• The Journal of the Korean dental association
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• v.58 no.11
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• pp.700-712
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• 2020

The conventional mouthguard fabrication process consists of elastomeric impression taking and followed gypsum model making is now into intraoral scanning and direct mouthguard 3D printing with an additive manufacturing process. Also, dental professionals can get various diagnostic data collection such as facial scans, cone-beam CT, jaw motion tracking, and intraoral scan data to superimpose them for making virtual patient datasets. To print mouthguards, dental CAD software allows dental professionals to design mouthguards with ease. This article shows how to make 3D printed mouthguard step by step.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.184-187
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• 2002

Two-dimensional (2-D) X-ray computerized tomography (CT) equipments are widely used in industrial and medical fields, and nowadays studies on reconstruction algorithm for 3-D cone-beam acquisition systems are active for better utilization. The authors recent-By have proposed a fast reconstruction aigorithm using tree-structured filter bank for 2-D C1, and shown the algorithm is applicable to an approximate reconstruction of 3-D CT. For exact 3-D CT reconstruction, however, we have to backproject 1-D signal into 3-D space. This paper proposes a fast implementation method for this back-projection by use of tree-structured filter bank. and shows the proposed method works approximately 700 times faster than the direct one with almost same reconstruction image quality.

• The korean journal of orthodontics
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• v.47 no.6
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• pp.394-400
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• 2017

Assessing the condition of the alveolar bone before and after orthodontic treatment is important. Recently, cone-beam computed tomography has been widely accepted as a useful tool for orthodontic treatment. Moreover, using a three-dimensional (3D) structural analysis software enables gathering detailed information and quantifying data. The aim of this study was to introduce various quantitative analyses performed before and after orthodontic treatment by using a 3D structural analysis software for evaluating the morphological condition of the alveolar bone of a patient with gingival recession around the canines.

• The korean journal of orthodontics
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• v.47 no.6
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• pp.384-393
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• 2017

Fusion of teeth is a developmental anomaly. It occurs at the stage of tooth formation, which determines the shape and size of the tooth crown, when one or more teeth fuse at the dentin level during the morphodifferentiation of the dental germs. Such teeth show macrodontia and may cause crowding, as well as esthetic and endodontic problems. In this article, we report a rare case of a maxillary central incisor fused to a supernumerary tooth showing labial and palatal talon cusps, which was orthodontically moved across the midpalatal suture. A 13-year-old Caucasian boy sought treatment for the unesthetic appearance of his maxillary central incisor and anterior crowding. He was rehabilitated successfully via a multidisciplinary approach involving orthodontic, nonsurgical endodontic, periodontal, and prosthodontic treatments. After a 26-month treatment period, the patient's macroesthetics and microesthetics were improved. The overall improvement of this macrodontic tooth and its surrounding tissues through multidisciplinary treatment was documented using cone-beam computed tomography.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.3 s.168
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• pp.7-14
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• 2005

본 논고에서는 microfocus X 선 발생장치와 평판형 영상센서를 이용한 micro-CT 시스템의 개발과 그 응용에 대해 소개하였다. 개발과 관련하여서는 영상센서 및 시스템의 동작원리뿐만 아니라 성능평가 결과에 대해서도 간단히 언급하였는데, 이와 같은 성능평가는 추후 개선된 혹은 새로운 설계 및 제작을 위해서는 필수적으로 수반되어야 할 부분이다. 개발된 micro-CT 시스템의 응용분야 소개와 관련하여서는 몇 가지 획득 영상을 토대로 바이오 영상과 산업용 영상에 관하여 언급하였다. 바이오 영상분야에서는 현재 세계적으로 유수 의료기기업체에서 이미 제작하여 판매하고 있으며, 대부분 X선 영상증배관 혹은 CCD(charge-coupled device)를 X 선 영상획득 센서로 사용한 반면, 본 논고에서 소개한 시스템은 평판형 영상센서를 사용했다는 점에서 차별성이 있다. Micro-CT 시스템의 산업용 영상분야로의 적용은 이제 시작 단계이며, 기존 라미노그라피 시스템을 대체하거나 혹은 새로운 응용으로 자리매김할 것으로 기대된다.

• Journal of Korea Multimedia Society
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• v.18 no.10
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• pp.1157-1163
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• 2015

In this paper, we propose a registration method of 3d facial scan data and CBCT data using voxelization and distance map. First, two data sets are initially aligned by exploiting the voxelization of 3D facial scan data and the information of the center of mass. Second, a skin surface is extracted from 3D CBCT data by segmenting air and skin regions. Third, the positional and rotational differences between two images are accurately aligned by performing the rigid registration for the distance minimization of two skin surfaces. Experimental results showed that proposed registration method correctly aligned 3D facial scan data and CBCT data for ten patients. Our registration method might give useful clinical information for the oral surgery planning and the diagnosis of the treatment effects after an oral surgery.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.3
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• pp.291-299
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• 2012

There are many kinds of techniques for imaging temporomandibular joints. None of them for imaging "best fit" for every patient of temporomandibular disorder is recommended ideally. It is more important to be able to select the modality that is most adequate and appropriate for a given clinical issue.

• Imaging Science in Dentistry
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• v.39 no.1
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• pp.51-54
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• 2009

Although odontogenic myxoma (OM) has various radiographic appearances, the characteristic features of OM are the multilocular radiolucent lesion, straight bony septa along the margin forming either square or triangular spaces. We present a case of OM in a 25-year old-male patient. Multilocular radiolucent lesion on the left mandible body showed tennis racket appearance. Cone beam computed tomography (CBCT) showed straight bony septa along the margin and cortical perforation. This CBCT features would have significantly contributed to allowing a diagnosis of OM. We think that this case shows characteristic radiographic features of odontogenic myxoma.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.39 no.5
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• pp.251-253
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• 2013

Inferior alveolar nerve block obtained maximum anesthetic effect using a small dose of local anesthetic agent, which also has low a complication incidence. Complications of an inferior alveolar nerve block include direct nerve damage, bleeding, trismus, temporary facial nerve palsy, and etc. Among them, the major iatrogenic complication is dental needle fracture. A fragment that disappears into the soft tissue would be hard to remove, giving rise to a legal problem. A 31-year-old woman was referred for the removal of a broken needle, following an inferior alveolar nerve block. Management involved the removal of the needle under local anesthesia with pre- and peri-operative computed tomography scans.

• The korean journal of orthodontics
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• v.45 no.1
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• pp.47-56
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• 2015

A 27-year-old man presented an anterior open bite relapse. He had low tongue posture positioned anteriorly at rest and during swallowing and reported chronic difficulty in nose breathing. Head cone-beam computed tomography revealed nasal septum deviation, right turbinate hypertrophy, and left maxillary sinus congestion, which were thought to contribute to the breathing problem, encourage the improper tongue posture, and thereby cause the relapse. Multidisciplinary treatment involving an otorhinolaryngologist, an orthodontist, and a periodontist resolved the upper airway obstruction and corrected the malocclusion. The follow-up examination after 3 years 5 months demonstrated stable results.