• 대한기관식도과학회:학술대회논문집
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• 대한기관식도과학회 1981년도 제15차 학술대회연제순서 및 초록
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• pp.13.3-13
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• 1981

이비인후과 영역에서 발생하는 골종은 아주 희소하나 부비동에서 발생하는 골종은 이 부위의 양성종양중 가장 많으며 전두동에서 가장 호발한다고 한다. 골종은 30대에서 가장 호발하며 조직학적으로 골수가 경성인것, 연성인것, 혼합형인것 등으로 분류할 수 있으며 발생원인으로는 간배세포 종양설, 외상설, 염증설 등이 있다. 최근, 저자들은 좌측 전두동의 거대한 골종으로 인해 안구돌출 및 안구하강을 동반한 44세의 남자환자에서 성형적 전두동 수술로 종양을 제거하고 그 결손부위를 지방조직으로 이식하여 좋은 결과를 얻었기에 문헌과 함께 보고하는 바이다.

• 대한치과보철학회지
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• 제44권2호
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• pp.217-228
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• 2006

Statement of problem: Standard type of ITI solid implant model in the 6.2mm thick jaw bone was axisymmetrically modelled for finite element stress analyses. Purpose: Primary objective was to investigate the influences or the characteristic design configuration of the ITI solid implant model on the bone stress with the course of osseointegration process at the bone/implant interfaces. To simulate the characteristics of the osseointegration process, five different stages of the bone/implant interface model were implemented. As load conditions, vertical load of 50N was taken into consideration. Bone at the cervical region of implant was the areas of concern where the higher level of stress were likely to take place. Results: The results indicated that rather slightly different stress level could be obtained as a function of the osseointegration conditions. Conclusion: Under vertical load, the lower level of stress was observed at the cervical cortical bone in the initial and final stages of osseointegration. Relatively higher stress level, however, was observed during the transitional stages where the osseointegration at the cancellous bone interface were yet to fully develop.

• Journal of Korean Neurosurgical Society
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• 제64권5호
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• pp.763-775
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• 2021

Objective : Hemorrhagic transformation (HT) can be occurred after acute cerebral infarction. HT can worse symptoms in severe cases and adversely affect long-term prognosis. As bone and vascular smooth muscle are composed of type 1 collagen, we aimed to identify a potential relationship between bone mineral density (BMD) and HT after acute cardioembolic stroke. Methods : As an indicator of BMD, we used mean frontal skull Hounsfield unit (HU) values on brain computed tomography (CT). Multivariative hazard ratios were calculated using Cox regression analysis to identify whether the osteoporotic condition was an independent predictor of HT after acute cardioembolic stroke. Results : This 11-year analysis enrolled 506 patients who diagnosed as acute cardioembolic infarction. The first tertile of skull HU value was an independent predictor of HT development compared to the third tertile (hazard ratio, 2.12; 95% confidence interval, 1.13-3.98; p=0.020). We observed no interactions between age and skull HU with respect to HT statistically. Conclusion : The results of this study revealed an association between osteoporotic conditions and HT development after acute cardioembolic stroke. A convenient method to measure the cancellous bone HU value of the frontal skull using brain CT images may be useful for predicting HT in patients with acute cerebral infarction.

• The Journal of Advanced Prosthodontics
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• 제14권3호
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• pp.182-202
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• 2022

PURPOSE. The aim of this study is to summarize various biomechanical aspects in evaluating the long-term stability of dental implants based on finite element method (FEM). MATERIALS AND METHODS. A comprehensive search was performed among published studies over the last 20 years in three databases; PubMed, Scopus, and Google Scholar. The studies are arranged in a comparative table based on their publication date. Also, the variety of modeling is shown in the form of graphs and tables. Various aspects of the studies conducted were discussed here. RESULTS. By reviewing the titles and abstracts, 9 main categories were extracted and discussed as follows: implant materials, the focus of the study on bone or implant as well as the interface area, type of loading, element shape, parts of the model, boundary conditions, failure criteria, statistical analysis, and experimental tests performed to validate the results. It was found that most of the studied articles contain a model of the jaw bone (cortical and cancellous bone). The material properties were generally derived from the literature. Approximately 43% of the studies attempted to examine the implant and surrounding bone simultaneously. Almost 42% of the studies performed experimental tests to validate the modeling. CONCLUSION. Based on the results of the studies reviewed, there is no "optimal" design guideline, but more reliable design of implant is possible. This review study can be a starting point for more detailed investigations of dental implant longevity.

• 구강회복응용과학지
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• 제30권3호
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• pp.215-222
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• 2014

본 연구는 수평적, 수직적 안면 골격 유형에 따른 하악 전치부 치조골의 형태학적 차이를 알아보기 위하여 시행 하였다. 연구 재료 및 방법: 40명의 Cone-beam computed tomography (Cone-beam CT)를 선별하여, 4개 군으로 분류하였다. Cone-beam CT 자료를 이용하여 하악 전치부 치조골의 부피($mm^3$), 하악 4절치 치축 기준 시상단면의 단면적(총 단면적, 해면골 단면적: $mm^2$), 백악법랑경계(cemento-enamel junction: CEJ) 2 mm, 3 mm 아래 순, 설측 치조골 두께를 측정하였다. 통계분석은 GLM, Kruskal-Wallis test and Tukey HSD를 사용하였다. 결과: 측절치의 백악법랑경계 2 mm, 3 mm 하방 설측 치조골 두께가, Class I low angle군이 나머지 3군 보다 두꺼웠다 (P < 0.05). 하악 전치 치조골의 부피, 전체 치조골 및 해면골의 단면에서의 통계적으로 유의한 차이는 없었다. 결론: Class I low angle군은 Class II high angle군에 비해 하악 전치 치조골의 설측 부위가 더 두껍다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제40권
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• pp.35.1-35.7
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• 2018

Background: After the resection at the mandibular site involving oral cancer, free vascularized fibular graft, a type of vascularized autograft, is often used for the mandibular reconstruction. Titanium mesh (T-mesh) and particulate cancellous bone and marrow (PCBM), however, a type of non-vascularized autograft, can also be used for the reconstruction. With the T-mesh applied even in the chin and angle areas, an aesthetic contour with adequate strength and stable fixation can be achieved, and the pores of the mesh will allow the rapid revascularization of the bone graft site. Especially, this technique does not require microvascular training; as such, the surgery time can be shortened. This advantage allows older patients to undergo the reconstructive surgery. Case presentation: Reported in this article are two cases of mandibular reconstruction using the ready-made type and custom-made type T-mesh, respectively, after mandibular resection. We had operated double blind peer-review process. A 79-year-old female patient visited the authors' clinic with gingival swelling and pain on the left mandibular region. After wide excision and segmental mandibulectomy, a pectoralis major myocutaneous flap was used to cover the intraoral defect. Fourteen months postoperatively, reconstruction using a ready-made type T-mesh (Striker-Leibinger, Freibrug, Germany) and iliac PCBM was done to repair the mandible left body defect. Another 62-year-old female patient visited the authors' clinic with pain on the right mandibular region. After wide excision and segmental mandibulectomy on the mandibular squamous cell carcinoma (SCC), reconstruction was done with a reconstruction plate and a right fibula free flap. Sixteen months postoperatively, reconstruction using a custom-made type T-mesh and iliac PCBM was done to repair the mandibular defect after the failure of the fibula free flap. The CAD-CAM T-mesh was made prior to the operation. Conclusions: In both cases, sufficient new-bone formation was observed in terms of volume and strength. In the CAD-CAM custom-made type T-mesh case, especially, it was much easier to fix screws onto the adjacent mandible, and after the removal of the mesh, the appearance of both patients improved, and the neo-mandibular body showed adequate bony volume for implant or prosthetic restoration.

• 대한족부족관절학회지
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• 제21권3호
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• pp.98-103
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• 2017

Purpose: The aim of this study was to analyze the factors related to nonunion in tibiotalar arthrodesis. Materials and Methods: Eighty cases of ankle arthritis treated with tibiotalar arthrodesis in our hospital from November 2008 to November 2015 with more than one year follow up were analyzed. Simple anteroposterior and lateral radiographs after 6 and 12 months of surgery were analyzed. Union was defined as more than 50% connection of the trabecular bone at the ankle joint surface in the anteroposterior and lateral radiographs. The nonunion group was defined as no signs of union with persistent pain 9 months after surgery. The surgical approach, type of used screw, preoperative and postoperative ankle alignment, body mass index (BMI), bone mineral density, and patients' prior history were compared between the two groups. Results: There were 69 union cases and 11 nonunion cases. In the patient factors, the gender and BMI was related to nonunion (p<0.05). The mean preoperative and postoperative ankle alignment in the nonunion group was $9.93^{\circ}{\pm}6.92^{\circ}$ and $5.43^{\circ}{\pm}3.35^{\circ}$ respectively, and $9.80^{\circ}{\pm}7.55^{\circ}$ and $5.63^{\circ}{\pm}3.45^{\circ}$ in the union group, respectively; the difference was not statistically significant (p>0.05). In the technical factors, the transfibular approach showed a better relationship but the association was not significant (p<0.05). In 40 cases of the transfibular approach, 12 cases used cancellous screws, and 4 cases showed nonunion due to screw breakage. Conclusion: Technical factors, such as the surgical approach and the type of screw used can be a risk factor in nonunion. In addition, patients' factors, such as gender and BMI, must be considered to reduce the nonunion rate.

• 대한골관절종양학회지
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• 제5권1호
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• pp.56-62
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• 1999

Purpose : This study was conducted to analyze the clinical materials and treatment results of 13 cases of subungual exostosis. Materials and Methods : Thirteen subungual exostoses of the foot treated from January 1991 to December 1997 were studied. We analyzed the clinical data and results of treatment to identify the clinical characteristics of this disease. We investigated the location, shape and relation of exostosis to phalanx with simple x-ray of the foot to identify the radiological characteristics. All the cases were sent to pathologic examination after resection to determine the pathological characteristics. Results : The results of physical examination on presentation were various. Most cases were located at the dorsomedial side of the distal phalanx and were involved in the toe nail. Eleven cases were located at great toes and one each at the 2nd and 3rd toe. Causes of exostosis were not clear, but 2 cases were related to trauma. For the type of exostosis, 7 cases were sessile and 6 were stalk type. On histologic examination, 9 cases showed a cartilaginous portion with overlying proliferating fibrous tissue and underlying bone formation. There was a gradual maturation of spindle cell proliferation from cartilage to cancellous bone. The cartilage was moderately cellular with some pleomorphism, but true anaplasia was not present. Conclusion : The clinical presentation and findings of simple x-rays were most helpful in diagnosing subungual exostosis. Complete excision of the mass achieved complete relief of symptoms and recovery without recurrence in all cases.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제29권2호
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• pp.140-144
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• 2003

Ameloblastoma is cytologically a benign tumor, but is clinically characterized by infiltrative growth and high recurrency. The criteria for surgical treatment of ameloblastoma has not yet established and it is generally accepted that ameloblastoma be treated differently based on clinical types. The purpose of this paper is to consider effectiveness of enucleation in large-sized intraosseous ameloblastoma that has treated more frequently by radical treatment. 39 cases of the intraosseous ameloblastomas were treated by enucleation in the department of oral and maxillofacial surgery of Yonsei University, dental college from February 1990 to January 2001. 25 cases were selected because they were large in size that could produce facial disfigurement or pathologic fracture of jaws. They were radiographically characterized by the cortical bone that was expanded or eroded locally and histopathologically by 19 solid ameloblastomas and 6 intramural type of unicystic ameloblastomas. Among the 25 cases, 4 cases - 3 solid ameloblastomas and 1 intramural type of ameloblastoma - recurred. Recurrence rate was 16%. The compact bone which is not invaded by ameloblastoma was used as surgical margin of enucleation with accompanying chemical cauterization for killing the residual tumor cells. This may have been the reason for the low recurrence rate. So, it is considered that enucleation and long-term follow-up enable the large-sized intraosseous ameloblastomas that were characterized by almost destroyed cancellous bone and expanded or discontinued cortical bone to treat minimizing facial disfigurement and masticatory dysfunction and sociopsychological impact produced by radical treatment. I recommend that the large-sized intraosseous ameloblastomas without involvement to the surrounding soft tissues be first treated by enucleation.

• Clinics in Shoulder and Elbow
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• 제2권2호
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• pp.126-132
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• 1999

Purpose : To evaluate the functional and radiographic outcome of the modified Bosworth method in the surgical treatment of acute type V acromioclavicular joint dislocation. Materials and Methods: From June 1995 to May 1998, 20 patients were operated on for acute and complete acromioclavicular dislocation(Rockwood type V). The operative technique includes fixation of the coracoclavicular joint with Bosworth screw or 6.5mm cancellous screw and imbrication of trapezius and deltoid muscles. The average age was 34 years(range, 19 to 51 years). These 20 patients with an average follow-up of 18months, were evaluated clinically using the UCLA scoring system. Additional radiographical assessment was performed with stress radiographs. Results: Excellent or good clinical results were obtained in 95%(19 cases). And the average coracoclavicular interval ratio was decreased from 3.31(2.2-6.0) to 1.13(1-1.4) in stress radiographs. There were 4 cases of hetero­topic calcification postoperatively but there was no correlation with clinical result. Posttraumatic A-C joint arthritis was developed in one case. In that case, the distal clavicular resection was done under the arthroscopic technique. Conclusion: The severe displacement observed with type V injuries is incompatible with normal shoulder function if the shoulder is left in its displaced position. In type V injuries, significant damage to the deltoid and trapezius musculature and overlying fascia occurs, therefore open reduction and good fixation must be obtained with imbrication of trapezius and deltoid muscles. In our type V acute complete acromioclavicular dislocation, the modified Bosworth technique provides excellent results with a low complication rate.