• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권3호
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• pp.238-244
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• 2000

The present study was aimed to investigate the effect of osseointegration according to implant placement timing in the distracted alveolar bone using intraoral distraction device. Six adult mongrel dogs of either sex, weighing about 15kg, were used. The animals were divided into 4-week and 8-week groups according to the timing of implant installation. The left upper and lower premolars and first molars were extracted and an alveoloplasty was performed to simulate an atrophic ridge. After 12 weeks of healing, a segmental osteotomy was made and an intraoral distraction device which was designed for augmentation of vertical height of the edentulous ridge was applied. Latency period was allowed for 5 days and then distraction was made at a rate of 1.2mm/day for 8 days. Four or eight weeks after distraction, implants were installed. Twelve weeks after implant installation, the animals were sacrificed. Macroscopic, radiographic, and histologic examinations of distracted alveolar ridge were performed. No significant abnormalities such as infection and dehiscence of overlying soft tissue were observed. Radiographically, there was slight bone resorption around the medial and distal edges of the alveolar bone segment, and a new bone deposition was observed in the neighboring alveolar crest area in the both groups. The satisfactory osseointegration was achieved in the distracted gap of the both groups, but fibrous tissue appeared on the buccal side of implant in the distracted gap in 4-week group. These results suggest that proper timing of implant installation is 8 weeks rather than 4 weeks after distraction when dental implant is to be placed onto the distracted bone.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제37권6호
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• pp.539-544
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• 2011

Maxillary canting and vertical shortening of the unilateral mandibular ramus height is common in cases of severe facial asymmetry. Normally, mandibular distraction osteogenesis (DO) with horizontal osteotomy at the ascending ramus is used for vertical lengthening of the mandibular ramus to correct facial asymmetry with an absolute shortened ascending ramus. In this case report, vertical lengthening of the ascending ramus was performed successfully with unilateral DO and sagittal split ramus osteotomy (SSRO), where the posterior part of the distal segment can be distracted simultaneously in an inferior direction with maxillary DO, resulting in a lengthening of the medial pterygoid muscle. This case describes the acquired unilateral mandibular hypoplasia caused by a condylar fracture at an early age, which resulted in abnormal mandibular development that ultimately caused severe facial trismus. The treatment of this case included two-stage surgery consisting of bimaxillary distraction osteogenesis for gradual lengthening of the unilateral facial height followed by secondary orthognathic surgery to correct the transverse asymmetry. At the one year follow-up after SSRO, the vertical length was maintained without complications.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제46권2호
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• pp.143-149
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• 2020

Objectives: Long-term facial paralysis results in degeneration of the distal nerve segment and atrophy of the supplied muscles. Options for these patients include free muscle transfer, temporalis myoplasty, and botulinum toxin injections for smile reanimation. In this study we aimed to evaluate the subjective and objective outcomes of these procedures. Materials and Methods: In our study, we retrospectively analyzed smile symmetry in patients with facial palsy (n=8) who underwent facial reanimation procedures. Results: Subjective analysis showed high satisfaction in seven out of eight patients. Objective analysis showed statistically significant improvement postoperatively in both vertical and horizontal smile symmetry at rest and during maximum smile (P<0.001). Conclusion: Choosing the ideal procedure for the patients is the most critical aspect for facial reanimation. Though free muscle transfer is considered gold standard procedure, temporalis myoplasty also gives satisfactory results. Residual synkinesis which can lead to disturbing aesthetic deformity can be effectively treated with botulinum toxin.

• 한국방사선학회논문지
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• 제6권4호
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• pp.275-279
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• 2012

16MD CT(n=93) and dual source CT(n=100)를 이용해 촬영된 심장 CT 중 그 결과 협착으로 진단되어 심장영화 촬영을 시행한 환자를 대상으로 심장영화 촬영과의 협착 유무에 대한 비교를 하였다. 그 결과 16MDCT의 경우 가장 높은 민감도, 특이도, 양성예측도, 음성예측도는 LAD(73.5%), RCA(74.5%), LAD(66.7%), LCX(75%), LCX(67.7%)로 나타났고, 16Slice MDCT에서 각 관상동맥 혈관별 정확도는 평균67%로 다소 떨어지는 것으로 나타났고, Somatom Definition dual source CT의 경우 평균 정확도 84%로 16Slice MDCT보다는 17%더 높은 정확도를 나타내었다. 관상동맥영역별(segaments) 구분에서는 16Slice MDCT와 Somatom Definition 모두 근위부(proximal)보다는 원위부로 갈수록 더 높은 정확도를 나타내었다. 하지만 그 결과 값이 10% 오차 범위 내에 있어 명확한 차이라 보기는 힘들 것 이다. 또한 Dual source CT의 경우 역시 관상동맥 영역별 구분에서 큰 차이를 보이지 않았다.

• Journal of Plant Biology
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• 제34권1호
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• pp.25-30
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• 1991

포플라의 잎을 기본배지인 WPM에 BA 0.2 ppm, NAA 0.01 ppm을 첨가하여 배양하면 극성분화가 일어나서 대부분의 조직에서 기부 절단면에 부정아가 형성되는데, 본 연구는 $Ca^{2+}$과 몇 가지 양이온이 포플라의 극성분화에 미치는 영향을 조사하였다. WPM내에 $Ca^{2+}$의 농도를 높여주면 잎절편에서 분화된 전체부정아의 수는 증가하지만 극성분화는 억제되었고, EGTA를 처리하면 $Ca^{2+}$에 의한 극성분화의 억제가 다소 둔화되었다. 한편 $Ca^{2+}$의 농도를 높여주면서, $^{14}C-NAA$의 흡수 및 분포를 관찰하면 auxin의 차등분포는 크게 영향을 받지 않았다. $Ca^{2+}$에 의한 극성분화의 억제현상은 $Ca^{2+}$ 뿐만 아니라 배지내에 첨가되는 다른 양이온인 $Mg^{2+}과\;K^{+}$의 농도를 높여준 경우에도 나타났다. 따라서 포플라의 극성분화에 미치는 양이온의 영향은 지금까지 극성분화의 조절요인이라 알려진 auxin과 상호작용하기보다는 세포막 내외의 이온분포차에 의한다고 생각된다.

• Clinical and Experimental Pediatrics
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• 제48권12호
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• pp.1389-1389
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• 2005

저자들은 출생 시 납작한 후두골, 낮은 변형 귀, 양안 격리증, 넓고 낮은 콧등, 얇은 입술, 넓고 짧은 목의 덧살, 저긴장증, 피부의 다모증, 잠복고환 등의 소견을 보이는 미숙아의 염색체 핵형 분석에서 부모의 불균형 전도로부터 재조합된 염색체 이상의 결과로 인해 46,XY,rec(3)dup(3)(q21)del(3)(p25)inv(3)(p25q21)로 진단된 증례를 경험하였기에 문헌 고찰과 함께 보고하는 바이다.

• 한국운동역학회지
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• 제24권3호
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• pp.239-248
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• 2014

The purpose of this study was to quantify kinematic and kinetic characteristics of Yin-yang Bo gait according to their motor expertise, one of the Seokmun Ilwol martial art gait patterns. Yin-yang Bo gait pattern shows initial forefoot contact instead of heel contact, and increased time of stance phase time, internal-external rotation of ankle-knee-hip joints and pelvic. It aims to produce and store the more energy through continuous homeostasis of center of gravity (COG) and performance of stretch-shortening cycle. Some of these characteristics also were similar to the gait modification strategies for reducing knee adduction moment such as toe-out progression, medial thrust, internal rotation of hip joint. To identify the characteristics, four factors of expert Yin-yang Bo gait performance group were compared to that of none expert group; 1) angles of COG displacement and rotation 2) distal joint pre-rotation in internal-external rotation of ankle-knee-hip joints and pelvic, 3) invariability pelvic potential and pelvic segment total energy 4) knee abduction moment. Six healthy(three male) subjects participated in the experiment to perform Yin-yang gait pattern. Three-dimensional and force plate data were collected. Kinematic and kinetic data were compared between two groups using t-tests. Results showed that 1) the peak point of COG internal rotation angle was reduced in expert group, 2) kneeexternal and hip joint -internal and pelvic rotation angle peak frames were more near points in expert group.

• 한국운동역학회지
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• 제26권1호
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• pp.39-50
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• 2016

Objective: The purposes of this study were to compare the kinematics of a two-arm kettlebell swing between experts and beginners and to identify the correct postures and biomechanical key points in an attempt to prevent sports injuries induced by a kettlebell swing. Methods: Four experts (height, $169.7{\pm}1.5cm$; weight, $70.5{\pm}1.8kg$; age, $32.0{\pm}1.0years$) licensed to teach kettlebell exercises and three beginners (height, $173.7{\pm}4.1cm$; weight, $78.3{\pm}3.8kg$; age, $30.0{\pm}1.4years$) with no kettlebell exercise experience participated in this study. Each participant performed 15 repetitions of a two-arm kettlebell swing using a 16-kg weight. Joint angles, angular velocities, and peak angular velocity sequences were calculated and compared between the two groups. Results: Large ranges of motion (ROM) of the pelvic angle and hip joints were detected in the experts, while beginners showed greater ROM of the shoulder joint. Peak angular velocity magnitudes and sequences were significantly different between the two groups. Experts lifted the kettlebell upward using the hip joints, pelvis, and shoulder joints (proximal to distal order) sequentially and lowered it using the reverse order of peak angular velocities from the shoulder to hip joints. Conclusion: Mobility of the pelvic segment and hip joint are required, while stability of the other joints is needed to produce appropriate two-arm kettlebell swings. The activation and coordination of the gluteal and hamstring muscles are key points in kettlebell exercises.

• Archives of Plastic Surgery
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• 제38권5호
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• pp.642-648
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• 2011

Purpose: The recent advances in microsurgical techniques and their refinement over the past decade have greatly expanded the indications for digital replantations and have enabled us to salvage severed fingers more often. Many studies have reported greater than 80% viability rates in replantation surgery with functional results. However, replantation of multi-level amputations still remain a challenging problem and the decision of whether or not to replant an amputated part is difficult even for an experienced reconstructive surgeon because the ultimate functional result is unpredictable. Methods: Between January of 2002 and May of 2008, we treated 10 multi-level amputated digits of 7 patients. After brachial plexus block, meticulous replantation procedure was performed under microscopic magnification. Postoperatively, hand elevation, heat lamp, drug therapy and hyperbaric oxygen therapy were applied with careful observation of digital circulation. Early rehabilitation protocol was performed for functional improvement. Results: Among the 19 amputated segments of 10 digits, 16 segments survived completely without any complications. Overall survival rate was 84%. Complete necrosis of one finger tip segment and partial necrosis of two distal amputated segments developed and subsequent surgical interventions such as groin flap, local advancement flap and skin graft were performed. The overall result was functionally and aesthetically satisfactory. Conclusion: We experienced successful replantations of multi-level amputated digits. When we encounter a multi-level amputation, the key question is whether or not it is a contraindication to replantation. Despite the demand for skillful microsurgical technique and longer operative time, the authors' results prove it is worth attempting replantations in multi-level amputation because of the superiority in aesthetic and functional results.

• 대한치과교정학회지
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• 제51권5호
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• pp.321-328
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• 2021

Objective: To examine the accuracy of computer-aided intraoperative navigation (Ci-Navi) in bimaxillary orthognathic surgery by comparing preoperative planning and postoperative outcome. Methods: The study comprised 45 patients with congenital dentomaxillofacial deformities who were scheduled to undergo bimaxillary orthognathic surgery. Virtual bimaxillary orthognathic surgery was simulated using Mimics software. Intraoperatively, a Le Fort I osteotomy of the maxilla was performed using osteotomy guide plates. After the Le Fort I osteotomy and bilateral sagittal split ramus osteotomy of the mandible, the mobilized maxilla and the distal mandibular segment were fixed using an occlusal splint, forming the maxillomandibular complex (MMC). Real-time Ci-Navi was used to lead the MMC in the designated direction. Osteoplasty of the inferior border of the mandible was performed using Ci-Navi when facial symmetry and skeletal harmony were of concern. Linear and angular distinctions between preoperative planning and postoperative outcomes were calculated. Results: The mean linear difference was 0.79 mm (maxilla: 0.62 mm, mandible: 0.88 mm) and the overall mean angular difference was 1.20°. The observed difference in the upper incisor point to the Frankfort horizontal plane, midfacial sagittal plane, and coronal plane was < 1 mm in 40 cases. Conclusions: This study demonstrates the role of Ci-Navi in the accurate positioning of bone segments during bimaxillary orthognathic surgery. Ci-Navi was found to be a reliable method for the accurate transfer of the surgical plan during an operation.