• Journal of Chest Surgery
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• v.51 no.6
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• pp.390-394
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• 2018

Background: The nonsurgical treatment of chest wall deformity by a vacuum bell or external brace is gradual, with correction taking place over months. Monitoring the progress of nonsurgical treatment of chest wall deformity has relied on the ancient methods of measuring the depth of the excavatum and the protrusion of the carinatum. Patients, who are often adolescent, may become discouraged and abandon treatment. Methods: Optical scanning was utilized before and after the intervention to assess the effectiveness of treatment. The device measured the change in chest shape at each visit. In this pilot study, patients were included if they were willing to undergo scanning before and after treatment. Both surgical and nonsurgical treatment results were assessed. Results: Scanning was successful in 7 patients. Optical scanning allowed a visually clear, precise assessment of treatment, whether by operation, vacuum bell (for pectus excavatum), or external compression brace (for pectus carinatum). Millimeter-scale differences were identified and presented graphically to patients and families. Conclusion: Optical scanning with the digital subtraction of images obtained months apart allows a comparison of chest shape before and after treatment. For nonsurgical, gradual methods, this allows the patient to more easily appreciate progress. We speculate that this will increase adherence to these methods in adolescent patients.

• Transactions of Materials Processing
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• v.16 no.4 s.94
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• pp.323-328
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• 2007

The residual stress in axial direction of the steel wires has been measured by using a method based on the combination of the focused ion beam(FIB) milling and digital image correlation(DIC) program. The residual stress is calculated from the measured displacement field before and after the introduction of a slot along the steel wires. The displacement is obtained by the digital correlation analysis of high-resolution scanning electron micrographs, while the slot is introduced by FIB milling with low energy beam. The experimental procedures are described and the feasibilities are demonstrated in steel wires fabricated with different conditions. It reveals that the tensile residual stress is formed in all steel wires and this is strongly influenced by the fabrication conditions.

• The Journal of the Korean dental association
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• v.52 no.1
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• pp.8-16
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• 2014

The introduction of cone-beam computed tomography(CBCT) and computer software in orthodontics has allowed orthodontists to provide more accurate diagnosis and treatment. The most common use of CBCT imaging allows orthodontists to visualize the precise position of supernumerary or impacted teeth, especially impacted canines. In doing so, the exact angulation of impaction and proximity of adjacent roots can be evaluated by orthodontists, allowing them to choose vector forces for tooth movement while minimizing root resorption. Even though 2-dimensional panoramic images can be used to view the position of the impacted canines, they have limitations because it is not possible to evaluate the impacted tooth position 3-dimensionally. An accurate knowledge of root position improves the determination of success in orthodontic treatment. Nowadays, considering the fast pace of technological development, a combination of intraoral scanning, digital setups, custommade brackets and wires, and indirect bonding may soon become the orthodontic standard. In this paper, this will be discussed along with the digital models.

• Journal of Korean Dental Science
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• v.15 no.2
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• pp.132-140
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• 2022

Purpose: Dental diagnostic records derived from study models are a popular method of obtaining reliable and vital information. Conventional plaster models are the most common method, however, they are being gradually replaced by digital impressions as technology advances. Moreover, three-dimensional dental models are becoming increasingly common in dental offices, and various methods are available for obtaining them. This study aimed to evaluate the accuracy of the measurement of dental digital models by comparing them with conventional plaster and to determine their clinical validity. Materials and Methods: The study was conducted on 16 patients' maxillary and mandibular dental models. Tooth size (TS), intercanine width (ICW), intermolar width (IMW), and Bolton analysis were taken by using a digital caliper on a plaster model obtained from each patient, while intraoral scans were manually measured using two digital analysis software. A one-way analysis of variance test was used to compare the dental measurements of the three methods. Result: No significant differences were reported between the TS, the ICW and IMW, and the Bolton analysis through the conventional and two digital groups. Conclusion: Measurements of TS, arch width, and Bolton analysis produced from digital models have shown acceptable clinical validity. No significant differences were observed between the three dental measurement techniques.

• Nuclear Engineering and Technology
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• v.55 no.9
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• pp.3206-3212
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• 2023

We developed a miniaturized multi-dimensional radiation sensor system consisting of an inorganic scintillator array and plastic optical fibers. This system can be applied to remotely obtain the radioactivity distribution and identify the radionuclides in radioactive waste by utilizing a scanning method. Variation in scintillation light was measured in two-dimensional regions of interest and then converted into radioactivity distribution images. Outliers present in the images were removed by using a digital filter to make the hot spot location more accurate and cubic interpolation was applied to make the images smoother and clearer. Next, gamma-ray spectroscopy was performed to identify the radionuclides, and three-dimensional volume scanning was also performed to effectively find the hot spot using the proposed array sensor.

• Journal of Technologic Dentistry
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• v.37 no.1
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• pp.1-7
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• 2015

Purpose: The aim of this study was to evaluate the marginal and internal gap of wax copings fabricated from extraoral scanning with intraoral scanning. Methods: Fifteen study models(abutment of teeth 16) were made by PMMA. STL files of thirty abutment were prepared by intraoral scanning with extraoral scanning. Wax copings of thirty fabricated using CAD/CAM system. Marginal and internal gap of wax copings of thirty were measured by silicone replica technique and digital microscope(${\times}140$). Date were analyzed by using independent samples t-test. Results: Mean (SD) of two group were measured $55.61(27.42){\mu}m$ for totally gap of ES group and $60.67(33.14){\mu}m$ for totally gap of IS group. But marginal and internal gap of two group were not differences statistically significant(p>0.05). Conclusion: Evaluation of marginal and internal gap of two group showed that no differences statistically significant and clinically acceptable results.

• Journal of Technologic Dentistry
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• v.33 no.3
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• pp.211-218
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• 2011

Purpose: The purpose of the study was a quantitative evaluation of common errors in digital impression procedure using CEREC$^{(R)}$ AC system. Methods: Two-hundreds digital impression data comprising 174 inlays, 26 onlays by CEREC$^{(R)}$ AC in-office CAD/CAM system were obtained from a dental clinic. One evaluator assessed errors of the digital impression data and divided into five categories of errors: inappropriate scanner positioning (ISP), improper handling with a scanner (IHS), irregular powder arrangement (IPA), improper cavity preparation (ICP), and insufficient scanned data (ISD). Results: The most common errors were IPA(21%), and ISP and ISD were followed by 17% respectively. IHS was found in 14.5% of all digital impression data. ICP comprising only 6.5% was the rarest. Conclusion: Most errors were due to inaccurate manipulation with an intraoral scanner or improper cavity preparation for scanning. A deliberate manipulation to prevent common errors mentioned may deliver an optimal result in the digital impression procedure.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.4 s.181
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• pp.183-190
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• 2006

Digital 3D Real Object Duplication System (RODS) consists of 3D Scanner and Solid Freeform Fabrication System (SFFS). It is a device to make three-dimensional objects directly from the drawing or the scanning data. In this research, we developed an office type SFFS based on Three Dimensional Printing Process and an industrial SFFS using Dual Laser. An office type SFFS applied sliding mode control with sliding perturbation observer (SMCSPO) algorithm for control of this system. And we measured process variables about droplet diameter measurement and powder bed formation etc. through experiments. In case of industrial type SFFS, in order to develop more elaborate and speedy system for large objects than existing SLS process, this study applies a new Selective Dual-Laser Sintering (SDLS) process and 3-axis Dynamic Focusing Scanner for scanning large area instead of the existing f lens. In this process, the temperature has a great influence on sintering of the polymer. Also the laser parameters are considered like that laser beam power, scan speed, and scan spacing. Now, this study is in progress to evaluate the effect of experimental parameters on the sintering process.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.8
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• pp.164-170
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• 2004

The skin movement artifacts are referred to as the relative motion of skin with respect to the motion of underlying bones. This is of great importance in joint biomechanics or internal kinematics of human body. This paper describes a novel experiment that measures the skin movement of a hand based on MR(magnetic resonance) images in conjunction with surface modeling techniques. The proposed approach consists of 3 phases: (1) MR scanning of a hand with surface makers, (2) 3D reconstruction from the MR images, and (3) registration of the 3D models. The MR images of the hand are captured by 3 different postures. And the surface makers which are attached to the skin are employed to trace the skin motion. After reconstruction of 3D models from the scanned MR images, the global registration is applied to the 3D models based on the particular bone shape of different postures. The results of registration are then used to trace the skin movement by measuring the positions of the surface markers.

• Journal of Dental Anesthesia and Pain Medicine
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• v.17 no.1
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• pp.55-59
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• 2017

Digital dentistry has influenced many dental procedures, such as three-dimensional (3D) diagnosis and treatment planning, surgical splints, and prosthetic treatments. Patient-specific protective appliances (PSPAs) prevent dental injury during endotracheal intubation. However, the required laboratory work takes time, and there is the possibility of tooth extraction while obtaining the dental impression. In this technical report, we utilized new digital technology for creating PSPAs, using direct intraoral scanners and 3D printers for dental cast fabrication.