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디지털방사선영상에서 추출한 해면질골의 강도와 미세구조의 형태계측학적 분석에 대한 연구
한승윤,이선복,오성욱,허민석,이삼선,최순철,박태원,김종대,Han Seung-Yun,Lee Sun-Bok,Oh Sung-Ook,Heo Min-Suk,Lee Sam-Sun,Choi Soon-Chul,Park Tae-Won,Kim Jong-Dae 대한영상치의학회 2003 Imaging Science in Dentistry Vol.33 No.2
Purpose : To evaluate the relationship between morphometric analysis of bone microstructure from digital radiographic image and trabecular bone strength. Materials and Methods : One hundred eleven bone specimens with 5 mm thickness were obtained from the mandibles of 5 pigs. Digital images of specimens were taken using a direct digital intraoral radiographic system. After selection of ROI (100 × 100 pixel) within the trabecular bone, mean gray level and standard deviation were obtained. Fractal dimension and the variants of morphometric analysis (trabecular area, periphery, length of skeletonized trabeculae, number of terminal point, number of branch point) were obtained from ROI. Punch sheer strength analysis was performed using Instron (model 4465, Instron Corp., USA). The loading force (loading speed 1 mm/min) was applied to ROI of bone specimen by a 2 mm diameter punch. Stress-deformation curve was obtained from the punch sheer strength analysis and maximum stress, yield stress, Young's modulus were measured. Results: Maximum stress had a negative linear correlation with mean gray level and fractal dimension significantly (p<0.05). Yield stress had a negative linear correlation with mean gray level, periphery, fractal dimension and the length of skeletonized trabeculae significantly (p < 0.05). Young's modulus had a negative linear correlation with mean gray level and fractal dimension significantly (p < 0.05). Conclusions : The strength of cancellous bone exhibited a significantly linear relationship between mean gray level, fractal dimension and morphometric analysis. The methods described above can be easily used to evaluate bone quality clinically.
Retinoic acid가 사람 정상 구강각화세포의 방사선감수성에 미치는 영향에 관한 연구
이진,허민석,이삼선,오성욱,이설미,최항문,최순철,박태원,Lee Jean,Heo Min-Suk,Lee Sam-Sun,Oh Sung-Ook,Lee Sul-Mi,Choi Hang-Moon,Choi Soon-Chul,Park Tae-Won 대한영상치의학회 2003 Imaging Science in Dentistry Vol.33 No.2
Purpose : To evaluate the effect of all-trans-retinoic acid (ATRA) on the radiosensitivity of normal human oral keratinocyte (NHOK). Materials and methods: Relative cell survival fraction including SF2 (survival fraction at 2 Gy) was calculated on the basis of colony formation assay. Data were fitted to the linear-quadratic model to establish the survival curve and calculate α and β values. Using flow cytometry at 1, 2, 3, 4, and 5 days after exposure to 2 and 10 Gy irradiation, cell cycle arrest and apoptosis were analysed. To understand the molecular mechanism of the radiosensitization of ATRA on NHOK, proteins related with apoptosis and cell cycle arrest were investigated by Western blot analysis. Results: Treatment with ATRA resulted in a significant decrease of SF2 value for NHOK from 0.63 to 0.27, and increased α and β value, indicating that ATRA increased radiosensitivity of NHOK. ATRA increased LDH significantly, but increasing irradiation dose decreased LDH, suggesting that the radiosensitizing effect of ATRA is not directly related with increasing cell necrosis by ATRA. ATRA did not induce appotosis but increased G2 arrest after 10 Gy irradiation, implying that the increased radiosensitivity of NHOK may be due to a decrease in mitosis casued by increasing G2 arrest. ATRA inhibited the reduction of p53 at 3 days after l0Gy irradiation and increased p21 at 1 day after 10 Gy irradiation. Further study is required to determine the precise relationship between this effect and the radiosensitizing effect of A TRA. Conclusion: These results suggested that ATRA increase radiosensitivity by inhibiting mitosis caused by increasing G2 arrest.
양선 ( Sun Yang ),오성욱 ( Sung Ook Oh ),신준암 ( Jun Am Shin ),박신실 ( Sin Sil Park ),오영재 ( Young Jae Oh ),장기택 ( Kee Taek Jang ),이규택 ( Kyu Taek Lee ) 대한내과학회 2007 대한내과학회지 Vol.72 No.2
Adenomyoma is a nonneoplastic lesion that can be found anywhere in the gastrointestinal tract, but it`s rarely found in the extrahepatic bile duct. To the best of our knowledge, it is a completely benign lesion, but making a clear distinction from malignancy on preoperative evaluation is very difficult. Its clinical importance mainly lies in the possibility that they may be confused with carcinoma, leading to unnecessarily extensive surgical resections. We report here on a case of distal common bile duct adenomyoma that presented with right upper quadrant abdominal pain, and the preoperative examinations could not reveal whether the tumor was benign or malignant. It was finally diagnosed by histological examination after performing pylorus preserving pancreaticoduodenectomy. (Korean J Med 72:217-221, 2007)
임플란트 CT에서 방향 표시자의 방향과 잔존골을 고려한 임플란트 식립 방향의 관계에 관한 연구
김도훈,허민석,이삼선,오성욱,최항문,전인성,최순철,Kim Do-Hoon,Heo Min-Suk,Lee Sam-Sun,Oh Sung-Ook,Choi Hang-Moon,Jeon In-Seong,Choi Soon-Chul 대한영상치의학회 2003 Imaging Science in Dentistry Vol.33 No.2
Purpose : To assess the relationship between the direction of the indicating rod of the radiographic stent for ideal prosthetic design and the actual possible path of implant fixture placement when residual ridge resorption is considered. Materials and Methods: The study materials consisted of 326 implant sites (male 214 cases and female 112 cases) from a total of 106 patients (male 65 patients and female 41 patients) who desired implant prostheses. Computed tomography of patients were taken and reformatted using ToothPix/sup (R)/ software. Bony defects, bony sclerosis, the change of the direction of indicating rod, and root proximity of the adjacent teeth were examined on the CT-derived images. Results: The rate of the irregular crestal cortex was relatively high on premolar and molar area of maxilla. Mandibular molar area showed relatively high rate of focal sclerosis on the area of implant fixture insertion. The position of the indicating rods were relatively acceptable on the molar areas of both jaws. However, the position of the indicating rods should be shifted to buccal side with lingual rotation of the apical end on maxillary anterior teeth and premolar area. Conclusion: Clinically determined rod direction and position of the indicating rod for implant placement was not always acceptable for insertion according to the reformatted CT images. The pre-operative treatment plan for implant should be determined carefully, considering the state of the alveolar bone using the reformatted CT images.