• 한국CDE학회논문집
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• 제17권4호
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• pp.253-261
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• 2012

In order to make dental implant surgery successful, it is important to perform proper planning for dental implant placement. In this paper, we propose a decent approach to dental implant placement planning based on geometric processing of 3D models of jawbones, a nerve curve and neighboring teeth around a missing tooth. Basically, the minimum enclosing cylinders of the neighboring teeth around the missing tooth are properly used to determine the position and direction of the implant placement. The position is computed according to the radii of the cylinders and the center points of their top faces. The direction is computed by the weighted average of the axes of the cylinders. For a cylinder whose axis passes the position along the direction, its largest radius and longest length are estimated such that it does not interfere with the neighboring teeth and the nerve curve, and they are used to select the size and type of an implant fixture. From the geometric and spatial information of the jawbones, the teeth and the fixture, we can construct the 3D model of a surgical guide stent which is crucial to perform the drilling operation with ease and accuracy. We have shown the validity of the proposed approach by performing the finite element analysis of the influence of implant placement on bone stress distribution. Adopted in 3D simulation of dental implant placement, the approach can be used to provide dental students with good educational contents. It is also expected that, with further work, the approach can be used as a useful tool to plan for dental implant surgery.

• 한국CDE학회논문집
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• 제20권4호
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• pp.348-356
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• 2015

It is important to devise methods for assisting dentists to consistently determine implant positions and directions and to accurately perform drilling tasks during dental implant surgery. In this paper, we propose a novel approach to tooth implant placement planning which deals with the determination of the positions and directions of multiple implant fixtures for a set of missing mandibular teeth and suggests the selection of the sizes and types of the implant fixtures. We combine Korean standard data in the sizes and positions of human teeth with the patient specific 3D models of mandibular jawbones, nerve curves, and neighboring teeth around the missing teeth in order to determine the positions and directions of the implant fixtures for the missing teeth. Using the geometric and spatial information of the jawbones, the teeth and the implant fixtures, we can construct the 3D models of surgical guide stents which are crucial to perform drilling tasks with ease and accuracy. Adopted in 3D simulation of dental implant placement, the approach can provide surgeon students with good educational contents. We also expect that, with further work, the approach can be used as a useful tool to plan for dental implant surgery.

• 대한치과의사협회지
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• 제54권2호
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• pp.108-122
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• 2016

Prosthetic-driven implant placement is a concept considering the dental implant restoration first based on the final form of that prosthesis to be restored. The latest development of the imaging technology and digital dentistry was able to be obtained the high quality images of CBCT with low radiation exposure and it has also enabled the process to reconstruct the intraoral state in three dimensions due to the development of the intraoral, model and impression scanner. Computer-guided implant placement simulations and template production was able to be more widely used in this context. In this narrative review, the features and the types of implant surgical guides will be introduced. It will also be described the diagnosis and treatment plan using computerguided implant software to reduce the number of visit and to increase the accuracy of the implant surgery through the top-down approach based on the shape and location of the final prosthesis.

• Journal of Periodontal and Implant Science
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• 제44권4호
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• pp.184-193
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• 2014

Purpose: The aim of the present study was to evaluate the in vivo accuracy of flapless, computer-aided implant placement by comparing the three-dimensional (3D) position of planned and placed implants through an analysis of linear and angular deviations. Methods: Implant position was virtually planned using 3D planning software based on the functional and aesthetic requirements of the final restorations. Computer-aided design/computer-assisted manufacture technology was used to transfer the virtual plan to the surgical environment. The 3D position of the planned and placed implants, in terms of the linear deviations of the implant head and apex and the angular deviations of the implant axis, was compared by overlapping the pre- and postoperative computed tomography scans using dedicated software. Results: The comparison of 14 implants showed a mean linear deviation of the implant head of 0.56 mm (standard deviation [SD], 0.23), a mean linear deviation of the implant apex of 0.64 mm (SD, 0.29), and a mean angular deviation of the long axis of $2.42^{\circ}$ (SD, 1.02). Conclusions: In the present study, computer-aided flapless implant surgery seemed to provide several advantages to the clinicians as compared to the standard procedure; however, linear and angular deviations are to be expected. Therefore, accurate presurgical planning taking into account anatomical limitations and prosthetic demands is mandatory to ensure a predictable treatment, without incurring possible intra- and postoperative complications.

• Journal of Korean Dental Science
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• 제4권1호
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• pp.20-25
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• 2011

Purpose: To describe the newly developed Film image transfer system (FITS) for proper positioning of the orthodontic mini-implant in the narrow interdental space and considerations for better application. Materials and Methods: A patient who was planning to have orthodontic mini-implant treatment on the posterior maxilla was recruited to assess the feasibility of FITS. Dental radiographic film and bite record was taken. And then the film image was transferred on the photographic emulsion coated model using transfer light through film projector (enlarger). After exposing the photo emulsion coating on the model, the image was developed with a working solution for a paper developer and fixed. The surgical guide for the mini-implant was fabricated from the transported FITS data. Results: The completed surgical guide was easily placed intraorally, and allowed a simple and rapid placement of the mini-implant. The site of the implant placement was accurate as planned position. Conclusion: In the reported case, The FITS technique represents an effort to minimize risk to the patient and produce consistently good results based upon accurate information about the anatomy of the implant site.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제37권1호
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• pp.43-48
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• 2011

Introduction: This study examined the anatomical morphology of the medial surface of the posterior mandible using 3-dimensional cone-beam computed tomography (CT) images to reduce the number of complications related to dental implant placement. Materials and Methods: Fifty patients were enrolled in this study with an average age (${\pm}$standard deviation) of 44.28 (${\pm}13.05$). On the coronal views cone-beam CT of the first molars, the distance between the top of the canal and alveolar crest vertical distance (VD), the distance between the upper-most point of the canal and the point perpendicular to the lingual cortical margin of the mandible lingual distance (LD), the location of the starting point of VD for reducing from the vertical reference line (VD point), and the inclination of the mandibular medial surface (lingual inclination) were measured, and a statistical evaluation was performed using SPSS for Windows version 15.0. Results: The mean VD0 was $16.91{\pm}2.47\;mm$ and VDx decreased with increasing x value. The mean LD was $5.27{\pm}1.36\;mm$. The VD began to decrease at the mean location of $6.12{\pm}0.96\;mm$ from the vertical reference line. The mean lingual inclination was $1.52{\pm}0.72^{\circ}$. Conclusion: These results will assist in the accurate placement of dental implants and the reduction of complications, particularly in the case of preoperative implant planning using only 2-dimensional imaging methods. (ex. panoramic radiography)

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권4호
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• pp.386-390
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• 2007

This is about the case of loss of multiple teeth and alveolar bone caused by trauma, which needed alveolar bone augmentation before implant treatment. Alveolar bone was reconstructed using iliac bone graft, and thereafter first implant surgery was followed by consolidation period of 3 months. Iliac bone resorption was observed at the time of implant placement. And that resorption was more in the horizontal dimension than in the vertical. We conclude that additional treatment planning(e.g. using alveolar distraction osteogenesis or tissue expander) should be considered besides bone graft for vertical alveolar bone augmentation. For both maxilla and mandible, prosthodontic treatment was carried out $4{\sim}5$ months after implant placement. To compensate alveolar bone deficiency, partial hybrid overdenture on maxilla and implant-supported fixed bridge on mandible were fabricated, and the total treatment was finished.

• 대한소아치과학회지
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• 제42권3호
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• pp.270-274
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• 2015

성인에서의 임플란트 식립에 관해서는 치료 계획, 술식, 예후 등의 다양한 주제가 연구되어 왔으나 성장기 소아 청소년 환자에서의 임플란트 식립에 대해서는 연구가 제한적이다. 본 종설의 목적은 성장기 환자에서의 임플란트 식립에 대해 논하고 악골 및 치조골의 성장이 임플란트 장기적 예후에 갖는 영향을 살펴보고자 한다. 전반적인 골격성장의 유형에 대해 간략히 살펴보고 실제 임상적 치료법 선택에 대해 고찰하고자 한다.

• Journal of Periodontal and Implant Science
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• 제53권5호
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• pp.388-401
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• 2023

Purpose: This study investigated the accuracy of free-hand implant surgery performed by an experienced operator compared to static guided implant surgery performed by an inexperienced operator on an anterior maxillary dental model arch. Methods: A maxillary dental model with missing teeth (No. 11, 22, and 23) was used for this in vitro study. An intraoral scan was performed on the model, with the resulting digital impression exported as a stereolithography file. Next, a cone-beam computed tomography (CBCT) scan was performed, with the resulting image exported as a Digital Imaging and Communications in Medicine file. Both files were imported into the RealGUIDE 5.0 dental implant planning software. Active Bio implants were selected to place into the model. A single stereolithographic 3-dimensional surgical guide was printed for all cases. Ten clinicians, divided into 2 groups, placed a total of 60 implants in 20 acrylic resin maxillary models. Due to the small sample size, the Mann-Whitney test was used to analyze mean values in the 2 groups. Statistical analyses were performed using SAS version 9.4. Results: The accuracy of implant placement using a surgical guide was significantly higher than that of free-hand implantation. The mean difference between the planned and actual implant positions at the apex was 0.68 mm for the experienced group using the free-hand technique and 0.14 mm for the non-experienced group using the surgical guide technique (P=0.019). At the top of the implant, the mean difference was 1.04 mm for the experienced group using the free-hand technique and 0.52 mm for the non-experienced group using the surgical guide technique (P=0.044). Conclusions: The data from this study will provide valuable insights for future studies, since in vitro studies should be conducted extensively in advance of retrospective or prospective studies to avoid burdening patients unnecessarily.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제50권2호
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• pp.70-79
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• 2024

Objectives: The surgical guide is a static computer-assisted device used for implant surgery planning and guidance. By taking an impression and referring to the patients' three-dimensional computed tomography scan of the desired implant site, a surgical guide can be created. During surgery, the surgical guide aids in achieving the designed implant placement position and direction. We examined and evaluated the long-term clinical outcomes of implant surgery using surgical guides. Materials and Methods: This study investigated a total of 15 patients with 32 implants that were placed using surgical guides from 2009 to 2011 with a mean follow-up period extended beyond 10 years. Patient demographics and implant survival rates were recorded. We analyzed marginal bone loss (MBL) by assessing the radiographs acquired at installation, three months after installation, and one month, one, two, and five years after prosthesis delivery. Results: The mean patient age was 57.33 years at implant placement. Of the 32 implants, five implants were placed in the anterior region and 27 implants were in the posterior region. Six implants failed and three of them were replaced, resulting in an 81.25% survival rate. The mean follow-up period was 10 years and nine months. Mean MBL compared to post-installation was significantly higher than at three months after installation, and one month, one, two, and five years after prosthesis delivery. Mean MBL at three months after installation, and one month, one year, and two years were significantly higher compared to the previous visit (P<0.05). However, MBL at five years after prosthesis delivery did not differ significantly compared to at two years. Conclusion: In this study, implant rehabilitation assisted by surgical guides exhibited favorable survival rates. With the limitation of the sample amount in this study, further research and more samples are required to evaluate the long-term clinical effectiveness of surgical guides.