• 대한치과교정학회지
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• 제35권1호
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• pp.23-34
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• 2005

본 연구에서는 III급 수술-교정 치료 방법에 영향을 미치는 치열 상의 요소를 파악함으로써 술전 교정시 상악 소구치 발치와 비발치의 판단에 필요한 임상적 정보를 얻고자 골격성 III급 부정교합 환자의 수술-교정 치료시 흔히 선택되는 상악 제1소구치 발치로 치료된 군과 비발치로 치료된 군 간의 치료전/후 상/하악 개별 치아 이동 양상과 치열궁 폭경의 변화 양상을 비교 분석하였다 이를 위하여 비발치로 III급 수술-교정 치료를 마친 환자 (24명) 와 술전교정 치료시 상악 제1소구치가 발치된 환자 (31 명)의 치료 전/후 모형 상에서 개개 치아의 근원심/협설측 각도 변화와 상/하 치열궁 폭경의 변화를 측정한 후, 두 군 사이의 교정적 치아 이동 양상을 비교 분석한 후 상/하 치열궁의 조화를 이루는데 필요한 치열궁 폭경의 변화와 이에 기여하는 치아 변위와의 관계를 분석하기 위하여 상관 분석과 회귀 분석을 시행한 결과 발치 군은 비발치 군에 비하여 상악 치열궁 폭경의 감소가 컸으며 이는 상악 구치의 inclination 감소에 크게 영향 받은 것으로 관찰되었다. 하악 치열에서는 inclination의 증가와 폭경의 증가가 있었으나, 비발치/발치군간의 차이는 유의하지 않았다 본 연구의 결과 결론적으로 III급 수술-교정 치료시 술전 상악 소구치 발치는 상악 구치부 치열궁 폭경의 감소에 크게 영향을 미치므로, 상악 소구치 발치에 대한 판단은 상/하악 치열궁의 폭경 및 구치부 경사도 문제와 연계하여 고려해야 할 사항으로 생각되었다.

• 대한소아치과학회지
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• 제49권3호
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• pp.340-347
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• 2022

하악 제2소구치 치배의 원심 변위는 해당 치아의 매복 뿐만 아니라 하악 제1대구치의 맹출 경로를 방해하여 추가적인 맹출 지연을 야기할 수 있다. 이 증례 보고는 원심으로 변위된 하악 제2소구치로 인해 하악 제1대구치의 맹출 지연이 나타난 두 증례를 소개하고 있다. 원심으로 변위된 하악 제2소구치 치배의 근심 이동을 위해 선행 유치의 의도적 발거술을 시행할 수 있다. 하지만 제2유구치의 조기 상실 시 바람직하지 않은 하악 제1소구치의 원심 이소맹출이 나타날 수 있다. 하악 제1소구치의 바람직하지 않은 원심 이소맹출을 방지하면서 원심으로 변위된 하악 제2소구치 치배를 근심으로 이동시키기 위해 하악 제2유구치의 편측치아절제술 및 순차적 발거를 수행하였다.

• 대한치과교정학회지
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• 제42권4호
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• pp.207-217
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• 2012

Objective: This study aimed to evaluate the effect of an intentionally created socket on bone remodeling with orthodontic tooth movement in rabbits. Methods: Eighteen male rabbits weighing 3.8 - 4.25 kg were used. An 8-mm deep and 2-mm wide socket was drilled in the bone 1 mm mesial to the right mandibular first premolar. The left first premolar was extracted to serve as an extraction socket. A traction force of 100 cN was applied to the right first premolar and left second premolar. Sections were obtained at the middle third of the moving tooth for both the drilled and extraction sockets and evaluated with hematoxylin and eosin staining and immunohistochemical analyses. The amount of tooth movement and tartrate-resistant acid phosphatase (TRAP)-positive cell count were compared between the 2 groups using the Mann-Whitney U test. Results: At week 2, the distance of tooth movement was significantly higher in the intentional socket group (p < 0.05) than in the extraction socket group. The number of TRAP-positive cells decreased in week 2 but increased in week 3 (p < 0.05). However, there were no significant differences between the groups. Furthermore, results of transforming growth factor (TGF)-${\beta}$ staining revealed no significant differences. Conclusions: The intentional socket group showed greater distance of tooth movement than did the extraction socket group at week 2. Osteoclast counts and results of immunohistochemical analyses suggested elevated bone remodeling in both the groups. Thus, osteotomy may be an effective modality for enhancing tooth movement in orthodontic treatment.

• 대한치과의사협회지
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• 제22권2호통권177호
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• pp.129-140
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• 1984

• 대한치과교정학회지
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• 제52권4호
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• pp.258-267
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• 2022

Objective: This study aimed to evaluate the superimposition accuracy of digital modes for measuring tooth movement in patients requiring anterior retraction after premolar extraction based on the proposed reference regions. Methods: Forty patients treated with bilateral maxillary first premolar extraction were divided into two groups: moderate retraction (< 7.0 mm) and maximum retraction (≥ 7.0 mm). Central incisor displacement was measured using cephalometric superimpositions and three-dimensional (3D) digital superimpositions with the 3rd or 4th ruga as the reference point. The Wilcoxon signed-rank test and linear regression analyses were performed to test the significance of the differences and relationships between the two measurement techniques. Results: In the moderate retraction group, the central incisor anteroposterior displacement values did not differ significantly between 3D digital and cephalometric superimpositions. However, in the maximum-retraction group, significant differences were observed between the anteroposterior displacement evaluated by the 3rd ruga superimposition and cephalometric methods (p < 0.05). Conclusions: This study demonstrated that 3D digital superimpositions were clinically as reliable as cephalometric superimpositions in assessing tooth movements in patients requiring moderate retraction. However, the reference point should be carefully examined in patients who require maximum retraction.

• 대한치과의사협회지
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• 제57권6호
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• pp.326-332
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• 2019

Extraction treatment has been used for a long time to treat crowding or lip protrusion patients and still extraction decision is the most difficult and important decision during diagnosis and treatment planning. If the amount of crowidng is severe, premolar extraction is often considered. Because of their location, premolar extractions would seem to allow for the most straightforward relief of crowding and the improvement of soft tissue profile. But patients and their parents often prefer nonextraction approach if possible and such a preference gives us serious question about the boundary of nonextraction treatment. Because Orthodontic Mini-Implant (OMI) become popular these days, distalization of posterior teeth can be obtained easily without patient's compliance. For this reason, many orthodontists are trying to treat crowding patient with nonextraction than before. But sometime, unexpected side effects are observed including unesthetic profile, impaction of second molar and long treatment time. All the tools for space gaining - extraction, arch expansion, molar distalization and interproximal enamel reduction - have their limitations and indications. Possible side effects and limitations should be carefully considered during the treatment planning. Although Korean patients usually require extraction more often than US or European patients, more knowledge about the tools for space gaining would help us to decrease the rate of extraction and the problems during treatment of crowding patients.

• Journal of Korean Dental Science
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• 제11권1호
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• pp.32-41
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• 2018

As the adult population continues to increase, orthodontic treatment for adult patients is becoming more common. This case report describes comprehensive orthodontic treatment of a middle-aged patient with closure of the extraction space without prosthetic restoration. A 55-year-old woman with her maxillary left first premolar extracted because of a periodontal problem, wanted to close the space with orthodontic treatment. Since she had generalized crowding and mild skeletal discrepancy, we planned comprehensive orthodontic treatment, including closure of the extraction space by protraction of the left maxillary molars using miniscrews and aesthetic alignment of anterior teeth. The total treatment period was 28 months. As a result of these treatments, the extraction space was successfully closed, good tooth alignment and satisfactory occlusion were achieved.

• 대한치과교정학회지
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• 제23권1호
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• pp.123-136
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• 1993

The purpose of this report is to present the successful improvement of occlusal relationship and facial esthetics in class II division 1 malocclusion with severe labioversion of upper anterior teeth and severe overjet, and in class II malocclusion with infraversion of bilateral maxillary canines by MEAW mechanics, which enables us to get effective distal on mass movement of maxillary dentition, with upper second molar extraction. After treatment, there were natural contact points at canine and premolar regions, normal occlusal relation-ship and treatment results, satisfied the gnathologic concept, in this 2 cases. Compared with the routine treatment with premolar extraction, the treatment time and patients' discomfort were reduced. And the MEAW mechanics, which enables us to get effective distal on mass movement of maxillary dentition, resulted in reduction of the treatment time and getting the good treatment results. Consequently, the majot concerns in orthodontic treatment are appropriate diagnosis and treatment plan, so, the application of second molar extraction with appropriate case analysis and diagnosis is very helpful to orthodontic treatment.

• 대한두개안면성형외과학회지
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• 제22권5호
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• pp.239-246
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• 2021

Background: Bone grafts can provide an optimal environment for permanent tooth to erupt and enhance the stability of the alveolar maxilla. Although autologous bone is an optimal source for osteogenesis, its inevitable donor site morbidity has led to active research on bone substitutes. This study was designed to evaluate the safety and feasibility of using biphasic calcium phosphate (BCP; Osteon) as a bone substitute in dogs. Methods: Bilateral third and fourth premolars of four 15-week-old mongrel dogs were used. All teeth were extracted except the third premolar of the right mandible, which was used as a control. After extraction of the premolars, each dog was administered BCP (Osteon), demineralized bone matrix (DBM; DBX), and no graft in the hollow sockets of the right fourth premolar, left fourth premolar, and left third premolar, respectively. Radiographs were taken at 2-week intervals to check for tooth eruption. After 8 weeks, each dog was sacrificed, and tooth and bone biopsies were performed to check for the presence of tooth and bone substitute particle remnants. Results: Four weeks after the operation, permanent tooth eruptions had started at all the extraction sites in each dog. Eight weeks after the operation, all teeth had normally erupted, and histological examination revealed BCP particles at the right fourth premolar. Conclusion: In all four dogs, no delay in the eruption of the teeth or shape disfigurement of permanent teeth was observed on gross inspection and radiologic evaluation. On histological examination, most of the BCP and DBM were replaced by new bone. Bone substitutes can be used as graft materials in patients with alveolar clefts.

• Journal of Periodontal and Implant Science
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• 제47권3호
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• pp.143-153
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• 2017

Purpose: The aim of the present exploratory study was to evaluate extraction socket healing at sites with a history of periodontal and endodontic pathology. Methods: The mandibular 4th premolar teeth in 5 adult beagle dogs served as experimental units. Periodontal and endodontic lesions were induced in 1 premolar site in each animal using wire ligatures and pulpal exposure over 3 months (diseased sites). The contralateral premolar sites served as healthy controls. The mandibular 4th premolar teeth were then extracted with minimal trauma, followed by careful wound debridement. The animals were sacrificed at days 1, 7, 30, 60, and 90 post-extraction for analysis, and the healing patterns at the healthy and diseased extraction sites were compared using radiography, scanning electron microscopy, histology, and histometry. Results: During the first 7 days of healing, a significant presence of inflammatory granulation tissue was noted at the diseased sites (day 1), along with a slightly accelerated rate of fibrin clot resolution on day 7. On day 30, the diseased extraction sites showed a greater percentage of persistent fibrous connective tissue, and an absence of bone marrow formation. In contrast, healthy sites showed initial signs of bone marrow formation on day 30, and subsequently a significantly greater proportion of mature bone marrow formation on both days 60 and 90. Radiographs exhibited sclerotic changes adjoining apical endodontic lesions, with scanning electron microscopy showing collapsed Volkmann canals protruding from these regions in the diseased sites. Furthermore, periodontal ligament fibers exhibited a parallel orientation to the alveolar walls of the diseased sites, in contrast to a perpendicular arrangement in the healthy sites. Conclusions: Within the limitations of this study, it appears that a history of periodontal and endodontic pathology may critically affect bone formation and maturation, leading to delayed and compromised extraction socket healing.