• The Journal of Korean Academy of Prosthodontics
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• v.55 no.4
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• pp.436-443
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• 2017

In the past, computer-aided design / computer-aided manufacturing (CAD/CAM) technology was the closed system that users had to use the components of only one manufacturer. At present, it has changed to the open system with the flexibility to select and use the components of various manufacturers' components according to their needs. Despite the development of dental materials and prostheses manufacturing methods, denture manufacturing has followed conventional manufacturing methods for nearly 100 years. However, studies on CAD/CAM fabricated denture have been recently carried out to overcome the disadvantages of conventional denture manufacturing. Some commercialized products using milling or 3D printing have already been applied clinically. This case report confirms the possibility of CAD/CAM dentures using 3D face scan and compared them to conventionally fabricated dentures.

• The Journal of the Korea Contents Association
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• v.8 no.1
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• pp.212-227
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• 2008

Since 3D face can be rotated freely in 3D space and illumination effects can be modeled properly, 3D face modeling Is more precise and realistic in face pose, illumination, and expression than 2D face modeling. Thus, 3D modeling is necessitated much in face recognition, game, avatar, and etc. In this paper, we propose a 3D face modeling method based on 3D morphable shape modeling. The proposed 3D modeling method first constructs a 3D morphable shape model out of 3D face scan data obtained using a 3D scanner Next, the proposed method extracts and matches feature points of the face from 2D image sequence containing a face to be modeled, and then estimates 3D vertex coordinates of the feature points using a factorization based SfM technique. Then, the proposed method obtains a 3D shape model of the face to be modeled by fitting the 3D vertices to the constructed 3D morphable shape model. Also, the proposed method makes a cylindrical texture map using 2D face image sequence. Finally, the proposed method builds a 3D face model by rendering the 3D face shape model with the cylindrical texture map. Through building processes of 3D face model by the proposed method, it is shown that the proposed method is relatively easy, fast and precise than the previous 3D face model methods.

• Journal of Korean Dental Science
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• v.15 no.1
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• pp.19-30
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• 2022

Purpose: The purpose of the study was to assess the validity of three-dimensional (3D) facial scan taken with facial scanner and digital photo wrapping on the cone-beam computed tomography (CBCT). Materials and Methods: Twenty-five patients had their CBCT scan, two-dimensional (2D) standardized frontal photographs and 3D facial scan obtained on the same day. The facial scans were taken with a facial scanner in an upright position. The 2D standardized frontal photographs were taken at a fixed distance from patients using a camera fixed to a cephalometric apparatus. The 2D integrated facial models were created using digital photo wrapping of frontal photographs on the corresponding CBCT images. The 3D integrated facial models were created using the integration process of 3D facial scans on the CBCT images. On the integrated facial models, sixteen soft tissue landmarks were identified, and the vertical, horizontal, oblique and angular distances between soft tissue landmarks were compared among the 2D facial models and 3D facial models, and CBCT images. Result: The results showed no significant differences of linear and angular measurements among CBCT images, 2D and 3D facial models except for Se-Sn vertical linear measurement which showed significant difference for the 3D facial models. The Bland-Altman plots showed that all measurements were within the limit of agreement. For 3D facial model, all Bland-Altman plots showed that systematic bias was less than 2.0 mm and 2.0° except for Se-Sn linear vertical measurement. For 2D facial model, the Bland-Altman plots of 6 out of 11 of the angular measurements showed systematic bias of more than 2.0°. Conclusion: The facial scan taken with facial scanner showed a clinically acceptable performance. The digital 2D photo wrapping has limitations in clinical use compared to 3D facial scans.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.425-431
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• 2019

This clinical case report describes the digital workflow that combines a face scan, cone beam computed tomography and an intraoral scan to visualize the outcome of prosthodontic treatment in the anterior region. This approach improves communication between clinic, laboratory and patients. A patient with healthy general condition came for a restorative treatment to treat post-traumatic central incisors of maxilla. A virtual patient replica was made by incorporating a face scan, cone beam computed tomography and an intraoral scan. Design mockup of definitive restorations was shown to the patient and modified according to the patient's desire. This digital workflow facilitates the fabrication of optimal esthetic restorations, and enhances the predictability of outcome of restorations.

• Journal of Korean Dental Science
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• v.17 no.3
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• pp.121-137
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• 2024

It is possible to design dental prosthesis in harmony with the patient's face and functional pathway using virtual patient created by integrating 3D diagnostic data such as intraoral scan, facial scan and jaw motion data. Also, esthetic teeth-gingiva relationship can be obtained, and post-surgical gingival outline can be predicted by using CAD software designed 3D surgical template during gingivectomy procedure. In this case report, 3D diagnostic data was collected from patients in need of esthetic anterior restoration, integrated on CAD software and applied to virtual articulator. Treatment outcome was simulated by creating virtual patient with dynamic occlusion. Esthetic anterior fixed restoration was fabricated by applying 3D surgical template designed on CAD software to gingivectomy procedure. To make sure that anterior guidance was formed in harmony with the patient's function pathway, occlusion was assessed following every step. The results were both functionally and esthetically satisfying.

• Journal of Korean Dental Science
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• v.15 no.2
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• pp.166-171
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• 2022

This case report describes a dynamic digital esthetic rehabilitation procedure that integrates a new three-dimensional augmented reality (3D-AR) technique to treat a patient with multiple missing anterior teeth. The prostheses were designed using computer-aided design (CAD) software and virtually trialed using static and dynamic visualization methods. In the static method, the prostheses were visualized by integrating the CAD model with a 3D face scan of the patient. For the dynamic method, the 3D-AR application was used for real-time tracking and projection of the CAD prostheses in the patient's mouth. Results of a quick survey on patient satisfaction with the two visualization methods showed that the patient felt more satisfied with the dynamic visualization method because it allowed him to observe the prostheses directly on his face and be more proactive in the treatment process.

• Journal of Dental Rehabilitation and Applied Science
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• v.40 no.3
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• pp.135-141
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• 2024

Purpose: The purpose of this study was to investigate the accuracy of image merging of an intraoral scan of an edentulous arch to a facial scan using wax rim and markers. Materials and Methods: For registration of oral scan to face scan, a wax rim with markers was made. The markers were cuboid and divided into four groups according to size (5, 10 mm) and attachment location (midline, canine region). The evaluation of registration accuracy was compared with a standard created using cone-beam computed tomography data. Anterior linear variation of the edentulous arch and the 3D variation of the overall arch were measured. Kruskal-Wallis test and Mann-Whitney U test were used for statistics, and the significance level was set at 0.05 and evaluated under Bonferroni correction (0.05/6 = 0.083). Results: In the anterior deviation and global deviation results, there was no statistically significant difference in the oral scan position displacement values between the 5 mm and 10 mm groups. When the midline marker was used, the intraoral scan position displacement value was significantly lower than when only the canine marker was used. Conclusion: Marker attached wax rim can be used for image matching between facial and intraoral scans of the edentulous arch. Marker location at the middle area increases the accuracy of image matching.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10b
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• pp.212-216
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• 2007

3D 스캐너의 보급으로 3차원 모델 생성이 가능하게 되었으나 결과로 얻은 형상이 아직 사진에서와 같은 사실적 묘사에 미치지 못하고 있다. 본 논문에서는 얼굴의 3D 스캔 데이터에 효율적인 텍스처 매핑을 통해 사실적 렌더링 결과를 얻을 수 있는 방법을 기술한다. 3D 얼굴 스캔 데이터와 얼굴의 사진 이미지의 좌표를 정확하게 맞추어 3D 스캔 데이터와 얼굴 이미지의 버덱스를 매치시켜주고, 얼굴 이미지의 해당 버텍스에 들어 있는 칼라 값을 3D 스캔 데이터의 버텍스에 넘겨주는 텍스처 매핑을 구현한다. 본 논문에서는 정면, 좌측, 우측 3장의 이미지를 이용하여 간단히 멀티텍스처 매핑을 수행하는 방법과 이 때 발생하는 사진 간의 경계선에서 발생하는 문제 해결에 대해 기술한다.

• Tunnel and Underground Space
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• v.33 no.6
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• pp.508-518
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• 2023

This paper presents a new approach for the automatic mapping of discontinuities in a tunnel face based on its 3D digital model reconstructed by LiDAR scan or photogrammetry techniques. The main idea revolves around the identification of discontinuity areas in the 3D digital model of a tunnel face by segmenting its 2D projected images using a deep-learning semantic segmentation model called U-Net. The proposed deep learning model integrates various features including the projected RGB image, depth map image, and local surface properties-based images i.e., normal vector and curvature images to effectively segment areas of discontinuity in the images. Subsequently, the segmentation results are projected back onto the 3D model using depth maps and projection matrices to obtain an accurate representation of the location and extent of discontinuities within the 3D space. The performance of the segmentation model is evaluated by comparing the segmented results with their corresponding ground truths, which demonstrates the high accuracy of segmentation results with the intersection-over-union metric of approximately 0.8. Despite still being limited in training data, this method exhibits promising potential to address the limitations of conventional approaches, which only rely on normal vectors and unsupervised machine learning algorithms for grouping points in the 3D model into distinct sets of discontinuities.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.131.3-131
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• 2001

A 2-dimensional scanner have been generally used for an office, but 3-dimensional one was seldom used in industry. A footwear bonding process has been operated manually by the skilled operators, but it is needed to be operated automatically. So we developed an automatic outsole profile scanner, which consists of PC, CCD camera, laser beam diode and moving mechanism, to scan automatically the 3-dimensional profile of outsole inner face to be bonded. Here the developed algorithm makes 2D image into 3D outsole profile. This profile will be used enough to bond automatically the outsole to something like leather or clothes.