• 한국세라믹학회지
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• 제44권7호
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• pp.381-386
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• 2007

A porous reaction bonded silicon carbide (RBSC) was fabricated by a molten Si infiltration method. The porosity and flexural strength of porous RBSC fabricated in this study were dependent upon the amount of carbon source used in the SiC/carbon preform as well as the amount of Si infiltrated into the SiC/carbon preform. The porosity and flexural strength of porous RBSC were in the range of $20 vo1.{\sim}49 vo1.%$ and $38{\sim}61 MPa$, respectively. With increase of carbon contents and molten Si for infiltration, volume fraction of the pores was gradually decreased, and flexural strength was increased. The porous RBSCs fabricated with the same amount of molten Si show less residual Si around neck with increase of carbon source, as well as a new SiC was formed around neck which resulted in the decreased porosity and improvement of the flexural strength. In addition, decrease of the porosity and increase of the flexural strength were also obtained by increase of the amount of molten Si with the same amount of carbon source. However, it was found that the flexural strength of porous RBSC depends on the porosity rather than the amount of the newly formed SiC in neck phase between SiC particles used as a starting material.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제34권3호
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• pp.388-397
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• 2008

The present study was performed to evaluate the function of the mandible according to the pattern of fracture and treatment methods of condylar fractures of the mandible and help operators in making a treatment plan. Sixty patients (average follow-up period was $7.8{\pm}9.4$ months) who were treated for condylar fracture from June, 2002 to May, 2006 at the Department of Oral and Maxillofacial surgery, Chonnam National University Hospital were reviewed. The common causes of the condylar fracture were traffic accident and fall-down (35.0%). In concomitant injuries, laceration was 46.7% and the fracture of the mandibular symphysis was highest incidence (60.0%). The common site of the fracture was the condylar head (47.8%), followed by subcondyle (36.2%) and condylar neck (15.9%). Under 15 years old patients, the closed reduction was performed in 87.5% out of the patients. All of the condylar fragments were fixed to the mandible with titanium miniplates in cases of open reduction. The mean period of intermaxillary fixation (IMF) was $14.2{\pm}6.5$ days in closed reduction and $10.0{\pm}4.2$ days in open reduction. The old patient with bilateral condylar head fractures, who were treated by closed reduction with IMF for 3 weeks, showed the limitation of mandibular movements. But, there was no significant different results between open reduction and closed reduction with the respect of the Helkimo's mandibular mobility index and clinical dysfunction index (DI). Complications, such as fibrous ankylosis and resorption of the mandibular condyle, were not observed in all patients. These results suggest that the good results can be obtained by closed reduction with proper IMF periods and functional exercise in most condylar fractures of the mandible except severely displaced extracapsular fractures.

• Clinics in Shoulder and Elbow
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• 제13권2호
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• pp.230-236
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• 2010

목적: Mason 분류 제 2형 및 일부의 3형 요골 두 및 경부 골절에 대하여 제한적 피부절개 및 경피적 도수 정복술 시행 후 기능 및 방사선학적 평가를 통해 임상적 결과를 분석하고자 하였다. 대상 및 방법: 2001년 5월부터 2007년 2월까지 Mason 분류 제 2형 또는 3형의 요골 두 및 경부 골절로 경피적 도수 정복술을 시행받은 13명의 환자 (요골 경부 골절: 9예, 요골 두 및 경부골절: 4예)를 대상으로 하였으며, 환자의 평균 연령은 29세 (11세~59세)였고 남자는 8명, 여자는 5명 이었다. 평균 추시 기간은 1년 6개월 (12개월~2년 9개월)이었다. 요골 두 및 경부의 도수 정복술은 방사선 투시기를 사용하여 골절부위를 확인 후, 골절부위 2~3 cm 원위부에서 1 cm 정도의 피부절개 후 경막 거상기를 이용하여 압박이나 감입 (impacted)형태의 요골 경부골절 및 두부의 부분 함몰된 관절면 골편의 정복을 시행하였다. 정복 후 불안정한 3예에 대해 1예에서 골절부의 경피적 핀고정술을 시행하였고, 2예에서 근위 요척골 간에 경피적 횡 핀고정을 추가 하였으며, 나머지 10예에서는 석고 부목 고정술만 시행하였다. 결과: 방사선학적 평가상 전 예에서 골유합이 관찰되었다. 평균 골유합 기간은 6.2주였다. 요골두의 각형성은 수술 전 평균 33.2도 (30도~42도)에서 수술 후 평균 7.8도 (4도~15도)로 감소하였다. 수술 직후에서 최종 추시시까지의 각변형은 0.7도 (-1도~2도) 였다. 수술 후 주관절의 운동 범위는 굴곡 평균 133.1도 (120도~140도), 신전 평균 7.3도 (0도~25도), 회내전은 80도(72도~90도), 회외전은 84.3도 (78도~90도)였다. Mayo Elbow Performance Index는 평균 96.2점 (80점~100점), American Shoulder and Elbow Surgeons elbow score는 평균 97점 (83점~100점), Disabilities of the Arm, Shoulder and Hand score는 평균 1.2점 (0점~5.8점) 으로 우수한 결과를 얻었다. 합병증으로 각각 한 예에서 일시적인 후골간 요골 신경 마비 증상과 경도의 주관절 외반 변형이 발생하였다. 결론: 경피적 도수 정복술은 관절내 독립적인 감입이 없는 Mason 분류 제 2형 및 일부의 3형 요골 두 골절 및 경부 골절의 치료에 있어서 간단하고 합병증 발생이 적으면서 만족할 만한 결과를 얻을 수 있는 유용한 방법 중의 한가지로 생각된다.

• 대한족부족관절학회지
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• 제4권2호
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• pp.93-99
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• 2000

Eleven patients with calcaneal fracture had 2 acute compartment syndrome of the feet and 9 late complication of the compartment syndrome of the feet. An interstitial pressure of more than 30 mmHg in either the central or interosseous compartment was considered pathologic and was treated by fasciotomy performed medially. Rigid claw toe deformity was treated by excision of the head and neck of the proximal phalanx, dorsal capsular release of the metatarsophalangeal joint, and lengthening of the extensor tendon. Patients were evaluated at a mean of 35 months(range, 21 - 44 months) after operation, and the examination was directed specifically toward symptoms and signs of myoneural ischemia, and walking pain. At follow-up, 2 patients with acute compartment syndrome of the foot had no evidence of myoneural ischemia, 9 patients with claw toe deformity had no pain with walking. Based on our clinical observations, we concluded that compartment syndrome of the foot may occur after the calcaneal fracture and fasciotomy is effective treatment for the prevention of the long term sequelae of this debilitating condition.

• Journal of Korean Neurosurgical Society
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• 제29권11호
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• pp.1469-1475
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• 2000

Objective : The goal of this study was to evaluate the clinical outcome of the posterior C1-2 transarticular screw fixation without C1-2 sublaminar wiring in atlantoaxial instability. Methods : Between Apr. 1995 and Feb. 2000, we used this technique in treat randomly selected 17 patients (11 men, 6 women) who had atlantoaxial instability. The causes of instability were : type II-A odontoid process fracture(10 cases) ; type II-P odontoid process fracture(1 case) ; Os odontoideum(2 cases) ; transverse ligament laxity due to rheumatoid disease(1 case) ; and, transverse ligament injury without bone fracture(3 cases). All cases were operated with posterior C1-2 transarticular screw fixation with 3.5mm cortical screw and interlaminar iliac graft without sublaminar wire fixation. The mean follow-up period was 28 months(5 to 58 months) and the mean age at the time of operation was 41 years(15 to 68 years). All Patients were allowed to ambulate with Philadelphia neck collar on the first post-operation day. Results : Bony fusion was successfully achieved in all cases demonstrated at 3-month follow-up studies. There was no operative mortality or morbidity. Conclusion : The authors conclude that the posterior transarticular screw fixation without C1-2 sublaminar wiring provide adequate stability with high bony union rate in atlantoaxial instability of various causes.

• 대한의용생체공학회:의공학회지
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• 제24권3호
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• pp.233-239
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• 2003

측방 낙상에 관계된 상해는 노인들에 있어서 가장 치명적이고 빈번한 의료 문제를 야기한다. 측방 낙상에 의해 발생하는 심각한 결과 중 하나인, 고관절 골절은 넘어진 사람 중 약 1%에서만 발생하지만 고관절 골절은 신체장애, 사망 및 이에 관련된 의료비용의 상승 등을 초래한다. 본 연구에서는 측방 낙상시 고관절 골절에 큰 영향을 미치는 충돌 단계에서의 위험요소를 하중각도로 가정하여 이 요소에 대한 영향과 직립시와 비교하여 상대적인 위험도를 비교하고자 하였다. 실험 조건은 이전 연구자의 자료를 토대로 모사골반을 구성하였고, 이렇게 구성된 모사골반을 진자형 충격 시험기에 고정시키고 충격각도(0$^{\circ}$, 15$^{\circ}$, 30$^{\circ}$)를 변화시켜가며 대퇴골의 동적 거동을 조사하였다. 본 실험을 통하여 하중각도의 변화가 대퇴골 근위부에서의 변형에 영향을 주며, 다른 부위에 비해 대퇴골 경부에 상대적으로 큰 변형이 생겨 골절 가능성이 높다는 것을 확인하였다. 또한 낮은 충격속도에서도 직립 상태에 비해 큰 변형을 보였으며, 변형 분포의 차이도 나타내었다. 따라서 변형 크기의 차이뿐만 아니라 이러한 변형 분포의 차이도 고관절 골절 기전에 영향을 줄 것으로 사료된다.

• 대한치과보철학회지
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• 제45권4호
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• pp.534-545
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• 2007

Statement of problem: In spite of increasing sports injury, there was no collected data on the rate and type of dental injuries for athletes in Korea. Purpose: The purpose of this study was to investigate the occurrence of maxillofacial injuries and attitude of college sports player in Korea towards mouthguard. Material and methods: Total 617 athletes answered a series of questionnaire concerning their sports injury and using mouthguard. Results: 1. 81%(502) of athletes had, playing or training a sports, suffered an injury. Female athletes suffered an injury more than male athletes(p<0.05). Contact sports athletes were injured more than non contact sports athletes(p<0.05). 2. 335 athletes(54.8%) had suffered maxillofacial injuries while playing or training. 81.8% of athletes suffered an maxillofacial injury in contact sports(p<0.05). 3. Laceration of oral area, wrick in neck, fracture or avulsion on upper incisors, concussion, TMJ injury, fracture or avulsion on lower incisors, fracture or avulsion on lower molars were frequently injured area. 4. 67.2% of athletes answered that mouthguard could prevent sports injury especially high in contact sports(p<0.05). But only 39.1% of athletes required mouthguard while playing. 44.6% of athletes showed their intention of using mouthguard. Conclusion: This study shows that the incidence of maxillofacial injuries is very high while the actual use of mouthguard is very low. To prevent sports injury, a dentist must inform sports players and coaches of accurate information about mouthguard so that they can use it well. A dentist also has to provide them with better mouthguard on the basis of user's complaint.

• 대한족부족관절학회지
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• 제3권1호
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• pp.12-18
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• 1999

Eleven patients with calcaneal fracture had 2 acute compartment syndrome of the feet and 9 late complication of the compartment syndrome of the feet. An interstitial pressure of more than 30 mmHg in either the central or interosseous compartment was considered pathologic and was treated by fasciotomy performed medially. Rigid claw toe deformity was treated by excision of the head and neck of the proximal phalanx, dorsal capsular release of the metatarsophalangeal joint, and lengthening of the extensor tendon. Patients were evaluated at a mean of 35 months(range, 21 - 44 months) after operation, and the examination was directed specifically toward symptoms and signs of myoneural ischemia, and walking pain. At follow -up, 2 patients with acute compartment syndrome of the foot had no evidence of myoneural ischemla, 9 patients with claw toe deformity had no pain with walking. Based on our clinical observations, we concluded that compartment syndrome of the foot may occur after the calcaneal fracture and fasciotomy is effective treatment for the prevention of the long term sequelae of this debilitating condition.

• Genomics & Informatics
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• 제7권1호
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• pp.13-19
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• 2009

Osteoporosis is characterized by impaired osteogenesis. BMD is a major determinant of bone strength. The role of the VDR gene in predisposition to primary osteoporosis has been recognized. However, population-based case-control studies have been reported controversial results for known candidate genes in an ethnically distinct group. To determine the genetic effects of VDR variants on osteoporosis and BMD, we directly sequenced the VDR gene in 24 unrelated Korean individuals and identified eighteen sequence variants. We investigated the potential involvement of eight SNPs in osteoporosis in postmenopausal women (n = 729). Two SNPs (LD) in intron 2, -5294G>C (rs2238135) and -4817G>A (rs17882443) showed the evidence of association with enhanced BMD of the femoral neck ($p_{additive}$=0.031 for rs2238135; $p_{additive}$=0.017 and $p_{dominant}$= 0.019 for 17882443). Moreover, VDR -4817G>A was significantly associated with protective effect on all fracture risk ($p_{recessive}$=0.035, OR=0.2, 95% CI=$0.05{\sim}0.89$), and tended to be higher BMD values at various proximal femur sites. Therefore, we suggest that the -4817G>A may be useful genetic marker for vitamin D-related metabolism and may have an important role in the increased BMD of the proximal femur in postmenopausal Korean women.

• Hip & pelvis
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• 제35권4호
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• pp.253-258
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• 2023

Purpose: To figure out how complete control of family visits to prevent infection of coronavirus disease 2019 (COVID-19) affected the activity recovery of hip fracture patients admitted to nursing hospitals. Materials and Methods: Eighty-one patients with hip surgery in the two years prior to COVID-19 pandemic were classified as Group A, and 103 patients in the next two years were designated as Group B. The subjects' walking ability was evaluated by using the modified Koval index (MKI). In order to analyze the impact of the family visit control to the subjects, each group was classified into two different groups: (1) inpatients group who admitted to nursing hospitals and (2) home-treated patients. Additionally, statistical elements were processed in consideration of other factors that may affect the results of the experiment. Results: The MKI evaluated at 6 months postoperative was 3.31±1.79 in Group A and 2.77±1.91 in Group B, and it was meaningfully low after the pandemic (P=0.04). There was significantly low among both of Group A 2.74±1.76 and Group B 1.93±1.81 after the pandemic (P=0.03) among those treated at the nursing hospital. The rate of deterioration of the MKI was 35 (43.2%) in Group A and 57 (55.3%) in Group B, which increased by 12.1% after the pandemic. Conclusion: The pandemic had a negative effect on the recovery of postoperative activities of elderly hip fracture patients who admitted to nursing hospitals when family access was completely restricted to prevent infection.