• Journal of Korean Dental Science
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• 제2권2호
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• pp.18-23
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• 2009

Introduction : The purposes of this study were to analyze the differences between the anterior and posterior overjets using bracket slot points, and compare two methods of overjet calculation according to different reference points using clinical bracket points on three-dimensional digital models. Methods : A total of 35 normal occlusion models were scanned using a three-dimensional scanner (Orapix$^{(R)}$, Orapix Co., Ltd, Seoul, Korea) and then, virtual brackets (0.022" Slot MBT preadjusted brackets, 3 M Co.CA. USA) were placed on the digital models using virtual setup program (3Txer$^{(R)}$ ver. 1.9.6, Orapix co., Ltd). Archwire-like curves were designed to analyze labial and buccal overjet. Results : There were no statistically significance differences between the right and left overjet and between genders. The average overjet was found to be $1.67{\pm}0.85mm$ at the central incisor area, $2.16{\pm}0.88mm$ at the second premolar and $1.53{\pm}0.71mm$ at the first molar. Conclusion : It is recommended that overjet of individualized upper and lower arch to be 2.0mm at the anterior and posterior teeth.

• 대한치과교정학회지
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• 제13권1호
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• pp.15-30
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• 1983

This study was to investigate the effect of functional pressures of the tongue and lips on the incisor relationship. The incisor relationship was devided into two categories; one is vertical relationship which is subdevided into open bite, normal overbite and deep bite on the basis of overbite, and the other is anteroposterior relationship which is subdevided into cross bite, normal overjet and large overjet on the basis of overjet. The functional tongue and lip pressures exerted to incisors were measured with subminiature pressure sense from the 99 subjects, 19 of normal overbite and overjet, 26 of open bite, 18 of deep bite, 17 of cross bite and 19 of large overjet with age of 17-20, and cephalograms were taken from the same subjects. Functional pressures were analyzed and correlated to craniofacial veriables. The results of present investigation led to the following conclusions. 1. There were no differences in functional and maximum pressures by the tongue and lips exerted to maxillary incisors between normal occlusion, open bite, deep bite, cross bite and large overjet. 2. Significant differences in functional and maximum pressures by the tongue and lips exerted to mandibular incisors have been shown to exist between open bite and deep bite, but no differences between cross bite and large overjet. 3. Equilibrium between tongue pressures and lip pressures did not exist. 4. Significant differences in the ratio of upper functional and maximum pressures to lower pressures of the tongue and lips exerted to upper and lower incisors have been shown to exist between open bite and deep bite, and no differences between cross bite and large overjet. 5, There was significant correlation between functional and maximum pressures exerted to mandibular incisors and craniofacial variables, but not significant correlation between functional and maximum pressures exerted to maxillary incisors and craniofacial variables.

• The Journal of Advanced Prosthodontics
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• 제12권6호
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• pp.338-343
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• 2020

PURPOSE. The present study aimed to investigate the relationships between the crown form of the upper central incisor and their labial inclination, overbite, and overjet. MATERIALS AND METHODS. Maxillary and mandibular casts of 169 healthy dentitions were subjected to 3D dental scanning, and analyzed using CAD software. The crown forms were divided into tapered, square, and ovoid based on the mesiodistal dimensions at 20% of the crown height to that at 40%. The degree of labial inclination of the upper central incisor was defined as the angle between the occlusal plane and the line connecting the incisal edge and tooth cervix. The incisal edges of the right upper and lower central incisor that in contact with lines parallel to the occlusal plane were used to determine the overbite and overjet. One-way ANOVA was performed to compare the labial inclination, overbite, and overjet among the crown forms. RESULTS. The crown forms were classified into three types; crown forms with a 20%/40% dimension ratio of 1.00±0.01 were defined as square, >1.01 as tapered, and <0.99 as ovoid. The labial inclination degree was the greatest in tapered and the least in square. Both overbite and overjet in tapered and ovoid were higher than those in square. CONCLUSION. Upper central incisor crown forms were related to their labial inclination, overbite, and overjet. It was suggested that the labial inclination, overbite, and overjet should be taken into consideration for the prosthetic treatment or restoring the front teeth crowns.

• 대한치과교정학회지
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• 제13권2호
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• pp.185-192
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• 1983

The purpose of this study was to determine the mean value of overbite and overjet, and to find the correlation among overbite, overjet and relative maxillofacial structures using the data from orthodontic casts and cephalometric films of boys and girls aged from 9 to 18 years with normal occlusions. The results were obtained as follows: 1. Incisal overbite depth was decreased from Group I to Group III. 2. The highest value of correlation coefficient with incisal overbite was 0.368 of incisal angle. in Group III. 3. Overjet was not significantly correlated with the age and sex. 4. Ratio of mesiodistal diameters of upper and lower incisors was not significantly correlated with overbite and overjet.

• 대한치과의사협회지
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• 제13권10호
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• pp.929-933
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• 1975

A girl aged 15 years 6 months, had a class Ⅲ malocclusion characterized by severe maxillary anterior crowding and a retarded maxilla. Molar relationship was class Ⅲ on both sides, incisor overjet was - 2.9mm. and incisor overbite was 5.5mm. The patient underwent extraction of four first premolars and was trested with a multi-banded light force system. After 13 months, the patient gained a normal verbite-overjet relationship of anterior teeth and a class 1 molar relationship. Superimposition of pretreatment and posttreatment cephalograms upon the line SN registered at S showed backward downward rotation of the mandible.

• 대한치과교정학회지
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• 제44권5호
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• pp.268-277
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• 2014

A Brazilian girl aged 14 years and 9 months presented with a chief complaint of protrusive teeth. She had a convex facial profile, extreme overjet, deep bite, lack of passive lip seal, acute nasolabial angle, and retrognathic mandible. Intraorally, she showed maxillary diastemas, slight mandibular incisor crowding, a small maxillary arch, 13-mm overjet, and 4-mm overbite. After the diagnosis of severe Angle Class II division 1 malocclusion, a mandibular protraction appliance was placed to correct the Class II relationships and multiloop edgewise archwires were used for finishing. Follow-up examinations revealed an improved facial profile, normal overjet and overbite, and good intercuspation. The patient was satisfied with her occlusion, smile, and facial appearance. The excellent results suggest that orthodontic camouflage by using a mandibular protraction appliance in combination with the multiloop edgewise archwire technique is an effective option for correcting Class II malocclusions in patients who refuse orthognathic surgery.

• 대한치과교정학회지
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• 제47권1호
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• pp.31-38
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• 2017

Objective: This study aimed to quantitatively assess the relationship of smile esthetic variables with various types of malocclusion, and identify the cephalometric factors affecting smile measurements. Methods: This retrospective study included 106 patients who were treated with retention at the orthodontic department of Taipei Medical University Hospital. Hard-tissue variables were measured using lateral cephalographic tracings, and nine smile esthetic variables were measured using facial photographs. The patients were divided into three groups according to their overjet (< 0, 0-4, and > 4 mm). An analysis of variance was conducted to compare the pretreatment cephalometric variables and smile esthetic variables among the three groups. Multiple linear regression analysis was performed to identify the cephalometric factors affecting the smile measurements in each group. Results: Except the upper midline and buccal corridor ratio, all of the smile measurements differed significantly among the three groups before orthodontic treatment. Some of the smile characteristics were correlated with the cephalometric measurements in different types of malocclusion. The overjet was the major factor influencing the smile pattern in all three types of malocclusion. Conclusions: Smile characteristics differ between different types of malocclusion; the smile may be influenced by skeletal pattern, dental procumbency, or facial type. These findings indicate that establishment of an optimal horizontal anterior teeth relationship is the key to improving the smile characteristics in different types of malocclusion.

• 대한치과교정학회지
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• 제28권2호
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• pp.175-187
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• 1998

본 연구는 치료후 빈번한 재발로 인해 치료에 어려움을 겪는 III급 부정교합의 치료후 예후를 예측하는 데 도움을 주고자, 교정치료후 관찰기간동안 측모와 교합이 양호한 상태로 유지된 안정군(Stable group, n=12)과 그렇지 않고 재발의 경향을 보인 재발군(Relapse group, n=13)으로 나누고, 초진시 계측항목을 이용한 t-test, 상관분석 그리고 판별분석을 시행한 결과 다음과 같은 결론을 얻었다. 1. 상하악골의 전후방적인 위치와 관계를 나타내는 항목인 SNA, SNB, ANB, Angle of convexity 그리고 APDI에서 두 군간 통계학적으로 유의성 있는 차이를 보여주지 않아(p>0.05) 두 군간 전후방적 인 골격 형태에 있어서는 차이가 나지 않음을 알 수 있었다. 2. 교합평면의 경사도와 관련된 항목인 Wits, AB to Occlusal plane angle 그리고 Occlusal plane to Mandibular Plane angle에서 두 군간 통계학적으로 유의성 있는 차이를 보여(p<0.05)재발군의 교합평면이 안정군에 비해 전하방으로 많이 경사져 있음을 알 수 있었다. 3. 상하치열관계를 나타내는 항목인 Overjet에서 안정군이 재발군에 비해 절대치로 더 커(p<0.01) 전후방 골격부조화에 의한 것이 아닐 경우 치열의 전후방부조화가 클수록 치료후 예후가 좋음을 알 수 있었다. 4. 상관분석결과 Overjet과 Occlusal plane to Mandibular plane angle만이 통계학적으로 유의성 있는 상관관계를 보여 주었다(p<0.001, p<0.01). 5. 판별에 기여도가 높은 3항목 즉 Overjet, AB to Occlusal paine angle 그리고 Articular angle을 이용한 판별식을 도출하였으며, 이를 이용할 때 본 연구에 사용한 표본의 88%를 올바르게 판별할 수 있었다.

• 대한소아치과학회지
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• 제47권3호
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• pp.235-247
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• 2020

이 연구의 목적은 소아청소년에서의 2급 부정교합 치료에 사용되는 기능성 악교정 장치의 효과 및 치료 시기에 따른 효과를 평가하고자 하였다. 경희대학교 소아치과에 내원한 2급 부정교합환자 30명을 대상으로 하였으며 치료에 사용된 기능성 악교정 장치에 따라 군을 나누었다. 치료 시기에 따른 비교를 위하여 경추골 성숙도 방법을 이용하여 2개의 군으로 나누어졌다. 각 실험군은 치료 전(T0)과 치료 후(T1)의 측모두부방사선사진을 비교 분석하였다. 기능성 악교정 장치 중, Twin block과 Activator는 하악골의 길이(Co-Gn)와 하안모의 길이(ANS to Me)의 유의한 증가를 보였으며, overjet과 overbite의 유의한 감소를 보였다. 반면 Fränkel appliance를 이용한 환자에서는 상하악 간의 관계 및 overjet의 유의한 개선을 보였다. 최대성장기에 기능성 악교정 장치를 사용하였을 때 최대성장기 전에 사용한 것에 비하여 유의한 하악 길이의 증가, 상악과 하악간의 관계 개선, overjet의 감소, 하악 중절치의 순측 경사의 증가를 보였다. 이 연구를 통하여 2급 부정교합을 가진 소아청소년에서 기능성 악교정 장치의 효과를 검증하였으며, 최대성장기에 치료를 시행하는 것이 더 효과적인 것을 확인하였다.

• 대한치과의사협회지
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• 제11권6호
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• pp.387-399
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• 1973