• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.456-466
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• 2019

As digital dentistry technology is being developed, it is being used in various ways. This case covers how digital dentistry technology is being applied on the treatment of patients with loss of vertical dimension due to worn dentition and multiple loss of teeth. The loss of vertical dimension was carefully assessed and recovered, and implants were placed with surgical guides, designed considering the final restoration. The movement of the mandibular was measured with the electronic instrument for recording mandibular movement. Wax-up process was done with Naturgemäße Aufwachs-Technik (N.A.T.) and Natural functional reconstruction (N.F.R.). It was scanned, and the provisional restoration was fabricated using Computer-Aided-Design/Computer-Aided-Manufacturing (CAD/CAM) technology, and the adjustment process was done at the clinic to meet with the satisfaction both functionally and esthetically, and then, using double scanning and CAD/CAM technology, it was carried out as a final restoration. As a result, the patient obtained satisfying results, utilizing the benefits of digital dentistry technology and traditional methods.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.397-404
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• 2019

Bone and soft tissue conditions are important for successful implant treatment. But, the placement itself is also very important. Implants which is installed in the wrong position result in the biological, esthetical and mechanical problems. In order to place an implant in the correct position, the final restoration and diagnostic wax-up should be considered prior to the surgery. If the artificial teeth for the interim denture are directly transferred from the diagnostic wax-up, the operator can try the form of diagnostic wax-up in the mouth. If the surgical template is produced by duplicating the interim denture, the implant can be placed in the planned position. In this case, the polymethyl methacrylate (PMMA) artificial tooth was precisely milled by the digital duplication of diagnostic wax-up. And interim denture was fabricated by using these milled teeth. After the patient adapted for a sufficient period, the implant was placed at the planned position with surgical template produced by duplicating the interim denture. After confirming sufficient osseointegration, the final prostheses were made to reflect the shape of diagnostic wax-up. Through this procedure, the satisfactory functional and esthetic outcome could be acquired.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.42
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• pp.32.1-32.4
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• 2020

Background: Le Fort I osteotomy is a highly effective treatment for skeletal jaw deformities and is commonly performed. High Le Fort I osteotomy is a modified surgical procedure performed for improving the depression of the cheeks by setting the osteotomy higher than the conventional Le Fort I osteotomy. Developments in three-dimensional (3D) technology have popularized the use of 3D printers in various institutions, especially in orthognathic surgeries. In this study, we report a safe and inexpensive method of performing a high Le Fort I osteotomy using a novel 3D device and piezosurgery, which prevent tooth root injury without disturbing the operation field for patients with a short midface and long tooth roots. Results: A 17-year-old woman presented with facial asymmetry, mandibular protrusion, a short midface, and long tooth roots. We planned high Le Fort I osteotomy and bilateral sagittal split ramus osteotomy. Prevention of damage to the roots of the teeth and the infraorbital nerve and accurate determination of the posterior osteotomy line were crucial for clinical success. Le Fort I osteotomy using 3D devices has been reported previously but were particularly large in size for this case. Additionally, setting the fixing screw of the device was difficult, because of the risk of damage to the roots of the teeth. Therefore, a different surgical technique, other than the conventional Le Fort I osteotomy and 3D device, was required. The left and right parts of the 3D device were fabricated separately, to prevent any interference in the surgical field. Further, the 3D device was designed to accurately cover the bone surface from the piriform aperture to the infra-zygomatic crest with two fixation points (the anterior nasal spine and the piriform aperture), which ensured stabilization of the 3D device. The device is thin and does not interfere with the surgical field. Safe and accurate surgical performance is possible using this device and piezosurgery. The roots of the teeth and the infraorbital nerve were unharmed during the surgery. Conclusions: This device is considerably smaller than conventional devices and is a simple, low-cost, and efficient method for performing accurate high Le Fort I osteotomy.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.1
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• pp.79-87
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• 2021

The digital workflow of optical impressions by the intraoral scanner and CADCAM manufacture of dental prostheses is actively developing. The complex process of traditional impression taking, definite cast fabrication, wax pattern making, and casting has been shortened, and the number of patient's visits can also be reduced. Advances in intraoral scanner technology have increased the precision and accuracy of optical impression, and its indication is progressively widened toward the long span fixed dental prosthesis. This case report describes the long span implant case, and the operator fully utilized digital workflow such as computer-guided implant surgical template and CAD-CAM produced restoration after the digital impression. The provisional restoration and customized abutments were prepared with the optical impression taken on the same day of implant surgery. Moreover, the final prosthesis was fabricated with the digital scan while utilizing the same customized abutment from the provisional restoration. During the data acquisition step, stl data of customized abutments, previously scanned at the time of provisional restoration delivery, were imported and automatically aligned with digital impression data using an 'A.I. abutment matching algorithm' the intraoral scanner software. By using this algorithm, it was possible to obtain the subgingival margin without the gingival retraction or abutment removal. Using the digital intraoral scanner's advanced functions, the operator could shorten the total treatment time. So that both the patient and the clinician could experience convenient and effective treatment, and it was possible to manufacture a prosthesis with predictability.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.1
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• pp.88-96
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• 2021

Fixed implant prostheses or removable partial dentures are common treatment for partially dentulous patients. Recently, an implant-assisted removable partial denture (IARPD) has been introduced and is widely used. In the case of removable partial dentures using implant attachment and surveyed fixed prostheses, the consideration about parallelism of insertion path between implants and surveyed fixed prostheses is an important factor for success of IARPDs. In this case, she complained of discomfort while using the mandibular removable partial denture. Thus, an IARPD using implant surveyed fixed prostheses was fabricated. Thereafter, more implants were placed by a digital guide surgery to have the same insertion path as the existing surveyed fixed prostheses. Locator attachments were installed to the left and right premolar implants, and the left molar was able to obtain support of the removable partial denture with healing abutment. The clinical results were satisfactory on the aspect of aesthetic and masticatory function.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.2
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• pp.160-167
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• 2022

One of the treatment options for edentulous state patients with residual ridge resorption is implant overdenture using milled bar and attachment. It not only provides improved retention and stability but can also reduce the coverage of palatal surface. In addition, when a small number of implants are used, milled bar has the effect of being splinted between implant fixtures, which makes it mechanically advantageous under functions such as mastication. The patient in this case was a maxillary edentulous state patient with a considerable amount of residual alveolar bone resorption after removing the existing failed implants. Three implants were planted on both sides and an implant overdenture was fabricated using milled bar and ADD-TOC attachment.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.2
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• pp.168-174
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• 2022

In case of gingival recession or bone defect in maxillary anterior implant treatment, it is not easy to obtain satisfactory clinical results. In this case, loss of the labial alveolar plate was diagnosed in the maxillary right central incisor, so after tooth extraction, soft tissue was secured and implant placement with bone graft was planned. In addition, digital guide surgery was performed for the ideal implant position, and GBR (Guided Bone Regeneration) was accompanied with the xenogeneic bone and the autologous bone collected from the mandibular ramus since alveolar bone defects were extensive. After a sufficient period of osseointegration of the implant, a temporary prosthesis was fabricated through secondary stage surgery and impression taking, and through periodic external adjustment, the shape of soft tissue was improved. In the final prosthesis fabrication, a color tone of natural teeth was induced by an gold anodized customized abutment, and an aesthetic and functional zirconia prosthesis with reproducing the shape of the temporary prosthesis through intraoral scan was delivered.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.2
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• pp.202-210
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• 2022

Recently with the advance in digital dentistry, the fabrication of dentures using computer-aided design and computer-aided manufacturing (CAD-CAM) is on the rise. The denture designed through a CAD software can be produced in a 3-dimensional manufacturing process. This process includes a subtractive processing method such as milling and an additive processing method such as 3D printing and in which it can be applied efficiently in more complex structures. In this case, complete dentures were fabricated using Stereolithography (SLA)-based 3D printing to shorten the production time and interval of visits in patient with physical disabilities due to cerebral infarction. For definitive impression, the existing interim denture was digitally replicated and used as an individual tray. The definitive impression obtained with polyvinyl siloxane impression material was including information about the inclination and length of the maxillary anterior teeth, vertical dimension, and centric relation. In addition, facial scan data with interim denture was obtained so that it can be used as a reference in determination of the occlusal plane and in arrangement of artificial teeth during laboratory work. Artificial teeth were arranged through a CAD program, and a gingival festooning was performed. The definitive dentures were printed by SLA-based 3D printer using a FDA-approved liquid photocurable resin. The denture showed adequate retention, support, and stability, and results were satisfied functionally and aesthetically.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.3
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• pp.283-292
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• 2022

For fixed prosthetic treatment using implants, implants must be placed in a suitable location for prosthetic treatment. During surgery, minimally invasive prosthetic restoration is possible using a flapless method using a surgical guide. The patient in this case was an 86-year-old male patient who wanted treatment due to discomfort when using conventional dentures. Due to systemic disease, the patient had difficulty using removable local dentures, so full dentures for the maxilla and fixed implants for the mandible were restored. Because there is a high risk of bleeding due to systemic disease, the implant was placed in a flapless method using a surgical guide. Finally, prostheses were fabricated with maxillary full denture and mandibular screw-retained zirconia, and this report shows satisfactory esthetic and functional recovery.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.4
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• pp.313-319
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• 2022

Complete dentures are one of the most basic treatment methods for the treatment of edentulous patients. The manufacturing process of traditional complete dentures goes through the steps of taking primary impressions, secondary impressions, jaw relation record, trying in wax denture, and final denture insertion. Multiple visits and complex manufacturing procedures are required, and errors may occur in each step. With the development of digital technology, manufacturing steps have been reduced by introducing digital technology to the denture treatment process. In the process of manufacturing dentures by introducing a digital process, a more precise work is possible using Computer-Aided Design, and it is possible to shorten the period of labor and reduce the number of visits. In this case, the anterior teeth arrangement of the patient's existing dentures was transferred to the final dentures using a digital method. After taking impression, try-in dentures were digitally fabricated and tried in the oral cavity to evaluate their retention in the oral cavity. Final dentures were manufactured by milling process. The number of visits was reduced, satisfactory retention and stability of dentures were obtained, and aesthetic recovery was achieved.