• Maxillofacial Plastic and Reconstructive Surgery
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• 제34권1호
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• pp.12-16
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• 2012

Purpose: The purpose of this study is to evaluate the effect of exposure of hydroxyapatite coating on the amount of bone formation and stability in the dogs. Methods: In this study, hydroxyapatite coated implants (HAPTITE) was placed over the femur bone surface of four dogs about 1 mm. The experimental group was divided into 4 weeks group of 8 implants and 8 weeks group of 8 implants, and then they were sacrificed. The stability of implants was evaluated twice with Osstell$^{TM}$ mentor (Osstell AB, Goteborg, Sweden) at right after placement and sacrifice. The amount of bone formation was evaluated through histomorphometric examination. Results: The stability of implants was in normal range, and tended to increase as time goes by. Mean percentages of new bone formation rates were $90.5{\pm}6.6$ at uppermost 1 mm bone level adjacent to soft tissues (level 1) and $92.9{\pm}4.1$ at next 1 mm bone level (level 2) in 4 weeks group, $90.1{\pm}11.5$ at level 1 and $95.9{\pm}2.3$ at level 2 in 8 weeks group. Mean percentages of bone-implant contact rates were $85.1{\pm}10.8$ at level 1 and $88.1{\pm}13.8$ at level 2 in 4 weeks group, $88.5{\pm}14.4$ at level 1 and $95.3{\pm}3.1$ at level 2 in 8 weeks group. There was no statistically significant difference of new bone formation rate and bone-implant contact rate between uppermost 1 mm bone level adjacent to soft tissues and next 1 mm bone level. However, there was no significant difference in bone formation between 4 and 8 weeks groups. Conclusion: These results suggested that exposed hydroxyapatite coated implants to soft tissue showed favorable bone formation and implant stability.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제29권3호
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• pp.217-226
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• 2007

Purpose: Distraction osteogenesis is considered to take favorable effect on the TMJ and be beneficial to prevent the relapse after the mandibular advancement of Class II malocclusion patient. This is the report with literature review on the mandibular advancement in the patients showing preoperative condylar resorption and who need larger amount of advancement. Patients and method: Distraction osteogenesis using intraoral device was performed for three mandibular hypoplasia patients (one male and two females). All patients were adult over 18 years old. The patients showed condylar bony resorption preoperatively. The distraction was performed intraorally with modified SSRO. After 7 days of latency period, activation was performed at the rate of 1.0 mm/day with twice turn. The devices were removed after 4-8 month consolidation period. Results: Total advancement of mandible was average 13 mm. One patient showed openbite immediately after removal of distraction device. It took long time to guide the openbite with elastics. The comparison between cephalometries immediately after device removal and postoperative six month revealed average 3.4 mm relapse. This means that mandibular advancement with distraction osteogenesis needs overcorrection and elastic rehabilitation even after enough consolidation periods. Conclusion: Larger amount of mandibular advancement could be achieved with distraction osteogenesis in severe mandibular hypoplasia with condylar resorption. However, some relapse was found during the follow-up period and the over correction is considered to be needed. The effect of distraction osteogenesis seems to be investigated with long-term follow-up.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제35권3호
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• pp.167-173
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• 2013

Purpose: The aim of this study is to analyze the series of panoramic radiograph of implant patients using the system to measure peri-implant crestal bone loss according to the elapsed time from fixture installation time to more than three years. Methods: Choose 10 patients having 45 implant fixtures installed, which have series of panoramic radiograph in the period to be analyzed by the system. Then, calculated the crestal bone depth and statistics and selected the implant in concerned by clicking the implant of image shown on the monitor by the implemented pattern recognition system. Then, the system recognized the x, y coordination of the implant and peri-implant alveolar crest, and calculated the distance between the approximated line of implant fixture and alveolar crest. By applying pattern recognition to periodic panoramic radiographs, we attained the results and made a comparison with the results of preceded articles concerning peri-implant marginal bone loss. Analyzing peri-implant crestal bone loss in a regression analysis periodic filmed panoramic radiograph, logarithmic approximation had highest $R^2$ value, and the equation is as shown below. $y=0.245Logx{\pm}0.42$, $R^2=0.53$, unit: month (x), mm (y) Results: Panoramic radiograph is a more wide-scoped view compared with the periapical radiograph in the same resolution. Therefore, there was not enough information in the radiograph in local area. Anterior portion of many radiographs was out of the focal trough and blurred precluding the accurate recognition by the system, and many implants were overlapped with the adjacent structures, in which the alveolar crest was impossible to find. Conclusion: Considering the earlier objective and error, we expect better results from an analysis of periapical radiograph than panoramic radiograph. Implementing additional function, we expect high extensibility of pattern recognition system as a diagnostic tool to evaluate implant-bone integration, calculate length from fixture to inferior alveolar nerve, and from fixture to base of the maxillary sinus.

• 대한치과교정학회지
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• 제30권6호
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• pp.687-698
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• 2000

일반적이고 포괄적인 Edgewise방법으로 치료하고 유지시킨 II급 부정교합의 골격 및 치성요소의 변화를 치료 전, 후 및 유지시의 측모두부방사선사진을 비교하여 알아봄으로써 성인 II급 부정교합의 치료 양식을 살펴보고자 하였다. 비발치로 치료한 II급 부정교합자 22명과 상하악 제1소구치 발치로 치료한 20명을 대상으로 치료 전, 후의 측모두부방사선사진을 비교하였으며, 발치치료군 4명과 비발치치료군 4명의 유지시 측모두부방사선사진을 채득하여 유지시의 변화를 살펴보았다. 두개저 및 상,하악 기저골에 기준으로 서로 중첩시켜 골격양상의 변화 및 치아의 경사도와 수직적, 수평적 변화양상을 관찰하여 평가한 결과 다음과 같은 결론을 얻었다. 1. 발치군과 비발치군 모두에서 전,후방 안면고경과 하안면고경 등의 수직고경이 유의하게 증가하였으며, 교합평면의 유의한 경사를 보였다. 2. 비발치군에서 상악 중절치는 치료에 따른 후방견인과 정출을 보였으나 유지기간 동안 약간 순측경사 되었다. 상악 구치부는 수직적인 정출을, 하악 구치부는 원심경사를 보였으나, 근심이동은 보이지 않았다. 유지 기간 동안 상하악 구치는 약간의 근심경사를 보였다. 3. 발치군에서 상하악 중절치 모두 치료에 따른 후방견인과 정출을 보였으나 유지기간 동안 약간 순측경사되었다. 상악 구치부는 수직적인 정출과 동시에 유의한 근심이동을 보였으며, 하악 구치부는 원심경사와 수직적인 정출 및 근심이동을 보였으나 유지기간 동안 약간의 근심경사만을 보였다.

• Journal of Oral Medicine and Pain
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• 제24권1호
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• pp.25-36
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• 1999

저자는 이하두정방사선사진 (願下頭頂放射線寫眞, submentovertex radiographs)을 이용하여 하악과두의 수평각과 측두하악장애와의 연관성을 평가하고자 측두하악장애의 병력 및 증상이 없고, 자연치열로 형성된 정상교합을 가진 성인 34명과 전북대학교병원 구강내과에 내원한 측두하악장애환자 38명을 대상으로, 환자군을 임상검사 및 방사선학적 검사를 통해 편측 정복성 관절원판 전방변위 환자군, 양측 정복성 관절원판 전방변위 환자군 및 편측 비정복성 관절원판 전방변위 혹은 골관절염 환자군으로 세분한 후, 좌우측 외이도의 위치를 확인할 수 있도록 소강구 (小鋼球)가 내재된 장치물을 이용하여 채득한 규격화된 이하두정방사선사진상에서 하악과두의 내측극과 외측극을 이은 선과 양측 외이공에 위치한 소강구를 이은 선으로부터 하악과두의 수평각을 측정하였다. 평가 결과 정상군에서의 좌(평균 25.3도), 우(평균 24.8도)측 하악과두의 수평각 (평균 25.0도)은 유의한 차이를 보이지 않았으며 환자군에서는 이환측 하악과두의 수평각 (평균 28.5도)이 비이환측 하악과두 (평균 26.2도)보다 유의성있게 증가된 수치를 보였다 (p<0.05). 또한 환자군 (평균 27.55도)에서의 하악과두의 수평각이 정상군 (평균 25.0도)에서 보다 유의하게 증가된 수치를 보였다 (p<0.05). 임상적으로 세군으로 구분된 환자군의 경우, 각군의 이환측 또는 비이환측, 각 군을 합한 이환측 또는 비이환측의 경우에 있어서도 정상군에서 보다 하악과두 수평각이 유의성있게 증가된 수치를 보였다 (p<0.05). 세가지로 구분된 환자군 각각의 상호 비교에 있어서는 유의성있는 차이를 나타내지 않았다. 그리고 편측으로 이환된 환자군에서의 이환된 수평각 (평균 29.1도)은 비이환측 (평균 26.2도)보다 유의성있게 증가된 수치를 보였으나 (p<0.05), 양측으로 이환된 환자군에서의 좌우측 수평각은 유의한 차이를 보이지 않았다. 이로써 측두하악장애의 진단 차원에서 측두하악장애를 유발하는 여러 요소 중외 하나로 하악과두 수평각에 대한 평가가 고려되어야 할 것으로 사료된다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제37권5호
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• pp.406-414
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• 2011

Thermally induced bone necrosis during implant surgery is a rare phenomenon and a potential contributing factor to implant failure. The frictional heat generated at the time of surgery causes a certain degree of necrosis of the surrounding differentiated and undifferentiated cells. The bone necrosis occurred in the mandible in all three cases, leading to a soft tissue lesion and pain. In each case, radiolucent areas appeared in the middle and apical portions of the implant 4 weeks after surgery. Thermally induced bone necrosis did not improve following systemic antibiotic medication, necessitating surgical treatment. The nonintegrated implants were removed, and meticulous debridement of dead bone and granulation tissue was performed. Then, new implants were implanted along with the placement of autogenous and xenogenic bone covered with a collagen membrane. No further complications occurred after re-operation. The radiolucencies around the new implants gradually resolved entirely, and the soft tissue lesions healed successfully. At 4-5 months after reoperation, implant loading was initiated and the implant-supported restorations have been functioning. The aim of this case report is to present the successful clinical treatment of three cases suspected to be caused by thermally induced bone necrosis after implant drilling.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제37권5호
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• pp.386-395
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• 2011

Introduction: Osteoporosis is a major health problem in the elderly that involves changes in the properties of bone as well as impaired bone healing around a titanium implant in both humans and animals. This study examined effect of low intensity pulsed ultrasound (LIPUS) on the bone healing process around a titanium implant in osteoporosis-induced rats. Materials and Methods: Sixteen rats were divided into two groups. A control group with osteoporosis induced by removing both ovaries and an experimental group of rats that were applied with LIPUS after osteoporosis had been induced. A screw type titanium implant (diameter, 2.0 mm: length, 3.5 mm, Cowell-Medi, KOREA) was placed into the tibias of 16 rats. The control and experimental group contained 8 rats each. The rats were sacrificed at 1, 2, 4, and 8 weeks after implantation to examine the histopathology and immunochemistry. Results: The histopathology examination revealed earlier new bone formation in the experimental group than the control group. In particular, at 1 week after implantation, more new bone matrix and collagen were observed around the implant of the experimental group compared to the control group. Immunochemistry analysis showed that the level of OPG expression of the experimental group was higher in the early stages than in the control group. After 8 weeks, the levels of OPG expression were similar in both groups. The expression level of receptor activator of nuclear factor kB ligand (RANKL) was stronger in the experimental group than the control group. After 4 weeks, the level of RANKL expression was similar in both groups. Conclusion: These results suggest that the application of LIPUS to implantation can promote bone healing around titanium in osteoporosis animals.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제37권1호
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• pp.49-53
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• 2011

Introduction: This study compared the strength of osseointegration as determined by the resistance to reverse torque rotation of three different hydroxyapatite coated implants in the rabbit femur model. Materials and Methods: Three hydroxyapatite coated implants (HAPTITE), Tapered Screw-Vent (TSV) and BioTite-H - were used. A total of 40 implants were placed in the femur of 20 adult male rabbits. The animals were divided into two groups. In group A (n=10); one HAPTITE was placed into each right femur and one TSV was placed into each left femur. In group B (n=10); one HAPTITE was placed into each right femur and one BioTite-H was placed into each left femur. Five rabbits of each group were sacrificed at 4 and 8 weeks. The implants were removed by reverse torque rotation using a digital torque-measuring device. A total of 40 implants in 20 rabbits were used for the removal torque measurements. Results: In the Group A, 4 weeks after implant placement, the mean removal torque for the HAPTITE and TSV was $70.7{\pm}31.6$ N cm and $28.9{\pm}15.1$ N cm, respectively. Eight weeks after implant placement, the mean removal torque for the HAPTITE and TSV was $87.9{\pm}26.2$ N cm and $54.9{\pm}22.4$ N cm, respectively. In the Group B, 4 weeks after implant placement, the mean removal torque for the HAPTITE and BioTite-H was $58.0{\pm}29.6$ N cm and $37.7{\pm}14.1$ N cm, respectively. Eight weeks after implant placement, the mean removal torque for the HAPTITE and BioTite-H was $91.4{\pm}47.1$ N cm and $30.8{\pm}9.8$ N cm. HAPTITE showed a higher removal torque than the other implants. Conclusion: These results suggest that HAPTITE increases the strength of osseointegration significantly as determined by the resistance to reverse torque rotation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권3호
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• pp.238-246
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• 2007

This study is aimed to elucidate the abnormal growth pattern of human fetal maxilla with cleft lip and palate (CLP). Total 71 fetal maxillae with CLP were obtained from aborted human fetuses. They were examined radiologically for the dimensional changes of maxillary trapezoid (MT) formed by maxillary primary growth centers (MxPGC)(Lee et al., 1992). In palatal radiogram of the CLP maxilla, the MT was traced by the anterior and posterior MxPGCs, and the dimensions of anterior and posterior maxillary widths, maxillary length, and MT length (MTL), and MT area were measured for evaluation of the basic growth pattern of the developing maxilla. The growth of anterior and posterior MxPGCs was severely retarded in the prenatal maxillae with CLPs, showing abnormal shape of MT. Cleft lip subjects without cleft palate also showed arrested growth of MT. Unilateral cleft lipalveolar cleft or cleft palate (UCL-AC/CP) and bilateral cleft lip-alveolar cleft or cleft palate (BCL-AC/CP) showed enhanced abnormal MT pattern. The abnormality of MT was most marked in BCL-AC/CP. It was also observed that the craniofacial malformations other than CLPs produced abnormal MT. In conclusion, the MT growth of prenatal CLP maxilla was severely arrested and resulting in abnormal MT shape on the palatal radiogram. BCL-AC/CP showed more protruded nasal septum than other types of CLPs, while UCL-AC/CP showed severe deviation of the protruded nasal septum towards the non-cleft side. Cleft lip only subjects also showed the abnormal growth of MT. These data suggest that the MT is primarily involved in CLPs, and MT shape could be utilized as a sensitive indicator for the analysis of maxillary malformation in different types of CLPs.

• Investigative Magnetic Resonance Imaging
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• 제4권2호
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• pp.113-119
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• 2000

목적 : 산소호흡을 이용한 뇌의 관류 자기공명영상의 임상적용 가능성을 알고자 하였다. 대상 및 방법 정상 성인 지원자 2명과 3명의 환자, 각각 모야모야병 환자 1명, 뇌경색환자 1명, 뇌수막종 환자 1명을 대상으로 하였으며, 1.5 Tesla의 자기공명영상 장치를 이용하여 뇌의 자화율 대조 (susceptibility contrast) echo planar image (EPI) 방법으로 뇌영역을 10 slice씩 25회(검사시간은 검사당 1.6초) 영상을 얻었다. 검사자는 안면마스크를 착용한 상태로 스캔 시작 8초 후부터 35초가지 산소 15 liter/min를 실내 공기와 혼합되어 흡입되도록 하였다. 획득된 영상을 Magnetom Vision (Siemens Medical Systems, Erlangen, Germany)의 VB31C 프로그램을 이용하여 산소투여전(3골 번째 검사)과, 산소투여 후의 초기 (12-18 번째 검사)와 후기(19-25 번째 검사) 군으로 나누었다. 초기 및 후기 군과 산소투여전 군의 신호차이는 Z-score 0.7 내지 1.0으로 하여 여러번 영상후 처리를 반복하여 difference map을 얻어서, T1 강조영상에 중첩시켜 관류 영상을 얻었다. 모야모야병 환자는 추가로 Gd-DTPA를 0.1 mmol/kg급속주사 후 동일한 방법으로 관류 영상을 얻어 산소호흡에 의한 관류 영상과 비교하였다. 결과 : 산소 공급 후에 시행한 자화율 대조 EPI 방법으로 2명의 지원자와 각각 1예의 모야모야병, 뇌경색, 뇌수막종 증례에서 혈류 분포를 반영하는 관류 영상을 얻을 수 있었다. 모야모야병 1예의 산소 호흡에 의한 관류 영상은 Gd-DTPA투여후의 관류 영상과 유사한 양상을 보였다. 결론 : 산소호흡을 이용한 자화율 대조 EPI 방법은 향후 뇌의 관류 자기공명영상 방법으로 적용이 가능하리라고 생각된다.