• 대한치과교정학회지
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• 제42권4호
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• pp.182-189
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• 2012

Objective: The aims of this study were to use a 3-dimensional (3D) system to compare molar relationship assessments performed from the buccal and lingual aspects, and to measure differences in occlusal contact areas between Class II and Class I molar relationships. Methods: Study casts (232 pairs from 232 subjects, yielding a total of 380 sides) were evaluated from both the buccal and lingual aspects, so that molar relationships could be classified according to the scheme devised by Liu and Melsen. Occlusal contact areas were quantified using 3D digital models, which were generated through surface scanning of the study casts. Results: A cusp-to-central fossa relationship was observed from the lingual aspect in the majority of cases classified from the buccal aspect as Class I (89.6%) or mild Class II (86.7%). However, severe Class II cases had lingual cusp-to-mesial triangular fossa or marginal ridge relationships. Mean occlusal contact areas were similar in the Class I and mild Class II groups, while the severe Class II group had significantly lower values than either of the other 2 groups (p < 0.05). Conclusions: Buccal and lingual assessments of molar relationships were not always consistent. Occlusal contact areas were lowest for the Class II-severe group, which seems to have the worst molar relationships - especially as seen from the lingual aspect.

• 대한치과교정학회지
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• 제36권1호
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• pp.30-44
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• 2006

교정치료 영역에서 성인들의 심미적인 요구도가 증가되면서 설측 교정치료는 여러 가지 단점에도 불구하고, 가장 심미적이라는 이유로 많은 주목을 받아왔지만 실제 치아이동을 결정지을 수 있는 브라켓을 부착하는 기준평면의 위치에 대해서는 거의 보고된 바가 없다. 이에 본 연구는 실제 브라켓이 부착되는 평면의 상하 평행이동이나 기울기 변화에 따라 치아이동 양상이 어떻게 변화되는지 알아보고, 바람직한 전치부 치체이동을 얻기 위해서 힘의 적용점을 어디에 두어야 하는지, 그리고 전치부에 어느 정도의 모멘트를 부여해야 하는지 알아보고자 3차원 유한요소법을 이용하여 치아 변위 및 응력분포를 비교 분석하였다. 실험 결과 설측 브라켓 부착평면을 치은연쪽으로 평행이동 혹은 회전이동 시키고 견인하였을 경우, 절단연쪽으로 이동시켰을 때와 비교했을 때 비조절성 설측 경사이동이 감소하기는 하였으나 상하악 전치부 치아들의 설측경사 양상은 지속되었으며, 이러한 양상은 견치 브라켓의 hook 길이를 증가시켜도 계속 나타났다. 이와는 달리 설측 중심평면에 브라켓을 부착하고 각 치아별로 모멘트를 부여하였을 경우 설측 방향으로 개개 치아들의 치체이동이 발생하여 설측 교정치료 시 효과적인 전치부 치아의 후방견인이 가능함을 알 수 있었다.

• 대한치과교정학회지
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• 제45권2호
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• pp.74-81
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• 2015

Objective: The purposes of this study were 1) to classify lingual dental arch form types based on the lingual bracket points and 2) to provide a new lingual arch form template based on this classification for clinical application through the analysis of three-dimensional virtual models of normal occlusion sample. Methods: Maxillary and mandibular casts of 115 young adults with normal occlusion were scanned in their occluded positions and lingual bracket points were digitized on the virtual models by using Rapidform 2006 software. Sixty-eight cases (dataset 1) were used in K-means cluster analysis to classify arch forms with intercanine, interpremolar and intermolar widths and width/depth ratios as determinants. The best-fit curves of the mean arch forms were generated. The remaining cases (dataset 2) were mapped into the obtained clusters and a multivariate test was performed to assess the differences between the clusters. Results: Four-cluster classification demonstrated maximum inter-cluster distance. Wide, narrow, tapering, and ovoid types were described according to the intercanine and intermolar widths and their best-fit curves were depicted. No significant differences in arch depths existed among the clusters. Strong to moderate correlations were found between maxillary and mandibular arch widths. Conclusions: Lingual arch forms have been classified into 4 types based on their anterior and posterior dimensions. A template of the 4 arch forms has been depicted. Three-dimensional analysis of the lingual bracket points provides more accurate identification of arch form and, consequently, archwire selection.

• 대한치과교정학회지
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• 제46권2호
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• pp.65-72
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• 2016

Objective: The purposes of this study were to measure the orthodontic forces generated by thermoplastic aligners and investigate the possible influences of different activations for lingual bodily movements on orthodontic forces, and their attenuation. Methods: Thermoplastic material of 1.0-mm in thickness was used to manufacture aligners for 0.2, 0.3, 0.4, 0.5, and 0.6 mm activations for lingual bodily movements of the maxillary central incisor. The orthodontic force in the lingual direction delivered by the thermoplastic aligners was measured using a micro-stress sensor system for the invisible orthodontic technique, and was monitored for 2 weeks. Results: Orthodontic force increased with the amount of activation of the aligner in the initial measurements. The attenuation speed in the 0.6 mm group was faster than that of the other groups (p < 0.05). All aligners demonstrated rapid relaxation in the first 8 hours, which then decreased slowly and plateaued on day 4 or 5. Conclusions: The amount of activation had a substantial influence on the orthodontic force imparted by the aligners. The results suggest that the activation of lingual bodily movement of the maxillary central incisor should not exceed 0.5 mm. The initial 4 or 5 days is important with respect to orthodontic treatment incorporating an aligner.

• 대한치과교정학회지
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• 제48권4호
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• pp.236-244
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• 2018

Objective: The aim of this study is to compare the adaptation of a straight wire between brackets positioned at the mid-lingual surface and those placed gingivally by using a three-dimensional simulation software. Methods: This cross-sectional study was performed using OrthoAid, an in-house software. The subjects were 36 adolescents with normal Class I occlusion. For each dental cast, two bracket positioning approaches, namely the middle and gingival, were examined. In the middle group, the reference points were placed on the mid-lingual surface of each tooth, while in the gingival group, the reference points were positioned lingually on the anterior teeth. A 4th degree polynomial was adopted, and the in-plane and off-plane root mean squares (RMSs) of the distances between the reference points and the fitted polynomial curve were calculated using the software. Statistical analysis was performed using the paired-samples t-test (${\alpha}=0.05$). Results: The mean in-plane RMS of the polynomial curve to the bracket distance in the gingival group was significantly lower than that in the middle group (p < 0.001). The off-plane RMS was higher in the gingivally positioned brackets in the maxilla than in the middle group (p < 0.001). However, the off-plane RMS in mandible was not statistically significantly different between the two groups (p = 0.274). Conclusions: The results demonstrated that the gingival placement of lingual brackets on the anterior teeth could decrease the distance between a tooth and the straight wire.

• 대한치과교정학회지
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• 제43권5호
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• pp.235-241
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• 2013

Objective: The purpose of this study was to investigate whether extension of the custom base is necessary for enhancement of bond strength, by comparing the debonding forces and residual adhesives of 3 different lingual bracket systems. Methods: A total of 42 extracted upper premolars were randomly divided into 3 groups of 14 each for bonding with brackets having (1) a conventional limited resin custom base; (2) an extended gold alloy custom base: Incognito${TM}$; and (3) an extended resin custom base: KommonBase${TM}$. The bonding area was measured by scanning the bracket bases with a 3-dimensional digital scanner. The debonding force was measured with an Instron universal testing machine, which applied an occlusogingival shear force. Results: The mean debonding forces were 60.83 N (standard deviation [SD] 10.12), 69.29 N (SD 9.59), and 104.35 N (SD17.84) for the limited resin custom base, extended gold alloy custom base, and extended resin custom base, respectively. The debonding force observed with the extended resin custom base was significantly different from that observed with the other bases. In addition, the adhesive remnant index was significantly higher with the extended gold alloy custom base. Conclusions: All 3 custom-base lingual brackets can withstand occlusal and orthodontic forces. We conclude that effective bonding of lingual brackets can be obtained without extension of the custom base.

• 대한치과교정학회지
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• 제26권6호
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• pp.705-715
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• 1996

The lingual multibracket appliance was developed to overcome the unesthetic nature of traditional fixed orthodontic labial appliances; however, treatment with this appliance was regarded as very difficult as well as a time-consuming. Recently, these problems have been reduced because of advances in lingual bracket systems, improved indirect bonding technique and the development of more flexible wires. There has been a marked increase in the number of adults desiring orthodontic treatment over recent years and many of these patients tend to seek invisible orthodontic appliances due to esthetic reasons. Although the lingual multibracket treatment is not ideal, this form of treatment is currently the best option for the patients with esthetic concerns. Here, I would like to present a case treated successfully with lingual multibracket appliance.

• 대한치과교정학회지
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• 제25권2호
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• pp.209-221
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• 1995

한국인에게 적합한 설측교정장치와 이상적인 설측 치열궁 아치와이어 제작의 기초자료를 얻기위하여 정상교합자 경석고 모형 30개를 재료로 하여 설측치관의 형태와, 후지타 설측 브라켓을 위치시킨 모형에서 설측치열궁 형태를 조사하여 다음과 같은 결과를 얻었다. 각 치아에 대한 치관의 근원심 경사도와 설면의 순설측 치관 경사도의 평균치를 얻었다. 각 치아에 대한 브라??? 위치에서 설면의 수평 및 수직적 형태를 얻은 결과 대구치, 소구치, 견치는 상하악이 비슷한 모양을 보였으며, 강하악의 중절치와 측절치도 비슷한 모양을 보여 각각 브라켓 기저부를 공유할 수 있을 것으로 나타났다. 브라켈 부착위치에서의 평균 설측치열궁 형태를 얻은 결과, 그 형태는 전치부는 반원형이며 견치와 소구치 사이에 강한 오프??? 밴드가 있는 버섯 형태로서 소구치간 및 제2소구치와 대구치간에도 오프??? 밴드가 필요한 것으로 나타났다. 남녀간의 평균 설측치열궁 형태는 상악은 거의 일치하였고 하악은 여자가 남자보다 다소 작은 형태를 나타내었다.

• 대한치과교정학회지
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• 제21권2호
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• pp.309-324
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• 1991

저자는 3명의 제1급 부정교합 환자를 소구치 발치를 동반하여 설측교정장치로 치료한 결과 비교적 만족할 만한 치료결과를 얻을 수 있었다. 설측교정장치에 의한 치료는 순측장치에 의한 치료보다는 적절한 치아이동에 어려움이 있으며 아직 해결해야 할 많은 문제점이 있으나 향후 재료 및 치료기술의 개발로 대부분의 문제점들이 해결될 수 있을 것으로 생각한다. 앞으로 설측교정장치는 교정치료동안 심미성인 문제로 교정치료를 포기하는 많은 사람들에게 교정치료에 대한 동기유발과 함께 기회를 제공해 줄 수 있는 미래의 교정치료장치라고 생각한다.

• 대한치과교정학회지
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• 제49권6호
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• pp.381-392
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• 2019

Objective: The objective of this two-arm parallel trial was to compare the type of tooth movement during en masse retraction of the maxillary anterior teeth using labial versus lingual biocreative therapy. Methods: Twenty-eight subjects were randomized in a 1 : 1 ratio to either the labial or lingual group. En masse anterior retraction was performed using labial biocreative therapy in group A and lingual biocreative therapy in group B. Cone beam computed tomography scans were taken before and after retraction and the primary outcome was the type of tooth movement during anterior retraction. Data were analyzed using paired t-tests for comparisons within each group and independent-sample t-test for comparison of the mean treatment changes between the two groups. Results: Significant differences were found between the two groups in relation to the type of tooth movement (labiolingual inclination of the central incisor; mean difference, $5.85{\pm}1.85^{\circ}$). The canine showed significant distal tipping in the lingual group (mean difference, $6.98{\pm}1.25^{\circ}$). The canine was significantly more intruded in the lingual group (mean difference, $1.67{\pm}0.49mm$). Good anchorage control and significant soft tissue changes occurred in both groups. No serious adverse effects were detected. Conclusions: With a 10-mm retraction hook, the labial biocreative technique with the reverse curve overlay provided anterior retraction with good torque control, while in the lingual group, anterior retraction occurred with controlled tipping movement with significant distal tipping and intrusion of the canine (trial registration: The trial was registered at ClinicalTrials.gov [NCT03239275]).