaxillary fixtion were 4.45L, 88%, 4.03L, 90.9%, 10.26L/s, 5.53L/s, and 136.14L/min, and with intermaxillary fixation were 3.51L, 68.67%, 3.06L, 69.39L, 6.52L/s, 3.94L/s, and 69.39L/min. The results with intermaxillary fixation and occusal splint were 2.15L, 42.41%, 1.71L, 38.81%, 2.83L/s, 1.74L/s, and 37.14L/min. 2. Compared with before and after intermaxillary fixation, all values of pulmonary function test were decreased and after intermaxillary fixation and intermaixillary fixation with occulasal splint, the results were decreased. 3. MVV and PEF were decreased significantly with interaxillary fixtion and occusal splint, and FVC was less decreased. It meant that intermaxillary fixation and occluasal splint induced reduction of respiratory flow significantly, but less reduction of respiratory volume. 4. Intermaxillary fixation and occulsal splint induced increase of airway resistance, decrease of expiratory volume and air flow. So severe respiratory difficulty could be seen to all volunteers who kept intermaxillary fixtion and occusal splint. 5. In classification of respiratory difficulty, intermaxillary fixation with occulsal splint induced complex respiratory difficulty more than intermaxillary fixation only did. From the above results, doctors who care patients kept intermaxillary fixation and occusal splint should be aware of respiratory depression caused by these treatment.

• Journal of Korean Neurosurgical Society
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• v.42 no.4
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• pp.305-310
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• 2007

Objective : Combined antero-posterior fixation has been a standard method for bilateral interfacetal dislocation in cervical spine. The purpose of this study is to evaluate the efficacy and complication of anterior cervical stabilization in treatment of bilateral interfacetal dislocation. Methods : A total of 65 cases of traumatic bilateral interfacetal dislocation in cervical spine who were managed in our institution, from Mar. 1997 to Feb. 2006, were included in this study. Closed reduction was tried in all cases before operation. If closed reduction was accomplished successfully, only anterior cervical fixation was performed (Group I), and attempted to place screws bicortically as possible with unicortical screws. If failed, posterior open reduction with fixation was first tried, followed by anterior cervical fixation (Group II). All patients were evaluated for neurological outcome and radiological evidence of healing. Results : The Group I included 47 patients and the Group II, 18 patients. The improvement of Frankel grade and increase of mean cervical lordosis angles were not statistically different between two groups. Screw-plate system used did not influence the outcome. On follow up, solid bone fusion was evident and there were no cases of instability in both groups. Conclusion : Our study demonstrated that anterior cervical fixation on BID is safe and effective in comparison with combined antero-posterior cervical fixation.