• 구강회복응용과학지
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• 제35권3호
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• pp.180-190
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• 2019

병적 치아 이동된 상악 전치를 가진 중등도 치주염 환자에서는 치태 관리를 통한 치주 염증의 해소뿐만 아니라 치아를 재위치 시키기 위한 교정치료가 함께 필요하다. 이 때의 교정치료는 더 적은 힘의 적용과 치아의 저항중심, 최적의 힘 등을 세심하게 고려해야 하는데, 이동하고자 하는 치아에만 적용되는 분절호선은 이동의 예측성을 높여주고, 힘을 조절할 수 있어 보다 효율적이다. 또한 교정치료 시, 고정원으로 사용되는 치아의 원치 않는 움직임을 차단하여 구치 교합 상태를 유지할 수 있는 장치 설계가 필요하며, 이를 위해 다양한 종류의 골성 고정원이 사용될 수 있다. 본 증례에서는 정출되고 변위된 상악 전치를 가진 환자에서, 철저한 치주 치료와 적절한 힘과 역학이 설계된 교정 장치로, 양호한 치료 결과를 얻을 수 있었으므로, 소개하고자 한다.

• 대한치과교정학회지
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• 제43권3호
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• pp.147-158
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• 2013

This article describes the orthodontic treatment of a 31-year-old Korean female patient with gummy smile and crowding. The patient showed excessive gingival display in both the anterior and posterior areas and a large difference in gingival heights between the anterior and posterior teeth in the maxilla. To correct the gummy smile, we elected to intrude the entire maxillary dentition instead of focusing only on the maxillary anterior teeth. Alignment and leveling were performed, and a midpalatal absolute anchorage system as well as a modified lingual arch was designed to achieve posterosuperior movement of the entire upper dentition. The active treatment period was 18 months. The gummy smile and crowding were corrected, and the results were stable at 21 months post-treatment.

• 대한치과교정학회지
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• 제35권3호
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• pp.196-206
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• 2005

이 연구는 비타민 C 결핍이 guinea pig에서의 실험적 치아이동속도와 치조골 개조에 미치는 영향을 알아보고자 시행되었다 이를 위하여 웅성 guinea pig 30마리를 대상으로 정상량의 비타민 C (5 mg/day) 를 투여한 군(정상군)과 결핍량(0.2mg/day)을 투여한 군(결핍군)으로 나누고 치아이동 실험을 시행하였다. 초기 교정력 75gm으로 상악의 좌우 중절치를 이개시키는 치아이동을 시행하고, 순차적으로 실험 경과기간이 지나면 치아이동양을 계측하고 희생시켜 조직 소견을 관찰하였다. 실험 결과. 결핍군에서 치조골과 치주인대의 교원섬유 함량은 현저한 감소와 불규칙한 배열을 보였으며 인대세포의 수적 감소 및 출혈이 관찰되었고 치조골에서 골형성의 감소와 파골세포의 출현 및 골소강의 크기증가와 골소강내의 다수의 파골세포가 관찰되었다. 정상군의 인장측 치조골은 치아이동 시간경과에 따라 조골세포와 골형성이 지속적인 증가를 보였으나, 결핍군에서는 조골세포가 감소하고 골형성은 미약한 양상을 보였다. 치아 이동양은 실험 초기 1일, 3일, 5일, 7일 결핍군의 치아이동양이 정상군보다 많게 나타났다 (p<0.05) 이상의 결과에서 비타민 C 결핍은 치주조직의 교원질의 합성을 억제하여 치조골의 형성을 감소시키고 흡수를 증가시키는 골개조를 초래하며, 치아이동중 인장측 치조골 형성을 억제하고 압박측 치조골 흡수를 촉진하여 치아이동 초기에는 빠른 치아이동을 가져오는 것을 시사한다.

• 대한치과의사협회지
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• 제52권1호
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• pp.8-16
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• 2014

The introduction of cone-beam computed tomography(CBCT) and computer software in orthodontics has allowed orthodontists to provide more accurate diagnosis and treatment. The most common use of CBCT imaging allows orthodontists to visualize the precise position of supernumerary or impacted teeth, especially impacted canines. In doing so, the exact angulation of impaction and proximity of adjacent roots can be evaluated by orthodontists, allowing them to choose vector forces for tooth movement while minimizing root resorption. Even though 2-dimensional panoramic images can be used to view the position of the impacted canines, they have limitations because it is not possible to evaluate the impacted tooth position 3-dimensionally. An accurate knowledge of root position improves the determination of success in orthodontic treatment. Nowadays, considering the fast pace of technological development, a combination of intraoral scanning, digital setups, custommade brackets and wires, and indirect bonding may soon become the orthodontic standard. In this paper, this will be discussed along with the digital models.

• 대한치과교정학회지
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• 제23권2호
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• pp.283-294
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• 1993

The friction of orthodontic appliances is recogonized to be detrimental to tooth movement. The purpose of this study was to determine the magnitude of frictional force changes between bracket$(018'\times025'\;solt)$ and orthodontic wires(stainless steel, cobalt-chromium, and $\beta-titanium$, $017'\times0.25'$ rectangular) with time. The wire was secured in the bracket slot with a elastomeric ligature. Frictional forces were measured by universal testing machine. The following conclusions were obtained. 1. The frictional forces under dry condition were greater than those in saliva. 2. The frictional forces produced by cobalt-chromium wire were less than those generated by stainless steel and $\beta-titanium$ wire. 3. The frictional forces increased progressively with time, and the amount of increase on first two weeks was greater than on last two weeks. 4. The change of frictional force under dry condition was greater than in artificial saliva.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.198-203
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• 2004

In these days, the orthodontic surgery including lingual orthodontics has attracted a person' attention due to its functional and esthetic appreciation. The delivery of the optimal orthodontic treatment is greatly influenced by clinician' ability to predict and control the tooth movement by applying force system to dentition. The skeletal anchorage system with the miniscrew has been used recently in the lingual orthodontics to assist the anchorage control. Precise understanding of the force system produced from the various orthodontic appliances is necessary. However, the qualitative and quantitative effect of the miniscrew has not been identified well. In this paper, three dimensional finite element analysis is introduced on the lingual orthodontics to investigate the effect of anterior retraction force on the miniscrew and transpalatal arch wire. The purpose of this study is to determine the location of the miniscrew and the point of force application of the anchorage system in the lingual orthodontics. The analysis results indicate the efficient position of the miniscrew and the transpalatal arch wire in the lingual orthodontics.

• Journal of Periodontal and Implant Science
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• 제50권3호
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• pp.146-158
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• 2020

Purpose: The aim of this study was to investigate and identify the main causes of periodontal tissue change associated with labial gingival recession by examining the anterior region of patients who underwent orthodontic treatment. Methods: In total, 45 patients who had undergone orthodontic treatment from January 2010 to December 2015 were included. Before and after the orthodontic treatment, sectioned images from 3-dimensional digital model scanning and cone-beam computed tomography images in the same region were superimposed to measure periodontal parameters. The initial labial gingival thickness (IGT) and the initial labial alveolar bone thickness (IBT) were measured at 4 mm below the cementoenamel junction (CEJ), and the change of the labial gingival margin was defined as the change of the distance from the CEJ to the gingival margin. Additionally, the jaw, tooth position, tooth inclination, tooth rotation, and history of orthognathic surgery were investigated to determine the various factors that could have affected anterior periodontal tissue changes. Results: The mean IGT and IBT were 0.77±0.29 mm and 0.77±0.32 mm, respectively. The mean gingival recession was 0.14±0.57 mm. Tooth inclination had a significant association with gingival recession, and as tooth inclination increased labially, gingival recession increased by approximately 0.2 mm per 1°. Conclusions: In conclusion, the IGT, IBT, tooth position, tooth rotation, and history of orthognathic surgery did not affect labial gingival recession. However, tooth inclination showed a significant association with labial gingival recession of the anterior teeth after orthodontic treatment.

• 대한치과교정학회지
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• 제21권3호
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• pp.635-656
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• 1991

It was the aim of this investigation to evaluate some histologic aspect of rat pulp tissue after it had been compromised by an experimental orthodontic force. Experimental animals of thirty five Spraque-Dawley rats were employed. The first upper molars had been successively mesial moved (initial load 100 gr.) with a closed coil spring during 21 days. The experimental periods were set on immediate, 1 day, 1 week, 2 weeks, 3 weeks, 4 weeks following retention time. On each experimental period, the rats were killed and prepared for the light microscopy. After prepared with H/E stain and Gomori's one-step trichrome stain, the specimens were analyzed with evaluation criteria which were adopted in this study. The result may be summarized as follows; 1. The main pulp changes due to experimental orthodontic force included vacuolization of odontoblastic layer, circulation disturbance, root resorption, reduced pulp collagenous fiber density and mean cell count of pulp fibroblast in the immediate group. 2. The pulp tissue changes were revealed reversible because the relieved pulp tissues from experimental orthodontic force were recovered rapidly in each evaluation criteria during retention periods. 3. Compared with normal control group, pulp collagenous fiber density were decreased in immediated group (p < 0.01), but increased in each retention groups. These seem to suggest that the pulp tissues were aged after experimental orthodontic force conditions. 4. Compared with normal control group, mean cell counts of pulp fibroblasts were decreased in immediate group (p < 0.05), but increased continuous in each retention groups. These seem to indicate that the pulp tissues were highly regenerative after experimental orthodontic force conditions. 5. Compared with normal control group, root resorptions occurred in all immediate specimens (p < 0.01) and they were healed in each retention periods, but often observed in 4 weeks retention group. These seem to indicate that root resorptions were recovered slowly after experimental orthodontic force conditions.

• 대한치과교정학회지
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• 제50권3호
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• pp.216-226
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• 2020

Root resorption can be caused by several factors, including contact with the cortical bone. Here we report a case involving a 21-year-old female with Angle Class II, division 1 malocclusion who exhibited significant root resorption in the maxillary right central incisor after orthodontic treatment. The patient presented with significant left-sided deviation of the maxillary incisors due to lingual dislocation of the left lateral incisor and a Class II molar relationship. Cephalometric analysis demonstrated a Class I skeletal relationship (A point-nasion-B point, 2.5°) and proclined maxillary anterior teeth (upper incisor to sella-nasion plane angle, 113.4°). The primary treatment objectives were the achievement of stable occlusion with midline agreement between the maxillary and mandibular dentitions and appropriate maxillary anterior tooth axes and molar relationship. A panoramic radiograph obtained after active treatment showed significant root resorption in the maxillary right central incisor; therefore, we performed cone-beam computed tomography, which confirmed root resorption along the cortical bone around the incisive canal. The findings from this case, where different degrees of root resorption were observed despite comparable degrees of orthodontic movement in the bilateral maxillary central incisors, suggest that the incisive canal could be an inducing factor for root resorption. However, further investigation is necessary to confirm this assumption.

• 대한치과교정학회지
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• 제51권2호
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• pp.86-94
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• 2021

Objective: This study aimed to investigate the effect of micro-osteoperforations (MOPs) on external apical root resorption (EARR) during the initial orthodontic alignment phase of maxillary anterior crowding. Methods: Thirty patients (25 females, 5 males; mean age, 22.66 ± 3.27 years) who presented with moderate crowding of the upper labial segment and underwent extraction-based fixed appliance treatment were recruited. They were randomly allocated to receive adjunctive therapy with MOPs (n = 15) or treatment with fixed appliances only (control group; n = 15). EARR was measured from long-cone periapical radiographs taken at the start and the sixth month of treatment. A correction factor for the enlargement difference was used to calculate EARR. Data were analyzed with descriptive statistics and repeated-measures analysis of variance. Results: The mean root lengths of 168 teeth were measured and showed no statistically significant difference (p > 0.05) after six months of fixed appliance treatment in the MOP (mean difference [MD] = 0.13 mm; 95% confidence interval [CI] = -0.10-0.35) and control group (MD = 0.14 mm; 95% CI = -0.10-0.37). Most of the roots in the MOP and control groups (42.86% and 52.38%, respectively) showed only mild resorption. Less than 8% of the roots in both groups (7.14% in the MOP group and 4.76% in the control group) showed moderate resorption. Conclusions: Acceleration of orthodontic tooth movement with adjunctive MOPs therapy during the alignment phase does not exacerbate EARR in patients with moderate crowding of the upper labial segment in comparison with controls.