• 대한치과교정학회지
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• 제40권5호
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• pp.325-333
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• 2010

발음장애, 구토감 및 착용 불편감과 같은 보정장치에 대해 환자가 느끼는 불편감을 평가해보기 위해 고정식 교정장치로 교정치료를 받고 교정장치가 제거된 66명(남자 23명, 여자 43명; 평균연령 $23.42{\pm}10.19$)의 교정환자를 대상으로 무작위로 두 군으로 배정한 후 고정식 교정장치를 제거한 다음 날 CWR 장착군에게는 구개를 완전히 덮는 구개 완전 피개형 보정장치인 conventional wraparound retainer (CWR)를 장착시키고 CCR 장착군에게는 구개를 말 발굽 모양으로 부분 피개하는 보정장치인 circumferential comfortable retainer (CCR)를 4주 동안 장착시킨 후 발음장애, 구토감 및 착용 불편감의 정도에 대해 100-mm visual analog scale (VAS)로 표시할 수 있도록 제작된 설문지를 통해 얻은 점수에 대해 통계적으로 비교 분석하였다. 연구결과 발음장애와 착용 불편감의 비교에서 CCR 장착군이 CWR 장착군에 비해 통계적으로 유의하게 낮았다 ($p$ < 0.05). 구토감의 비교에서는 CCR 장착군이 CWR 장착군에 비해 낮은 점수를 보였지만 통계적으로는 유의한 차이를 보이지 않았다 ($p$ = 0.146). 이상의 연구 결과로 circumferential comfortable retainer (CCR)는 발음장애를 감소시키고, 착용 불편감을 완화시킴으로써 환자의 협조도를 증진시켜줄 수 있는바 고정식 교정장치를 이용한 교정치료 후 치료결과 유지에 도움이 될 수 있음을 시사하였다.

• 대한치과교정학회지
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• 제46권1호
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• pp.36-41
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• 2016

Objective: The aim of this study was to evaluate retention practices commonly employed by orthodontists. The objectives were to identify the types of retainer frequently used and to investigate the variations in retention practice. Methods: A total of 97 orthodontists were randomly selected, and a questionnaire consisting of 25 multiple-choice questions sent to them by mail. Upon receiving of the completed questionnaires, the data were statistically analyzed. Results: A total of 32 responses were received; among these, 59.4% of orthodontists' practiced is in a government setting and 40.6% were in private practice. A vacuum-formed retainer was the most commonly used removable retainer for both maxillary (46.9%) and mandibular (46.9%) arches, followed by a Hawley retainer (maxilla, 43.8%; mandible, 37.5%), and a fixed retainer (maxilla, 3.1%; mandible, 9.4%). Of the responding orthodontists, 78.1% prescribed full-time wear (more than 20 h per day) for a duration of 3-9 months for a maxillary arch, compared to 71.9% for the mandibular arch. Only 18.8% of the orthodontists prescribed part-time wear of the retainer for the maxillary arch, compared to 21.9% for the mandibular arch. The majority of orthodontists did not instruct their patients to stop wearing removable retainers (71.9%) or fixed retainers (66.8%) at any specific time and they preferred their patients to continue wearing retainers. Conclusions: Vacuum-formed retainers are the most commonly used retainers among orthodontists. The majority of orthodontists prescribed full-time wear for more than 20 h per day with a duration of 3-9 months and preferred indefinite use of the retainer.

• 대한치과교정학회지
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• 제45권5호
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• pp.268-272
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• 2015

Clear thermoplastic retainers have been widely used in daily orthodontics; however, they have inherent limitations associated with thermoplastic polymer materials such as dimensional instability, low strength, and poor wear resistance. To solve these problems, we developed a new type of clear orthodontic retainer that incorporates multi-layer hybrid materials. It consists of three layers; an outer polyethylenterephthalate glycol modified (PETG) hard-type polymer, a middle thermoplastic polyurethane (TPU) soft-type polymer, and an inner reinforced resin core. The resin core improves wear resistance and mechanical strength, which prevent unwanted distortion of the bucco-palatal wall of the retainer. The TPU layer absorbs impact and the PETG layer has good formability, optical qualities, fatigue resistance, and dimensional stability, which contributes to increased support from the mandibular dentition, and helps maintain the archform. This new type of vacuum-formed retainer showed improved mechanical strength and rate of water absorption.

• 대한치과교정학회지
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• 제39권6호
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• pp.402-419
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• 2009

성장이 종료된 치성 또는 골격성 개방교합 환자를 치료하는 것은 매우 어려운 일이다. 전치부 개방교합 환자는 증가된 전안면고경, 상악 구치부의 과도한 수직성장, 큰 하악각 등의 특징을 지닌다. 이러한 증례에서 구치의 압하를 통한 개방교합의 해소는 좋은 치료전략이다. 본 연구는 교정용 미니임플란트를 이용하여 개방교합을 치료하고 성공적인 유지를 얻은 두 명의 환자에 대한 보고이다. 적절한 진단이 시행되고 교정용 미니임플란트 등의 장치를 이용한 치료기법을 적용하면 수술치료 없이 교정치료만으로 개방교합의 치료가 가능하며, 하악구치부에 posterior bite block을 추가한 가철식 유지장치 및 SFR이 개교환자를 위한 유지장치 또는 보조유지장치로 유용하게 사용될 수 있다는 결론을 얻었다.

• 대한치과교정학회지
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• 제47권3호
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• pp.207-212
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• 2017

The popularity of clear overlay retainers (CORs) has increased recently because of their advantages such as better esthetics, cost effectiveness, easy fabrication, and good compliance. However, a deficiency in posterior occlusal settling is a reported limitation of CORs. The aim of this study was to evaluate the posterior occlusal contact changes in a new type of clear orthodontic retainer called Oral-treaper (OTP), which consists of three layers and has stronger mechanical characteristics than do conventional retainers. Three patients who completed fixed orthodontic treatment received OTP as a removable retainer. Cast models were fabricated after the removal of fixed appliances (T1) and after 4 to 11 months of using the retainers (T2). We evaluated all the cast models to compare the post-orthodontic settling pattern during the use of the OTPs. The depth of occlusal contacts was evaluated using color maps. The OTP did not prevent vertical settling in all patients but resulted in an improvement in posterior occlusal contact points.

• Imaging Science in Dentistry
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• 제51권1호
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• pp.63-71
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• 2021

Purpose: The aim of this study was to assess the artefacts of 12 fixed orthodontic appliances in magnetic resonance images obtained using 1.5-T and 3-T scanners, and to evaluate different imaging sequences designed to suppress metal artefacts. Materials and Methods: In vitro, study casts of 1 adult with normal occlusion were used. Twelve orthodontic appliances were attached to the study casts and scanned. Turbo spin echo (TSE), TSE with high readout bandwidth, and TSE with view angle tilting and slice encoding for metal artefact correction were used to suppress metal artefacts. Artefacts were measured. In vivo, 6 appliances were scanned: 1) conventional stainless-steel brackets; 2) nickelfree brackets; 3) titanium brackets; 4) a Herbst appliance; 5) a fixed retainer; and 6) a rapid maxillary expander. The maxilla, mandible, nasopharynx, tongue, temporomandibular joints, and cranial base/eye globes were assessed. Scores of 0, 1, 2, and 3 indicated no artefacts and minor, moderate, and major artefacts, respectively. Results: In vitro, titanium brackets and the fixed retainer created minor artefacts. In vivo, titanium brackets caused minor artefacts. Conventional stainless-steel and nickel free brackets, the fixed retainer, and the rapid maxillary expander caused major artefacts in the maxilla and mandible. Conventional stainless-steel and nickel-free brackets caused major artefacts in the eye globe (3-T). TSE with high readout bandwidth reduced image artefacts in both scanners. Conclusion: Titanium brackets, the Herbst appliance, and the fixed retainer caused minor artefacts in images of neurocranial structures(1.5-T and 3-T) when using TSE with high readout bandwidth.

• 대한치과의사협회지
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• 제21권5호통권168호
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• pp.395-402
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• 1983

The purpose of this study was to apply the etched metal ceramometal retainer using a composite resin and acid-etch procedure with minimal tooth reduction of abutments for the replacement of one missing anterior or posterior tooth. Author obtained the following conclusions. 1. conservation of tooth structure and minimal chair time and patient expense were the primary advantages of etched metal retainer. 2. This fixed partial denture permitted good esthetic results. 3. This retainer was successfully applied for the replacement of one missing anterior or posterior tooth. 4. Proper retainer etching ws an important procedure. 5. Etched castings could be applied to periodontal splinting and post orthodontic fixation.

• Journal of Periodontal and Implant Science
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• 제51권3호
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• pp.163-178
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• 2021

Purpose: The aim of this study was to evaluate clinical factors affecting the longevity of fixed retainers and the influence of fixed retainers on periodontal health in periodontitis patients. Methods: In total, 52 patients with at least 2 years of follow-up after periodontal and orthodontic treatment were included in this study. After scaling and root planing, orthodontic treatment with fixed appliances or clear aligners was performed. Fixed retainers with twist-flex stainless steel wires were bonded to the palatal or lingual sides of anterior teeth. Changes in clinical parameters, including the plaque index, gingival index, calculus index (CI), probing pocket depth, and radiographic bone levels, were evaluated before bonding of fixed retainers and at a 12-month follow-up. Cumulative survival rates (CSRs) for retainer failure were evaluated according to sex, site, CI, stage of periodontitis, and the severity of the irregularity with the log-rank test and hazard ratios (HRs). Results: Twelve months after bonding of fixed retainers, improvements were observed in all clinical parameters except CI and radiographic bone gain. The overall CSR of the retainers with a CI <1 at the 12-month follow-up after bonding of fixed retainers was significantly higher than that of the retainers with a CI ≥1 at the 12-month follow-up (log-rank test; P<0.001). Patients with stage III (grade B or C) periodontitis had a higher multivariate HR for retainer failure (5.4; 95% confidence interval, 1.22-23.91; P=0.026) than patients with stage I (grade A or B) periodontitis. Conclusions: Although fixed retainers were bonded in periodontitis patients, periodontal health was well maintained if supportive periodontal treatment with repeated oral hygiene education was provided. Nonetheless, fixed retainer failure occurred more frequently in patients who had stage III (grade B or C) periodontitis or a CI ≥1 at 12-month follow-up after bonding of fixed retainers.

• 대한치과교정학회지
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• 제41권1호
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• pp.51-58
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• 2011

Objective: To evaluate the shear bond strength (SBS), fracture mode, wire pull out (WPO) resistance and microleakage between low-shrinking and conventional composites used as a lingual retainer adhesive. Methods: A total of 120 human mandibular incisor teeth, extracted for periodontal reasons, were collected. Sixty of them were separated into two groups. To determine the SBS, either Transbond-LR (3M-Unitek) or Silorane (3M-Espe) was applied to the lingual surface of the teeth by packing the material into standard cylindrical plastic matrices (Ultradent) to simulate the lingual retainer bonding area. To test WPO resistance, 20 samples were prepared for each composite where the wire was embedded in the composite materialand cured. Then tensile stress was applied until failure of the composite occurred. The remaining 60 teeth were divided into two groups and multi-stranded 0.0215-inch diameter wire was bonded with the same composites. Microleakage was evaluated by the dye penetration method. Statistical analyses were performed by Wilcoxon, Pearson chi-square, and Mann-Whitney-U tests at p < 0.05 level. Results: The SBS and WPO results were not statistically significant between the two groups. Significant differences were found between the groups in terms of fracture mode (p < 0.001). Greater percentages of the fractures showed mix type failure (85%) for Silorane and adhesive (60%) for Transbond-LR. Microleakage values were lower in low-shrinking composite than the control and this difference was found to be statistically significant (p < 0.001). Conclusions: Low-shrinking composite produced sufficient SBS, WPO and microleakage values on the etched enamel surfaces, when used as a lingual retainer composite.

• 대한치과교정학회지
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• 제32권2호통권91호
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• pp.143-153
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• 2002

콤포지트와 여러가닥 강선을 사용하여 제작된 접착식 보정장치는 심미적이며, 효과적인 보정장치라 할 수 있다. 이 연구는 접착식 보정장치의 전단접착강도를 측정하고, 접착식 보정장치의 제작 시 사용하는 여러가닥 강선 및 접착방법의 이상적인 조합을 제시하기 위해 디자인되었다. 교정치료를 위해 발거한 건전한 상하악 소구치 160개를 사용하여 80개의 시편을 제작하였다. 접착면적 및 강선의 길이, 콤포지트의 두께를 동일화하고, 직접접착 및 간접접착의 방법으로 여러가닥 강선을 접착하여 접착식 보정장치를 제작하였다. 만능시험기를 사용하여 각 시편에서의 전단접착강도 및 강선의 탈락시까지의 신장량을 측정하여, 다음과 같은 결론을 얻었다. 1. 6가닥, 0.0155인치의 강선에서 가장 큰 최대 접착강도를 보이고, 3가닥, 0.0195인치의 강선에서 가장 작은 최대 접착강도를 보였는데, 그 차이는 유의할 만큼 크지 않았다(p<0.05). 즉 강선의 직경 및 가닥수는 접착강도와 큰 연관성이 없다. 2. 3가닥, 0.015인치의 강선에서 가장 큰 신장량을 보여 주었고, 3가닥, 0.0195인치 강선에서 가장 작은 신장량을 보여주었다(p<0.05). 강선의 직경이 작을수록 신장량은 크게 나타났으나, 강선의 가닥수는 신장량과 큰 연관성이 없다. 3. 두 가지 접착방법의 비교에서 간접 접착술식을 사용했을 때 더 큰 접착강도 및 신장량을 보여 주었고, 통계적으로 유의한 차이를 나타냈다(p<0.05).