• The Journal of Korean Academy of Prosthodontics
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• v.55 no.1
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• pp.1-8
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• 2017

Purpose: The purpose of this study is to compare the accuracy of the CT guided implant template that was produced by using an intraoral scanner according to the edentulous distance. Materials and methods: Five maxillary casts were fabricated using radiopaque acrylic resin with the second premolars, first molars, and second molars missing. Then a virtual cast was acquired by scanning each resin cast. Implant treatment was planned on the missing sites by superimposing the presurgical CT DICOM file and the virtual cast. Then the implants were placed using a surgical template followed by postsurgical CT scan. The distance and angle of the platform and apex between the presurgical implant and postsurgical implant were measured using the X, Y, and Z axis of the superimposed presurgical CT and postsurgical CT via software followed by statistical analysis using Kruskall-Wallis test and Mann-Whitney test. Results: The implant placement angle error increased towards the second molars but there was no statistically significant difference. The implant placement distance error at the platform and apex also increased towards the second molars and there was a statistically significant error at the second molars. Conclusion: Although the placement angle had no statistically significant difference between the presurgical implant and postsurgical implant, the placement distance at the platform and apex showed a larger error and a statistically significant difference at the second molar implant.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.38
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• pp.15.1-15.6
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• 2016

Background: The utilization of a cone-beam computed tomography (CT)-assisted surgical template allows for predictable results because implant placement plans can be performed in the actual surgery. In order to assess the accuracy of the CT-guided surgery, angular errors and shoulder/apex distance errors were evaluated by data fusion from before and after the placement. Methods: Computer-guided implant surgery was performed in five patients with 19 implants. In order to analyze differences of the implant fixture body between preoperative planned implant and postoperative placed implant, angular error and distance errors were evaluated. Results: The mean angular errors between the preoperative planned and postoperative placed implant was $3.84^{\circ}{\pm}1.49^{\circ}$; the mean distance errors between the planned and placed implants were $0.45{\pm}0.48mm$ horizontally and $0.63{\pm}0.51mm$ vertically at the implant neck and $0.70{\pm}0.63mm$ horizontally and $0.64{\pm}0.57mm$ vertically at the implant apex for all 19 implants. Conclusions: It is important to be able to utilize these methods in actual clinical settings by improving the various problems, including the considerations of patient mouth opening limitations, surgical guide preparation, and fixation.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.38
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• pp.37.1-37.5
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• 2016

Background: The dimensions and shape of the forehead determine the esthetics of the upper third of the face. Korean young people consider a broad and smooth, rounded forehead more attractive. As a result, frontal augmentation becomes more popular in patients with dentofacial deformities. Various surgical procedures and materials have been used in frontal augmentation surgery, with associated advantages and disadvantages. Silicone is a good candidate for frontal augmentation. The author presents two cases of esthetic frontal augmentation with a prefabricated silicone implant in female patients with dentofacial deformities. Case presentation: In case 1, a 24-year-old female patient underwent frontal augmentation surgery with simultaneous maxillomandibular and zygomatic osteotomies to correct facial asymmetry. A silicone implant was fabricated preoperatively using a positive template stone mold of her forehead. In case 2, a 23-year-old female patient underwent total facial contouring surgery including frontal augmentation for improved facial esthetics. A computed tomography (CT)-guided rapid prototype (RP) model was used to make the silicone implants. The operative procedure was safe and simple, and the silicone implants were reliable for a larger degree of frontal augmentation. Six months later, both patients had recovered from the surgery and were satisfied with their frontal shape and projection. Conclusions: Frontal augmentation with silicone implants can be an effective adjuvant strategy to improve facial esthetics in patients with a flat and narrow forehead who undergo orthognathic reconstruction or total facial contouring surgery.

• The Journal of the Korean dental association
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• v.54 no.2
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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.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.6
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• pp.575-580
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• 2005

Transitional implants were developed to support provisional restorations and to allow for load-free osseointegration of conventional implants while a patient was provided with immediate esthetics and function and are usually placed simultaneously at the time of definitive implant placement. Transitional implants are placed in a non-submerged fashion in a single-stage surgery and are designed to be immediately loaded. They generally are made of commercially pure titanium or titanium alloy and are designed as 1-piece implants composed of root and crown replacement segments. Transitional implants can be used in a wide range of indications, such as basic use as temporary implant, to support and protect the primary implants during the healing phase, single crown in the edentulous anterior region of mandibular, anchorage for orthodontic treatment, support a surgical and radiographic template, and primary implant to extremely atrophied alveolar crests of the mandible and maxilla. This article describes the clinical use of transitional implants to support the provisional complete denture and single crown in the restricted edenturous central incisor region of mandible.

• Imaging Science in Dentistry
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• v.51 no.3
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• pp.313-321
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• 2021

Ankylosis of the temporomandibular joint (TMJ) is a disabling disease resulting from fibrous or bony fusion of the mandibular condyle and the glenoid fossa. Early diagnosis and surgical treatment are essential to prevent facial deformity and other complications. Conventional radiography has limitations in demonstrating the true extent of ankylosis. It is important for surgeons to be aware of the size and degree of bony ankylosis in order to perform complete resection of the ankylotic mass. In addition, a detailed evaluation of the relationship with adjacent vital structures such as the internal maxillary artery, inferior alveolar nerve canal, external auditory canal, and skull base are crucial to avoid iatrogenic injury. Multidetector computed tomography (MDCT) is the current imaging modality of choice for preoperative assessments. Herein, the authors propose a structured CT reporting template for TMJ ankylosis to strengthen the value of the preoperative imaging report and to reduce the rates of intraoperative complications and recurrence.

• Journal of Dental Rehabilitation and Applied Science
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• v.27 no.2
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• pp.175-184
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• 2011

With a development of implant restoration technique, there are increasing use of computer-guided system for edentulous patients. It was carried out simulated operation based on CT information about patient's bone quantity, quality and anatomical landmark. However, there are some difference between the programmed implant and post-operative implant about it's position. If the deviation was severe, it could happen a failure of 'passive fit' and not suited for path of implant restoration. The aim of this presentation is to evaluate about a degree of deviations between programmed implant and post-operative implant. Five patients treated by 'NobelGuide' system (Nobel Biocare AB, G$\ddot{o}$teborg, Sweden) in Department of Prosthodontics, Inha University were included in this study. The patients were performed CT radiograph taking and intra-oral impression taking at pre-operation. Based on CT images and study model, surgical stent was produced by NobelBiocareTM. To fabricated a pre-operative study model, after connected lab analog to surgical template, accomplished a pre-operative model using type 4 dental stone. At final impression, a post-operative study model was fabricated in the conventional procedures. Each study model was performed CT radiograph taking. Based on CT images, each implant was simulated in three dimensional position using $Procera^{(R)}$ software (Procera Software Clinical Design Premium, version 1.5; Nobel Biocare AB). In 3D simulated model, length and angulation between each implant of both pre- and post-operative implants were measured and recorded about linear and angular deviation between pre-and post-operative implants. A total of 24 implants were included in this study and 58 inter-implant sites between each implant were measured about linear and angular deviations. In the linear deviation a mean deviation of 0.41 mm (range 0~1.7 mm) was reported. In the angular deviation, a mean deviation was $1.99^{\circ}$ (range $0^{\circ}{\sim}6.7^{\circ}$). It appears that the both linear and angular mean deviation value were well acceptable to application of computer-guided implant system.

• Journal of Periodontal and Implant Science
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• v.44 no.4
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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.

• Archives of Reconstructive Microsurgery
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• v.18 no.1
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• pp.35-39
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• 2009

Purpose: Various techniques have been attempted for design of the flaps. However, there are some disadvantages. They have thin, pliable, and two dimensional methods. The aim of this study is to report usefulness of polyurethane foam dressing materials for three dimensional design of the digital island flap. Methods: From June of 2007 to september of 2008, 10 patients received digital island flap surgery for soft tissue defect of the finger. After minimal debridement of the wound, size and shape of the defect were measured using polyurethane foam. We used Medifoam-$5^{(R)}$ And then, designed this inset the wound. The flap was designed on the donor site with a arterial pedicle as the central axis according to size and shape. A full thickness skin graft from the groin is applied on the flap donor defect and secured with a tieover bolster dressing. Results: Reviewing sizes of the flaps, the length and width of flaps ranged from 1.5 to 3.3 cm and 1.0 to 2.5 cm. The PACS(Picture Archiving Communication System) program allows identification of the donor depth of finger. The distance for the soft tissue ranged from 4.3 mm to 6.7 mm. Mean depth of donor site was 5.3${\pm}$0.6 mm. Also, the thickness of Medifoam-$5^{(R)}$ ranged nearly 5 mm. On flap insetting, full-thickness skin graft was necessary. We did not experience any problems in the recipient site size either, regardless of the extended flaps. Conclusion: Polyurethane foam has many advantages over the more conventional templates. Refinements in flap design and surgical technique resulted in favorable functional and cosmetic results. Especially, for beginner, Polyurethane foam dressing material is a simple and safe tool and therefore is an excellent choice for design of the island flap.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.4
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• pp.478-486
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• 2021

This report demonstrates a method of generating a chair-side and computer-aided template for implant surgery based on the Top-Down and restoration-driven concept. Compared to the traditional CAD-CAM process which requires multiple steps to be taken between dental clinic and laboratory, this alternative procedure, VARO guide system (VARO Guide, CAD, Pre-Guide, VARO-mill, NeoBiotech, Seoul, South Korea) enables accurate and patient-friendly implant surgery as well as immediate provisional restoration in a single visit. First, bite-registration at centric jaw relation and CBCT were taken using the Pre-Guide. The CBCT data was then reorganized directly through the chair-side CAD, and we could determine the most appropriate 3-dimensional position of implant. The STL file was extracted and put into the chair-side CAM (VARO-mill) to fabricate a VARO. This surgical guide allowed the implants to be accurately positioned into the planned sites within an hour.