• 대한치과교정학회지
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• 제30권1호
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• pp.9-17
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• 2000

본 연구는 발치 후 인접치 이동을 위한 교정력 적용 시 적용 시기에 따른 치아이동 양상을 비교$\cdot$분석하기 위하여 시행되었다. 성견을 실험대상으로 상악 좌우 제 3절치를 3주 간격으로 각각 발거 하고, 양 견치 를 고정 원으로 제 2절치의 치체이동을 위한 장치를 장착하였다. 100 gm의 지속적인 힘을 내는 견인 스프링을 사용하여 발치 후 4주와 1주부터 좌우 제 2절치를 각각 12주간 동시에 견인하였다. 2주 간격으로 디지털 캘리퍼스를 이용하여 이동거리를 측정$\cdot$비교하고 실험에 사용된 좌우 제 2절치의 조직소견을 관찰하여 다음과 같은 결론을 얻었다. 1. 교정력 적용 후 처음 2주간에는 발치 후 4주에 견인한 치아가, 그 다음 2주간에는 발치 후 1주에 견인한 치아가 빠르게 이동하는 양상을 보였다. 2. 12주간의 실험기간 동안 견인 4주와 6주 사이에 가장 빠르게 이동하는 경향을, 이 후에는 이동 속도가 감소하는 양상을 보였다. 3. 실험기간 동안 이동한 전체 거리는 발치 후 4주에 비해 1주에 견인한 경우에서 크게 나타나는 경향을 보였다. 4. 발치 후 4주에 견인한 경우에 비하여 1주에 견인한 경우에서 유해한 조직소견이 나타나지 않았다. 이상의 결과는 발치 후 교정력 부여 시 조기 적용이 유리함을 시사하였다.

• 대한치과교정학회지
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• 제42권3호
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• pp.118-128
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• 2012

Objective: The aim of this study was to investigate and compare the in vivo effects of prostaglandin E2 (PGE2) administered by different methods on orthodontic tooth movement and bone metabolism macroscopically, histopatologically, and biochemically. Methods: Forty-five young adult New Zealand rabbits were randomly divided into 3 experimental groups (n = 10/group), 1 positive control group (n = 10), and 1 negative control group (n = 5). The experimental rabbits were fitted with springs exerting 20-g reciprocal force on the maxillary incisors and PGE2 (10 ${\mu}g/mL$) was administered by the intravenous, submucosal, or intra ligamentous route aft er appliance insertion and on days 1, 3, 7, and 14 thereafter. All rabbits were sacrificed on day 21 and their premaxillae were resected for histologic evaluation. Results: Tooth movement was observed in the experimental and positive control groups, but the intraligamentous PGE2 group had the highest values of all analyzed parameters, including serum calcium and phosphorus levels and osteoclastic and osteoblastic populations (p < 0.001). Conclusions: Sub mucosal and intraligamentous PGE2 administration significantly increases orthodontic tooth movement and bone metabolism, but the intraligamentous route seems to be more effective.

• 대한소아치과학회지
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• 제37권2호
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• pp.202-206
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• 2010

치아 맹출 속도는 여러가지 국소적 및 전신적 요소에 의해 영향을 받는다. 그 중 갑상선 호르몬은 치아 맹출 속도와 비례적인 관계를 갖는 것으로 알려져 있다. 갑상선 호르몬은 기초 대사율을 조절하는데 있어서 중요한 역할을 하며, 치과 영역과 관련하여 치아 맹출 속도에 영향을 줄 수 있다. 본 증례에서 만 11세 여아의 매복된 상악 견치의 교정적 견인 시 특정 시점에서 교정적 치아 이동이 빠르게 진행되었고, 이는 갑상선 기능 항진증이 나타난 시기와 일치하였다. 이는 혈청 갑상선 호르몬 수치와 교정적 치아 이동 속도 사이의 연관성을 시사한다.

• 대한치과교정학회지
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• 제24권3호
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• pp.673-693
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• 1994

Most adults, unlike growing children, have some periodontal problems which can influence the outcome of the orthodontic treatment. In cases where periodontal disease progression resulted in marked reduction of periodontium, orthodontic treatment could result in the worsening of the periodontal conditions, and therefore orthodontic treatment planning in such adult patients requires special considerations for the periodontal problems. This study investigates the effects of horizontal orthodontic tooth movement on the changes in the mesial, distal and furcation areas of the disease affected periodontium of adult dogs with advanced bone loss. Six adult dogs with healthy periodontium were selected, and mandibular 2nd premolars were extracted. In the mandibular 3rd premolars, angular bony defects in the mesial and distal sides, and horizontal bony defects in the furcation areas were created. Those that received the flap operation and plaque control were designated as the control, those that had horizontal tooth movement without plaque control after the flap operation as Experimental group I, those that had horizontal tooth movement under plaque control without the flap operation as Experimental group II, and those that had horizontal tooth movement under plaque control after the flap operation as Experimental group III. The control group was sacrificed 2 months postoperatively, and the experimental groups were sacrificed 5 months after the initiation of tooth movement. Specimens were histologically analyzed under light microscope. The results were as follows; 1. After the horizontal tooth movements, Experimental group I and II showed angular bony defects in the mesial sides of the roots and the distal side of the furcation areas, which correspond to the pressure sides. 2. After the horizontal tooth movements, Experimental group I and II showed decreased level of alveolar bone crest in the distal sides of the roots, which correspond to the tension sides. 3. Long junctional epithelium in the control group has not been replaced by periodontal connective tissue after the horizontal tooth movements. 4. Limited formation of new bone was observed in the angular bony defects in the mesial and distal aspects of the roots in the control group. 5. Inflammatory cell infiltration in the connective tissue was most severe in the Experimental group I, followed by Experimental group II, III, and the control group in that order. These results seem to indicate that plaque control was the most influencing factor in the alteration of the periodontal tissue after the horizontal tooth movements in the periodontal tissue with alveolar bone defects.

• 대한치과교정학회지
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• 제46권4호
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• pp.228-241
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• 2016

Objective: Root mobility due to reciprocating movement of the tooth (jiggling) may exacerbate orthodontic root resorption (ORR). "Jiggling" describes mesiodistal or buccolingual movement of the roots of the teeth during orthodontic treatment. In the present study, buccolingual movement is described as "jiggling." We aimed to investigate the relationship between ORR and jiggling and to test for positive cell expression in odontoclasts in resorbed roots during experimental tooth movement (jiggling) in vivo. Methods: Male Wistar rats were divided into control, heavy force (HF), optimal force (OF), and jiggling force (JF) groups. The expression levels of cathepsin K, matrix metalloproteinase (MMP)-9 protein, interleukin (IL)-6, cytokine-induced neutrophil chemoattractant 1 (CINC-1; an IL-8-related protein in rodents), receptor activator of nuclear factor ${\kappa}B$ ligand (RANKL), and osteoprotegerin protein in the dental root were determined using immunohistochemistry. Results: On day 21, a greater number of root resorption lacunae, which contained multinucleated odontoclasts, were observed in the palatal roots of rats in the JF group than in rats from other groups. Furthermore, there was a significant increase in the numbers of cathepsin K-positive and MMP-9-positive odontoclasts in the JF group on day 21. Immunoreactivities for IL-6, CINC-1, and RANKL were stronger in resorbed roots exposed to jiggling than in the other groups on day 21. Negative reactivity was observed in the controls. Conclusions: These results suggest that jiggling may induce ORR via inflammatory cytokine production during orthodontic tooth movement, and that jiggling may be a risk factor for ORR.

• 대한치과교정학회지
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• 제44권6호
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• pp.320-329
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• 2014

Objective: To investigate the involvement of ephrinB2 in periodontal tissue remodeling in compression areas during orthodontic tooth movement and the effects of compressive force on EphB4 and ephrinB2 expression in osteoblasts and osteoclasts. Methods: A rat model of experimental tooth movement was established to examine the histological changes and the localization of ephrinB2 in compressed periodontal tissues during experimental tooth movement. RAW264.7 cells and ST2 cells, used as precursor cells of osteoclasts and osteoblasts, respectively, were subjected to compressive force in vitro. The gene expression of EphB4 and ephrinB2, as well as bone-associated factors including Runx2, Sp7, NFATc1, and calcitonin receptor, were examined by quantitative real-time polymerase chain reaction (PCR). Results: Histological examination of the compression areas of alveolar bone from experimental rats showed that osteoclastogenic activities were promoted while osteogenic activities were inhibited. Immunohistochemistry revealed that ephrinB2 was strongly expressed in osteoclasts in these areas. Quantitative real-time PCR showed that mRNA levels of NFATc1, calcitonin receptor, and ephrinB2 were increased significantly in compressed RAW264.7 cells, and the expression of ephrinB2, EphB4, Sp7, and Runx2 was decreased significantly in compressed ST2 cells. Conclusions: Our results indicate that compressive force can regulate EphB4 and ephrinB2 expression in osteoblasts and osteoclasts, which might contribute to alveolar bone resorption in compression areas during orthodontic tooth movement.

• 대한치과교정학회지
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• 제48권4호
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• pp.262-267
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• 2018

The aim of this study was to test the clinical application of an intraoral scanner for serial evaluation of orthodontic tooth movement. The maxillary dentitions of eight patients with fixed orthodontic appliances were scanned using an intraoral scanner at the beginning of treatment (T0), and at 1 month (T1), 2 months (T2), 3 months (T3), and 4 months (T4) after T0. The serial digital models were superimposed on the palatal surface as a reference area, and the linear and angular changes of the central incisors, canines, and first molars were evaluated. The intraclass correlation coefficient and method errors showed that this method was clinically acceptable. Various types of orthodontic tooth movements, including minute movements, could be observed every month. The intraoral scanner and digital superimposition technique enabled the serial evaluation of orthodontic tooth movement without taking serial impressions and/or acquiring radiographs.

• Journal of Korean Dental Science
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• 제16권2호
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• pp.115-127
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• 2023

The demand for orthodontic clear aligner therapy (CAT) has increased significantly over the last decade, offering advantages over the fixed appliances (FA) including enhanced aesthetics, better hygiene and comfort, along with minimal restrictions on the patient's diet. Moreover, a marked improvement in the efficacy of tooth movement using aligners has been documented. On the contrary, there have been known limitations of CAT including the compliances issues and the apparent lack of efficacy for certain types of tooth movement such as closure of extraction space compared to FA. Thus, evidence-based evaluation of the accuracy of prediction of tooth movement with clear aligners and their ability to effectively perform major tooth and root movements compared to FA are crucial. Although several systematic reviews have investigated various aspects of the effectiveness of CAT, we are yet to obtain a rather conclusive answer to this question. The current review attempted to summarize the evidence-based findings of most systematic reviews about CAT available to date. Major issues regarding the predictability of tooth movement, the role of attachments and auxiliaries in improving the effectiveness of CAT, and the treatment outcomes in comparison to FA were investigated. Clinical recommendation have been also elaborated based on the interpretation of the findings of all systematic reviews included in this study.

• 대한치과교정학회지
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• 제13권2호
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• pp.165-176
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• 1983

The hyalinized zone in compressed periodontal ligament seems to be an unavoidable aspect during certain phases of orthodontically produced tooth movement. And these hyalinized zones leads to a standstill of tooth movement. But when hyalinized zones disappears after a certain period of time and tooth movement is established. In the basic aspect of clinical science of orthodontics, it is very important, to study about the process involved and to establish whether a difference of periodontal response by the amount of the applied experimental force exists. The 35 Guineapigs were divided into the control group (5 animals) and the experimental group (Group I-Group VI 30 animals). The experimental tooth movement of Guineapig's maxillary incisors were carried out by rendering continuous force, 5g (Group I, Group II) 35g (Group III, Group IV), 100g (Group V, Group VI) respectively. 15 animals (Group I, Group III, Group V) were sacrificed one week after this experiment. Another 15 animals (Group II, Group IV, Group VI) were sacrificed one week after the removal of active appliences. At the end of the experimental periods, specimens containing tooth and adjacent periodontal structure were obtained and processed for light and electron microscopy. The results were as follows: 1. In Group I, cellular changes of pressured zones showed swollen mitochondria, dilation of rough surfaced endoplasmic reticulum (RER), vesicles and pyknosis of nucleus. 2. In Group III and Group V, the hyalinized tissues showed cell necrosis accompaning ruptures of cytoplasmic membrane and perinuclear envelope, large cytoplasmic vacuoles and many necrotic cell debris. 3. In Group IV and Group VI, hyalinized tissue were eliminated and the primitive mesenchymal cells and blood capillaries were proliferated. 4. In group V, the destruction of the collagenous fibers were observed, while in group I and group III were not observed. 5. In Croup IV and Group VI, the hyalinized zones were still remained partly.

• 대한치과교정학회지
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• 제31권1호
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• pp.97-105
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• 2001

교정 치료 시 많은 경우 상악 전치부를 상당량 견인하게 되며 이 때 치아의 이동량과 전방 피질골의 개조량이 동일하게 일어나지 않는다면 치주적인 문제가 발생할 수 있게 된다. 이에 본 연구에서는 상악 전치가 후방 견인될 때 치아의 이동량과 피질골의 개조량의 관계를 알아보기 위하여 성장이 완료된 만 18세 이상의 성인 여자환자 56명을 대상으로 치료 전후의 측모두부 방사선 사진을 계측하였다. 연구대상 56명은 전치의 후방견인 시 경사이동이 주로 일어난 환자(26명 )와 치체 이동이 동반된 환자(30명)로 나누었으며 치료 전후의 측모두부방사선 사진을 true horizontal plane 을 기준으로 하여 중첩하였다. Tip-Group(경사이동된 군)에서는 수평적인 bone remodeling/tooth movement ratio가 1:1.63, Torque-Group(치체 이동이 동반된 군)에서는 1:1.66이었다. 두 군 모두에서 치아의 이동량과 골의 개조량이 동일하지 않았기 때문에 경사 이동 시에는 치근첨이 구개측피질골판에서 멀어지고 순측피질골판에 가까워지며, 치체이동이 동반된 군에서는 치근이 순측피질골판에서는 멀어지고 구개측피질골판에 접근하게 된다. 따라서 상악의 전방 피질골의 두께가 매우 얇은 환자에서는 상악 전치의 후방견인량에 제한이 있게 되며 골격적 부조화가 심한 경우에는 악교정수술을 동반한 치료를 고려하고, 교정적 절충치료가 필요한 경우 술자는 그 치료한계를 명확히 인식해야할 것이다.