• The korean journal of orthodontics
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• v.23 no.2 s.41
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• pp.147-163
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• 1993

The purpose of this stuy was to evaluated the cytotoxicity of brackets which were recycled thermally or chemically. New brackets and used brackets which had been in mouth for at least 2years were used as samples and human gingival cell culture and agar overlay technique was used to evaluate the cytotoxicity. From the experiment the following results were obtained : 1. New brackets in the as received state showed mild cytotoxicity. 2. Thermally recycled brackets except the used bracket not electropolished showed moderate cytotoxicity and among them new brackets showed greater cytotoxicity than used ones. 3. Used brackets which were thermally recycled without electropolishing showed mild cytotoxicity. 4. Among thermally recycled brackets, electropolished brackets showed greater cytotoxicity than not electro-polished ones. 5. Chemically recycled brackets showed moderate cytotoxicity, and among them, new brackets appeared to be more cytotoxic than used ones.

• The korean journal of orthodontics
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• v.2 no.1
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• pp.29-34
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• 1971

저자는 교정환자 치료에 흔히 사용되는 Light wire torquing auxiliary의 반경의 크기 및 교합면에 대한 spur 각도의 증감에 따라 Light wire torquing auxiliary 애서 발생되는 힘이 어떻게 변화하는 가를 Dentiform typodont 위에서 측정 관찰하여 아래와 같은 결과를 얻었다. 1) Light wire torquing auxiliary circle의 반경의 크기가 감소할 수록 발생되는 힘의 크기는 증가하였으나, 반경의 크기에 반비례하지는 않았다. 즉, Light wire torquing auxiliary circle의 반경을 20 mm.에서 10mm.로 하였을때 발생되는 force는 2배로 나타나지는 않았다. 2) 교합 평면에 대한 spur의 각도가 감소할 수록 force는 증가하였다. 이때 교합 평면에 대한 spur의 각도를 감소시킨 상태에서 교합 평면과 치아가 이루는 각도를 증가시켜 줌으로써 항속적인 힘의 증가를 나타냈다.

• The korean journal of orthodontics
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• v.2 no.1
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• pp.41-46
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• 1971

The role of the Orthodontist in cleft lip and cleft palate therapy is primarily ill correction of malocclusion which is required by practically every child who has these defects. He can contribute to the assessment of dento-facial growth and development. We may gain the possible limited correction of delayed malocclusion due to cleft lip and palate. The authors have attempted delayed orthodontic treatment of a cleft lip and palate of 12.9 years old girl, who had a cleft lip and palate of surgical closure at 2,3 and 4 years old.

• The korean journal of orthodontics
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• v.12 no.1
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• pp.37-43
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• 1982

The patient,20 year-old female, complained of anterior open bite. She had tongue thrusting habit and suffered from maxillary sinusitis since 12-years old. Cephalometric analysis revealed slightly forward relationship in maxilla, but normal in mandible. The anterior open bite was corrected through retraction and extrusion of anterior segment and mesial movement of posterior segment under multibanded system after extraction of 4-first premolars. After 2 years and 3 months, she gained ideal overbite, overjet and good interdigitation of buccal segment.

• The korean journal of orthodontics
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• v.15 no.2
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• pp.291-301
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• 1985

Fifty subjects who were to be treated with fixed orhodontic appliances by light wire edgewise technique were selected. Bands with different marginal depth were made in first molar and direct bonding brackets were bonded in second premolar. For determining the effects of fixed orthodontic appliance on the gingival tissue, the changes of clinical crown length, periodontal pocket depth, gingival sulcus fluid were checked. The results were as follows: 1. Gingival condition was deteriorated after wearing the fixed orthodontic appliance, and the deteriorative rate was decreased gradually. 2. The greatest gingival change was occurred in the maxillary first molar among the experimental teeth. 3. The gingival change of maxillary teeth was greater than that of mandibular teeth. $(p\leq0.01)$ 4. The greater gingival change was occurred around subgingivally located band than around supragingivally located band. 5. Comparing the gingival changes of banded teeth with them of bonded teeth, the gingival tissue was more effected by oral hygiene than by type of appliances. 6. In the quantitive changes of gingival crevicular fluid, there was no exact relationship with gingival inflammation.

• The korean journal of orthodontics
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• v.21 no.3
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• pp.711-722
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• 1991

The first patient of this case was 13 year and 8 month old girl who had the Angle's class I malocclusion with uneruption of upper left central incisor and left canine. The second patient was 12 year old boy who had the Angle's class I malocclusion with uneruption of right central incisor. After surgical exposure of impacted teeth of those patients and bonding of attachment on exposed crown, those teeth were orthodontically pulled with removable appliances. The results were obtained as follow. 1. The functionally proper occlusion was established by guidance of the impacted teeth into the normal position in the arch. 2. Establishment of esthetic and balanced arch form was achieved. 3. The possibility of restorative prosthetic treatment induced by extraction of impacted teeth was eliminated. 4. The psychologic relief of pubertal patient who was very sensitive to facial esthetics was gained.

• The korean journal of orthodontics
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• v.21 no.3
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• pp.701-709
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• 1991

This paper presents 2 clinical cases of facial asymmetry resulted from vertical asymmetry of the maxilla and unilateral hyperplasia of the mandibular condyle. Both patients, a 27 year 4 month old female and a 17 year 1 month old male, had a anterior crossbite with deviated dental midline and a concave profile. Both cases were treated with orthodontic and orthognathic procedure. The following results were obtained; 1. The facial asymmetry was favorably corrected. 2. The concave profile was improved. 3. The anterior crossbite was corrected. 4. The upper and lower dental midlines against the facial midline were corrected. 5. The functional overbite and overjet were established.

• The korean journal of orthodontics
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• v.24 no.2
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• pp.419-430
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• 1994

The purpose of this study was to investigate the cytotoxicity of orthodontic bands in vitro and in vivo4 types of orthodontic bands were applied to cultured fibroblast and the supernatants were injected into dorsal subcutaneous tissue of mice. In vitro.the cytotoxixity was evaluated by an MTT assay after 2 and 6days. In vivo, the histopathologic observation was performed 2 days after injection. The results were : 1. The cell viability was significantly decreased in the group added phosphoric acid in comparison to control group, but there was not any significance among the experimental group after 2 days. 2. Cell viability decreased in the high Ni containing group after 6 days. 3. The histopathological finding was that the Cr-containing group showed severe infiltration of inflammatory cells and muscular destruction.

• The korean journal of orthodontics
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• v.19 no.3
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• pp.79-86
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• 1989

The wires for initial alignment purposes require a combination of excellent strength, excellent springiness, and a long rang of action. The variables in selecting appropriate arches for alignment are the arch wire material, its diameter, and the distance between attachments. The principle that there should be 0.02 inch clearance for initial wires means that an .016 diameter wire is the largest that should be considered for initial alignment in the .018 slot system. The three major possibilities for alignment arches are multistranded steel wires, nickel-titanium wires, and single-stranded steel wires with loops. The excellent choice for initial alignment in .018 bracket is .014 steel wire with loops.

• The korean journal of orthodontics
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• v.19 no.3
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• pp.49-58
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• 1989

The permanent second molars, erupted about 12-13 years old, are finally erupted except wisdom teeth. Although they are likely to be excluded in the orthodontic treatment because located in the most posterior area of the dentition, about twenty percents of the orthodontic patients have abnormal occlusion of the permanent second molars, and we usually observed the malalignment of the permanent second molars in the finished case without including this teeth. These permanent second molars should be necessarily corrected by orthodontic appliances for the dynamic-normal occlusion. Moreover, according to the previously mentioned treatment philosophy, there are clear advantages in the cases which the permanent second molars were used for anchorage source, and this has been proposed convincingly by many authers. Therefore it is reasonable that orthodontists determine to include the permanent second molars among orthodontic treatment, but particular cases.