• 대한치과교정학회지
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• 제23권4호
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• pp.619-631
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• 1993

Tooth movement by segment is one of the means which are frequently used in daily orthodontic practice. When we retract or intrude a tooth or teeth, we should recognize the center of resistance of the certain tooth or teeth. There have been many studies about the center of resistance of a single tooth, not so much was about the tooth-segment. At the present study the center of resistance of the maxillary anterior segment is experimentally investigated by using laser reflection technique and metal splints on the human dry skull. The variables of intrusive force magnitude are divided into two groups, 50g and 100g groups. The results were as follows ; 1. The center of resistance of the maxillary anterior segment composed of the central and lateral incisors was at the mesial portion of canine crown at the coronal level. 2. The center of resistance of the maxillary anterior segment composed of the central and lateral incisors and canines is between the canine and the 1st premolar crowns at the coronal level.

• 대한치과의사협회지
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• 제16권1호통권104호
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• pp.37-42
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• 1978

A study on the impacted teeth of the anterior segment was carried out. The data for this study were compiled form 1739 outpatients of the Department of Orthodontics, College of Dentistry, Seoul National University. The following conclusions were obtained; 1. The frequency of the impacted teeth of the anterior segment was 2.8% and the frequency of male was 4.0%, that of female was 2.1%., respectively. 2. The order of occurrence of the impacted teeth in the anterior segment was maxillary canine mesiodens, maxillary central incisor, maxillary lateral incisor, mandibular canine. 3. The etiologic factors of the impaction were the space deficiency for eruption, cleft palate, the prolonged retention of deciduous teeth, dentigerous cyst. 4. The favorable results of treatment and prognosis were obtained from the impacted teeth of the normal shape after surgical exposure and adhered the plastic attachment and inducted them into the dental arch.

• 대한구순구개열학회지
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• 제15권2호
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• pp.89-96
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• 2012

Le Fort 1 osteotomy or maxillary advancement with distraction osteogenesis (DO) is main treatment strategy for cleft palate patients with maxillary hypoplasia. Maxillary DO allows greater maxillary advancement within physiological limit than Le Fort 1 osteotomy. Moreover, it is better for velopharyngeal function. However, there is a greater tendency for an increase in nasal sound when maxilla is advanced excessively. Therefore, the advancement of anterior maxillary segment using DO has been utilized. It offers advantages such as an increase in the length of the palate, a prevention of the change in palatopharyngeal depth, and a preservation of the velopharyngeal function. Moreover, it will obliterate the necessity of bone graft, and it prevents the occurrence of oronasal or oroantral fistula. Finally, it stimulates the regeneration of the soft and hard tissue of alveolus, and subsequently makes possible to place implant.

• 대한치과교정학회지
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• 제31권3호
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• pp.347-355
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• 2001

상하악 전치부 치열은 치아의 형태 변위, 선천결손 등에 의해 종종 교합관계나 심미성에 문제점을 나타내게 된다. 이러한 문제점을 극복하기 위해 임상의는 전치부 비율을 진단시 이용하게 되나, 치열궁 형태, 견치간 폭경(intercanine width), 치열궁 장경(segment depth)과 치열궁 둘레(arch perimeter)에 따른 전치부 비율의 변화로 인해 이러한 비율을 전치부 교합관계 예측에 직접 적용하는데는 한계가 있다. 이에 본 연구에서는 한국성인 정상교합자 모델(남자:20쌍, 여자:20쌍)에서 상하악 전치부 치열궁 형태를 least square method로 조사하였다. 한국인 정상교합자의 상하악 전치부 치열궁 형태는 다항 함수(polynomial function), 베타 함수(beta function), 하이퍼볼릭 코사인 함수(hyperbolic cosine function) 순으로 곡선 접합(curve fitting)하였으며, 이러한 곡선 접합도는 남녀, 상하악에 관계없이 일정하였다. 또한 곡선접합(curve fitting)된 치열궁 형태를 바탕으로 견치간 폭경(intercanine width), 치열궁 장경(segment depth)과 치열궁 둘레(arch perimeter)간의 상관관계를 구하였다. 이러한 상관관계는 견치간 폭경에 따른 치열궁 형태 예측과 보다 정확한 전치부 비율에 대한 정보를 제공할 것이다.

• 대한치과교정학회지
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• 제49권6호
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• pp.393-403
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• 2019

Objective: Sliding mechanics using orthodontic miniscrews is widely used to stabilize the anchorage during extraction space closure. However, previous studies have reported that both posterior segment displacement and anterior segment displacement are possible, depending on the mechanical properties of the archwire. The present study aimed to investigate the effect of archwire stiffness and friction change on the displacement pattern of the maxillary posterior segment during anterior segment retraction with orthodontic miniscrews in sliding mechanics. Methods: A three-dimensional finite element model was constructed. The retraction point was set at the archwire level between the lateral incisor and canine, and the orthodontic miniscrew was located at a height of 8 mm from the archwire between the second premolar and first molar. Archwire stiffness was simulated with rectangular stainless steel wires and a rigid body was used as a control. Various friction levels were set for the surface contact model. Displacement patterns for the posterior and anterior segments were compared between the conditions. Results: Both the anterior and posterior segments exhibited backward rotation, regardless of archwire stiffness or friction. Among the conditions tested in this study, the least undesirable rotation was found with low archwire stiffness and low friction. Conclusions: Posterior segment displacement may be unavoidable but reducing the stiffness and friction of the main archwire may minimize unwanted rotations during extraction space closure.

• 대한치과교정학회지
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• 제45권1호
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• pp.20-28
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• 2015

Objective: The purpose of this study was to observe stress distribution and displacement patterns of the entire maxillary arch with regard to distalizing force vectors applied from interdental miniscrews. Methods: A standard three-dimensional finite element model was constructed to simulate the maxillary teeth, periodontal ligament, and alveolar process. The displacement of each tooth was calculated on x, y, and z axes, and the von Mises stress distribution was visualized using color-coded scales. Results: A single distalizing force at the archwire level induced lingual inclination of the anterior segment, and slight intrusive distal tipping of the posterior segment. In contrast, force at the high level of the retraction hook resulted in lingual root movement of the anterior segment, and extrusive distal translation of the posterior segment. As the force application point was located posteriorly along the archwire, the likelihood of extrusive lingual inclination of the anterior segment increased, and the vertical component of the force led to intrusion and buccal tipping of the posterior segment. Rotation of the occlusal plane was dependent on the relationship between the line of force and the possible center of resistance of the entire arch. Conclusions: Displacement of the entire arch may be dictated by a direct relationship between the center of resistance of the whole arch and the line of action generated between the miniscrews and force application points at the archwire, which makes the total arch movement highly predictable.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제31권4호
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• pp.319-324
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• 2009

Kole's Anterior segmental osteotomy of the mandible is commonly used to close an anterior open bite, to depress an elevated anterior dentoalveolar segment, or to retrude or advance a dentoalveolar segment. The procedure is often combined with an anterior maxillary segmental osteotomy to correct bimaxillary protrusion. We report 53-year-old woman who the extruded state of mandibular anterior alveolar segment was corrected using an mandibular anterior alveolar segmental osteotomy and dental implantation of the anterior maxilla. We planned to remove the old prosthesis, and then perform an anterior mandibular segmental osteotomy and implant restoration of the anterior maxilla. We suggest that anterior segmental osteotomy is very useful for rehabilitating edentulous patients with malaligned alveolar segment.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제42권
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• pp.20.1-20.7
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• 2020

Background: Anterior open bite is a challenging malocclusion to correct orthodontic treatment. Anterior open bite associated with over-erupted posterior teeth and long lower facial height should be treated by reduction of posterior dimension for esthetic results. Although the possibility of orthodontic treatment of an anterior open bite has increased with the introduction of skeletal anchorage, there are still cases requiring surgery for various reasons. Case presentation: This case report covers an anterior open bite of a 25-year-old man successfully treated with the posterior maxillary segmental osteotomy (PMSO) and miniplates. After the pre-surgical orthodontic treatment, the PMSO between canines and first premolars was performed under local anesthesia and miniplates were placed on the zygomatic buttress. As a result of 28 months of treatment, an impaction amount of 3.5 mm was obtained in the maxillary posterior teeth, and the facial esthetics improved at rest and smile. Conclusion: The impaction of the posterior dentoalveolar segment using the PMSO can be a good treatment option in patients with anterior open bite showing long lower facial height.

• 대한치과교정학회지
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• 제12권1호
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• pp.37-43
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• 1982

The patient,20 year-old female, complained of anterior open bite. She had tongue thrusting habit and suffered from maxillary sinusitis since 12-years old. Cephalometric analysis revealed slightly forward relationship in maxilla, but normal in mandible. The anterior open bite was corrected through retraction and extrusion of anterior segment and mesial movement of posterior segment under multibanded system after extraction of 4-first premolars. After 2 years and 3 months, she gained ideal overbite, overjet and good interdigitation of buccal segment.

• 대한치과교정학회지
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• 제32권1호통권90호
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• pp.43-49
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• 2002

치아의 형태 이상, 선천결손 등에 의해 손상된 상하악 전치부 치열에서는 교정치료만으로는 적절한 기능 교합관계를 설정하지 못하는 경우가 많다. 치료후 상하악 전치부 치열에서 어떠한 치료가 필요할지를 미리 예측할 수 있다면 치료효율을 높일 수 있을 뿐 아니라, 타 분야와의 협진에도 보다 유리할 것이다. 이를 위해 이전의 연구에서는 한국인 정상 교합자를 이용한 견치간 폭경(intercanine width), 치열궁 장경(segment depth)과 치열궁 둘레(arch perimeter)간의 상관관계를 구했으며, 이번에는 이러한 관계를 이용한 컴퓨터 프로그램을 제작한 후 손상된 상하악 전치부 치열을 보이는 두 환자에게 이 프로그램을 치료 계획시 적용하여 보았다. 프로그램 적용 결과, 치료 계획시 필요한 변화량에 대한 정보와 각 변수간 변화(견치간 폭경, 치열궁 장경, 치열궁 둘레)에 따른 전치부 교합관계 변화를 보다 명확히 보여주었다. 추후 악안면 형태에 따른 전치부 치축변화와 치열궁 변화의 관계, 안정성 있는 견치간 폭경에 대한 정보를 제공한다면, 전치부에 대한 3차원 occlusogram의 제작이 가능할 것으로 기대된다.