• 대한치과교정학회지
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• 제52권5호
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• pp.372-382
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• 2022

Anterior open bite and transverse discrepancy are often accompanied by hyperdivergent skeletal patterns. In addition, degenerative joint disorders and vertical maxillary excess contribute to an unfavorable convex facial profile with a retruded chin. Correction of this complex three-dimensional problem with orthodontic treatment alone is considered challenging owing to anatomical limitations. Moreover, a history of orthodontic treatment with premolar extraction makes retreatment difficult. This case report illustrates the application of a maxillary tissue bone-borne expander and biocreative reverse curve system in a 23-year-old female patient with a severe anterior open bite and transverse discrepancy who underwent orthodontic treatment with four premolar extractions. By setting the treatment target under precise diagnosis and using appropriate appliances, a satisfactory treatment result could be achieved without orthognathic surgery.

• Journal of Korean Dental Science
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• 제3권1호
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• pp.5-10
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• 2010

This study sought to compare the amounts of posterior anchorage loss during the en masse retraction of the upper anterior teeth between orthodontic mini-implant (OMI) and conventional anchorage reinforcement (CAR) such as headgear and/or transpalatal arch. The subjects were 52 adult female patients treated with sliding mechanics (MBT brackets, .022" slot, .019X.025" stainless steel wire, 3M-Unitek, Monrovia, CA, USA). They were allocated into Group 1 (N=24, Class I malocclusion (CI), upper and lower first premolar (UP1LP1) extraction, and CAR), Group 2 (N=15, Cl, UP1LP1 extraction and OMI), and Group 3 (N=13, Class II division 1 malocclusion, upper first and lower second premolar extraction, and OMI). Lateral cephalograms were taken before (T0) and after treatment (T1). A total of 11 anchorage variables were measured. Analysis of variance was used for statistical analysis. There was no significant difference in treatment duration and anchorage variables at T0 among the three groups. Groups 2 and 3 showed significantly larger retraction of the upper incisor edge (U1E-sag, 9.3mm:7.3mm, P<.05) and less posterior anchorage loss (U6M-sag, 0.7~0.9mm:2mm, P<.05; U6A-sag, 0.5mm:2mm, P<.01) than Group 1. The ratio of retraction amount of the upper incisor edge per 1 of anchorage loss in the upper molar made for the significant difference between Groups 1 and 2 (4.6mm:7.0mm, P<.05). Group 3 showed a relatively distal inclination of the upper molar (P<.05) and the intrusion of the upper incisor and first molar (U1E-ver, P<.05; U6F-ver, P<.05) compared to Groups 1 and 2. Although OMI could not shorten the treatment duration, it could provide better maximum posterior anchorage than CAR.

• 대한치과교정학회지
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• 제48권4호
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• pp.224-235
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• 2018

Objective: The purpose of this study was to compare the skeletal, dental, and soft-tissue treatment effects of nonextraction therapy using the modified C-palatal plate (MCPP) to those of premolar extraction (PE) treatment in adult patients with Class II malocclusion. Methods: Pretreatment and posttreatment lateral cephalographs of 40 adult patients with Class II malocclusion were retrospectively analyzed. The MCPP group comprised 20 patients treated with total arch distalization of the maxillary arch while the PE group comprised 20 patients treated with four PE. Fifty-eight linear and angular measurements were analyzed to assess the changes before and after treatment. Descriptive statistics, paired t-test, and multivariate analysis of variance were performed to evaluate the treatment effects within and between the two groups. Results: The MCPP group presented 3.4 mm of retraction, 1.0 mm of extrusion, and $7.3^{\circ}$ lingual inclination of the maxillary central incisor. In comparison, the PE group displayed greater amount of maxillary central incisor retraction and retroclination, mandibular incisor retraction, and upper lip retraction (5.3 mm, $14.8^{\circ}$, 5.1 mm, and 2.0 mm, respectively; p < 0.001 for all). In addition, the MCPP group showed 4.0 mm of distalization and 1.3 mm of intrusion with $2.9^{\circ}$ distal tipping of the maxillary first molars. Conclusions: These findings suggest the MCPP is an effective distalization appliance in the maxillary arch. The amount of incisor retraction, however, was significantly higher in the PE group. Therefore, four PE may be recommended when greater improvement of incisor position and soft-tissue profile is required.

• 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.

• Journal of Periodontal and Implant Science
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• 제33권4호
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• pp.705-715
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• 2003

Procedures for treatment of molar furcation invasion defects range from open flap debridement, apically repositioned flap surgery, hemisection, tunneling or extraction, to regenerative therapies using bone grafting or guided tissue regenerative therapy, or a combination of both. Several clinical evaluations using regenerative techniques have reported the potential for osseous repair of treated furcation invasions. Regenerative treatment of maxillary molars are more difficult due to the multiple root anatomy and multiple furcation entrances therefore, purpose of this study was to evaluated histologically compomer and Ketac Silver as a barrier in the treatment of a bi-furcated maxillary premolar. Five adult beagle dogs were used in this experiment. With intrasulcular and crestal incision, mucoperiostcal flap was elevated. Following decortication with 1/2 high speed round bur, furcation defect was made on maxillary premolar. 2 month later one premolar was filled with compomer and the other premolar was filled with Ketac Silver. After 4, 8 weeks, the animals were sacrificed by vascular perfusion. Tissue block was excised including the tooth and prepared for light microscope with H-E staining. Results were as follows. 1. Compomer & Ketac Silver restoration were encapsulated fine connective tissue. 2. In 4 weeks, compomer & Ketac Silver restoration slightly infiltrated inflammatory cells but not disturb the new bone or new cementum formation. 3. In 8 weeks, compomer & Ketac Silver restoration were less infiltrated iflammatory cell and encapsulated fine connective tissue. 4. Therefore, compomer & Ketac Silver filling to the grade III maxillary furcations with multiple root anatomy and multiple furcation entrances is possible clinical method and this technique is useful method for maxillary furcation involvement but it is thought that periodic maintenance should be needed

• Journal of Periodontal and Implant Science
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• 제35권2호
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• pp.371-381
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• 2005

The masticatory function of tooth is maintained by the periodontal health, and periodontal health is also maintained by the masticatory function. Bite forces are withstanded by the PDL, and this thought to be through the viscoelastic theory. Mobility test and Bite force test are used to evaluate the viscoelastic theory of the PDL. In this study, the bite force test was used. In the same conditions of quantity of the supporting tissue, the maximum bite force according to the quality of the supporting tissue was evaluated. The study was conducted on 40 patients with moderate adult periodontitis, who were indications to the modified widman flap treatment. The maximum bite force in the premolar and molar regions were tested before treatment, 3weeks and 4 weeks after treatment. and the results were as follows. 1. In the premolar region, 3 weeks and 4 weeks after treatment showed higher maximum bite force than before treatment. And in the molar region the maximum bite force decreased 3 weeks after treatment, but increased after 4 weeks, compared to before treatment. 2. In the 1st premolar, there were only significant difference between before and 3 weeks after treatment, and between and 4 weeks after treatment. 3. In the 2nd premolar, there were only significant difference between before and 3 weeks after treatment, and between and 4 weeks after treatment. 4. In the 1st molar, there were no significant difference between before, 3 weeks after treatment, 4 weeks after treatment. 5. In the 2nd molar, there were no significant difference between before, 3 weeks after treatment, 4 weeks after treatment. From the results above, it shows that there were improvements in the maximum bite force through specific periodontal treatments, and thus it can be considered in clinical situations, that selection of the prosthodontic material, decisions of extraction, evaluation of the prognosis after periodontal treatment is a helpful method.

• 대한치과교정학회지
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• 제40권3호
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• pp.176-183
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• 2010

고정식 교정장치를 이용한 교정치료 후 교합의 기능적 변화를 평가하기 위해, 교합력 및 교합접촉면적을 측정하여 단기적인 변화 양상을 확인하고 소구치 발치 여부에 따른 차이를 파악하였다. 고정식 교정장치로 치료를 종료한 18세 에서40세 사이의 성인을 남자군과 여자군으로 분류하고, 각각의 군을 4개의 소구치를 발치한 군과 비발치로 치료한 군으로 세부 분류하였다(남자발치군 16명, 남자비발치군 18명, 여자발치군 19명, 여자비발치군 21명). Dental prescalesystem (Fuji Film Corp., Tokyo, Japan)의 pressure sensitive sheet를 5초간 최대교두감합위에서 최대근력으로 교합하도록 한 뒤 CCD camera를 이용해 교합력과 교합면적을 측정하였다. 고정식 교정장치를 제거하고 고정식유지장치를 붙인 직후, 교정장치 제거 1주일, 1개월, 3개월, 6개월, 1년 뒤에 각각 측정하여 비교하였다. 모든 군에서 교정장치 제거 후 1년간의 유지기간 동안 교합력과 교합면적은 점진적으로 증가하였다 (p < 0.05). 모든 측정 시기에서 남자군은 여자군보다 높은 교합력과 교합면적을 보였으며 (p < 0.05), 남자, 여자군 모두에서 발치군과 비발치군 사이에는 교합력 및 교합면적에서 통계적으로 유의한 차이가 관찰되지 않았다 (p > 0.05). 본 연구를 통해 교정치료 후 1년간의 유지기간 동안 교합이 기능적으로 향상됨을 파악하였고, 소구치 발치로 인한 교합의 기능적 저하는 없을 것이라 추측할 수 있었다.

• 대한치과교정학회지
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• 제31권2호통권85호
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• pp.199-207
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• 2001

본 연구는 교정치료를 시행함에 있어 전치부 crowding을 해결하기 위한 견치의 단독견인 방법중 새로운 segmented TMA T-loop spring으로 견치 후방견인시 치근단과 그 주위 치조골에서의 응력상태를 알아보기 위해 시행되었다. PL-3 epoxy resin으로 광탄성 모형을 제작하여 B/L ratio가 0.25, 0.5, 0.75인 위치로 T-loop을 위치시키고 각 위치에서 5mm, 3mm, 1mm activation하였다. 이후 광탄성 응력 해석장치를 이용하여 견치견인시 치근단과 그 주위 치조골에서의 초기 응력 상태를 광탄성법으로 분석한 바, 다음과 같은 결론을 얻었다. 1. T-looP 위치에 상관없이 activation량이 감소할수록 상악 1소구치 발치부위에 응력이 감소하였고 상악 1대구치의 함입응력은 증가하였다. 2. 5mm activation시 T-loop위치가 구치부쪽으로 이동할수록 상악 1소구치 발치부위에 응력이 증가하였다. 3. 3mm activation시 T-loop위치가 구치부쪽으로 이동할수록 상악 1소구치 발치부위와 상악 1대구치 협측 근심치근 근심면하방 1/2부위에 응력이 증가하였다. 4. 1mm activation시 T-loop위치가 견치쪽으로 이동할수록 상악 견치의 근심치근면 상방과 치근첨 하방의 응력이 증가하였다. 5. B/L ratio가 0.25이고 3mm activation시 상악견치의 치체이동이 나타났다. 이상의 결과를 종합해볼 때 segmented T-loop spring의 근, 원심 위치 와 activation량을 조절하여 원하는 치아이동과 고정원 조절이 가능하다고 사료된다.

• 대한치과교정학회지
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• 제26권5호
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• pp.487-495
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• 1996

본 연구는 제 1 소구치 발치로 양호하게 치료된 Class I 전돌 환자의 치료 전 안모 골격 특성과 치료 전후 변화를 조사하여 Class I 전돌 환자의 치료 계획 수립에 이용하고자 하였다. 서울대학교 병원 치과 진료부 교정과에 내원하여 치열궁 길이 부조화의 양이 7.00mm 를 넘지 않고 Class I 전돌 환자로 진단되어 상, 하악 제 1소구치를 발거한 후 동일한 임상가에 의하여 동일 치료 기법으로 양호하게 치료된 환자 35명 (여자 27명, 남자 8명) 을 대상으로 치료 전후 측모 두부 방사선 사진을 계측하여 다음과 같은 결과를 얻었다. 1. 치료 전후 골격 형태는 크게 변하지 않았고 치열, 치조골, 연조직에서 치료 후 유의성 있는 변화가 있었다. 2. 치료 전 골격 형태는 SN-GoGn이 $36.56^{\circ}$, AB-MP이 $66.92^{\circ}$, ODI가 $69.17^{\circ}$, APDI가 $81.31^{\circ}$, CF $150.52^{\circ}$로서 수직적인 부조화 경향을 보였다. 3. 치료 전 치열 형태는 절치간 각이 $113.11^{\circ}$, U1 to FH가 $117.78^{\circ}$, L1 to A-Pog이 7.94mm 였으며 연조직 측모상 E line에 대하여 상순이 2.88mm, 하순이 5.43mm 돌출되어 있었다. 4. 치료 후 치열 형태는 절치간 각이 $14.46^{\circ}$ 증가되었으며 연조직 측모상 E line에 대하여 상순이 2.45mm, 하순이 3.2mm후방이동되었다. (P<0.001 ) 5. 치료 전 발치 지수 (EI)는 138.71이었고 치료 후 EI는 148.2였다.

• 대한치과교정학회지
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• 제27권6호
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• pp.905-916
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• 1997

본 연구는 교정치료시 발치가 안모의 수직 변화에 어떠한 영향을 미치는지 규명하기 위해서 비발치군과 발치군으로 구분하였고, 발치군은 비교분석을 위해 제1소구치 발치군, 제2소구치 발치군, 제2대구치 발치군으로 구분하여 교정치료 전, 후의 안모의 수직변화 여부를 평가함으로서 발치가 안모의 수직변화에 미치는 영향을 규명하고자 했다. 연구대상은 조선대학교 부속치과병원 교정과에 내원하여 교정치료를 받은 환자 중, 제2대구치까지 맹출하여 성장에 의한 변화요인이 적다고 인정되는 비발치군 남녀 50명, 발치군 남녀 88명으로 하였으며, 비발치군은 비교분석을 위해 42명의 제1소구치 발치군, 24명의 제2소구치 발치군, 22명의 제2대구치 발치군으로 구분하였다. 안모의 수직변화 여부를 규명할 수 있는 14개의 두부방사선 계측항목을 선정하여 교정치료 전, 후의 안모의 수직변화량을 측정하였고, $SPSS/PC^+$ 통계프로그램을 이용하여 교정치료 전, 후의 안모의 수직변화여부를 비교 분석함으로 써 다음과 같은 결과를 얻었다. 1. 교정적 발치여부에 관계없이 모든 군에서 교정치료 전,후의 두부방사선 계측치 사이에 통계학적인 유의성이 없었다. 2. 상, 하악 구치는 모든 군에서 교정치료에 의해 정출되었다. 이는 대부분의 교정치료의 역계 자체가 치아를 정출시키는 기전을 지니고 있음을 의미하며, 특히 발치에 의한 교정치료시 발치공간 폐쇄 및 치아배열을 위해 작용되는 역계로 인해 일어나는 결과로 보인다. 3. 제 2재구치 발치군에서 안모의 수직고경은 교정치료 후에 모두 증가되었다. 이는 치아배열 공간을 확보하기 위해 치열이 후방이동된 결과로 보인다. 4. 교정적 발치와 안모의 수직변화 사이에는 통계학적인 유의성이 없었다. 이는 안모의 수직변화와 교정적 발치는 아무런 관련이 없음을 나타낸다. 5. 두부방사선 계측항목 중 안모의 수직변화에 있어서 각 군 사이에 통계학적으로 유의성 있는 영향을 미치는 항목은 PP-MP, OP-MP, $\underline{1}$ to PP, $\overline{1}$ to MP였다.