• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.2
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• pp.217-223
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• 2005

The term 'impaction teeth' is used to designate a tooth which remains unerupted in jaw beyond the time at which it should normally be erupted. Most cases of impacted teeth reported in the literature are permanent teeth. The impaction of primary teeth occur rarely whereas impaction of second primary molars is more numerous than all other impactions. Failure of eruption of primary teeth may cause a number of complications, such as interference with development and eruption of successive permanent teeth, malocclusion, cystic change of tooth follicle. The clinican should consider the various treatment option available (a) No treatment and observation, (b) surgical extraction (c) space regainer. Proper treatment plan should be established after thought consideration of impacted tooth and it's relation with successive permanent tooth.

• The korean journal of orthodontics
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• v.31 no.1 s.84
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• pp.1-13
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• 2001

The extraction lot orthodontic treatment can be adopted for aligning crowded dentition, improving facial esthetics and solving a skeletal discrepancy as alternative for a surgical option. Mandibular second premolar extraction was often selected as treatment plan when there we very little or no space shortage in lower arch or limited retraction of the lower incisors was required. The primary object of this study was evaluate a pretreatment condition and examine the amount of tooth movement ior a mandibular second premolar extraction in growing patients. Pretreatment and posttreatment lateral cephalograms of 14 cases that had their four first premolar extracted (4/4 group), 15 cases with upper first and lower second premolar extraction (4/5 group) were selected. Structural method superimposition was conducted to evaluate a difference of dental change between 4/4 and 4/5 group. The results were as follows, 1. Pretreatment factor for 4/4 extraction or 4/5 extraction choice included maxillary incisor axis to occlusal plane, Class II molar relationship, IMPA and interincisal angle. 2. The amount of molar anterior movement in 4/5 group was greater than that of 4/4 group(p<0.05). 3. There was no significant difference between 4/4 group and 4/5 group in aspects of maxillary tooth movement(p<0.05).

• Restorative Dentistry and Endodontics
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• v.35 no.5
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• pp.395-400
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• 2010

The development of adhesive dentistry has allowed that the crown fragment reattachment can be another option in the treatment of crown fracture. However, additional crown lengthening procedure or extrusion of the tooth may be necessary in the treatment of crown root fracture because subgingival fracture line in close proximity to the alveolar bone leads to challenges for restorative procedure and the violation of the biologic width. This case report presents a modified crown fragment reattachment technique of crown root fracture with pulp exposure, which was done without additional crown lengthening procedures. After the endodontic treatment, the patient was treated using a post insertion and the fragment reattachment technique, which made it possible to preserve the space for the biologic width and maintain a dry surgical field for adequate adhesion through the modification of the fractured coronal fragment. Since a coronal fracture was occurred and reattached afterward, it was observed that the coronal fragment was well maintained without the additional loss of periodontal attachment through 2-year follow up.

• Geomechanics and Engineering
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• v.35 no.1
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• pp.29-39
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• 2023

As the intensity of urban underground space development increases, more and more tunnels are planned and constructed, and sometimes it is inevitable to encounter situations where tunnels have to underpass the river embankments. Most previous studies involved tunnels passing river embankments perpendicularly or with large intersection angle. In this study, a project case where two EPB shield tunnels with 8.82 m diameter run parallelly underneath a river embankment was reported. The parallel length is 380 m and tunnel were mainly buried in the moderate / slightly weathered clastic rock layer. The field monitoring result was presented and discussed. Three-dimensional back-analysis were then carried out to gain a better understanding the interaction mechanisms between shield tunnel and embankment and further to predict the ultimate settlement of embankment due to twin-tunnel excavation. Parametrical studies considering effect of tunnel face pressure, tail grouting pressure and volume loss were also conducted. The measured embankment settlement after the single tunnel excavation was 4.53 mm ~ 7.43 mm. Neither new crack on the pavement or cavity under the roadbed was observed. It is found that the more degree of weathering of the rock around the tunnel, the greater the embankment settlement and wider the settlement trough. Besides, the latter tunnel excavation might cause larger deformation than the former tunnel excavation if the mobilized plastic zone overlapped. With given geometry and stratigraphic condition in this study, the safety or serviceability of the river embankment would hardly be affected since the ultimate settlement of the embankment after the twin-tunnel excavation is within the allowable limit. Reasonable tunnel face pressure and tail grouting pressure can to some extent suppress the settlement of the embankment. The recommended tunnel face pressure and tail grouting pressure are 300 kPa and 550 kPa in this study, respectively. However, the volume loss plays the crucial role in the tunnel-embankment interaction. Controlling and compensating the tunneling induced volume loss is the most effective measure for river embankment protection. Additionally, reinforcing the embankment with cement mixing pile in advance is an alternative option in case the predicted settlement exceeds allowable limit.

• The Journal of Korean Academy of Prosthodontics
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• v.62 no.3
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• pp.193-200
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• 2024

In patients with severe alveolar bone resorption on mandibular anterior edentulous areas, it can be difficult to place implants in the location for crowns, and to create the fixed prosthesis having an adequate emergence profile or embrasure, which makes maintenance difficult. Fabricating a removable zirconia prosthesis with a milled bar on poorly positioned implants can be a good option because of easy maintenance. In this case, the patient had severe bone resorption on mandibular anterior region, and large vertical space. We report on the aesthetical and easy-to-maintain results by placing two implants and fabricating a zirconia prosthesis using milled bar.

• Journal of Chest Surgery
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• v.41 no.5
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• pp.568-572
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• 2008

Background: Minimally invasive surgery is currently popular, but this has been applied very sparingly to cardiac surgery because of some limitations. Our study evaluated the safety and efficacy of atrial septal defect (ASD) closure through a video-assisted mini-thoracotomy. Material and Method: Fifteen patients were analyzed. Their mean age was $31{\pm}6$ years. The mean ASD size was $24{\pm}5mm$ and there were 3 cases of significant tricuspid regurgitation. The working window was made through the right 4th intercostal space via a $4{\sim}5cm$ inframammary skin incision, CPB was conducted with performing peripheral cannulation. After cardioplegic arrest, the ASDs were closed with a patch (n=11) or direct sutures (n=4), and the procedures were assisted by using a thoracoscope. There were 3 cases of tricuspid repair and 1 case of mitral valve repair. The mean CPB time and aortic occlusion time were $160{\pm}47\;and\;70{\pm}26 $minutes, respectively. Result: There was no mortality, but there were 3 minor complications (one pneumothorax, one wound dehiscence and one arrhythmia). The mean hospital stay was $5.9{\pm}1.8$ days. The mean follow-up duration was $10.7{\pm}6.4$ months. The follow-up echocardiogram noted no residual ASD or significant tricuspid regurgitation. Three patients suffered from pain or numbness. Conclusion: This study showed satisfactory clinical and cosmetic results. Although the operative time is still too long, more experience and specialized equipment would make this technique a good option for treating ASD.

• Journal of Chest Surgery
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• v.43 no.4
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• pp.404-408
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• 2010

Background: Pleural symphysis is regarded as an important treatment option in reducing recurrence rates after surgical treatment of spontaneous pneumothorax. However, there is much debate over the best method for achieving pleural symphysis. We retrospectively compared apical pleurectomy (AP) with mechanical pleural abrasion (MPA). Material and Method: Between January 2000 and December 2007, 83 patients underwent video-assisted thoracoscopic surgery (VATS) for spontaneous pneumothorax. In addition to wedge resection of bullae, MPA was performed in 21 patients (group A) and AP in 62 patients (group B). Result: There were no significant differences in age, gender and site of pneumothorax between the two groups. Operative time was $97{\pm}44$ minutes in group A and $77{\pm}18$ minutes in group B (p>0.05). The mean amount of pleural drainage through the chest tube on the first postoperative day was $156{\pm}87 cc$ in group A and $147{\pm}87 cc$ in group B (p>0.05). There was no mortality or significant morbidity in all patients with the exception of reoperation for bleeding in two patients in group B. In the postoperative course, there were no statistical differences between the two groups in the rate of residual air space, air leak and indwelling time of chest tube, and hospital stay. Mean follow up time was $31.7{\pm}25.3$ months, and the recurrence rate of pneumothorax was 9.5% (2/21) in group A and 6.5% (4/62) in group B, without statistical significance. Conclusion: AP was no more advantageous than MPA in terms of operative time, postoperative course and prevention of recurrent pneumothorax. Therefore, complete resection of bullae and existence of residual bullae are more important factors in reducing the incidence of recurrent pneumothorax than pleural symphysis.

• Tuberculosis and Respiratory Diseases
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• v.60 no.1
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• pp.72-75
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• 2006

Background : This report reviews our experience with persistent air leaks in the peumothorax that were not considered candidates for surgical treatment in order to evaluate the efficacy and risks of the OK-432 plus autoblood or OK-432 pleurodesis. Material & Methods : From March 2004 to July 2005, 8 consecutive patients who had an air leak in the pneumothorax over 5 days and had been treated with OK-432 plus autoblood or OK-432 pleurodesis. The patients were not considered candidates for surgical treatments because the chest CT findings revealed severe chronic lung disease with multiple bullae and/or bullous changes. A prolonged air leak with/without dead space was treated with either OK-432 plus autoblood or OK-432 pleurodesis. The efficacy and side effects of OK-432 pleurodesis were assessed by determining the duration of the air leak, the number of pleurodesis, the patients' symptoms, measurements of the white blood cell count and the c-reactive protein level. Results : All of eight patients were male and the mean age was $72.4{\pm}8.5$. The mean number of pleurodesis was $1.9{\pm}1.1$ and the mean duration of the air leak was $4.6{\pm}4.6days$ after pleurodesis. Side effects after pleurodesis were encountered in 7 patients, which included a chilling sensation in 7 cases, chest pain in 5 cases, headache in 3 cases, local heat sensation in 2 cases, and fever in 1 case. Leukocytosis was observed in 6 patients, and the mean of WBC count and CRP were $14500{\pm}2100$ and $21.9{\pm}11.4mg/dL$, respectively. Conclusion : Either OK-432 plus autoblood or OK-432 pleurodesis has acceptable side effects, and can be considered a treatment option for persistent air leaks in the pneumothorax that are not candidates for surgical treatment.

• Journal of the Korean Orthopaedic Association
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• v.56 no.6
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• pp.512-518
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• 2021

Purpose: This study compared the change in foraminal space on magnetic resonance imaging (MRI) and the clinical outcome after anterior cervical discectomy and fusion (ACDF) versus foraminotomy in cervical foraminal stenosis. Materials and Methods: A retrospective case-control study was conducted from January 2018 to March 2019 on 186 patients who underwent ACDF and foraminotomy. One hundred and two cases were selected considering age, sex, and body mass index. MRI was performed before and on the 5^th day after surgery to compare the changes in the foraminal diameter between the ACDF group (group A-51) and foraminotomy group (group B-51). Results: Between groups A and B, the average change in foraminal vertical diameter was 1.7 mm and 1.2 mm, respectively; group A was 0.5 mm larger difference (p=0.042). The average change in foraminal transverse diameter was 1.2 mm and 1.8mm, respectively; group B showed a 0.6 mm larger change (p=0.21). Both the neck disability index (NDI) and Japanese orthopaedic association (JOA) scores improved in both groups. Group A showed more improvement, but there was no significant difference (p=0.356, p=0.607, respectively). Conclusion: Foraminotomy is a useful option for patients with foraminal stenosis of the cervical spine because it showed comparable clinical and morphological results to ACDF and could minimize motion segment loss and muscle and ligament damage.

• Journal of Service Research and Studies
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• v.13 no.4
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• pp.131-141
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• 2023

Changes in consumer needs and behaviors according to lifestyle changes lead to consumption culture, affecting the automobile market. However, research and research to provide options tailored to the lifestyle of consumers in related markets are still insufficient. Focusing on pickup truck accessories applied to pickup trucks that reflect lifestyle the most among vehicle types, this study first examined the theoretical background of the aftermarket market and lifestyle of pickup trucks. Second, through image mapping, the market possibilities and opportunity factors of pickup trucks were discovered through market size analysis and possibilities, and through this, user types could be classified. Third, interviews were conducted with those representing user types, the contents were organized, and interviews were conducted centering on related groups to create a persona of a user group, and what needs each group's persona wanted. Finally, a design concept suitable for the issue keywords and insights derived for each user lifestyle type was presented. In this study, the user type was divided into ① outdoor activity type, ② hobby activity type, and ③ small-scale work type, and a design case study was conducted by applying the concept suitable for the keyword for each group. For the outdoor activity type, a variable storage structure and a living space-type accessory design were presented, and for the hobby type, a modular decktop design and a sports coupe-type hardtop design were presented. For the small business type, a partition that is easy to fix the load and a stepper design that is easy to board the cargo box were presented. It is expected that the size of the pickup truck aftermarket will be expanded by diversifying the option designs that users want by lifestyle by applying them to the development of pickup truck accessories that fit the lifestyle of pickup truck users in the automobile market, which is currently mass customized.