• Structural Engineering and Mechanics
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• v.28 no.2
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• pp.239-257
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• 2008

Double-sided punched metal plate timber fasteners present projections on both sides, which offer improved joint fire resistance and better joint aesthetics. In this paper, 3-D nonlinear finite element models were developed to simulate double-sided nail plate fastener timber joints. The models, incorporating orthotropic elasticity, Hill's yield criterion and elasto-plasticity and contact algorithms, are capable of simulating complex contact between the tooth and the timber and between the base plate and the timber in a fastener. Using validated models, parametric studies of the double-sided nail plate joints was undertaken to cover the tooth length and the tooth width. Optimal configuration was assumed to have been attained when increase in nail plate tooth width did not result in a raise in joint capacity, in conjunction with the optimum tooth length. This paper presents the first attempt to model and optimise tooth profile of double-sided nail plate fastener timber joints, which offers rational designs of such fasteners.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.2 no.1
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• pp.53-57
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• 1972

The author measured the length of crown, root and tooth on the films which was taken by intraoral bisecting technic with mesh plate on the films. The films were taken from the dry skulls, dentiform and patients who had to be removed their upper incisors and the other patients who adimitted for dental care. From this serial experiment the results was made as follows: 1. By using the film and mesh plate in the oral cavity, the real tooth length can be measured easily on the film surfaces. 2. It can be avoided the film distortion in the oral cavity when taking the film using the mesh plate and film together. 3. When measuring the film, length of crown was elongated and length of root was shortened. 4. When using the well-trained bisecting technic, the real tooth length can be measured directly on the intraoral film.

• The Journal of Korean Academy of Prosthodontics
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• v.28 no.1
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• pp.43-61
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• 1990

The laser reflexion method is a new technique which permits precise contactless measurement and observation of tooth mobility as well as tooth movement. The purposes of this study were to clarify the reliability of the laser reflexion method in clinical application and to measure the abutment tooth movement according to clasp design. This study was designed to determine 1) How much a bending movement of the impression plate stand affects the position of the reflexion pattern and how precise the patient bites into plate 2) Which clasp design causes greater movement of the abutment tooth. Under medium and maximum bite forces, tests were performed on central loading position which was 13mm distal to terminal abutment tooth of distal extension removable partial denture. The movement in the mesiodistal and buccolingual directions was measured. The Duncan's New Multiple-Range test was used to compare the means for the four castings under each direction-load combination; and the paired sample t-test was for medium and maximum bite forces. From this experiment, the following results were obtained. 1. The Roach clasp, the combination clasp, the RPI clasp, and the Akers clasp did not significantly differ in their effects on buccolingual movement of the abutment tooth. 2. The direction of abutment tooth movement was not significantly altered by clasp design and all abutment tooth movements were oriented distobuccally. 3. Under medium bite force, the Akers clasp caused greater distal movement of the abutment tooth than did the combination clasp and the RPI clasp. Under maximum bite force, the Akers clasp caused greater distal movement of the abutment tooth than did the RPI clasp. 4. The testing apparatus and procedures used in this study(laser reflexion method) proved to be reliable in clinical application.

• The korean journal of orthodontics
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• v.31 no.1 s.84
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• pp.97-105
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• 2001

In many cases of orthodontic treatment the upper anterior teeth are retracted. Periodontal problems may arise during incisor retraction, if the amount of tooth movement and the amount of remodeling in the anterior cortical bone are not the same. Therefore in this study, to find out the relationship between the amount of tooth movement and the amount of bone remodeling during retraction of the upper anterior teeth, lateral cephalograms of 56 female patients over 18-year-old were taken before and after treatment. Among the 56 patients, two groups were divided according to the type of root movement during retraction. 26 patients mainly moved by tipping and 30 by bodily movement. The cephalograms taken before and after treatment were superimposed upon the true horizontal plane. In the Tip-Group, the horizontal bone remodeling/tooth movement ratio was 1:1.63, and in the Torque-Group it was 1:1.66. Because the amount of tooth movement and the amount of bone remodeling were not the same in both groups, in the Tip-Group the root apex moved away from the palatal cortical plate and closer to the labial cortical plate, whereas in the Torque-Group the root moved away from the labial cortical plate and closet to the palatal cortical plate. Therefore, there are limitations in the amount of incisor retraction in patients with a very thin anterior cortical plate in the maxilla, and in patients with severe skeletal discrepancies orthognathic surgery should be considered and when orthodontic camouflage treatment is the only possible method, the orthodontist must be aware of the limitations of treatment.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.2
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• pp.339-344
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• 2008

When a delayed eruption of tooth is diagnosed, the causative factor should be detected before an establishment of treatment plan, if possible. Although a panoramic radiograph is enough to evaluate the position of tooth and the stage of tooth development, a 3-D Dental CT would be a powerful tool to reveal a spatial relationships between objects. The reported case showed a delayed eruption of lower left permanent canine and a mini-plate with screws adjacent to the impacted canine. Although the screws adjacent to the root of impacted tooth showed a close proximity, it was not presumed that these screws would interfere the eruption of the tooth. The impacted canine did not show any spontaneous eruption during observation. After the mini-plate and screws were removed, an orthodontic traction using elastic power chain was performed. The position of mini-plates and screws should be carefully designed to avoid damaging the tooth follicles or tooth roots in the jaw. Also the screws should be removed before an orthodontic traction to prevent damaging the root surface of impacted tooth.

• Journal of Power System Engineering
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• v.15 no.4
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• pp.48-53
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• 2011

Upon reviewing recent trends for robots, it can be seen that robots are gradually being miniaturized. However, most commercially available speed reducers have limitations in terms of structure and vibration when applied to small robots. In this respect, a tooth profile manufactured using thin plates was designed using balls and data analyzed related to numerical and FEM analysis. The speed reducer was manufactured to check their performance. The manufactured thin plate type speed reducer imposes less compressive stress on its tooth profile and balls, which can greatly increase feasibility.

• The Journal of the Korean dental association
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• v.55 no.10
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• pp.725-732
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• 2017

Thin labial plate will be resorbed after extraction. Immediate implantation cannot prevent soft and hard tissue loss. Bone graft can be necessary in the immediate implantation after anterior tooth extraction. Slowly-resorbed or non-resorbable bone graft material have many advantages in esthetic area because of maintenance of volume. The clinicians should select the adequate cases of immediate implantation according to the indication and contraindication.

• Journal of Dental Rehabilitation and Applied Science
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• v.27 no.1
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• pp.109-115
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• 2011

Implants were placed after performing ridge expansion by inserting screws of gradually increasing thickness. Favorable clinical outcome was obtained. During surgery, buccal cortical plate fracture did not occur. Autogenous tooth bone graft material was grafted around the implant dehiscence defects and over the buccal cortical plate. The method involving the insertion of screws for ridge expansion is a successful and predictable technique for implant placement in narrow alveolar bone. Autogenous tooth bone graft material can be used for ridge augmentation and GBR.

• The korean journal of orthodontics
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• v.47 no.5
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• pp.289-297
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• 2017

Objective: The objective of this study was to analyze the patterns of tooth movements when distalization of mandibular molars using a mini-plate took place. A finite element analysis was applied to analyze patterns of tooth movements. Methods: The model of the mandible and teeth were used to build a finite element analysis model, and a mini-plate was inserted in the mandibular ramus. Two different orthodontic forces were established for displacement of mandibular molars. Orthodontic forces were applied at the level of the bracket and at the level of the cemento-enamel junction in the mandibular canine respectively. Results: Applying orthodontic forces at the level of the cemento-enamel junction resulted in a greater biomechanical bodily movement in distalization of the mandibular molars compared to when the orthodontic forces were applied at the level of the bracket. Applying orthodontic forces to the cemento-enamel junction also resulted in unwanted greater extrusive movements in distalization of the mandibular molars compared to the bracket level. Conclusions: With considering the mode of orthodontic teeth movement, applying different vertical orthodontic forces for distalization of mandibular molars can lead to more effective distalization of teeth.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.8 no.2
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• pp.134-138
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• 2012

In treatment of dentigerous cyst, complete enucleation, histopathologic examination and postoperative care are important to prevent the potential complications (mural ameloblastoma, squamous cell carcinoma). On the other hand, a maxillary impacted supernumerary anterior tooth are removed surgically, owing to the possibility of the cyst formation in future. After the cyst enucleation and extraction of the involved tooth, the wound area sutured and removable resin plate is then applied. In this operation, the postoperative bleeding and infection is likely to occur owing to postoperative accumulation of hematoma & seroma, psychologic stress and other contaminated factor. So, the authors established the immediate rubber & iodoform gauze drainage into the sutured wound of cyst enucleation & tooth extraction for the prevention of postoperative bleeding and infection. The removable resin splint are not used because of the poor cooperation and economic factor. The results were more favorable without the postoperative bleeding & wound infection in a cerebral palsy patient.