• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.04a
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• pp.73-76
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• 2001

We have simulated the effect of fracture characteristics on reduction of effective permeability of the fractured rocks due to in-situ bacteria growth. A nutrient is injected continuously for growth of in-situ bacteria. We used a power law for fracture length distribution and a fBm for fracture aperture spatial distribution. The results show that in-situ bacteria growth reduces the Permeability hyperbolically, but the porosity of backbone fracture does not change significantly. It shows that reduction of the permeability proceeds at faster speed for smaller value of length exponent(a) and for larger value of Hurst exponent(H). The fracture length distribution has stronger effect on speed of reduction than the aperture spatial distribution. The time needed to reduce permeability is inversely proportional to the hydraulic gradient.

• Archives of Plastic Surgery
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• v.34 no.4
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• pp.461-465
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• 2007

Purpose: Nasal bone fracture may be the most common fracture among facial trauma. However, diagnosis and treatment tend to be overlooked while the reduction and maintenance of fragments remain complicated. Thus, the results are plagued with high rate of nasal deformity which leads cosmetic and functional discomfort. We took advantage of the fact that the nasal bone is one of the thinnest facial bone while at the same time being located close to the skin and utilized ultrasound in performing reduction of nasal bone. Methods:This method was performed on 25 patients with nasal bone fracture. The CL 15-7 linear array transducer (10-15MHz) ultrasound which provides a total of 7 views (3 axial views and 4 transverse views) of the elevator under the bony fragments was enough for the surgeon to accurately perform the reduction. Results: In our class, an accurate and precise reduction has been made possible by real time images before, during, and after the procedure with the help of ultrasound while reducing the exposure to radiation. Conclusion: Compared to previous methods, satisfaction of patients has increased in the nasal tip, minimal fracture of the side wall and secondary reduction cases. Therefore, the incorporation of ultrasound in the closed reduction of nasal bone may prove to be a useful method.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.53.1-53.6
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• 2019

Background: The nasal bone is the most protruding bony structure of the facial bones. Nasal bone fracture is the most common facial bone fracture. The high rate of incidence of nasal bone fracture emphasizes the need for systematical investigation of epidemiology, surgical techniques, and complications after surgery. The objective of this study is to investigate the current trends in the treatment of nasal bone fractures and the effectiveness of closed reduction depending on the severity of the nasal bone fracture. Patients and methods: A total of 179 patients with a nasal bone fracture from 2009 to 2017 were enrolled. Their clinical examination, patient's records, and radiographic images of nasal bone fractures were evaluated. Results: Patients ranged from children to elderly. There were 156 (87.2%) males and 23 (12.8%) females. Traffic accident (36.9%) was the most common cause of nasal fracture. Orbit fracture (44 patients, 24.6%) was the most common fracture associated with a nasal bone fracture. Complications after surgery included postoperative deformity in 20 (11.2%) patients, nasal obstruction in 11 (6.1%) patients, and olfactory disturbances in 2 (1.1%) patients and patients with more severe nasal bone fractures had higher rates of these complications. Conclusion: Closed reduction could be performed successfully within 2 weeks after injury.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.19 no.2
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• pp.181-189
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• 1997

The mandible plays a crucial role in the vital human functions of breathing, eating, and speaking. No other bone in the body has such a distinctive shape and function. Because of its prominence in the facial structure, the mandible is highly prone to fracture. A clinical study on 122 patients with mandibular fracture who visited Kangnam General Hospital during 4 year(1992-1995) was done by analysing sex, age, cause, fracture site, teeth involvement, treatment method, complication and involvement of other body part. The results obtained were as follows : 1. The occurrence was more frequent in male than in female with the ratio of 5.4 : 1 and most frequently in twenties. 2. Violence was the most common cause of facial mandibular fracture. 3. In mandibular fracure, fracture site was average 1.5 sites, most frequently in symphysis and simple fracture was 86.1%. 4. As treatment methods, open reduction(78.6%) was used more frequently than closed reduction(21.4%). 5. Post-operational complication occurred in 27.0% of the cases. 6. Other injuries that were related to maxillofacial fracture occurred in 25.4%.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.48 no.5
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• pp.267-276
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• 2022

Objectives: Recently a modified high-submandibular approach (HSMA) has been introduced for treatment of condylar fracture. This approach involves an incision line close to the mandibular angle and transmasseteric transection, leading to a low incidence of facial palsy and allowing good visualization of the condyle area, especially the condylar neck and subcondyle positions. This study reports several cases managed with this modified HSMA technique for treating condylar fractures. Materials and Methods: Six cases of condylar fractures treated with modified HSMA technique were reviewed. Results: Three unilateral subcondylar fracture, 1 bilateral subcondylar fracture, 1 unilateral condylar neck fracture, 1 unlateral simultaneous condylar neck and subcondylar fracture cases were reviewed. All the cases were successfully treated without any major complication. Conclusion: Reduction, fixation, and osteosynthesis of condylar fractures via the modified HSMA technique enabled effective and stable treatment outcomes. Therefore, the described approach can be used especially for subcondylar and condylar neck fractures with minimal complications.

• Archives of Plastic Surgery
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• v.37 no.5
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• pp.619-625
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• 2010

Purpose: Trapdoor orbital blowout fracture is most common in orbital blowout fracture. Various materials have been used to reconstruct orbital floor blowout fracture. Absorbable alloplastic implants are needed because of disadvantages of nonabsorbable alloplastic materials and donor morbidity of autogenous tissue. The aim of the study is to evaluate usefulness of absorbable mesh plate as a reconstructive material for orbital blowout fractures. Methods: From December 2008 to October 2009, 18 trapdoor orbital floor blowout fracture patients were treated using elevator fixation, depressor fixation, or elevatordepressor fixation techniques with absorbable mesh plates and screw, depending on degree of orbital floor reduction, because absorbable mesh plates are less rigid than titanium plates and other artificial substitutes. Results: Among 18 patients, 5 elevator fixation, 4 depressor fixation, and 9 elevator and depressor fixation technique were performed. In all patients, postoperative computed tomographic (CT) scan showed complete reduction of orbital contents and orbital floor, and no displacement of bony fragment and mesh plate. Mean follow-up was 10 months. There were no significant intraoperative or postoperative complications. Conclusion: Three different techniques depending on the degree of orbital floor reduction are useful for open reduction and internal fixation of trapdoor orbital floor blowout fracture with absorbable mesh plates.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.6
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• pp.464-471
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• 2002

The purpose of this study was to evaluate the stress patterns within fractured mandibles generated by reduction forceps and to determine the optimal position of the reduction forcep. Twenty-seven mandibular models were fabricated using a photoelastic resin. Each of the three sets of mandible models prepared was osteotomized according to one of three different fracture types(symphysis, parasymphysis and body fractures). After reducing the cut segments, a reduction forcep was placed into different engagement holes to compress the segments. Photoelastic stress analysis was used to visualize the stress patterns within the fractured mandiblular models generated by the reduction forcep. In the case of symphysis or parasymphysis fractures, an optimum distribution of stress over the fracture site was achieved when placing the reduction forcep more than 12.5mm on either side of the fracture line between the midway level bisecting the mandible and 5mm below the level. In the case of body fractures, optimum stress distribution was achieved when the reduction forcep was placed more than 15mm from the fracture line on the midway level. In conclusion, a correct use of reduction forceps helps to provide a precise threedimensional reduction for mandibular fractures.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.1
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• pp.30-40
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• 2005

Purpose. The purpose of this study was to compare the fracture strength of the IPS Empress ceramic crown according to the incisal reduction (2.0mm, 2.5mm, 3.0mm) and axial inclination ($4^{\circ}$, $8^{\circ}$, $12^{\circ}$) of the upper canine. Material and methods. After 10 metal dies were made for each group, the IPS Empress ceramic crowns were fabricated and each crown was cemented on each metal die with resin cement. The cemented crowns mounted on the testing jig were inclined 30 degrees and the universal testing machine was used to measure the fracture strength. Results. 1. The fracture strength of the ceramic crown with 3.0mm depth and $12^{\circ}$ inclination was the highest (839N) Crowns of 2.0mm depth and $12^{\circ}$ inclination had the lowest strength (559N). 2. There was no significant difference in the fracture strength by axial inclination in the same incisal reduction group. 3. The fracture mode of the crowns was similar. Most of fracture lines began at the loading area and extended through proximal surface perpendicular to the margin irrespective of incisal reduction.

• Archives of Craniofacial Surgery
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• v.18 no.4
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• pp.238-242
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• 2017

Background: Conservative treatment is performed for isolated anterior wall of the maxillary sinus fractures, in many cases when the fracture is clinically not severe and asymptomatic. Despite the absence of symptoms, complications such as sinusitis, rhinitis, and chronic purulent secretion may develop; therefore, successful reduction is required. We attempted to reduce the risk of complications using an alternative technique: reduction of the fracture with two urinary balloon catheters inserted through the maxillary ostium and fixation using fibrin glue, which minimizes the damage to the bony fragments and sinus mucosa. Methods: In this study, 38 patients who were diagnosed with an isolated anterior wall of the maxillary sinus fracture at our hospital between January 2014 and January 2017 were enrolled. The fracture site was exposed via the Caldwell-Luc approach followed by reduction through the insertion of two urinary balloon catheters using a nasal endoscope and fixation with fibrin glue. The sex, cause of fracture, physical examination, and presence of complications were examined and patient's medical records and facial bone computed tomography scans were analyzed. Results: Radiological evaluation showed that there was no evidence of collapsed reduction fragments. Although some patients had remaining symptoms of hypoesthesia (15%; 3 patients), there were no complications such as infection, rhinitis, sinusitis, and chronic purulent secretion at the surgical site. Conclusion: In this study, we present an alternative surgical technique using two urinary balloon catheters and fibrin glue for the successful reconstruction of an isolated anterior wall of the maxillary sinus fracture. This technique enables precise restoration with a reduced risk of complications.

• Archives of Craniofacial Surgery
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• v.18 no.1
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• pp.30-36
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• 2017

Background: Nasal fractures have a tendency of resulting in structural or functional complications, and the results can vary according to the type of nasal bone fracture. The aim of this study was to evaluate the objective postoperative results according to the type of nasal bone fractures. Methods: We reviewed 313 patients who had a closed reduction of nasal bone fracture. The classification of nasal bone fracture by Stranc and Robertson was used to characterize the fracture type: frontal impact group type I (FI), frontal impact group type II (FII), lateral impact group type I (LI), lateral impact group type II (LII), and comminuted fracture group (C). For each patient, we tried to use the same axial image section of computed tomographic (CT) scans before and immediately after operation. Postoperative outcomes were classified into 4 grades: excellent (E), good (G), fair (F), and poor (P). We also analyzed postoperative complications by fracture type. Results: Regarding the postoperative CT images, 189 subjects showed E results, 99 subjects showed G, 18 subjects showed F, and 7 subjects showed P reduction. The rate of operation results graded as E by each fracture type was 66.67% in FI, 52.0% in FII, 64.21% in LI, 62.79% in LII, and 21.74% in C. Complications of FI (7.14%), LII (13.95%), and C (13.04%) groups occurred more than in the FII (4.00%) and LI (4.21%) groups. Conclusion: It seems that the operation result by fracture type was better in the FI, LI, and LII type than the FII and C type; after one month, however, LII type showed more complications than other types. The septal fracture can be thought to affect early reduction results in nasal bone fractures.