• 대한치과교정학회지
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• 제46권6호
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• pp.372-378
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• 2016

Objective: The purpose of the present study was to evaluate the postoperative three-dimensional (3D) changes in the proximal segments after mandibular setback sagittal split ramus osteotomy and to compare the changes between the conventional mini-plate fixation and semi-rigid sliding plate fixation. Methods: Cone-beam computed tomography (CBCT) images were used to evaluate the postoperative 3D changes in the proximal segments during the healing process. CBCT images were superimposed using the symphysis and the lower anterior mandible as references. Results: There were no statistically significant differences between the conventional mini-plate and semi-rigid sliding plate groups (p > 0.05). With respect to the distribution of changes greater than 2 mm in the landmarks, the right condylion, right coronoid process, and left condylion showed ratios of 55.6%, 50.0%, and 44.4%, respectively, in the semi-rigid sliding plate group; however, none of the landmarks showed ratios greater than 30% in the conventional mini-plate group. Conclusions: There were no statistically significant differences in postoperative changes in the segments between the conventional mini-plate and semi-rigid sliding plate groups. Nevertheless, while selecting the type of fixation technique, clinicians should consider that landmarks with greater than 2 mm changes were higher in the semi-rigid sliding plate group than in the conventional mini-plate group.

• 대한족부족관절학회지
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• 제18권2호
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• pp.76-79
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• 2014

In treatment of failure in ankle joint replacement therapy, talar avascular necrosis with massive bone defect, talus fracture with severe comminution and bone defect and ankle dislocation, treatment of large bone defects is considerably important for ankle joint stability and union, therefore, the choice of treatment for large bone defects is use of femoral head or iliac crest bone graft and rigid internal fixation. Because first generation total ankle arthroplasty performed for the first time using a cemented fixation technique requires a large amount of bone resection during re-surgery and there is some possibility of a larger bone defect after removal of implants, in cases where prosthesis for the defect is needed, performance of palliative femoral head or iliac crest bone graft and rigid internal fixation can be difficult. We report on a case of a 48-year-old woman who had experienced ankle pain for 25 years since undergoing total ankle arthroplasty. Because the patient had little ankle motion and rigid soft tissue despite a large bone defect caused by aseptic loosening, a good outcome was obtained only for the femoral cancellous bone graft using allo femoral head without internal fixation.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제16권3호
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• pp.290-302
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• 1994

This study was aimed to clarify the histopathological changes in the experimental animal model subjcted to rigid fixation performed across the frontonasal sutrue in growing rabbits. Sixteen rabbits aged 6 weeks used. In experimental group(n=12), rigid fixation with miniplates and screws was performed across the frontonasal suture. Control group(n=4) was those with periosteal elevation only. Experimental animals were sacrificed on the 2nd, 4th, 8th, and 12th week after operation, and frontonasal suture area was excised for light microscopic and scanning electron microscopic examination. The results obtained were as follows : 1. In control groups, collagen fiber bundles ran in the midportion of bone sutrue and cambial layers were seen at bone surface. Sutural surfaces are beveled and external and internal bony projected portions were observed. 2. In experimental groups, distance of bone suture was decreased by new bone formation on the 2nd week, while increased by bone resorption at the miniplate applied area and bone formation in the adjacent bone on the 4th week. 3. In experimental groups, the original bone surface was almost resorbed and new bone formation was found on the 8th week. Regulary-run collagen fibers, smooth and dense bone surfaces were similar to the bone patterns of control groups on the 12th week. Above results suggest that bone formation is restricted where the miniplate is applied, while compensatory growth is appeared in the adjacent bont. It is considered that rigid fixation with miniplates and acrews results in a little disturbance of sutural growth of the craniofacial bone in infancy and children when applied for short duration.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제27권4호
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• pp.334-345
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• 2005

The purpose of this study was to compare the postoperative stability and relapse according to 2 different fixation methods after bilateral sagittal split ramus osteotomies in mandibular prognathic patients. Tweenty one patients with Class III dental and skeletal malocclusion who were treated with bilateral sagittal split ramus osteotomy were selected for this retrospective study. We classfied the patients into two groups according to the fixation methods of bony segments after osteotomies. Group W (n = 10) had the bone segments fixed with nonrigid wire and Group S (n = 11) had bicortical screws inserted in the gonial area through a transcutaneous approach. Cephalometric radiographs were taken preoperatively, immediate postoperatively and more than six months postoperatively in each patient. After tracing the cephalometric radiographs, various parameters were measured. Before surgery, both groups were balanced with respect to linear and angular measurements of craniofacial morphology. Mean posterior sagittal setback amounts of the mandibular symphysis was 8.6 mm in the wire group and 6.79 mm in the rigid group, Six months postoperatively, the wire group had 33.1% relapse of the mandibular symphysis and 22.8% in the rigid group relapse. Both groups experienced changes in the orientation and configuration of the mandible. It is thought that Rigid screw fixation is a more stable method than nonrigid wire fixation for maintaining mandibular setback after sagittal split ramus osteotomy.

• 대한족부족관절학회지
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• 제15권4호
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• pp.243-246
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• 2011

Lisfranc injury is complex and difficult to treat. Making the correct diagnosis and achieving an anatomical reduction are important factors in regard to achieving a favorable outcome with this injury. We describe a new technique that we have found to be useful for stabilizing Lisfranc injury. This method is relatively fast and simple, and it provides non-rigid fixation. Also, it eliminates the need for implant removal. To date, we have achieved predictable results for stabilizing and treating this injury with the use of a $TightRope^{TM}$ Device, instead of traditional interfragmental screw fixation. In this report, we describe a case in which this method was used with satisfactory short-term results.

• Journal of Korean Neurosurgical Society
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• 제37권5호
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• pp.364-369
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• 2005

Objective: Spinal instrumentation without fusion often fails due to biological failure of intervertebral joints (spontaneous fusion, degeneration, etc). The purpose of this study is to investigate the influence of fixation rigidity on viability of intervertebral joints. Methods: Twenty pigs in growing period were subjected to posterior segmental fixation. Twelve were fixed with a rigid fixation system(RF) while eight were fixed with a flexible unconstrained implant(FF). At the time of the surgery, a scoliosis was created to monitor fixation adequacy. The pigs were subjected to periodic radiological examinations and 12pigs (six in RF, six in FF) were euthanized at 12-18months postoperatively for analysis. Results: The initial scoliotic curve was reduced from $31{\pm}5^{\circ}$ to $27{\pm}8^{\circ}$ in RF group (p=0.37) and from $19{\pm}4^{\circ}$ to $17{\pm}5^{\circ}$ in FF group (p=0.21). Although severe disc degeneration and spontaneous fusion of facet joints were observed in RF group, disc heights of FF group were well maintained without major signs of degeneration. Conclusion: The viability of the intervertebral joints depends on motion spinal fixation. Systems allowing intervertebral micromotion may preserve the viability of intervertebral discs and the facet joint articular cartilages while maintaining a reasonably stable fixation.

• 대한두개안면성형외과학회지
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• 제16권2호
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• pp.96-98
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• 2015

Maxillomandibular fractures usually require intermaxillary fixation as a means to immobilize and stabilize the fracture and to re-establish proper occlusion. Arch bars or intermaxillary fixation screws cannot be used for edentulous patients or for patients who have poor dental health. Here, we present a case of repeated intermaxillary fixation failure in a patient weak alveolar rigidity secondary to multiple dental implants. Because single-point fixation screws were not strong enough to maintain proper occlusion, we have used Y-shaped plates to provide more rigid anchoring points for the intermaxillary wires. We suggest that this method should be considered for patients in whom conventional fixation methods are inappropriate or have failed.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제22권2호
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• pp.184-190
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• 2000

Objective : To compare two different methods of rigid fixation in postoperative stability after mandibular setback. Material and Methods : 28 patients with Class III malocclusion were treated by bilateral sagittal split ramus osteotomy(BSSRO) and mandibular setback were selected for this study. Group A(n=14) had the bone segments fixed with monocortical miniplate on the lateral side of the mandibular body and Group B(n=14) had three noncompressive bicortical screw inserted at the genial area through a transcutaneous approach. Cephalograms were taken preoperatively, postoperatively within 1 weeks and at a follow-up period (mean 8.9 months after surgery) and the amount of setback and postoperative change were measured. Results : Postoperative relapse between two groups was minimal in setback of the mandible. Statistical analysis showed no significant difference in postoperative relapse. Conclusion : This study suggests that both methods of skeletal fixation investigated give comparable postoperative stability and their use in mandibular setback appears to be a fairly stable clinical procedure .

• Maxillofacial Plastic and Reconstructive Surgery
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• 제27권1호
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• pp.85-92
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• 2005

Reconstruction of defect in the anterior part of the maxilla to enable implant placement or prothesis is a complicated treatment due to the anatomical position and lack of soft tissues. Two cases are presented in which autogenous iliac PMCB(particulate marrow and cancellous bone) with titanium mesh were used for premaxilla reconstruction and alveolar bone repair of the anterior maxillas prior to denture and implants fixation respectively. Cancellous bone from the anterior iliac crest was compressed and placed against a titanium mesh fixed to the bone of palate in a patient with severe defect of the anterior maxilla. There were no problem in the healing, and the anterior maxillas of two patients had increased height and width during the initial healing and remodeling. The clinical reports describe the use of titanium mesh for reconstruction of premaxilla. Autogenous bone grafts were harvested from the iliac crest and were loaded on a titanium mesh that were left in the patient's maxilla for 6 months before they were removed respectively. The radiographic analysis demonstrated that a 10mm vertical ridge augmentation had been achieved. In guided bone regeneration, the quantity of bone regenerated under the barrier has been demonstrated to be directly related to the amount of the space under the membrane. This space can diminish as a result of membrane collapse. To avoid this problem which involved the use of a titanium mesh barrier to protect the regenerating tissues and to achieve a rigid fixation of the bone segments, were used in association with autologous bone in 2 cases. The aim of this study was to evaluate the capability of a configured titanium mesh to serve as a mechanical and biologic device for restoring a vertically defected premaxilla.

• Journal of Periodontal and Implant Science
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• 제44권5호
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• pp.251-258
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• 2014

Purpose: The preferred material for bone augmentation beyond the envelope of skeletal bone is the bone block graft, due to its dimensional stability. We evaluated the necessity of rigid fixation for the bone block graft, and compared the bone regeneration and volume maintenance associated with grafting using a synthetic hydroxyapatite block (HAB) and an autogenous bone block (ABB) without rigid fixation on rabbit calvaria over two different periods. Methods: Cylinder-shaped synthetic HAB and ABB were positioned without fixation on the rabbit calvarium (n=16). The animals were sacrificed at 4 or 8 weeks postoperatively, and the grafted materials were analyzed at each healing period using microcomputed tomography and histologic evaluation. Results: Integration of the graft and the recipient bed was observed in all specimens, although minor dislocation of the graft materials from the original position was evident in some specimens (six ABB and ten HAB samples). A tendency toward progressive bone resorption was observed in the grafted ABB but not in the grafted HAB, which maintained an intact appearance. In the HAB group, the area of new bone increased between 4 and 8 weeks postoperatively, but the difference was not statistically significant. Conclusions: The nonfixed HAB was successfully integrated into the recipient bed after both healing periods in the rabbit calvaria. In spite of limited bone formation activity in comparison to ABB, HAB may be a favorable substitute osteoconductive bone material.