• 대한치과교정학회지
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• 제50권2호
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• pp.120-128
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• 2020

Objective: The aims of the present study were to evaluate the changes in the maximum lip-closing force (MLF) after orthodontic treatment with or without premolar extractions and verify the correlation of these changes with dentoskeletal changes. Methods: In total, 17 women who underwent nonextraction orthodontic treatment and 15 women who underwent orthodontic treatment with extraction of all four first premolars were included in this retrospective study. For all patients, lateral cephalograms and dental models were measured before (T0) and after (T1) treatment. In addition, MLF was measured at both time points using the Lip De Cum LDC-110R^® device. Statistical analyses were performed to evaluate changes in clinical variables and MLF and their correlations. Results: Both groups showed similar skeletal patterns, although the extraction group showed greater proclination of the maxillary and mandibular incisors and lip protrusion compared to the nonextraction group at T0. MLF at T0 was comparable between the two groups. The reduction in the arch width and depth and incisor retroclination from T0 to T1 were more pronounced in the extraction group than in the nonextraction group. MLF in the extraction group significantly increased during the treatment period, and this increase was significantly greater than that in the nonextraction group. The increase in MLF was found to be correlated with the increase in the interincisal angle and decrease in the intermolar width, arch depth, and incisor-mandibular plane angle. Conclusions: This study suggests that MLF increases to a greater extent during extraction orthodontic treatment than during nonextraction orthodontic treatment.

• 대한치과교정학회지
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• 제48권3호
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• pp.172-181
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• 2018

Objective: This study was performed to investigate buccal facial depth (BFD) changes after extraction and nonextraction orthodontic treatments in post-adolescent and adult female patients, and to explore possible influencing factors. Methods: Twelve and nine female patients were enrolled in the extraction and nonextraction groups, respectively. Changes in BFD in the defined buccal region and six transverse and two coronal measuring planes were measured after registering pretreatment and posttreatment three-dimensional facial scans. Changes in posterior dentoalveolar arch widths were also measured. Treatment duration, changes in body mass index (BMI), and cephalometric variables were compared between the groups. Results: BFD in the buccal region decreased by approximately 1.45 mm in the extraction group, but no significant change was observed in the nonextraction group. In the extraction group, the decrease in BFD was identical between the two coronal measuring planes, whereas this differed among the six transverse measuring planes. Posterior dentoalveolar arch widths decreased in the extraction group, whereas these increased at the second premolar level in the nonextraction group. The treatment duration of the extraction group was twice that of the nonextraction group. No differences were found in BMI and Frankfort horizontal-mandibular plane angle changes between the groups. BFD changes in the buccal region moderately correlated with treatment duration and dental arch width change. Conclusions: BFD decreased in adult female patients undergoing extraction, and this may be influenced by the long treatment duration and constriction of dentoalveolar arch width. However, nonextraction treatment did not significantly alter BFD.

• 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.

• 구강회복응용과학지
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• 제29권2호
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• pp.119-126
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• 2013

교정 치료 시 발치에 대한 개념은 수없이 변화되어 왔었고, 현재도 발치 치료와 비발치 치료에 대한 기준은 변하고 있다. 본 연구에서는 한국인에서 발치, 비발치 치료에 따른 주관적 안모심미변화를 조사하고, 또한 평가자에 따른 치료결과에 대한 인식의 차이를 알아보았다. 본 연구는 단국대학교 치과대학병원 교정 클리닉에 내원하여 교정치료를 종료한 환자 중, 소구치 발치 환자 59명, 비발치 환자 60명, 총 119명을 대상으로 하였다. 전문가와 비전문가로 이루어진 평가단원이 치료 전 후 측방 두부방사선사진의 연조직 트레이싱을 VAS 평가하여 그 결과를 통계처리 하였다. 그리하여 도출한 결론은 다음과 같다. 1. 발치와 비발치의 평균 점수는 발치가 5.76, 비발치가 5.28로 발치를 한경우의 안모 개선 정도가 더 양호하게 받아들여졌다. 2. 일반인의 평균 점수는 5.165, 전문가 집단은 5.875로 이 연구에서는 일반인 집단보다 전문가 집단에서 전체적으로 더 높은 평가를 하였다. 3. 전문가 집단에서 발치와 비발치 환자를 평가하였을 때, 발치를 한 경우 유의하게 더 높은 점수가 나왔다. 4. 일반인 집단에서 발치와 비발치 환자를 평가하였을 때, 발치를 한 경우 더 높은 점수가 나왔으나 유의성 있는 차이는 존재하지 않는다. 5. 비발치 case에서는 전문가 집단이 일반인 집단 보다 유의성 있게 더 높은 평가를 내렸다. 6. 발치 case에서는 일반인보다 전문가 집단의 점수가 더 높았으나 유의성 있는 결과는 아니다.

• 대한치과교정학회지
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• 제31권2호통권85호
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• pp.187-197
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• 2001

전통적 교정술식인 edgewise technique으로 치료한 경우 잔여성장, 안모 유형과 발치 여부가 안모고경에 미치는 영향과 요소를 알아보고자 165명을 대상으로 조사하였다. 이 대상군들은 SN-GoGn angle, Frankfort mandibular plane angle, Occluso-mandibular plane angle을 이용하여 수직 비발치군, 수직 발치군, 수평 비발치군, 수평 발치군으로 구분하였다. 치료 전후에 두부계측방사선사진을 계측하고 통계처리하여 다음과 같은 결론을 얻었다. 1.모든 군에서 치료 후의 전하안모고경, 전안모고경, 후안모고경이 유의하게 증가하였으며 상하악 구치고경이 유의하게 증가하였다. 2. 치료 전후의 안모고경 변화에서 수직, 수평 안모 유형 간에 유의한 차이는 인정되지 않았다. 3. 발치군과 비발치군 간의 안모고경 변화는 유의한 차가 없었다. 4. 전하안모고경의 변화량이 성장군에서 상악 구치고경의 변화와, 성인군에서 하악 구치고경의 변화와 유의한 상관성을 보였다. 5. 전하안모고경의 변화량에 영향을 미치는 요소는 뚜렷하지 않았다.

• 대한치과교정학회지
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• 제46권5호
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• pp.280-289
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• 2016

Objective: The aim of this study was to analyze tooth movement and arch width changes in maxillary dentition following nonextraction treatment with orthodontic mini-implant (OMI) anchorage in Class II division 1 malocclusions. Methods: Seventeen adult patients diagnosed with Angle's Class II division 1 malocclusion were treated by nonextraction with OMIs as anchorage for distalization of whole maxillary dentition. Three-dimensional virtual maxillary models were superimposed with the best-fit method at the pretreatment and post-treatment stages. Linear, angular, and arch width variables were measured using Rapidform 2006 software, and analyzed by the paired t -test. Results: All maxillary teeth showed statistically significant movement posteriorly (p < 0.05). There were no significant changes in the vertical position of the maxillary teeth, except that the second molars were extruded (0.86 mm, p < 0.01). The maxillary first and second molars were rotated distal-in ($4.5^{\circ}$, p < 0.001; $3.0^{\circ}$, p < 0.05, respectively). The intersecond molar width increased slightly (0.1 mm, p > 0.05) and the intercanine, interfirst premolar, intersecond premolar, and interfirst molar widths increased significantly (2.2 mm, p < 0.01; 2.2 mm, p < 0.05; 1.9 mm, p < 0.01; 2.0 mm, p < 0.01; respectively). Conclusions: Nonextraction treatment with OMI anchorage for Class II division 1 malocclusions could retract the whole maxillary dentition to achieve a Class I canine and molar relationship without a change in the vertical position of the teeth; however, the second molars were significantly extruded. Simultaneously, the maxillary arch was shown to be expanded with distal-in rotation of the molars.

• 대한치과교정학회지
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• 제50권1호
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• pp.52-62
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• 2020

This case report presents the orthodontic treatment of a 25-year-old patient with skeletal Class II and severe maxillary arch crowding, moderate mandibular arch crowding, anterior crossbite, and a missing lower incisor. He was treated with molar distalization using a modified C-palatal plate and temporary anchorage devices to create sufficient space for retraction. The total treatment duration was 21 months. After treatment, his occlusion and smile esthetics showed significant improvement. The modified C-palatal plate represents a treatment modality that enhances the prospects of non-extraction treatment and reduces the need for extraction.

• 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.

• 대한치과교정학회지
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• 제49권2호
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• pp.116-123
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• 2019

As an alternative to the conventional fixed appliance that uses orthodontic brackets, a simple round tube without a bonding base can be bonded to the tooth surface by covering the tube with flowable resin. In this technique, bent wires cannot be inserted into the simple tubes; therefore, repositioning of the simple tubes is often required for adjustments. To reduce repositioning of simple tubes, a dome-shaped resin covering of the simple tube can be designed with a customized in-and-out compensation, using three-dimensional computer-aided design software based on digital simulation of orthodontic tooth movement. In the present case, the use of simple tubes bonded with customized resin coverings in a Class I nonextraction case is described in a 17-year-old male, in whom moderate crowding of the anterior teeth was treated over an 8-month period. This case shows that simple tubes can be used as an alternative to brackets in some Class I nonextraction cases, with the potential benefit of reducing decalcification.

• 대한치과교정학회지
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• 제47권2호
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• pp.100-107
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• 2017

Objective: To analyze the long-term changes in maxillary arch widths and buccal corridor ratios in orthodontic patients treated with and without premolar extractions. Methods: The study included 53 patients who were divided into the extraction (n = 28) and nonextraction (n = 25) groups. These patients had complete orthodontic records from the pretreatment (T1), posttreatment (T2), and postretention (T3) periods. Their mean retention and postretention times were 4 years 2 months and 17 years 8 months, respectively. Dental models and smiling photographs from all three periods were digitized to compare the changes in three dental arch width measurements and three buccal corridor ratios over time between the extraction and nonextraction groups. Data were analyzed using analysis of variance tests. Post-hoc multiple comparisons were made using Bonferroni correction. Results: Soft-tissue extension during smiling increased with age in both groups. The maximum dental width to smile width ratio (MDW/SW) also showed a favorable increase with treatment in both groups (p < 0.05), and remained virtually stable at T3 (p > 0.05). According to the MDW/SW ratio, the mean difference in the buccal corridor space of the two groups was $2.4{\pm}0.2%$ at T3. Additionally, no significant group ${\times}$ time interaction was found for any of the buccal corridor ratios studied. Conclusions: Premolar extractions did not negatively affect transverse maxillary arch widths and buccal corridor ratios. The long-term outcome of orthodontic treatment was comparable between the study groups.