• Journal of Periodontal and Implant Science
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• 제51권3호
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• pp.179-188
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• 2021

Purpose: Due to the difficulty of the hygienic care and sanitary management of abutment teeth and subpontic areas associated with fixed dental prostheses (FDPs), intrabony defects occur and accelerate due to the accumulation of plaque and calculus. This study aimed to evaluate the efficacy of regenerative periodontal surgery for intrabony defects associated with FDPs. Methods: The study inclusion criteria were met by 60 patients who underwent regenerative treatment between 2016 and 2018, involving a total of 82 intrabony defects associated with FDPs. Periodontal osseous lesions were classified as 1-, 2-, and 3-wall intrabony defects and were treated with an enamel matrix derivative in combination with bone graft material. The changes in clinical (pocket probing depth [PPD] and clinical attachment level [CAL]) and radiographic (defect depth and width) outcomes were measured at baseline and at 6, 12, and 24 months. Results: Six months after regenerative treatment, a significant reduction was observed in the PPD of 1-wall (P<0.001), 2-wall (P<0.001), and 3-wall (P<0.001) defects, as well as a significant reduction in the CAL of 2-wall (P<0.001) and 3-wall (P<0.001) intrabony defects. However, there was a significant increase in the CAL of 1-wall intrabony defects (P=0.003). Radiographically, a significant reduction in the depth of the 3-wall (P<0.001) defects and a significant reduction in the width of 2-wall (P=0.008) and 3-wall (P<0.001) defects were observed. The depth decreased in 1-wall defects; however, this change was not statistically significant (P=0.066). Conclusions: Within the limitations of the current study, regenerative treatment of 2- and 3-wall intrabony defects associated with FDPs improved clinical and radiological outcomes. Additional prospective studies are necessary to confirm our findings and to assess long-term outcomes.

• Advances in nano research
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• 제16권1호
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• pp.91-109
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• 2024

Carbon nanotubes are drawing wide attention of research communities and several industries due to their versatile capabilities covering mechanical and other multi-physical properties. However, owing to extreme operating conditions of the synthesis process of these nanostructures, they are often imposed with certain inevitable structural deformities such as single vacancy and nanopore defects. These random irregularities limit the intended functionalities of carbon nanotubes severely. In this article, we investigate the mechanical behaviour of double-wall carbon nanotubes (DWCNT) under the influence of arbitrarily distributed single vacancy and nanopore defects in the outer wall, inner wall, and both the walls. Large-scale molecular simulations reveal that the nanopore defects have more detrimental effects on the mechanical behaviour of DWCNTs, while the defects in the inner wall of DWCNTs make the nanostructures more vulnerable to withstand high longitudinal deformation. From a different perspective, to exploit the mechanics of damage for achieving defect-induced shape modulation and region-wise deformation control, we have further explored the localized longitudinal and transverse spatial effects of DWCNT by designing the defects for their regional distribution. The comprehensive numerical results of the present study would lead to the characterization of the critical mechanical properties of DWCNTs under the presence of inevitable intrinsic defects along with the aspect of defect-induced spatial modulation of shapes for prospective applications in a range of nanoelectromechanical systems and devices.

• 치과방사선
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• 제27권2호
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• pp.49-61
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• 1997

The purpose of this study was to compare E-speed film, CDR, and modified CDR images by means of observing some artificial defects of alveolar bone wall in the sound human dried mandibles. High diagnostic accuracy was shown in 1 wall and 4 wall defects by all 5 observers (2 Radiologists, 2 Periodontists, 1 General practitioner), but the diagnosis in 2 wall and 3 wall defects was inaccurate. Modified CDR images had the more diagnostic accuracy than E-speed film and CDR images, but there was no statistical difference among them. Finally, radiologist used modified CDR images more than others and used equalization effect more than the change in contrast and/or brightness.

• 치과방사선
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• 제26권2호
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• pp.153-163
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• 1996

The purpose of this study was to evaluate the ability of radiographs in detecting experimental bony defect in the posterior wall of the maxillary sinus. For this study, experimentally five skulls were used, the bony defects with a diameter of 5mm were created at different locations in the posterior wall of the right maxillary sinus and the bony defects of 10mm were created at different locations in the posterior wall of th maxillary sinus. Panoramic view, panoramic sinus view, water's view, and computed tomogram were taken and the results analyzed. The obtanined results were as follows: 1. The panoramic view was superior to the panoramic sinus view in detecting the bony defects in the posterior wall of the maxillary sinus. 2. Panoramic view, panoramic sinus view, and waters's view were limitation to the detection of the bony defects in the posterior wall of the maillary sinus. 3. All the bony defects in the posterior wall of the maxillary sinus were excellently visualized on the computed tomogram.

• 치과방사선
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• 제24권1호
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• pp.115-124
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• 1994

The purpose of this study was to examine the differences in representation of a globular radiopaque mass on the pantomograms and Waters' views and to compare the efficacy of periapical radiograms, pantomograms and Waters' views in detection of defects on the internal walls of the maxillary sinus. This study was performed with dried human skull. For the study of difference of radiopaque mass shadow in the two views, rubber ball with a diameter of 10㎜ was used as the experimental lesion. It was placed successively on the internal wall of the anterior, posterior, medial, lateral walls and floor of the maxillary sinus. To examine the detectability of defects for radiographic techniques, defects were formed in the anterior, posterior, medial, lateral walls, and floor of the maxillary sinus. They were formed with 0.5㎜, 0.75㎜, 1.0㎜, 2.0㎜ and 3.0㎜ sized steel round burs with a slow speed dental handpiece. By subsequently plugging the holes with zinc oxide eugenol paste, radiopaque defects were produced. After that the periapical radiograms, the pantomograms and the Waters' views were taken each and every defect. The obtained results were as follows: 1. Rubber balls placed on each internal wall of the maxillary sinus were correctly depicted on the posterior wall and the floor in case of the pantomogram, and on the anterior wall and the medial wall in case of the Waters' view. 2. On the detectability of defects for each radiographic technique, radiolucent defects were detected in different places for each technique. Periapical radiogram could detect 1.0㎜ defect on the floor of the maxillary sinus, pantomogram could detect 2.0㎜ defect on every internal wall of the maxillary sinus, and Waters' view could detect 3.0㎜ defect on the anterior wall of the maxillary sinus. 3. On the detectability of defects for each radiographic technique, radiopaque defects were detected in different places for each technique. Periapical radiogram could clearly detect 0.5㎜ defect on the floor of the maxillary sinus, pantomogram could detect 0.5㎜ defect on every internal wall of the maxillary sinus, and finally Waters' view could detect 0.5㎜defect on the anterior wall of the maxillary sinus but 0.75㎜ defect on the anterior wall, lateral wall and floor of the maxillary sinus. As the result, the periapical radiogram is the most simple and satisfactory method for investigating in the maxillary sinus. The pantomogram is suitable method for screening of changes in the maxillary sinus. And the Waters' view is available for detect of lesion in the anterior wall of the maxillary sinus. For the purpose of accurate diagnosis and evaluation of lesion in the maxillary sinus, these techniques supplement each other.

• 한국임상수의학회지
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• 제26권5호
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• pp.467-471
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• 2009

This report describes Neural Tube Defects (NTDs) with Abdominal Wall Defects (AWDs) on the sibling of Yorkshire terriers. The NTDs and AWDs are rare serious congenital defects. The NTDs are neurulation abnormality that results from to failed transformation of the neurual tube by the incomplete closure of the embryonic neural plate. These dysraphic states range form mild to severe according to developmental malformation that include fusion defects of skull (crania bifida; CB) and fusion defects of vertebrae (spina bifida; SB). The AWDs are genetic defects that results from to failed formation of abdominal wall and cavity. These dysraphic states are omphalocele and gastroschisis. The 12-month dam was delivered by caesarian section and 4 littermate had obvious malformations. One male dead stillbirth fetus (L1) was revealed the extruded abdominal viscera, omphalocele. One female fetus (L2) was died within 1 hour after birth with defects of abdominal muscle upper umbilicus, gastroschisis. 3rd fetus (L3) was died within 36 hours after parturition and revealed a copious dermal and vertebral defects on the midline thorax, upper SB asperta. 4th fetus (L4) is still growing well now at 6 months but at the 2 week age, appears hairy nevus on the frontal cranium and dorsal thoracic portion. The radiograph of L1 and L2 are shown decrease bony density of calvarium and L3 was shown defect of spinose processes of the T9-T13. On our knowledge, this is first report of the SB and CB in Yorkshire terrier. And also sibling of NTDs with AWDs that has not previously been reported in the dog.

• Journal of Chest Surgery
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• 제27권5호
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• pp.422-426
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• 1994

Recently, we experienced one case of multiple ribs fracture with large chest wall defects. This patient was treated with internal fixation of ribs by use of Judet`s struts and reconstruction of chest wall defects by use of Teflon mesh. Postoperative outcome was satisfactory result and its advantages were reduced duration of operation, prevention of pulmonary herniation and reduced risk of postoperative infection.

• Journal of Chest Surgery
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• 제8권1호
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• pp.29-36
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• 1975

We have experienced 49 cases of tumors of chest wall at St. Mary`s Hospital from Jan. 1963 to Dec.1974. In four cases of them, the reconstruction of chest wall defects performed. 1] Out of 49 cases of tumors of the chest wall, 27 cases were benign tumors, 14 cases metastatic malignant tumors, and 8 cases primary malignant tumors. 2] Twenty-six cases [50%] of tumors of the chest wall were on the bony cage. Among them benign tumors were 9 cases [35%], metastatic malignant tumors 14 cases [53%], and primary malignant tumors 3 cases [12%]. Of these, 24 cases were located on the ribs and 2 cases on the sternum.3] The malignant tumors of bony chest wall were excised in en bloc resection including involved ribs. The wide defects of bony chest wall were reconstructed by means of displacement of neighboring ribs and mobilized diaphragm, in the two osteogenic sarcomas of rib, and of prosthesis with silastic sheets in one rhabdomyosarcoma and one metastatic adenocarcinoma of lung.

• Journal of Periodontal and Implant Science
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• 제28권1호
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• pp.145-160
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• 1998

The ultimate goal of periodontal therapy is the regeneration of periodontal tissue which has been lost due to destructive periodontal disease, and numerous kinds of materials and techniques have been developed to achieve this goal. Bone grafts include autografts, allografts, xenografts and synthetic grafts. Among the synthetic grafts, bioactive glass has been used in dentistry for more than ten years and Fetner reported improved new bone formation and more amount of new attachment after grafting PerioGlas, a kind of bioactive glass, in 2-wall defects of monkeys in 1994. It Is well known that 1-wall defects have less osteogenic potential and more epithelial migration, so we need to study the erect of bioactive glass in 1-wall dejects in dogs. The present study evaluates the effect of bioactive glass on the epithelial migration, alveolar bone regeneration, cementum formation and gingival connective tissue attachment in intrabony detects of dogs. Four millimeter deep and four millimeter wide 1-wall defects were surgically cheated in the mesial aspects of premolars. The test group received bioactive glass with a flap procedure and the control underwent flap procedure only. Histologic analysis after 8 weeks of healing revealed the following results: 1. The height of gingival margin was 1.30{\pm}0.73mm$ above CEJ in the control and $1.40{\pm}0.78mm$ in the test group. There was no statistically significant difference between the two group. 2. The length of epithelial growth (the distance from CEJ to the apical end of JE) was $1.74{\pm}0.47mm$ in the control and $1.12{\pm}0.36mm$ in the test group. These was a statistically significant difference between the two groups (P<0.01). 3. The length of new cementum was $2.06{\pm}0.73mm$ in the control and $2.62{\pm}0.37mm$ in the test group. There was no statistically significant difference between the two groups. 4. The length of new bone was $1.83{\pm}0.74mm$ in the control and $2.39{\pm}0.59mm$ in the test group. There was no statistically significant difference between the two groups. These results suggest that the use of bioactive glass 1-wall intrabony defects has significant effect on the prevention of junctional epithelium migration, but doesn't have any significant effect on new bone and new cementum formation.

• 제어로봇시스템학회논문지
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• 제8권1호
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• pp.37-45
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• 2002

A method of measuring the length of defects on the wall and restructuring the defect image is proposed based on the estimation algorithm of a camera orientation, which uses the declination angle of a laser slit beam. The estimation algorithm of the horizontally inclined angle of CCD camera adopts a 3-dimensional coordinate transformation of the image plane where both the laser beam and the original image of the defects exist. The estimation equation is obtained by using the information of the beam projected on the wall and the parameters of this equation are experimentally obtained. With this algorithm, the original image of the defect can be reconstructed as an image normal to the wall. From the result of a series of experiments, the measuring accuracy of the defect is measured within 0.5% error bound of real defect size under 30 degree of the horizontally inclined angle. The proposed algorithm provides the method of reconstructing the image taken at any arbitrary horizontally inclined angle as the image normal as the wall and thus, it enables the accurate measurement of the defect lengths by using a single camera and a laser slit beam.