• 대한치과교정학회지
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• 제49권6호
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• pp.360-371
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• 2019

Objective: We sought to determine the predictors of midpalatal suture expansion by miniscrew-assisted rapid palatal expansion (MARPE) in young adults. Methods: The following variables were selected as possible predictors: chronological age, palate length and depth, midpalatal suture maturation (MPSM) stage, midpalatal suture density (MPSD) ratio, the sella-nasion (SN)-mandibular plane (MP) angle as an indicator of the vertical skeletal pattern, and the point A-nasion-point B (ANB) angle for anteroposterior skeletal classification. For 31 patients (mean age, 22.52 years) who underwent MARPE treatment, palate length and depth, MPSM stage and MPSD ratio from the initial cone-beam computed tomography images, and the SN-MP angle and ANB angle from lateral cephalograms were assessed. The midpalatal suture opening ratio was calculated from the midpalatal suture opening width measured in periapical radiographs and the MARPE screw expansion. Statistical analyses of correlations were performed for the entire patient group of 31 subjects and subgroups categorized by sex, vertical skeletal pattern, and anteroposterior skeletal classification. Results: In the entire patient group, the midpalatal suture opening ratio showed statistically significant negative correlations with age, palate length, and MPSM stage (r = -0.506, -0.494, and -0.746, respectively, all p < 0.01). In subgroup analyses, a strong negative correlation was observed with the palate depth in the skeletal Class II subgroup (r = -0.900, p < 0.05). Conclusions: The findings of this study indicated that age, palate length, and MPSM stage can be predictors of midpalatal suture expansion by MARPE in young adults.

• 대한치과교정학회지
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• 제24권4호
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• pp.799-817
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• 1994

The purpose of this study was to evaluate the initial skeletal pattern and growth change of whom had responsed well to chincap therapy. 93 patients seleted for this study were in mixed dentition and treated with chincap for more than 2 years. And 54 subjects were selected from these total samples and classified into two groups by the improvement of four measurements : ANB difference, APDI, Wits appraisal, and AF-BF. One was good response group which consisted of 26 children and the other was poor response group with 19 patients. Various measures of the craniofacial structure in the initial lateral cephalograms and the annual increments were calculated and analyzed by comparing two groups with t-test. The results were as follows : 1. Good response group had more horizontal growth pattern in initial stage of treatment than poor response group, and the contributing factors of this result were anterior posterior facial height ratio, gonial angle, lower genial angle and SN-mandibular plane angle. 2. The maxilla was positioned more anteriorly in good response group. 3. The amounts of vertical growth of maxilla was smaller but the horizontal growth of maxilla was larger in good response group. 4. The mandible rotated more infero-posteriorly in good response group. 5. The good response group had more vertical growth pattern of mandibular condyle.

• 대한치과교정학회지
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• 제47권4호
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• pp.248-255
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• 2017

Objective: The purpose of this study was to investigate whether the craniofacial patterns of Korean children with snoring and adenotonsillar hypertrophy (ATH) could be categorized into characteristic clusters according to age. Methods: We enrolled 236 children with snoring and ATH (age range, 5-12 years) in this study. They were subdivided into four age groups: 5-6, 7-8, 9-10, and 11-12 years. Based on cephalometric analysis, the sagittal and vertical skeletal patterns of each individual were divided into Class I, II, and III, as well as the normodivergent, hypodivergent, and hyperdivergent patterns, respectively. Cluster analysis was performed using cephalometric principal components in addition to the age factor. Results: Three heterogeneous clusters of craniofacial patterns were obtained in relation to age: cluster 1 (41.9%) included patients aged 5-8 years with a skeletal Class I or mild Class II and hyperdivergent pattern; cluster 2 (45.3%) included patients aged 9-12 years with a Class II and hyperdivergent pattern; and cluster 3 (12.8%) included patients aged 7-8 years with a Class III and hyperdivergent pattern. Conclusions: This study found that the craniofacial patterns of Korean children with snoring and ATH could be categorized into three characteristic clusters according to age groups. Although no significantly dominant sagittal skeletal discrepancy was observed, hyperdivergent vertical discrepancy was consistently evident in all clusters.

• Imaging Science in Dentistry
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• 제48권1호
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• pp.51-57
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• 2018

Purpose: To perform a comparative analysis of the palatal bone thickness in Thai patients exhibiting class I malocclusion according to whether they exhibited a normal or open vertical skeletal configuration using cone-beam computed tomography (CBCT). Materials and Methods: Thirty CBCT images of Thai orthodontic patients (15-30 years of age) exhibiting class I malocclusion with a normal or open vertical skeletal configuration were selected. Palatal bone thickness was measured in a 3.0-mm grid pattern on both the right and left sides. The palatal bone thickness of the normal-bite and open-bite groups was compared using the independent t-test. The level of significance was established at P<.05. Results: The palatal bone thickness in the normal-bite group ranged from $2.2{\pm}1.0mm$ to $12.6{\pm}4.1mm$. The palatal bone thickness in the open-bite group ranged from $1.9{\pm}1.1mm$ to $13.2{\pm}2.3mm$. The palatal bone thickness was lower at almost all sites in patients with open bite than in those with normal bite. Significant differences were found at almost all anteroposterior sites along the 3 most medial sections (3.0, 6.0, and 9.0 mm lateral to the midsagittal plane)(P<.05). Conclusion: Class I malocclusion with open vertical skeletal configuration may affect palatal bone thickness, so the placement of temporary anchorage devices or miniscrew implants in the palatal area in such patients should be performed with caution.

• 대한치과교정학회지
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• 제45권4호
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• pp.153-163
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• 2015

Objective: The purpose of this study was to assess rotational patterns of dentofacial structures according to different vertical skeletal patterns by cone-beam computed tomography (CBCT) and analyze their influence on menton deviation in skeletal Class III deformity with mandibular asymmetry. Methods: The control group consisted of 30 young adults (15 men, 15 women) without any severe skeletal deformity. The asymmetry group included 55 adults (28 men, 27 women) with skeletal Class III deformity and at least 3-mm menton deviation from the midsagittal plane; it was divided into the hyperdivergent and hypodivergent subgroups using a mandibular plane angle cutoff of $35^{\circ}$. Fourteen rotational variables of the dental arches and mandible were measured and compared among the groups. Correlations between menton deviation and the other variables were evaluated. Results: The asymmetry group showed significantly larger measurements of roll and yaw in the mandible than the control group. The hypodivergent subgroup showed significant differences in maxillary posterior measurements of yaw (p < 0.01) and maxillary anterior shift (p < 0.05) compared with the hyperdivergent subgroup. All the mandibular measurements had significant correlations with menton deviation (p < 0.01). Most measurements of roll were positively correlated with one another (p < 0.01). Measurements of yaw and roll in the posterior regions were also positively correlated (p < 0.05). Conclusions: Menton deviation in skeletal Class III deformity with mandibular asymmetry is influenced by rotation of mandibular posterior dentofacial structures. The rotational patterns vary slightly according to the vertical skeletal pattern.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제23권1호
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• pp.21-30
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• 2001

The purpose of this study was to evaluate the skeletal relapse pattern of the mandibular prognathic patients after mandibular set back surgery by sagittal split ramus osteotomy. The horizontal and vertical position of the cephalometric points were measured before, after surgery and after one-year follow up period. The next, the positional change of the proximal and distal mandibular segment were evaluated respectively. The obtained results were as follows; 1. The horizontal and vertical position of Cd was not changed before and after surgery, and it was maintained its original position during the observation periods. 2. As the mandibular prognathism of the patients was severe before surgery, the more skeletal relapse tendency was observed during follow-up period(p<0.05). 3. As the horizontal positional change of the mandible which was obtained by mandibular set-back surgery was large, the more horizontal relapse tendency was observed during follow-up period(p<0.05). 4. The corpus axis angle decreased by sagittal split ramus osteotomy(p<0.01), but it was kept its reoriented position during follow-up period. 5. During the follow-up period after mandibular set-back by sagittal split ramus osteotomy, the forward relapse of mandible correlated with not only the forward rotation of the proximal segment but also the forward movement of the distal segment(p<0.05).

• 대한치과교정학회지
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• 제26권4호
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• pp.349-358
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• 1996

부정교합을 치료하기 위해 영구치 발거여부를 결정하는 것은 교정학의 역사상 커다란 논쟁거리였고, 따라서 진단과정에서 사용되는 많은 분석법들과 발치의 기준들이 제시되었다. 이제까지 제시되어 온 발치기준들(Extraction formulas)을 검토해 보면, 치열궁 장경 부조화, 치열의 전방돌출, 그리고 환자의 골격형태에 기초하여 발치를 결정함을 알 수 있다. 이들 중에서 가장 중요하게 고려되어야 할 진단요소는 환자의 골격형태로, 결국 개개 환자의 부정교합은 그 환자의 골격형태 범위 내에서 치료되어야 하기 때문이다. EI(Extraction Index)는 환자의 골격형태를 감별진단 할수 있는 CF를 기본으로 구성되어 있고, CF는 부정교합의 수직적, 수평적 요소를 감별해내는 ODI이와 APDI로 이루어져 있다. 또한 피에는 환자의 안모에 영향을 미치는 절치간 각과 입술의 전후방 위치가 포함되어 있어서 안모형태도 고려되어 있다. 본 연구에서는 정상 교합자로서 골격이 조화를 이루며 좋은 안모를 가지고 있고 교정치료를 받은 적이 없는 11.2 - 14.4 세의 아동을 대상으로 하여 두부계측 방사선 사진을 분석하여 EI에 관련된 항목들을 측정한 결과, 다음과 같은 결론을 얻었다. 1. ODI이는 $73.5^{\circ}$, APDI는 $82.8^{\circ}$, CF는 $156.3^{\circ}$ 였다. 2. 절치간 각은 $123.6^{\circ}$ 였다. 3. E-line에 대한 상순의 거리는 0.0mm, 하순은 1.4mm 였다. 4. Extraction Index는 153.8 였다.

• 대한소아치과학회지
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• 제42권2호
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• pp.126-135
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• 2015

본 연구의 목적은 3급 부정교합 환자에서 facemask 치료 시 수직적 골격 양상에 따른 치료 효과를 비교하고, 구내 장치로서 bonded expander의 고정원을 평가하는 것이다. Facemask 치료를 받은 20명의 환자를 대상으로 FMA를 기준으로 두 군으로 분류하였고(HV군; FMA > $27^{\circ}$, AV군; $23^{\circ}$ < FMA < $27^{\circ}$), 치료 전과 후 측모두부방사선사진을 촬영하여 계측치를 비교하였다. 치료 후 두 군 모두 상악의 전방이동 및 하악의 후하방 회전이 관찰되었고, 두 군간에 유의한 차이는 없었다. 두 군 모두 수직적 골격 계측치가 증가하였고, FMA의 증가량은 HV군이 AV군에 비해 유의하게 크게 관찰되었다. 고정원 소실로서 상악구치의 근심이동 및 상악 전치의 전방경사가 관찰되었고, 두 군간에 유의한 차이는 없었다. 결론적으로 수직적 골격 양상에 따라 상악의 전방이동 및 고정원 소실면에서는 유의한 차이가 없었으나, HV군에서 수직적 성장 경향이 더 증가하였다.

• 대한치과교정학회지
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• 제22권4호
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• pp.837-853
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• 1992

The purpose of this study was to investigate the positional changes of the mandibular condyles after orthognathic surgery In patients with severe skeletal Class III malocclusion. This study was based on 21 patients who had received bilateral sagittal split osteotomy for mandibular setback. Among them 14 were fixated non - rigidly (W group), and 7 were fixated rigidly (R group). After submental vertex view analysis, each subject was given the T.M.J. Tomogram in both centric occlusion and centric relation immediate before, $4\~6$ weeks after and more than 6 months after surgery. The anteroposterior and vertical changes between each time interval were measured and analyzed statistically. Following results were obtained. 1. There was no significant difference between right and left condyles in their anteroposterior and vertical changes of the condylar position. 2. In anteroposterior changes of condylar position of the wire fixation group, the condyles were moved anteriorly 4-6 weeks after surgery, and then the pattern of reestablishment to their preoperative position was observed more than 6 months after surgery. In the rigid fixation group, there was no significant difference in any observation periods of centric occlusion and centric relation. 3. In vertical changes of condylar position of the wire fixation group. the condyles were moved inferiorly 4-6 weeks after surgery, and then the pattern of reestablishment to their preoperative position was observed more than 6 months after surgery. In the rigid fixation group, the condyles were moved inferiorly 4-6 weeks after surgery, and then the pattern of reestablishment to their preoperative position was observed more than 6 months after surgery in centric occlusion only.

• 대한치과교정학회지
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• 제32권2호통권91호
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• pp.91-105
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• 2002

일반적으로 교정 환자의 문제점을 파악하고 치료 계획을 수립할 때에 여러 분석법의 정상치를 기준으로 하는 경우가 많다. 하지만 다양한 악골관계 하에서 정상적인 악궁관계를 유지하기 위해 3차원적으로 발생하는 치아치조부 보상 기전을 고려한다면 좀 더 개별화된 치료 목표와 치료계획을 수립하는데 도움이 될 수 있을 것이다. 이에 본 연구에서는 정상교합자 125명의 측모 두부계측방사선사진을 계측하여 정상교합자의 골격양상의 다양성을 살펴보았다. 또한 여러 골격계측 기준을 이용한 군집분석을 적용하여 정상교합자의 골격형을 전후방으로 세 군, 수직적으로 세 군으로 분류하고 각 골격형에 따른 치아치조부 보상양상을 조사하여 다음과 같은 결과를 얻었다. 1. 정상교합자의 전후방적, 수직적 악골관계는 매우 다양하였다. 2. 하악골이 상악골에 비해 전방 위치할수록 상악 전치는 순측으로 경사 되고 하악 전치는 설측으로 경사 되며 교합평면의 경사도는 완만해졌다. 3. 수직적인 골격양상일수록 상악 전치부의 치아치조 고경이 증가하고, 하악 구치부의 치아치조 고경이 감소하였으며 구개평면에 대한 상악 구치와 하악평면에 대한 하악 전치 및 하악 구치는 직립 하였고 교합평면과 하악평면사이의 각(OMA)은 증가하였다. 4. 상악 전치보다 하악 전치에서 전후방 및 수직적인 악골관계에 대해 더 많은 치아치조부 보상양상을 보였다.