• 한국임상수의학회:학술대회논문집
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• 한국임상수의학회 2006년도 춘계학술대회
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• pp.210-210
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• 2006

• 대한치과보철학회지
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• 제39권6호
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• pp.633-640
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• 2001

Statement of problem. Relatively low success rate of root analogue implant system was supposed to be due to the time duration between extraction and implant installation. The use of three-dimensional computer tomography and the reconstruction of objects using rapid prototyping methods would be helpful to shorten this time. Purpose. This aim of this study was to evaluate the application possibility of the 3-dimensional computer tomography and the rapid prototyping to root analogue implants. Material and methods. Ten single rooted teeth were prepared. Width and height of the teeth were measured by the marking points. This was followed by CT scanning, data conversion and rapid prototyping model fabrication. 2 methods were used; fused deposition modelling and stereolithography. Same width and height of this models were measured and compared to the original tooth. Results. Fused deposition modelling showed an enlarged width and reduced height. The stereolithography showed more exact data compared with the fused deposition modelling. Smaller standard deviation were recorded in the stereolithographic method. Overall width error from tooth to rapid prototyping was 7.15% in fused deposition modelling and 0.2% in stereolithography. Overall height showed the tendency of reducing dimensions. Conclusion. From the results of this study, stereolithography seems to be very predictable method of fabricating root analogue implant.

• Computers and Concrete
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• 제31권2호
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• pp.163-171
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• 2023

Face gear transmission is widely used in aerospace shunt-confluence transmission system. Tooth wear is one of the main factors affecting its bearing transmission performance. Furthermore, the installation errors of face gear are inevitable. In order to study the wear mechanism of face gear tooth surface with installation errors, based on tooth contact analysis numerical method and Archard wear theory, the UMESHMOTION subroutine in ABAQUS is developed.Combining with Arbitrary Lagrangian-Eulerian adaptive mesh technology, the finite element mesh wear model of abraded face gear pair is established.The preprocessing conditions are set to generate the inp files.Then,the inp files for each corner are imported and batch processed in ABAQUS.The loading tooth contact problem at each rotation angle is solved and the load distribution coefficient among gear tooth, tooth root bending stress, tooth surface contact stress and loaded transmission error are obtained. Results show that the tooth root wear is the most serious and the wear at the pitch cone is close to 0.The wear law of tooth surface along tooth width direction is convex parabola and the wear law along tooth height direction is concave parabola.

• 대한치과의사협회지
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• 제54권8호
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• pp.658-665
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• 2016

Treatment of immature permanent teeth with irreversibly damaged pulp has been challenging in dental practice because of the lack of apical constriction, thin dentinal walls, and short roots. This may lead to the extrusion of filling materials, and fracture of the root due to its more fragile feature during shaping of the root canal. Apexification with calcium hydroxide or MTA is one of the treatment options for these cases. Although favorable results of apexification have been reported, these treatment procedures do not guarantee the increase of root length and/or width even after a long term period. Thus, treated teeth are still prone to fractures. Recently, pulp revascularization has been proposed as an alternative treatment for immature teeth with necrotic pulp and periapical pathosis. Pulp revascularization allows the stimulation of the apical development and the root maturation. There have been many treatment protocols using various materials such as antibiotics and calcium hydroxide medicament. In this case report, literature review about pulp revascularization and two related cases are presented.

• Restorative Dentistry and Endodontics
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• 제39권3호
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• pp.226-229
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• 2014

Orthodontic extrusion is usually performed by means of a fixed orthodontic appliance that utilizes arch wire attached to adjacent teeth and transfers the desired force by elastic from the wire to the root. However, clinicians often encounter cases where the bonding required for tooth traction is not possible because the adjacent teeth have been restored with ceramic or veneer. The purpose of this case report is to describe a modified orthodontic extrusion appliance that is useful when conventional orthodontic treatment is not possible. The modified appliance was fabricated using an artificial tooth, clear plastic sheeting, and a braided fiber-reinforced composite strip that covered adjacent teeth without bonding. It satisfied the esthetic and functional needs of the patient and established the optimal biologic width.

• Restorative Dentistry and Endodontics
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• 제41권3호
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• pp.210-217
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• 2016

Exposing sound structure of a subgingivally fractured tooth using orthodontic extrusion is considered to be a conservative way to re-establish biologic width without sacrificing esthetics or jeopardizing periodontal support of neighboring teeth. When a misaligned tooth is traumatically involved, a more comprehensive approach combining tooth extrusion and re-alignment may be necessary for a successful restorative outcome. This case report describes a successful esthetic management of a patient with complicated crown-root fracture on the maxillary right central incisor and pre-existing malocclusion in the maxillary anterior region. Forced eruption along with re-alignment of teeth by orthodontic movement seems to allow re-positioning of the fracture line to a favorable position and correction of crowding, providing a better esthetic result.

• 대한소아치과학회지
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• 제35권2호
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• pp.305-312
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• 2008

치아의 치관-치근 파절은 치아파절이 치관과 치근에 걸쳐 발생되어 법랑질, 상아질 및 백악질까지 이환된 경우로 정의되며, 치수이환여부에 따라 복잡파절과 비복잡파절로 분류될 수 있다. 치관-치근 파절의 빈도는 유치열에서 2%, 영구치열에서 5%로 나타나며, 보통 상악 전치부에 호발한다. 이러한 치관-치근 파절된 치아의 수복을 위해서는 생물학적 폭경이 유지되어야 한다. 이를 위하여 사용되는 방법은 골삭제 후 치은절제술, 교정적 견인, 외과적 정출 후 수복하는 방법과, 인위적으로 발치하여 근관치료와 수복 후 재식하는 방법 등이 있다. 이중 외과적 정출술은 치아를 발거하여 파절부를 치은 연상으로 이동시켜 재식하는 방법으로서, 이는 치관부 파절편이 임상치근의 1/2 미만인 경우에 적응증이 될 수 있으며, 발견하지 못한 다른 파절편을 직접 시진할 수 있고 때로는 파절선을 순측에 위치시켜 치료시 시야확보 및 접근이 용이하다는 등의 장점이 있다. 본 증례에서는 외상으로 치관-치근 파절된 미완성 치근단의 상악 중절치를 가진 환아에서 외과적 정출술 후 근관치료와 광중합복합레진을 이용한 치관수복을 시행하였으며, 정기적 검진시 양호한 결과가 관찰됨을 확인할 수 있었다.

• 대한치과교정학회지
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• 제38권4호
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• pp.265-274
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• 2008

3D CT를 이용하여 파노라마에서 얻어진 상악 매복 견치 위치 정보의 유용성을 평가하기 위해, 상악 견치 매복을 주소로 경북대학교병원에 내원한 환자를 대상으로 파노라마 방사선 사진과 3D CT에서의 매복 견치의 위치를 평가하였다. 대상은 25명(남자 7명, 여자 18명)으로 평균 나이는 10.9세(범위 : 8.2 - 15.7세)이며, 35개의 상악 매복 견치증례를 분석하여 다음의 결과를 얻었다. 첫째, 파노라마 방사선 사진은 확대되어 촬영되므로 3D CT의 계측치보다 상악 견치의 tooth length, crown width, vertical distance 그리고 lateral shift값에서 큰 값을 가졌다. 단, angulation to occlusal plane은 파노라마에서 더 작은 값으로 계측되었다. 둘째, 파노라마 방사선 사진상 상악 견치가 구개측으로 매복된 경우, angulation to occlusal plane은 3D CT보다 작게 측정되고 vertical distance는 더 크게 측정되었다. 셋째, 파노라마 방사선 사진에서 상악 매복 견치의 tooth length, crown width 그리고 순측으로 매복된 경우 상악 견치의 angulation to occlusal plane은 3D CT와 근접된 계측치를 가졌다. 또한 CT와 비교하였을 때, 치근 흡수 정도 평가에 대한 파노라마 방사선 사진의 감수성은 33.3%인 것으로 측정되었다. 파노라마 방사선 사진은 협측 매복견치의 위치는 실제와 유사하다고 생각되나 구개측 매복의 경우 3D CT보다 더 높게, 각도는 더 작게 나타나는 등 상당한 차이가 있어 CT를 이용한 추가적인 검사가 필요하다고 생각된다.

• 구강회복응용과학지
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• 제24권3호
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• pp.243-251
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• 2008

외상으로 치아가 파절되었거나 우식으로 인해 치질이 치조정 수준이나 그 하방까지 소실된 경우 특별한 치료가 동반되지 않는다면 만족스럽게 수복할 수 없다. 이럴 경우 발치 후 임플란트 식립이나 레진 접착 가공 의치, 고정성 가공 의치 등을 이용할 수 있는데 각각의 상황에 따라 여러 가지 제한이 따른다. 이를 극복하는 방법의 하나로 치아 정출술을 이용할 수 있는데, 치아 정출술이란 연조직 및 골 변화를 일으키는 약한 힘을 지속적으로 적용하여 치아를 치관 방향으로 이동시키는 교정 술식으로 치주 건강을 유지하면서 보철 수복을 가능하게 하는 술식이다. 본 증례는 상악 전치부 파절이 발생한 치아를 치아 정출 술식을 이용하여 효과적으로 수복할 수 있었기에 이를 보고하는 바이다.

• Imaging Science in Dentistry
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• 제44권4호
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• pp.287-292
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• 2014

Purpose: To describe the features of impacted upper canines and their relationship with adjacent structures through three-dimensional cone-beam computed tomography (CBCT) images. Materials and Methods: Using the CBCT scans of 79 upper impacted canines, we evaluated the following parameters: gender, unilateral/bilateral occurrence, location, presence and degree of root resorption of adjacent teeth (mild, moderate, or severe), root dilaceration, dental follicle width, and presence of other associated local conditions. Results: Most of the impacted canines were observed in females (56 cases), unilaterally (51 cases), and at a palatine location (53 cases). Root resorption in adjacent teeth and root dilaceration were observed in 55 and 47 impacted canines, respectively. In most of the cases, the width of the dental follicle of the canine was normal; it was abnormally wide in 20 cases. A statistically significant association was observed for all variables, except for root dilaceration (p=0.115) and the side of impaction (p=0.260). Conclusion: Root resorption of adjacent teeth was present in most cases of canine impaction, mostly affecting adjacent lateral incisors to a mild degree. A wide dental follicle of impacted canines was not associated with a higher incidence of external root resorption of adjacent teeth.