• The Journal of the Acoustical Society of Korea
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• 제29권3E호
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• pp.140-145
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• 2010

In the present study, tubular polyvinyl chloride (PVC) cortical bone mimics that simulate the cortical shell of long bones were used to validate the axial transmission technique for assessing the cortical thickness by measuring the ultrasonic velocities along the cortical shell of long bones. The ultrasonic velocities in the 9 PVC cortical bone mimics with wall thicknesses from 4.0 to 16.1 mm and inner diameters from 40 to 300 mm were measured as a function of the thickness by using a pair of custom-made transducers with a diameter of 12.7 mm and a center frequency of 200 kHz. In order to clarify the measured behavior, they were also compared with the predictions from a theory of guided waves in thin plates. This phantom study using the PVC cortical bone mimics provides useful insight into the dependencies of ultrasonic velocities on the cortical thickness in human long bones.

• Clinics in Shoulder and Elbow
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• 제20권1호
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• pp.37-41
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• 2017

Background: Increased frequency of comminuted clavicle mid-shaft fractures and importance of functional satisfaction through early joint exercise has resulted in higher emphasis on surgical treatments. This study aimed to evaluate the clinical radiological results of treatment of clavicle mid-shaft fractures by open reduction and internal fixation using a plate with a small incision. Methods: The subjects of this study were 80 clavicle mid-shaft fracture cases treated with internal fixation using a plate from October 2010 to July 2014. Clavicle mid-shaft fractures were internally fixated using anatomical plates or locking compression plates. Achievement of bone union, union period, and clavicle length shortening were evaluated radiologically, and clinical assessment was done by using Constant and University of California at Los Angeles (UCLA) scores. Results: All 80 cases were confirmed to have achieved bone union through radiographs with an average union period of 10.9 weeks (range: 7-18 weeks). The average clavicle length of shortening in the affected side was 1.8 mm (range: 0-17 mm). The average UCLA score and Constant score were 33.6 (range: 25-35) and 92.5 (range: 65-100), respectively. Regarding complications, four cases reported skin irritation by metal plates, and one case reported a screw insertion site fracture due to minor trauma history. Conclusions: We were able to induce successful bone union and obtain clinically satisfactory results in displaced mid-shaft fractures of the clavicle without major complications such as nonunion through treatment of internal fixation using a plate.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제29권6호
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• pp.438-443
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• 2003

Purpose : This study evaluated the usefulness of resorbable plate and screw for treatment of maxillofacial bone fractures. Patients and methods : From july, 2000 to july, 2002, we used resorbable plates and screws($Biosorb^{(R)}$ FX, Bionix Inc, Finland) on 126 patients for treatment of maxillofacial bone fractures. Among them, 80 patients were capable of periodic following up to present season. We evaluated these patients with clinical, radiographic findings and subjective satisfaction. Results : 80 patients composed of 63 men and 17 women. Complication rates are 7.5%(6/80) recorded. 1 of bulging sensation, 3 of infection sign, 2 of the plate detachment were shown. The plates involved in such complications were removed. The other patients(92.5%) were not shown any problems. We could not find complete resorption of screw holes in the mandibular symphysis area even though two years later after surgery. Conclusion : Bioresorbable plates and screws are useful as fixation material at maxillofacial fractures although strength is thought to be weaker than titanium plate. But to reduce the possible complicaions, need to careful clinical and radiographical evaluations.

• 대한두개안면성형외과학회지
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• 제20권4호
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• pp.233-238
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• 2019

Background: The open reduction of craniofacial bone fractures requires internal fixation using metal plates and screws, which have been considered the gold standard. However, metal implants pose a risk of palpation, protrusion, and foreign body reaction, and they may require an additional operation for removal. Recently, good results have been reported for absorbable implants which complement the disadvantages of metal implants. This study presents the results of using absorbable mesh, plates, and screws with cyanoacrylate for more accurate and firmer fixation of comminuted fractures of the maxilla. Methods: In total, 235 patients underwent operations for comminuted fractures of the maxilla. From January 2012 to December 2014, absorbable mesh and screws were used in 114 patients, while from January 2015 to December 2017, absorbable mesh, plates, and screws with cyanoacrylate were used in 121 patients. Open reduction of the bone fragments was performed, after which absorbable implants were accurately molded and fixed by screws. Results: All patients underwent postoperative computed tomography scans, which showed highly accurate reduction and firm fixation in the patients who underwent procedures using absorbable implants, screws, and cyanoacrylate. There were no postoperative complications or cases of abnormal facial contour. Conclusion: When absorbable implants and screws are used for maxillary fractures, no additional surgery to remove the metal plate is required. In addition, the use of cyanoacrylate enables accurate and firm fixation of the tiny bone fragments that cannot be fixed with screws.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제35권6호
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• pp.451-458
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• 2009

Metallic bone plates and screws have been commonly used in oral and maxillofacial surgery for internal fixation. However, there are several disadvantages such as atrophy of cortical bone inherent to excessive rigid fixation systems, growth disturbance in growing individual, allergy reaction, interference with radiographic imaging, palpability, thermal sensitibity and the need for subsequent removal. To overcome these disadvantages and avoid additional surgery of removal of plates and screws, there have been many studies of biodegradable plates and screws. But, It also has complication such as foreign body reactions. We have undertaken a clinical and retrospective study on 140 patients in Dept. of Oral and Maxillofacial Surgery, Inha University Hospital from February 2006 to March 2009. The purpose of this study is to report the clinical cases and review of the literatures with biodegradable plates and screws. And we concluded following results. 1. 6 cases(3.4%) of the 177 operation sites(140 patients) experienced complications. 1 case(0.6%) was a failure of initial fixation, 1 case(0.6%) was a postoperative infection, 4 cases(2.3%) were inflammations or foreign body reaction. 2. Postoperative infections, inflammations and foreign body reactions were completely recovered with incision and drainage, supporative care with antibiotic coverage and removal of biodegradable plates. 3. Biodegradable plates and screws provide acceptable rigidity and stability clinically. But, long-term observation is required for the tissue reactions around the biodegradable plates and screws because of long resorption periods of the biodegradable materials.

• Composites Research
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• 제22권3호
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• pp.29-34
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• 2009

본 논문에서는 유한요소해석을 이용하여 경극 골절부의 변형률 분포를 계산하였다. 16주에 걸친 골절 회복기간 동안 최적의 가골 형성의 조건을 찾기 위해 스테인리스 강 고정판과 다양한 적층순서를 가지는 복합재료 고정판이 고려되었다. 이 연구를 통해 골절부 가골 형성을 촉진하는 $2{\sim}10%$ 변형률을 유발하는 최적 하중 조건을 계산하였다. 해석결과로부터 복합재료 고정판의 경우 최적의 변형률을 가지게 하는 하중조건은 스테인리스 강 고정판의 경우보다 낮았으며, 응력방패 현상을 감소시켜 골절치료에 유리함을 가지는 것을 알 수 있었다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권5호
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• pp.499-503
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• 2007

Introduction: In orthognathic surgery, internal fixation has been usually done with titanium plates and screws. Recently, Biodegradable plates and screws have been frequently used but the reports of long term results of postoperative stability are rare, especially after maxillary reposition in orthognathic surgery. Objective: In order to clarify the clinical utility of self-reinforced bioresorbable poly-70L/30DL-Lactide miniplates & screws in maxillary fixation after LeFort I osteotomy, this study examined the postsurgical changes in maxilla and complications of biodegradable plates and screws. Study design: Nineteen patients who had undergone maxillary internal fixation using biodegradable plates and screws were evaluated radiographically and clinically. A comparison study of the changes in maxilla position after surgery in all 19 patients was performed with 1-week, 1-month, 3-months, 6-months and/or 1-year postoperative lateral cephalograms by tracing. Complication of the biodegradable plates and screws was evaluated by follow-up roentgenograms and clinical observation. And one-way ANOVA test was used for statistical analysis. Results: The position of the maxillary bone was stable after surgery and was not changed significantly from 1 week to 1 year after operation. And we could not find any complication of biodegradable plates and screws. Conclusions: Internal fixation of the maxilla after LeFort I osteotomy using self-reinforced biodegradable plates and screws is a reliable method for maintaining postoperative position of the maxilla after LeFort I osteotomy.

• 대한두개안면성형외과학회지
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• 제17권2호
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• pp.51-55
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• 2016

Background: Nasal bone fractures are managed by closed reduction within the 2-week period, and are managed by secondary correction after this time. There is little literature on the delayed reduction for nasal bone fractures beyond the 2-week duration. We report our experience with nasal fractures, which were reduced beyond this period. Methods: A retrospective review was performed for all patients who had undergone closed reduction of isolated nasal bone fracture. Patients were included for having undergone reduction of nasal bone fractures at or more than 2 weeks after the injury. Medical records were reviewed for demographic information, injury mechanism, fracture type, delay in treatment, and cause for delay. Postoperative outcomes were evaluated using computed tomography images. Results: The review identified 10 patients. The average reduction time was 22.1 days. Five of patients underwent reduction between days 15 and 20, and the remaining five patients underwent reduction between days 21 and 41. The postoperative outcomes were excellent in 8 patients and good in 2 patients. Conclusion: Outcomes were superior for nasal fractures with displaced end plates and multiple fracture segments. Our study results appears to support delayed reduction of isolated nasal fractures in the presence of factors that delay bony reunion.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제35권6호
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• pp.397-402
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• 2009

The purpose of this study is to investigate the effects of alendronate and pamidronate on proliferation and the alkaline phosphatase activity of human bone marrow derived mesenchymal stem cells and to relate the results with bisphosphonate related osteonecrosis of the jaw(BRONJ). With the consent of patients with no systemic disease and undergoing iliac bone graft, cancellous bone was collected to obtain human bone marrow derived mesenchymal stem cells through cell culture. 96 well plate were prepared with a concentration of $10^4$cell/ well. Alendronate and pamidronate were added to each well with the concentration of $10^{-6}M$, $10^{-8}M$ and $10^{-10}M$, respectively. Then proliferation capacity of each well was evaluated with the cell counting kit. 24 well plates were prepared with a concentration of $10^5$cell/ml/well and with the bone supplement, alendronate and pamidronate were added with the concentration of $10^{-6}M$, $10^{-8}M$ and $10^{-10}M$, respectively on each plate. The plates were cultured for either 24 or 72 hours. Then the cells were sonicated to measure the alkaline phosphatase activity and protein assay was done to standardize the data for analysis. As the concentration of alendronate or pamidronate added to the culture increased, the proliferation capacity of the cells decreased. However, no statistical significance was found between the group with $10^{-10}M$ of bisphophonate and the control group. Pamidronate was not capable of increasing the alkaline phosphatase activity in all trials. However, alkaline phosphatase activity increased with 24 hours of $10^{-8}M$ of alendronate treatment and with 48 hours of $10^{-10}M$ of alendronate treatment. Cell toxicity increased as the bisphosphonate concentration increased. This seems to be associated with the long half life of bisphosphonate, resulting in high concentration of bisphosphonate in the jaw and thus displaying delayed healing after surgical procedures. Alendronate has shown to increase the alkaline phophatase activity of human bone marrow derived mesenchymal stem cells. However, this data is insufficient to conclude that alendronate facilitates the differentiation of human bone marrow derived mesenchymal stem cells. Further studies on DNA level and animal studies are required to support these results.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제20권3호
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• pp.269-273
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• 1998

To clarify the clinical utility of the calvarial bone graft in the maxillofacial reconstruction, we performed on anatomical study by measuring the regional thickness of the parietal bone on 17 Korean adult dry skulls. Before the sectioning the calvarium, the anatomical landmarks were marked on each specimens. And then we measured the total thickness of the parietal bone, the thickness of the outer and inner cortical plates on various points in each sections of parietal bones using a digital caliper under the stereomicroscope. The total thickness of the parietal bone was ranged from 5.17mm to 7.50mm, and there were no statistical difference in the total thickness of the parietal bone on the same points bilaterally. But there was a tendency that the thickness of the parietal bone was thicker toward to the lambda point than the coronal suture area. At the other hand, the thickness of the outer and inner plate of the parietal bone was the thickest at the first point of the right aspect on the line 1, the first point of the left aspect on the line 5, respectively. In conclusion, this study showed that the donor site of the parietal bone for the maxillofacial reconstruction should be located at more posterior and medial area of the parietal bone than the prevalent known donor site.