• The Journal of Advanced Prosthodontics
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• 제9권3호
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• pp.170-175
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• 2017

PURPOSE. The aim of the present study was to evaluate the fracture resistances of zirconia, cast nickel-chromium alloy (Ni-Cr), and fiber-composite post systems under all-ceramic crowns in endodontically treated mandibular first premolars. MATERIALS AND METHODS. A total of 36 extracted human mandibular premolars were selected, subjected to standard endodontic treatment, and divided into three groups (n=12) as follows: cast Ni-Cr post-and-core, one-piece custom-milled zirconia post-and-core, and prefabricated fiber-glass post with composite resin core. Each specimen had an all-ceramic crown with zirconia coping and was then loaded to failure using a universal testing machine at a cross-head speed of 0.5 mm/min, at an angle of 45 degrees to the long axis of the roots. Fracture resistance and modes of failure were analyzed. The significance of the results was assessed using analysis of variance (ANOVA) and Tukey honest significance difference (HSD) tests (${\alpha}=.05$). RESULTS. Fiber-glass posts with composite cores showed the highest fracture resistance values ($915.70{\pm}323N$), and the zirconia post system showed the lowest resistance ($435.34{\pm}220N$). The corresponding mean value for the Ni-Cr casting post and cores was reported as $780.59{\pm}270N$. The differences among the groups were statistically significant (P<.05) for the zirconia group, as tested by ANOVA and Tukey HSD tests. CONCLUSION. The fracture resistance of zirconia post-and-core systems was found to be significantly lower than those of fiber-glass and cast Ni-Cr post systems. Moreover, catastrophic and non-restorable fractures were more prevalent in teeth restored by zirconia posts.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제35권2호
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• pp.120-124
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• 2009

The concept of biostimulation of wounds by low-level laser therapy(LLLT) is attracting considerable attention. Although its effect on whole tissues has been studied quite extensively, the biological and cellular mechanisms underlying LLLT have not been clarified. In an experimental radius fracture in rabbits, Tang and Chai reported that LLLT enhanced the activity of red blood cells, macrophages, fibroblasts, chondrocytes, and osteoclasts within the fracture area. The purpose of the present study was to evaluate the effect of LLLT with a GaAlAs diode laser device on bone healing in rabbit mandibular fractures. We use 12 rabbits for this study. All rabbits were fractured mandible angle area using saw in anesthetic condition. In control group(n=6), none treatment was performed at fracture site. In experimental group(n=6), LLLT with a GaAlAs diode laser was radiated at fracture site daily for 7 days. All rabbits were sacrificed at 6 weeks later from performed fracture day. We studied the immunohistochemical staining of CD34 and Vimentin and the histochemical analysis for calcium and phosphorus content. The results were as follows. 1. In the histological and immunohistological staining, after 6week, fibroblasts, osteogenic cells and collgen fibers were observed more in experimental group than in control group. 2. In the histochemical analysis, the amount of calcium and phosphorus contents of the experimental group were more than the control group. From the results obtained, we suggest that the bone healing is stimulated by low-level laser irradiation in bone fractures.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제11권1호
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• pp.249-254
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• 1989

Transverse mandibular deficiency is rare maxillomandibular malrelationship. Most of this malrelationship is considered to be caused by loss of bone substances. This can be corrected by subapical osteotomy, midsagittal vertical osteotomy, midline horizontal L sliding osteotomy, etc., case by case. In these cases, malrelationship after malunion of mandibular fracture, combination of vertical osteotomy and sliding autogenous cortical bone graft was used and favorable results were obtained. Advantages over previous traditional surgical methods were as follows : 1. This method provided easy access and good visibility. 2. It provided broad bone contact area, thus no other operation to obtain bone graft was needed. 3. There were little circumstances to extract teeth. 4. There were no difficulty in tongue movement after operation.

• 대한두개안면성형외과학회지
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• 제18권2호
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• pp.73-75
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• 2017

The management of mandibular angle fractures is often challenging and results in the highest complication rate among fractures of the mandible. In addition, the optimal treatment modality for angle fractures remains controversial. Traditional treatment protocols for angle fractures have involved rigid fixation with intraoperative maxillomandibular fixation (MMF) to ensure absolute stability. However, more recently, non-compression miniplates have gained in popularity and the use of absolute intraoperative MMF as an adjunct to internal fixation has become controversial. In this article, the history of, and current trends in, the treatment of mandibular angle fractures will be briefly reviewed. In addition, issues regarding the management of the third molar tooth will be discussed.

• 한국임상수의학회지
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• 제20권1호
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• pp.138-141
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• 2003

First case, a one-year-old female Shih Tzu weighing 3 kg with closed transverse fractures of bilateral mandibular body between 2nd and 3rd premolar teeth were treated surgically with bone plates and screws, and cranial luxation of temporomandibular joints were reduced to closed method. Second case, a 8.4 years old male Yorkshire terrier weighing 2.6 kg with closed transverse/oblique fractures of bilateral mandibular body between premolar and molar teeth were treated surgically with bone plates and screws. Radiographic examination revealed that the fractures in two cases fixed well and temporomandibular joint was stabilized. One month after operation, jaw activity was excellent and malocclusion wasn't observed.

• 대한치과의사협회지
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• 제19권8호통권147호
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• pp.707-714
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• 1981

• Imaging Science in Dentistry
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• 제40권1호
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• pp.33-38
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• 2010

Purpose : The purpose of this study was to evaluate the diagnostic efficacy of panoramic radiographs for detection of mandibular fractures. Materials and Methods : The sample was comprised of 65 patients (55 fractured, 10 non-fractured) with 92 fracture sites confirmed by multi-detector computed tomography (CT). Panoramic radiographs were evaluated for mandibular fractures by six examiners; two oral & maxillofacial radiologists (observer A&B), two oral & maxillofacial surgeons (observer C&D), and two general dentists (observer E&F). Results : Sensitivity of panoramic radiography for mandibular fractures was 95.7% in observer A&B, 93.5% in observer C&D and 80.4% in observer E&F. The lowest sensitivity was shown in symphyseal/parasymphyseal areas, followed by subcondylar/condylar regions. Conclusion : Panoramic radiography is adequate for detection of mandibular fractures. However, additional multidetector CT is recommended to ascertain some indecisive fractures of symphysis and condyle, and in complicated fractures.

• Archives of Plastic Surgery
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• 제32권6호
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• pp.739-743
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• 2005

Subcondylar fractures have generally been treated by intermaxillary fixation except in cases where there is an absolute indication for open reduction. The reason behind a less aggressive surgical approach lies on the inherent difficulties in manipulating fragments in such a small area at the risk of damaging facial nerves or vessels such as the internal maxillary artery. However, long-term follow-up studies showed that conservative treatment of subcondylar fractures results in disturbances of occlusal function, deviation of the mandible, internal derangement of the temporomandibular joint, and ankylosis of the joint. We carried out open reduction of dislocated subcondylar fractures in 14 patients from 2000 to 2004 by a retromandibular approach. After the reduction of fractured bone, two H-shaped miniplates with 6 holes were fixed with screws at the anterior and posterior surfaces of the subcondyle. The retromandibular approach allowed good access and easy manipulation of the subcondyle. Immediate relief from malocclusion and correction of mandibular midline shifting were observed in all patients. Late temporomandibular dysfunction and ankylosis were not observed. Open reduction with plate osteosynthesis made it possible to avoid IMF in 7 of the 14 patients. The present study shows that open reduction through this retromandibular approach can produce good outcome in adult patients with subcondylar fracture.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제17권3호
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• pp.277-282
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• 1995

With the use of antibiotics and improved dental care, osteomyelitis of the jaw is less common these days, But sometimes the management of osteomyelitis is more difficult because of appearance of resistant organisms to antibiotics. Treatment of the steomyelitis are incision and drainage, closed catheter irrigations, sequestrectomy, saucerization, hyperbaric ocygen therapy, and resection with or without bone graft. We experienced advanced osteomyelitis due to delayed treatment of left mandibular angle fracture. He have medical history of pschysoprenia. We decided to treat the patient with open reduction and closed cather irrigation. We achived reconsolidation of mandibular fracture accompanied by osteomyelitis by complete removal of inflammatory tissues, rigid fixation with miniplate and closed catheter irrigation.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제29권1호
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• pp.50-54
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• 2007

This report constitutes a 7-year study of facial fractures based on a series of 616 patients who were treated for facial fractures as in-patients at Chosun University Dental Hospital between 1998 and April 2005. The following results were obtained : 1. The ratio of men to women was 5 : 1. 2. The major etiological factors were falls (36.2%), traffic accidents (23.4%), punches (18.1%), sports (8.3%), and accidents related to work (2.8%). 3. They were most frequent in the second (28.8%), first (26.6%), and third (12.3) decades, in that order. 4. The sites of frequent mandible fracture are the symphysis (32%), left mandibular angle (25.3%), and right mandibular angle (10.9%). 5. The most frequent maxillary fractures were zygomatic fractures (46.4%), Le Fort I fractures (28.8%), and Le Fort II (12.0%) fractures.