• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.4
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• pp.649-653
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• 2001

The Chiari malformation is a deformation within the central nervous system which the lower brain stem and the cerebellum migrate into the foramen magnum causing herniation. In 1891, Arnold Chiari classified such symptoms into 3 categories. This case report is of a 8-year-old female with the complaint of a slight facial swelling and pain on the upper right molar during tooth brushing since 10 days before. Clinical examination showed gingival pocket formation on distal of the upper right first molar with pain and mobility of the tooth. Radiographic examination showed generalized low bone density in the upper molar area, and especially no bone support above the upper right and left first molars were noted. With a temporary diagnosis of Early-onset periodontitis, consultations with medical doctors for the possibility of an underlying systemic disease were made during periodontal treatment. 3D CT was taken with after a final diagnosis of Chiari malformation. Generalized thinning and defect of the cranial bone was noted and the foramen magnum was slightly enlarged. The occipital and maxillary bone was low in density, and the alveolar bone of maxillary posterior teeth was especially almost non-existing causing the upper right and left first molar to be floating. For this, the patient went under consultation with the department of neurosurgery and is still under observation. Periodontitis in childreren is very rare. When symptoms of periodontitis appear in a child, due to the possibility of an underlying systemic disease such as leukemia, histiocytosis X, and hypophosphatasia, proper examinations should be carried out so that the primary factor the symptoms can be treated.

• Journal of Dental Rehabilitation and Applied Science
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• v.19 no.3
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• pp.169-183
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• 2003

According to our recent investigation that the increase in the occlusal vertical dimension made the appendage muscle strength got higher, the occlusal appliances were made by increasing the occlusal vertical dimension "from the centric relation" position of the mandible. In this experiment, the authors tried to study the change in the appendage muscle strength due to increase in occlusal vertical dimension from intercuspal position(ICP) of mandible with the same subjects and manner as the former experiment. For this study, ten male athletes in a mean age of 23 year who were joined the former study were selected. All the subjects had a complete or almost complete set of natural teeth and reported no subjective symptoms of temporomandibular disorders. Upper and lower casts were mounted on the semi-adjustable articulator at the intercuspal position and a point was marked on the attached gingival area between the right canine and the right 1st. premolar in each upper and lower cast. From the points, the occlusal vertical dimension was increased by 2mm, 3.5mm and 5mm, and then each 10 maxillary type occlusal splint at each 3-increased position were fabricated with heat curing clear acrylic resin. Including the intercuspal position, the 3 kinds of occlusal splints were placed on the subjects individually, and then isokinetic muscle strength on 7 parts of the human appendage which are shoulder, knee, ankle, wrist, forearm, elbow and hip was measured with the CYBEX 6000 SYSTEM (Lumex, NewYork, USA). The results were as follows: The highest mean value in muscular strength was shown at the position of 2mm-increased vertical dimension. The muscle strength during internal/external rotation of shoulder and knee, plantarflexion of ankle, flexion of elbow, and flexion and extension of hip at the increased occlusal vertical dimension position were significantly higher than them at the intercuspal position (p<0.05). Only in view of the increase in the appendage muscle strength, regardless of the way of making the occlusal splints by elevating the occlusal vertical dimension from the centric relation position or intercuspal position, the occlusal splints had an effect on the increase of isokinetic muscle strength at the occlusal vertical dimension which increased within the proper range on the habitual arc of closure.

• Journal of Periodontal and Implant Science
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• v.26 no.1
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• pp.1-26
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• 1996

This study was performed to estimate the effects of cultured bone cell inoculated on porous type hydroxyaptite for the regeneration of the artificial alveolar bone defect. In this experiment 3 beagle dogs were used, and each of them were divided into right and left mandible. Every surgical intervention were performed under the general anesthesia by using with intravenous injection of Pentobarbital sodium(30mg/Kg). To reduce the gingival bleeding during surgery, operative site was injected with Lidocaine hydrochloride(l:80,000 Epinephrine) as local anesthesia. After surgery experimental animal were feeded with soft dietl Mighty dog, Frisies Co., U.S.A.) for 1 weeks to avoid irritaion to soft tissue by food. 2 months before surgery both side of mandibular 1st premolar were extracted and bone chips from mandibular body were obtained from all animals. Bone cells were cultured from bone chips obtained from mandible with Dulbecco's Modified Essential Medium contained with 10% Fetal Bovine Serum under the conventional conditions. Porous type hydroxyapatite were immerse into the high concentrated cell suspension solution, and put 4 hours for attachin the cells on the surface of hydroxyapatite. Graft material were inserted on the artificial bone defect after 3 days of culture. Before insertion of cellinoculated graft material, scanning electronic microscopic observation were performed to confirm the attachment and spreading of cell on the hydroxyapatite surface. 3 artificial bone defects were made with bone trephine drill on the both side of mandible of the experimental animal. First defect was designed without insertion of graft material as negative control, second was filled with porous replamineform hydroxyapatite inoculated with cultured bone marrow cells as expermiental site, and third was filled with graft materials only as positive control. The size of every artificial bone defect was 3mm in diameter and 3mm in depth. After the every surgical intervention of animals, oral hygiene program were performed with 1.0% chlorhexidine digluconate. All of the animals were sacrificed at 2, 4, 6 weeks after surgery. For obtaining histological section, tissus were fixed in 10% Buffered formalin and decalcified with Planko - Rycho Solution for 72hr. Tissue embeding was performed in paraffin and cut parallel to the surface of mandibular body. Section in 8um thickness of tissue was done and stained with Hematoxylin - Eosin. All the specimens were observed under the light microscopy. The following results were obtained : 1. In the case of control site which has no graft material, less inflammatory cell infiltration and rapid new bone forming tendency were revealed compared with experimental groups. But bone surface were observed depression pattern on defect area because of soft tissue invasion into the artificial bone defect during the experimental period. 2. In the porous hydroxyapatite only group, inflammatory cell infiltration was prominet and dense connective tissue were encapsulated around grafted materials. osteoblastic activity in the early stage after surgery was low to compared with grafted with bone cells. 3. In the case of porous hydroxyapatite inoculated with bone cell, less inflammatory cell infiltration and rapid new bone formation activity was revealed than hydroxyapatite only group. Active new bone formation were observed in the early stage of control group. 4. The origin of new bone forming was revealed not from the center of defected area but from the surface of preexisting bony wall on every specimen. 5. In this experiment, osteoclastic cell was not found around grafted materials, and fibrovascular invasion into regions with no noticeable foreign body reaction. Conclusively, the cultured bone cell inoculated onto the porous hydroxyapatite may have an important role of regeneration of artificial bone defects of alveolar bone.

• The korean journal of orthodontics
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• v.26 no.1 s.54
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• pp.17-32
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• 1996

It is important to understand the operating mechanism and force system of fixed appliance that most effective for individual tooth movement in various orthodontic appliances. The archwire system of fixed appliance is devided into 3 types, which is continuous arch, segmented arch and sectional arch. The last two types have longer interbracket distance and simple force operating points, so it is easy to control force system by operator. But the continuous arch has shorter interbracket distance and various bracket geometry, so it is hard to control and anaylze the force system. The purpose of this study was three dimentional force and moment analysis of continuous arch system by finite element method, which is similar situation to three dimentional elastic beam in structural engineering. Several sample form of various bracket geometry and artificial lower crowding typodont made by author were constructed, analyzed and compared each other. The results were as follows : 1. The force magnitude is linear proportional to the degree of displacement or tilting of the bracket. 2. The force magnitude is inversely non-linear proportional to the interbracket distance. 3. In three dimensional typodont model, while the force can be compared with that of the sample form in the area where adjacent bracket geometry is simple, the force is much more than the expected value in the area where adjacent bracket geometry is complex.