• 한국임상수의학회지
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• 제26권6호
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• pp.644-646
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• 2009

5년령의 체중 4.58 kg 수컷 긴 팔 원숭이가 후지 파행 증상으로 건국대학교 동물 병원에 내원하였다. 신체 검사에서 우측 후지 경골 부위의 연부조직 손상을 보였으며 방사선 사진에서 우측 경골과 비골의 단순 골절이 관찰되었다. 개방형 정복을 실시한 후 tubular dynamic compression plate와 나사를 이용한 고정을 실시하였다. 수술 9주 후 방사선 사진 검사에서 잘 발달된 가골 형성이 골절 부위 피질에서 관찰되었다. 수술 3개월 후 후지 파행 증상을 보이 지 않고 정상 보행이 가능하였다.

• Journal of Korean Neurosurgical Society
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• 제46권3호
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• pp.181-188
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• 2009

Objective : To evaluate the anatomical parameters that must be considered when performing thoracic transpedicular or extrapedicular screw fixation. Methods : We selected 958 vertebrae (1,916 pedicles) from 98 patients for analysis. Eight parameters were measured from CT scans : the transverse outer pedicular diameter, transverse inner pedicular diameter, length, angle, chord length of the pedicles and the transverse width, angle, and chord length of the pedicle-rib units. Results : The age of the patients ranged from 21 to 82 years (mean: 48.2 years) and there were 57 men and 41 women. The narrowest transverse outer pedicular diameter was at T5 (4.4 mm). The narrowest pedicle length was at T1 (15.9 mm). For pedicle angle, T1 was 31.6 degrees, which was the most convergent angle, and it showed the tendency of the lower the level, the lesser the convergent angle. The chord length showed a horizontal pattern with similar values at all levels. For the PRU width, T5 showed a similar pattern to the pedicle width at 13.4 mm. For the PRU angle, T1 was the largest angle at 46.2 degrees and the tendency was the lower the level. the narrower the angle. For chord length, T1 was the shortest at 46.9 mm and T8 was the longest at 60.1 mm. Conclusion : When transpedicular screw fixations carried out at the mid-thoracic level, special care must be taken because there is a high chance of danger of medial wall violation. In these circumstances, extrapedicular screw fixation may be considered as an alternative treatment.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제29권6호
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• pp.513-519
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• 2007

Typical surgical methods for the treatment of mandibular fractures include intermaxillary-fixation (IMF) for obtaining temporary intraoperative occlusion. Traditionally IMF has been achieved with arch-bars or interdental eyelet wiring. However, these techniques are time-consuming procedures, can produce periodontal damage, and are not well tolerated by the patient even under local anesthesia. Moreover, daily maintenance of oral hygiene is difficult for patients with an arch bar. Recently, intermaxillary fixation using intraoral skeletal anchorage screws (SAS) has been introduced for the treatment of mandibular fractures. This method solves the problems above, but they have the potential for tooth damage, screw fractures and intraoperative occlusal instability. In this study, patients with mandiblular fractures were divided into three groups. Group 1 was treated by IMF using archbars(both maxilla and mandible), Group 2 was treated with SAS(maxilla) and arch-bar (mandible), Group 3 was treated with SAS(both maxilla and mandible). The aim of this study was to evaluate the influence of the different IMF methods on periodontal tissue health and intraoperative occlusal rehabilitation about each groups, and to discuss the most favorable IMF method.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제40권6호
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• pp.285-290
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• 2014

Objectives: We compared resorbable plates with titanium plates for treatment of combined mandibular angle and symphyseal fractures. Materials and Methods: Patients with mandibular angle and symphysis fractures were divided into two groups. The control (T) group received titanium plates while the experimental (R) group received resorbable plates. All procedures were carried out under general anesthesia using standard surgical techniques. We compared the frequency of wound dehiscence, development of infection, malocclusion, malunion, screw breakage, and any other technical difficulties between the two groups. Results: Thirteen patients were included in the R group, where 39 resorbable plates were applied. The T group consisted of 16 patients who received 48 titanium plates. The mean age in the R and T groups was 28.29 and 24.23 years, respectively. Primary healing of the fractured mandible was obtained in all patients in both groups. Postoperative complications were minor and transient. Moreover, there were no significant differences in the rates of various complications between the two groups. Breakage of 3 screws during the perioperative period was seen in the R group, while no screws or plates were broken in the T group. Conclusion: Resorbable plates can be used to stabilize combined mandibular angle and symphysis fractures.

• 대한치과보철학회지
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• 제39권3호
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• pp.297-305
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• 2001

Statement of problem. There have been previous studies about instability according to screw material by means of calculating preload in tightening screw or recording of the torque necessary to loosen screw after tightening screw. Purpose. The purpose of this study was to evaluate screw joint stability through the analysis of fitness at the mating thread surfaces between implant and screw after tightening screws made of different materials. Material and methods. In this study, screws were respectively used to secure a cemented abutment to a hexlock implant fixture; teflon coated titanium alloy screw and titanium alloy screw(Steri-Oss), gold-plated gold-palladium alloy screw and titanium alloy screw(Implant Innovation), gold screw and titanium screw(AVANA Dental Implant System). Each abutment screw was secured to the implant with recommended torque value using a digital torque controller. Each screw was again tightened after 10minutes. All samples were cross sectioned with sandpaper and polished. Then samples were evaluated with an scanning electron microscope analysis. Results. In titanium alloy screw, irregular contact and relatively large gap was present at mating thread surface. Also in teflon-coated titanium screw, incomplete seating and only partially contact was present at the mating thread surface. In gold-plated gold-palladium alloy screw, relatively close and tight contact without the presence of large gap was present by existing of gold coating at the mating thread surfaces. In gold alloy screw, relatively small gap between the mating components was seen. Conclusions. This result suggested that gold plated gold-palladium alloy screw and gold alloy screw achieved a greater degree of contact at the mating thread surfaces compared to titanium alloy screw and teflon-coated titanium alloy screw.

• 대한족부족관절학회지
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• 제18권4호
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• pp.189-194
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• 2014

Purpose: The purpose of this study was to compare the clinical and radiologic results of arthrodesis between anterior approach and transfibular approach arthrodesis in ankle arthritis. Materials and Methods: There were 61 cases of ankle arthritis treated by anterior or transfibular ankle arthrodesis in our hospital from April 2008 to March 2012. We investigated 29 cases (27 patients) who underwent ankle arthrodesis with an anterior approach (15 cases) and transfibular approach (14 cases), and were followed for over two years. Clinically, American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, pain visual analogue scale (VAS), and subjective satisfaction degrees were evaluated. In addition, ankle coronal and sagittal alignments were evaluated using plain radiographs at 6 and 24 months, postoperatively. Results: Clinically, preoperative mean AOFAS score and VAS was 41.3 and 6.4, and were changed to 58.9 and 3.3 postoperatively in the anterior approach group. In the transfibular approach group, preoperative mean AOFAS score was 36.6 and VAS was 7.1, and they were changed to 54.9 and 3.4 postoperatively. However, no significant differences in the clinical results were observed between the two groups (p=0.297). Duration of attaining union was 8.1 weeks in the anterior approach group and 10.4 weeks in the transfibular approach group. Complications were delayed union in one case, nonunion in three cases, cancellous screw breakage in three cases, and complex regional reflex syndrome in one case. Conclusion: After transfibular ankle arthrodesis as treatment of ankle osteoarthritis, the tendency for valgus angulation of the ankle at the final follow-up was observed and 6.5 mm cancellous screw breakage occurred frequently. Therefore, in order to achieve better stability, it is necessary to use 6.5 mm cannulated screws rather than 6.5 mm cancellous screws for ankle arthrodesis.

• 한국산학기술학회논문지
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• 제16권6호
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• pp.3692-3697
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• 2015

나사는 나선형의 홈으로 구성된 체결용 기계요소이다. 최근의 모바일 기기의 소형화 추세로 인하여 나사의 소형화 및 경량화 요구도 크게 증가하고 있는 실정이다. 우수한 기계적 성질과 높은 정밀도의 나사를 생산하기 위해서는 금형 및 공정설계가 성공적으로 수행되어야 한다. 본 연구에서는 유한요소해석을 통하여 초소형 나사의 머리부 냉간 단조 성형에 대한 공정설계를 수행하였다. 특히, 금형의 형상과 마찰력이 성형에 미치는 영향을 분석하기 위하여 실험계획법을 적용하였고, 그 결과 마찰력이 성형 시 발생하는 접힘 결함의 지배적인 요인임을 밝혀내었다. 이러한 결과로부터 금형 형상을 개선하였고, 개선된 금형으로 단조 실험을 수행하였고, 실험 결과로부터 접힘 결함 불량이 해소된 것을 확인하였다.

• 한국임상수의학회지
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• 제30권2호
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• pp.127-130
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• 2013

13년령의 4.2 kg 암컷 푸들이 하악의 병적 골절 후 지역병원에서 받은 양측성 하악 수술의 실패로 내원하였다. 수술은 2.0-mm miniplates/screws, 돼지해면질골 및 흡수성 막을 사용해 시행되었다. 수술 후 1일, 1, 4, 8, 12주에 예후를 평가하였다; 치아 부정교합, 골절 불유합, 또는 연부조직 감염의 징후는 보이지 않았다. 그러나 1년 후 장기간 검진에서 콜라겐 막을 사용하지 않았던 왼쪽 하악골절부위에 불유합이 관찰되었다. 따라서 노령견에서 하악골 불유합의 치유에 돼지해면골과 흡수성 막을 함께 사용하는 것은 효과적이라 생각된다.

• 대한치과기공학회지
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• 제43권3호
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• pp.99-105
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• 2021

Purpose: This study aims to examine the stress distribution effect of tightening torques of different abutment screws in a custom-abutment implant system on the abutment-fixture connection interface stability using finite element analysis. Methods: The custom-abutment implant system structures used in this study were designed using CATIA program. It was presumed that the abutment screws with a tightening torque of 10, 20, and 30 N·cm fixed the abutment and fixture. Furthermore, two external loadings, vertical loading and oblique loading, were applied. Results: When the screw tightening torque was 10 N·cm, the maximum stress value of the abutment screw was 287.2 MPa that is equivalent to 33% of Ti-6Al-4V yield strength. When the tightening torque was 20 N·cm, the maximum stress value of the abutment screw was 573.9 MPa that is equivalent to 65% of Ti-6Al-4V yield strength. When the tightening torque was 30 N·cm, the maximum stress value of the abutment screw was 859.6 MPa that is similar to the Ti-6Al-4V yield strength. Conclusion: As the screw preload rose when applying each tightening torque to the custom-abutment implant system, the equivalent stress increased. It was found that the tightening torque of the abutment influenced the abutment-fixture connection interface stability. The analysis results indicate that a custom-abutment implant system should closely consider the optimal tightening torque according to clinical functional loads.

• Hip & pelvis
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• 제30권4호
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• pp.254-259
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• 2018

Purpose: Internal fixation using compression hip screws (CHS) and traction tables placing patients in the supine position is a gold standard option for treating intertrochanteric fractures; however, at our institution, we approach this treatment with patients in a lateral decubitus position. Here, the results of 100 consecutive elderly (i.e., ${\geq}45$ years of age) patients who underwent internal fixation with CHS in lateral decubitus position are analyzed. Materials and Methods: Between March 2009 and May 2011, 100 consecutive elderly patients who underwent internal fixation with CHS for femoral intertrochanteric fracture were retrospectively reviewed. Clinical outcomes (i.e., Koval score, Harris hip score [HHS]) and radiographic outcomes (i.e., bone union time, amount of sliding of lag screw, tip-apex distance [TAD]) were evaluated. Results: Clinical assessments revealed that the average postoperative Koval score decreased from 1.4 to 2.6 (range, 0-5; P<0.05); HHS was 85 (range, 72-90); and mean bone union time was 5.0 (range, 2.0-8.2) months. Radiographic assessments revealed that anteroposterior average TAD was 6.95 (range, 1.27-14.63) mm; lateral average TAD was 7.26 (range, 1.20-18.43) mm; total average TAD was 14.21 (range, 2.47-28.66) mm; average lag screw sliding was 4.63 (range, 0-44.81) mm; and average angulation was varus $0.72^{\circ}$(range, $-7.6^{\circ}-12.7^{\circ}$). There were no cases of screw tip migration or nonunion, however, there were four cases of excessive screw sliding and six cases of varus angulation at more than $5^{\circ}$. Conclusion: CHS fixation in lateral decubitus position provides favorable clinical and radiological outcomes. This technique is advisable for regular CHS fixation of intertrochanteric fractures.