• 대한치과보철학회지
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• 제28권1호
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• pp.43-61
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• 1990

The laser reflexion method is a new technique which permits precise contactless measurement and observation of tooth mobility as well as tooth movement. The purposes of this study were to clarify the reliability of the laser reflexion method in clinical application and to measure the abutment tooth movement according to clasp design. This study was designed to determine 1) How much a bending movement of the impression plate stand affects the position of the reflexion pattern and how precise the patient bites into plate 2) Which clasp design causes greater movement of the abutment tooth. Under medium and maximum bite forces, tests were performed on central loading position which was 13mm distal to terminal abutment tooth of distal extension removable partial denture. The movement in the mesiodistal and buccolingual directions was measured. The Duncan's New Multiple-Range test was used to compare the means for the four castings under each direction-load combination; and the paired sample t-test was for medium and maximum bite forces. From this experiment, the following results were obtained. 1. The Roach clasp, the combination clasp, the RPI clasp, and the Akers clasp did not significantly differ in their effects on buccolingual movement of the abutment tooth. 2. The direction of abutment tooth movement was not significantly altered by clasp design and all abutment tooth movements were oriented distobuccally. 3. Under medium bite force, the Akers clasp caused greater distal movement of the abutment tooth than did the combination clasp and the RPI clasp. Under maximum bite force, the Akers clasp caused greater distal movement of the abutment tooth than did the RPI clasp. 4. The testing apparatus and procedures used in this study(laser reflexion method) proved to be reliable in clinical application.

• 대한치과교정학회지
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• 제49권6호
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• pp.372-380
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• 2019

Objective: To determine the effects of a local injection of leukocyte-platelet-rich plasma (L-PRP) on orthodontic tooth movement in rabbits. Methods: Twenty-three male New Zealand white rabbits were included in a split-mouth design. Tooth movement with a 100-g nickel-titanium closed-coil spring was performed on the maxillary first premolars. L-PRP was injected submucosally at the buccal and lingual areas of the first premolar in one random side of the maxilla and the other side served as the control and received normal saline. The amount of tooth movement was assessed on three-dimensional digital models on days 0, 3, 7, 14, 21, and 28. Histological findings and osteoclast numbers were examined on day 0 as the baseline and on days 7, 14, and 28. Results: The L-PRP group showed significantly greater cumulative tooth movement at all observed periods. However, a significantly higher rate of tooth movement was observed only on days 0-7 and 7-14. The osteoclast numbers were significantly increased in the L-PRP group on days 7 and 14. Conclusions: Local injection of L-PRP resulted in a transient increase in the rate of tooth movement and higher osteoclast numbers.

• 대한치과교정학회지
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• 제24권3호
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• pp.721-733
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• 1994

Orthodontic tooth movement is closely related to the stress on the periodontal tissue. In this research the finite element method was used to observe the stress distribution and to find the best condition for effective tooth movement in the case of unilateral molar expansion. The author constructed the model of lower dental arch of average Korean adult and used $.032'\times.032'\times60mm$ TMA wire. The wire was deflected in the horizontal and vertical direction to give the 16 conditions. The following results were obtained ; 1. When the moment and force were controlled properly the movement of anchor tooth was minimized and the movement of moving tooth was maximized. 2. As the initial horizontal deflection increased the buccal displacement of both teeth was also increased. As the initial horizontal deflection increased the lingual movement of anchor tooth and the buccal movement of moving tooth increased. 3. When the initial horizontal and vertical deflection rate was 1.5 the effective movement of moving tooth was observed with minimal displacement of anchor tooth.

• 대한치과교정학회지
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• 제33권5호
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• pp.399-405
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• 2003

빠르며 정확하고 안전한 치아이동을 목표로 삼고 있는 교정치료에서 새로운 패러다임이라고 여겨지는 피질골 절제술과 견인 골형성술을 응용한 치아이동에 대하여 알아보았다. 일반적인 방법으로는 어렵거나 불가능하다고 여겨지는 치아의 함입 이동을 피질골 절제술과 견인 골형성술을 응용하여 도모하였다. 전치군 및 구치군 각각의 함입 이동 증례를 통해 피질골 절제술과 견인 골형성술의 적용 술식, 견인장치 등을 논하고 그 효과를 파악하였다. 빠른 치아이동과 이에 따른 교정치료 기간의 감소가 가능하고 기존의 교정치료로는 어려웠던 치아이동을 도모할 수 있었으며 무리한 치아이동 시 발생할 수 있는 치근 흡수나 치주조직의 파괴 같은 부작용도 줄일 수 있었다.

• 대한치과기공학회지
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• 제8권1호
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• pp.85-90
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• 1986

The effect of splinting on aqbutment tooth distal movement was performed in vitro study. An acrylic resin mandibular model with missing 2nd premolars, molars and a removable partial denture framework were constructed. The roots of the canines, 1st premolars and edentulous ridges were coated with silicone rubber. A modified Ney Surveyor was used for vertical load appkication, and abutment tooth distal movement were measured with a dial gauge with four conditions of splinting methods were tested by applying unilateral vertical loadings. The results are follows; 1. The magnitude of abutment tooth distal movement on the non-load side was less 40$\sim$69% than that occurred on the load side. 2. On the load side, reducing effect of splinting on abutment tooth movement in the condition of load side double abutment(30%), non-load side double abutment(10%), double abutments of both sides(40%) was compared with single abutments of both sides. 3. On the non-load side, reducing effect of splinting on abutment tooth movement in the condition of load side double abutment(5%), non-load side double abutment(22%), double abutments of both sides(59%) was compared with single abutments of both sides. 4. The magnitude of abutment tooth distal movement in the condition of double abutments of both sides was less 40$\sim$59% than that in the condition of single abutments of both sides.

• Journal of Korean Dental Science
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• 제16권2호
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• pp.182-191
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• 2023

Purpose: This study investigated the orthodontic tooth movement after weekly parathyroid hormone (PTH) injection in mongrel dogs and analyzes bone formation activity on the tension and pressure sides of the tooth movement in mongrel dogs. Materials and Methods: Three mongrel dogs were used in this study. The first premolar was extracted and orthodontic force using 150 g of closed coil springs between the canine and second premolar was applied. The low-dose PTH group (PTH_1) and high-dose PTH group (PTH_2) received weekly injections of 1.61 ㎍/kg and 3.23 ㎍/kg of PTH, respectively. The control group received weekly injections of 1 ml of saline. Clinical, histomorphometric analysis were carried out. Result: The orthodontic tooth movement was greatest in the PTH_2 group and the lowest in the control group. Fluorescence staining images showed higher bone remodeling on the tension side of the tooth movement in the PTH_1 and PTH_2 groups. PTH_2 group showed a thicker labeling band than the PTH_1 group. PTH_2 group showed the highest mineral apposition rate and bone formation rate, followed by the PTH_1 group and the control group. Conclusion: Weekly intermittent PTH injection, especially in the short-term and at higher doses with orthodontic force, successfully increased orthodontic tooth movement and bone remodeling in mongrel dogs.

• 대한치과교정학회지
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• 제48권3호
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• pp.200-211
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• 2018

The aim of this systematic review was to evaluate the effectiveness and complications of corticotomy and piezocision in canine retraction. Five electronic databases (PubMed, SCOPUS, Web of Science, Embase, and CENTRAL) were searched for articles published up to July 2017. The databases were searched for randomized control trials (RCTs), with a split-mouth design, using either corticotomy or piezocision. The primary outcome reported for canine retraction was either the amount of tooth movement, rate of tooth movement, or treatment time. The secondary outcome was complications. The selection process was based on the PRISMA guidelines. A risk of bias assessment was also performed. Our search retrieved 530 abstracts. However, only five RCTs were finally included. Corticotomy showed a more significant (i.e., 2 to 4 times faster) increase in the rate of tooth movement than did the conventional method. For piezocision, both accumulative tooth movement and rate of tooth movement were twice faster than those of the conventional method. Corticotomy (with a flap design avoiding marginal bone incision) or flapless piezocision procedures were not detrimental to periodontal health. Nevertheless, piezocision resulted in higher levels of patient satisfaction. The main limitation of this study was the limited number of primary research publications on both techniques. For canine retraction into the immediate premolar extraction site, the rate of canine movement after piezocision was almost comparable to that of corticotomy with only buccal flap elevation.

• 대한치과교정학회지
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• 제30권4호
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• pp.413-421
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• 2000

임신중 전신의 호르몬 변화는 골대사과정에 영향을 주고 임신 중에는 골교체가 증가하며, 교정력에 의한 치아이동에는 치조골 교체가 수반된다고 알려져 있다. 이 연구는 임신으로 인한 전신의 호르몬 변화가 치아이동 중 치조골 교체에 주는 영향을 알아보기 위하여 시행되었다. 생후 10주령의 암컷 백서 60마리를 대상으로 정상군과 정상-치아이동군, 임신-치아이동군의 3군으로 나누고 치아이동일수에 따라 1,3,7,14일군으로 세분한 후 상악 제1대구치 에 40g의 교정력을 가하여 근심측으로 치아이동을 시행하였다. 치아이동 전후에 촬영한 X-ray사진을 계측하여 치아이동 거리를 비교하고 치조골에서의 alkaline phosphatase, tartrate-resistant acid phosphatase 농도를 측정하여 치아이동에 따른 골형성과 흡수 활성을 비교하여 다음과 같은 결과를 얻었다. 1. 치아이동량은 임신-치아이동군이 정상-치아이동군에 비하여 더 크게 나타났다(p<0.01). 2. 정상-치아이동군의 치아이동에 따른 골형성은 대조군과 차이가 없었지만 골흡수 경향은 증가되었고(p<0.01), 정상-치아이동군에서는 대조군에 비하여 치조골의 형성과 흡수 활성이 모두 치아이동 7일에 가장 크게 증가하였고 (p<0.01) 이후 골형성 활성은 감소하였지만(p<0.05) 골흡수 활성은 대조군보다 높게 유지되었다(p<0.01). 3. 임신군과 정상군의 치아이동에 따른 골형성과 흡수 경향에는 차이가 없었지만, 임신-치아이동군의 치조골 형성 (p<0.01)과 흡수(p<0.05) 활성의 증가는 3일경에 가장 높게 나타났으며, 이후 골형성 활성은 감소하였으나 골흡수 활성은 높게 유지되었고, 정상-치아이동군은 7일경에 치조골 형성과 흡수 활성의 증가가 나타났다. 임신중의 치아이동량이 정상 치아이동에 비하여 크게 나타났으며, 치조골 흡수와 형성 활성의 증가가 빠르게 나타났고 치조골 흡수가 더 오랬동안 지속되어 빠른 치조골 교체를 보이므로 임신상태에서 치 아이동은 정상상태보다 촉진될 가능성이 있음을 시사한다.

• Journal of Korean Dental Science
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• 제5권1호
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• pp.37-44
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• 2012

Purpose: Among the facilitation of tooth movement in adult orthodontic treatment methods, surgical approaches are gaining popularity but complications following mechanical bone reduction are a problem. In this study, tooth movement was observed after alveolar bone was chemically demineralized to verify whether tooth movement had been facilitated. Materials and Methods: Twelve rabbits were used. In the experimental group, the alveolar bone of the left first molar area was exposed and demineralized. Thirty seven percents phosphoric acid was applied for 5 minutes for demineralization. The opposite first molar area was used as control. Two teeth were pulled with 200 g force and 4 rabbits each were sacrificed at 3, 7, and 14 days after the force was applied. Histologic examination was done with hematoxylin and eosin and tartrate-resistant acid phosphatase staining. Result: The histologic examination results revealed more bone resorption in the demineralized area. As time passed, the number of osteoclasts increased in the compressed area. The amount of tooth movement was larger in the experimental group compared to the control group but the difference was not statistically significant. Conclusion: The demineralization with etchant resulted in limited bone resorption, more tooth movement and less damage of the cementum after applied orthodontic force.

• 대한치과교정학회지
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• 제48권6호
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• pp.405-411
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• 2018

Objective: This study was performed to investigate the rate of tooth movement and histological characteristics of extraction sockets those were subjected to corticotomy. Methods: A split-mouth randomized controlled trial experiment was designed. Thirty-two adult, male Wistar rats were divided into 2 groups: healing extraction socket (H) and recent extraction socket (R); these groups were randomly classified into 4 subgroups (0/7/21/60 days). The first maxillary molar was extracted on 1 side and 2 months were allowed for complete bone healing; then, the corresponding molar was extracted on the other side and surgical intervention was performed at the mid-alveolar point of the first maxillary molar. Ten grams of continuous force was applied. The outcomes measured were rate of tooth movement, percentage of periodontal space and histological evaluation. The rate of tooth movement was calculated as the measured distance divided by the duration of molar movement. Histomorphometric evaluations were performed on the second and third maxillary molars. The Wilcoxon signed rank test was used to compare differences between the two groups. Results: There were no significant differences in the rates of tooth movement between H and R groups at any of the 4 time points. The histological appearance and percentage of periodontal space between the R and H groups also demonstrated no significant differences. Conclusions: The rates of orthodontic tooth movement into recent and healed socket sites did not differ between the groups. Histological analysis of tooth movement revealed regional acceleration during every time period.