• 대한치과교정학회지
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• 제13권1호
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• pp.45-62
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• 1983

To recognize the problems in malocclusion by roentgenocephalograms, the author designed a new pentagonal frame based on maxillary and mandibular bones. The subjects consisted of 44 normal occlusions (20 male and 24 female), 44 Class II division 1 malocclusions (15 male and 29 female) and 67 Class III malocclusions (31 male and 36 female). The results are as follows; 1. In normal group, the maxillary and mandibular skeletons of female we placed more closely to FH plane, so more anteriorly and upward than those of male. 2. In normal group, the posterior vertical height is longer in male than in female and the upper anterior teeth of female are in more labioversion than those of male. 3. By the X, Y coordinate values in pentagonal frame, it is helpful to recognize certain problems in malocclusions. 4. The posterior vertical height is a good indicator in detecting Angle's Class III malocclusion. 5. The maxillary and mandibular body length, the anterior point of maxillary and mandibular body length and the axial inclination of upper and lower anterior teeth can be useful in discerning Angle's Class II & Class III malocclusion.

• 대한소아치과학회지
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• 제27권4호
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• pp.479-484
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• 2000

III급 부정교합, 특히 전치부 반대 교합은 부모나 주위 사람에 의해 쉽게 인지되기 때문에 비교적 어린 시기에 내원하는 빈도가 높아지고 있다. 이에 따라 치과의사는 치료시기에 대한 결정, 적절한 case의 선택, 장기간에 걸친 치료, 치료후의 재발 등에 대한 심리적 부담감을 안게 되며 보호자 또한 시간적, 경제적인 어려움을 겪게 된다. 그러나, 반대 교합 그 자체는 조기 개선시 상악골의 성장 저해를 막을 수 있으며, 하악 과성장을 억제함으로써 기능성 인 경우에 골격성으로의 발전을 억제 할 수 있다. 그리고 상하악골의 골격 부조화가 매우 크거나 좋은 예후를 기대하기 힘든 골격 구조에 대해서도 정확한 평가가 병행 되어야 한다. 골격성 III급 부정교합으로 내원한 환아를 성장기 동안 치료함으로써 다음과 같은 결론을 얻었다. 1. 상악골의 정상적 인 성장 저해 요소를 제거하고, 하악골의 과성장을 조절해줌으로써 전치부 반대교합을 해소하였다. 2. 상악골과 상악 전치는 전하방으로, 하악골과 하악 전치는 후하방으로 이동하였다. 3. 경조직, 연조직의 변화로 인해 안모의 개선을 나타내었다.

• International Journal of Oral Biology
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• 제43권2호
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• pp.101-111
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• 2018

Understanding the classification of malocclusion is a crucial issue in Orthodontics. It can also help us to diagnose, treat, and understand malocclusion to establish a standard for definite class of patients. Principal component analysis (PCA) and k-means algorithms have been emerging as data analytic methods for cephalometric measurements, due to their intuitive concepts and application potentials. This study analyzed the macro- and meso-scale classification structure and feature basis vectors of 1020 (415 male, 605 female; mean age, 25 years) orthodontic patients using statistical preprocessing, PCA, random matrix theory (RMT) and k-means algorithms. RMT results show that 7 principal components (PCs) are significant standard in the extraction of features. Using k-means algorithms, 3 and 6 clusters were identified and the axes of PC1~3 were determined to be significant for patient classification. Macro-scale classification denotes skeletal Class I, II, III and PC1 means anteroposterior discrepancy of the maxilla and mandible and mandibular position. PC2 and PC3 means vertical pattern and maxillary position respectively; they played significant roles in the meso-scale classification. In conclusion, the typical patient profile (TPP) of each class showed that the data-based classification corresponds with the clinical classification of orthodontic patients. This data-based study can provide insight into the development of new diagnostic classifications.

• 대한치과의사협회지
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• 제48권3호
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• pp.196-204
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• 2010

To establish the ideal occlusal relationship, the values of tooth size and ratio must be in a normal range. In this study, the means and standard deviations of Bolton's anterior ratio and overall ratio using mesiodistal dimensions of teeth measured on diagnostic models of 334 Korean malocclusion patients were calculated and differences in Bolton ratio according to the groups of malocclusion patients were studied. Also the changes that can occur in overall ratio before and after hypothetical tooth extractions were observed. The results are as follows. 1. The mean anterior ratio of Korean malocclusion patients was $78.0\;{\pm}\;2.69%$, and the mean overall ratio was $91.56\;{\pm}\;2.28%$. 2. The largest value of tooth size ratio could be found in Class III group, followed by Class I and Class II groups in order. However there was no statically significant difference. 3. The values of overall ratio reduced significantly after premolar extractions in all malocclusion groups, which was much more significant in the extraction of upper second premolar and lower first premolar(U5L4) or upper second premolar and lower second premolar(U5L5). 4. The values of overall ratio reduced significantly after premolar extractions in all 3 groups divided based on Bolton ratio, which was much more significant in the extraction of upper second premolar and lower first premolar(U5L4) or upper second premolar and lower second premolar(U5L5).

• 대한치과교정학회지
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• 제52권5호
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• pp.324-333
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• 2022

Objective: The aim of this study was 1) to investigate the prevalence and pattern of dental anomalies (DAs), 2) to compare DAs according to the type of malocclusion, and 3) to investigate the correlation between tooth impaction and other DAs in the Korean orthodontic population. Methods: A total of 3,240 orthodontic patients were classified as Class I, Class II, or Class III malocclusion groups. The presence and location of common DAs, including impaction, microdontia, agenesis, supernumerary tooth, transposition, and fusion, were identified by examining diagnostic records. Furthermore, samples were classified as Group 1 without impaction or Group 2 with impaction. The prevalence of other DAs concurrent with impaction was investigated and compared to Group 1. Results: Impaction was the most prevalent DA, followed by microdontia, agenesis, and supernumerary. Class I and Class III groups showed the same order of prevalence, but agenesis was more frequent than microdontia in the Class II group. The prevalence of the four DAs was lowest in the Class III group. Overall, 8.6% of patients were classified into Group 2. The incidence of DAs other than impaction and the prevalence of multiple concurrent DAs were significantly higher in Group 2. Impaction showed a significant relationship with supernumerary tooth, transposition, and fusion. Conclusions: The prevalence and pattern of DAs varied depending on the type of malocclusion. As there was a higher risk of other DAs in patients with impacted teeth, early detection of the impacted tooth and a detailed diagnosis of other possible DAs may be essential.

• 대한치과교정학회지
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• 제10권1호
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• pp.65-70
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• 1980

The purpose of this study was giving some helpful datas in analysing the degree of anteroposterior jaw disharmony with the 'Wits' appraisal. The cephalograms of 105 Korean adults with normal occlusion ranging from 17 to 20 years of age and 76 Koreans with various malocclusion ranging from 12 to 24 years of age were studied and analyzed statistically. The results were as follows; 1. The mean value of 'Wits' appraisal in normal occlusion group was -0.82mm in males and -0.17mm in females. 2. There was no significant difference between the males and females in normal occlusion group. 3, The mean value of 'Wits' appraisal in Angles class II malocclusion group was 2.67mm and higher than normal group. 4. The mean value of 'Wits' appraisal in Angles class III malocclusion group was -8.11 mm and lower than normal group.

• 대한치과교정학회지
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• 제23권3호
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• pp.391-403
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• 1993

For the purpose of investigating mesiodistal axial inclination of posterior teeth in normal occlusion group, open bite and deep bite group and investigating the correlationship between the axial inclination of posterior teeth and overbite of anterior teeth, a cephalometric study was performed on the subjects consisted of normal occlusion group(40), open bite group(71 : Angle's Class I, Class II, division 1 25, Class III 25) and deep bite group(64 : Angle's Class I 23, Class II, division 1 21, Class III 20). Mesiodistal axial inclination of posterior teeth to occlusal, mandibular and palatal plane were measured. The findings of this study were as follows : 1. Upper and lower posterior teeth were more mesially inclined to occlusal plane in open bite group than in deep bite group. 2. Lower posterior teeth were more mesially inclined in deep bite group than in open bite group in Angle's Class II, division 1 malocclusion but there were no significant differences in Angle's Class I and Class III malocclusion. 3. There was no significant correlationship between the axial inclination of posterior teeth to each plane and overbite of anterior teeth in open bite group. 4. There was a significant correlationship between the axial inclination of upeer and lower second premolar to occlusal plane and overbite of anterior teeth in Angle's Class I, Class II, division 1 and Class III malocclusion.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제38권3호
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• pp.139-144
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• 2012

This study was performed in order to evaluate the occurrence of temporomandibular joint disorder after surgical correction of skeletal class II malocclusion. Materials and Methods: This study included 21 patients who underwent orthognathic surgery for the correction of dentofacial deformities by a single surgeon at Mokdong Hospital, Ewha Womans University from 2000 to 2010. They underwent bilateral sagittal split ramus osteotomy for the treatment of undesirable mandibular advancement. The temporomandibular disorder (TMD) symptoms prior to surgery were recorded and the radiographic evaluation (panorama, bone scan, and magnetic resonance imaging [MRI]) of the post-surgery temporomandibular joint (TMJ) were assessed in order to evaluate condylar resorption, remodeling and disc displacement. The minimum follow-up period, including orthodontic treatment, was 12 months. Orthognathic procedures included 1-jaw surgery (n=8 patients) and 2-jaw surgery (n=13 patients). The monocortical plate was used for bilateral sagittal split ramus osteotomy fixation. Results: Among class II malocclusion patients with TMD symptom, clicking improved in 29.1%, and maximum mouth opening increased from $34.5{\pm}2.1$ mm to $37.2{\pm}3.5$ mm. The differences were not statistically significant, however. Radiographic changes in bone scan improved slightly based on the report by radiologist but not in TMJ dynamic MRI. Conclusion: No particular improvements were found in patients with joint sound only. Patients with limitation of mouth opening showed an increase in the degree of opening, but the difference was not statistically significant (P>0.05).

• 대한치과교정학회지
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• 제30권5호
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• pp.521-533
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• 2000

본 연구의 목적은 피개교합 양상에 따른 성인 I급 부정교합자의 골격적 특징과 수직부조화를 야기하는 치성 및 골격성 요인들을 분석하기 위한 것이다. 서울대학교 치과대학 교정학교실에 소장되어 있는 정상교합군 표본 중 40명을 정상교합군, 서울대학교병원 교정과에 내원하여 I급 부정교합으로 진단받은 성인 환자중 전치부 수직피개량이 -0.1mm 이하인 40명을 개방교합군, 4.0mm 이상인 40명을 과개교합군으로 선정하여 측모 두부 X-선 계측사진을 촬영하였다. 46개의 계측항목을 선정하고 SPSS program을 이용하여 각 군별 ANOVA, 판별분석, 다중회귀분석을 시행하여 다음과 같은 결론을 얻었다. 1. 주로 하악골 형태와 하안면부의 치성, 골격성 요인이 수직부조화의 양상에 많은 영향을 끼쳤다. 2. 개방교합군의 수직부조화 양상은 하안면부에서 두드러지게 나타났으며 하악골 형태와 하악하연평면 경사도와 관련이 있었고, 판별분석 결과 골격적 요인의 기여도가 높았다. 3. 과개교합자의 수직부조화에는 주로 curve of Spee, 상악구치의 수직고경 등 치성 요인들의 기여도가 높았으며, 골격적 요인으로는 articular angle의 기여도가 높았다. 4. 다중회귀분석 결과 I급 구치관계를 갖는 성인에서 overbite의 결정요인에는 주로 하악전치와 교합평면각, curve of Spee, 절치간 각도 등의 치성요인이 기여하였다.

• 대한치과교정학회지
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• 제38권5호
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• pp.358-370
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• 2008

골격성 III급 부정교합자는 교정치료와 악교정 수술을 병행하여 치료하는 경우가 많아 골격형태에 대한 정확한 파악과 이해가 필수적이다. 이에 본 연구는 골격성 III급 부정교합자와 정상교합자 간의 골격 형태의 차이를 밝히고자 시행되었다. 실험군으로는 단국대학교 교정과에서 골격성 III급 부정교합으로 진단되어 술 전 교정치료를 받기로 예정된 총 20명을 선정하였고, 대조군으로는 골격성 I급 정상교합군으로 I급 교합관계를 보이며, 교정치료와 보철치료의 경험이 없는 정상 교합자 10명을 선정하여 CT촬영을 시행한 후 3차원 입체영상을 제작, 분석하여 상, 하악 기저골을 횡적으로 비교하여 다음과 같은 결론을 얻었다. 골격성 III급 부정교합자군의 특징을 살펴보면, 상악 기저골의 폭경이 유의성 있게 더 작았고, A point에서 ANS로 갈수록 제1소구치 부위에서 유의하게 폭이 감소하였으며, 제2소구치 부위에서 폭의 증가량이 유의하게 작았다. 하악 기저골은 B point, Antegonion 기준 횡단면에서 견치, 제1소구치 부위의 폭경이 유의성 있게 크게 나타났다. 상하악의 비교 시, 실험군의 견치부, 제1소구치부, 제2소구치부에서 하악에 비해 상악의 폭경이 유의성 있게 작음을 보였다.