• 제목/요약/키워드: retraction

검색결과 493건 처리시간 0.033초

The effect of different micro-osteoperforation depths on the rate of orthodontic tooth movement: A single-center, single-blind, randomized clinical trial

  • Ozkan, Tugba Haliloglu;Arici, Selim
    • 대한치과교정학회지
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    • 제51권3호
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    • pp.157-165
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    • 2021
  • Objective: This study aimed to identify the clinical effectiveness of two different penetration depths of micro-osteoperforations (MOPs) on the rate of orthodontic tooth movement. Methods: Twenty-four patients requiring the removal of the upper first premolar teeth were selected and randomly divided into two groups. The control group participants did not undergo MOPs. Participants in the experimental group underwent three MOPs each at 4-mm (MOP-4) and 7-mm (MOP-7) depths, which were randomly and equally performed to either the left or right side distal to the canine. The retraction amount was measured on three-dimensional digital models on the 28th day of retraction. MOP-related pain was measured using a visual analog scale (VAS). Between-group statistical differences in the VAS scores were determined using an independent t-test and those in canine retraction were determined using analysis of variance and post-hoc Tukey test. Results: No significant difference was found between the MOP-4 (1.22 ± 0.29 mm/month) and MOP-7 (1.29 ± 0.31 mm/month) groups in terms of the canine retraction rate. Moreover, both the groups demonstrated a significantly higher canine movement than the control group (0.88 ± 0.19 mm/month). MOPs did not significantly affect the mesialization of the posterior teeth (p > 0.05). Moreover, the pain scores in the MOP-4 and MOP-7 groups were similar and showed no statistically significant difference. Conclusions: Three MOPs with a depth of 4 mm can be performed as an effective method to increase the rate of tooth movement. However, three MOPs with depths of 4-7 mm does not additionally enhance tooth movement.

Comparison of soft tissue changes between incisor tipping and translation after premolar extraction

  • Baik, Wonkyeong;Choi, Sung-Hwan;Cha, Jung-Yul;Yu, Hyung-Seog;Lee, Kee-Joon
    • 대한치과교정학회지
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    • 제52권1호
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    • pp.42-52
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    • 2022
  • Objective: This study compared soft tissue changes after extraction of the four premolars followed by maximum retraction of the anterior teeth according to the type of anterior teeth movement: tipping and translation. Methods: Patients who had undergone orthodontic treatment involving the extraction of four premolars were retrospectively selected and divided into either the tipping (n = 27) or translation (n = 26) groups based on the retraction of the incisor root apex and the axis changes of the incisors during the treatment period. Lateral pre- and post-treatment cephalograms were analyzed. Results: There were no significant differences between the tipping and translation groups before treatment. The retraction amounts of the root apex of the upper and lower incisors in the tipping group were 0.33 and 0.26 mm, respectively, and 5.02 and 5.31 mm, respectively, in the translation group (p < 0.001). The posterior movements of soft tissue points A and B in the tipping group were 0.61 and 1.25 mm, respectively, and 1.10 and 3.25 mm, respectively, in the translation group (p < 0.01). The mentolabial sulcus angle increased by 5.89° in the tipping group, whereas it decreased by 8.13° in the translation group (p < 0.001). Conclusions: An increased amount of retraction of the incisor root apex led to the increased posterior movement of soft tissue points A and B, and this appeared more distinct in cases involving the lower incisor and lower lip.

An objective assessment of the impact of tendon retraction on sleep efficiency in patients with full-thickness rotator cuff tears: a prospective cohort study

  • Ashley E. MacConnell;William Davis;Rebecca Burr;Andrew Schneider;Lara R Dugas;Cara Joyce;Dane H. Salazar;Nickolas G. Garbis
    • Clinics in Shoulder and Elbow
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    • 제26권2호
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    • pp.169-174
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    • 2023
  • Background: Sleep quality, quantity, and efficiency have all been demonstrated to be adversely affected by rotator cuff pathology. Previous measures of assessing the impact of rotator cuff pathology on sleep have been largely subjective in nature. This study was undertaken to objectively analyze this relationship through the use of activity monitors. Methods: Patients with full-thickness rotator cuff tears at a single institution were prospectively enrolled between 2018 and 2020. Waist-worn accelerometers were provided for the patients to use each night for 14 days. Sleep efficiency was calculated using the ratio of the time spent sleeping to the total amount of time that was spent in bed. Retraction of the rotator cuff tear was classified using the Patte staging system. Results: This study included 36 patients: 18 with Patte stage 1 disease, 14 with Patte stage 2 disease, and 4 patients with Patte stage 3 disease. During the study, 25 participants wore the monitor on multiple nights, and ultimately their data was used for the analysis. No difference in the median sleep efficiency was appreciated amongst these groups (P>0.1), with each cohort of patients demonstrating a generally high sleep efficiency. Conclusions: The severity of retraction of the rotator cuff tear did not appear to correlate with changes in sleep efficiency for patients (P>0.1). These findings can better inform providers on how to counsel their patients who present with complaints of poor sleep in the setting of full-thickness rotator cuff tears.

Identification of Motion Platform Using the Signal Compression Method with Pre-Processor and Its Application to Siding Mode Control

  • Park, Min-Kyu;Lee, Min-Cheol
    • Journal of Mechanical Science and Technology
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    • 제16권11호
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    • pp.1379-1394
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    • 2002
  • In case of a single input single output (SISO) system with a nonlinear term, a signal compression method is useful to identify a system because the equivalent impulse response of linear part from the system can be extracted by the method. However even though the signal compression method is useful to estimate uncertain parameters of the system, the method cannot be directly applied to a unique system with hysteresis characteristics because it cannot estimate all of the two different dynamic properties according to its motion direction. This paper proposes a signal compression method with a pre-processor to identify a unique system with two different dynamics according to its motion direction. The pre-processor plays a role of separating expansion and retraction properties from the system with hysteresis characteristics. For evaluating performance of the proposed approach, a simulation to estimate the assumed unknown parameters for an arbitrary known model is carried out. A motion platform with several single-rod cylinders is a representative unique system with two different dynamics, because each single-rod cylinder has expansion and retraction dynamic properties according to its motion direction. The nominal constant parameters of the motion platform are experimentally identified by using the proposed method. As its application, the identified parameters are applied to a design of a sliding mode controller for the simulator.

양악 전돌증 환자에서 소구치 발치를 통한 교정치료시 입술 주위 연조직변화에 관한 연구 (LIP PROFILE CHANGES AFTER ORTHODONTIC TOOTH MOVEMENT IN FEMALE ADULT WITH BIMAXILLARY PROTRUSION)

  • 김태경;유영규
    • 대한치과교정학회지
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    • 제24권1호
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    • pp.135-147
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    • 1994
  • Facial esthetics is one of the most important goal of the orthodontic treatment and main concern of many patients. Facial esthetics should be considered in orthodontic diagnosis and treatment planning. Prediction of soft tissue profile changes after orthodontic tooth movement should be considered as well. The purpose of this study was to find out the effect of orthodontic treatment on lip profile in adult patient. The pre and post treatment cephalometric roentgenograms of 87 female adult with bimaxillary protrusion were used to analyze lip profile change. All subjects were treated with four bicuspids extraction. Obtained results were as follows . 1. Lip thickness changes after incisor retraction showed different patterns according to areas of the lip. The thickness of the red lip area showed 2.78 mm increase in average. In contrast the thickness of the cutaneous area showed 0.65 - 0.7 mm decrease according to the different cutaneous areas. 2. The length of the red lip area decreased(1.3mm) after incisor retraction. 3. The length of the cutaneous lip area increased(2.9mm) after incisor retraction.

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Postoperative Tracheal Mucosa Ischemia by Endotracheal Tube Cuff Pressure Change During the Anterior Cervical Spine Surgery

  • Kim, Seok-Won;Shin, Ho
    • Journal of Korean Neurosurgical Society
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    • 제39권6호
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    • pp.419-422
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    • 2006
  • Objective : Endotracheal tube cuff-pressure[ETCP] increases significantly during anterior cervical spine surgery with neck retraction. Clinically, postoperative hoarseness with sore throat is correlated with vocal cord edema due to longer intubation time and higher ETCP during neck retraction. Methods : Fifty patients of anterior cervical spine surgery were randomized to a control [no adjustment, 25 cases] and a treatment group [ETCP adjusted to 20mmHg, 25 cases]. Patients were blinded to their group assignments. They were questioned about the presence of ischemic symptoms [sore throat, dysphagia, hoarseness] postoperatively at different time points; 4 hours, 24 hours, and 1 week postoperatively. Results : No differences between groups at 4 hours and 1 week postoperatively were demonstrated. At 24 hours, 36% of patients in the treatment group complained of sore throat while 56% of control group patients did [p < 0.05]. Female patients correlated with development of all ischemic discomfort [p < 0.05 : sore throat, hoarseness, dysphagia]. Conclusion : Our results suggest that postoperative ischemic symptom following anterior cervical spine surgery may be associated with the two predictors; increased ETCP during neck retraction and female. The simple procedure of maintaining ETCP to 20mmHg can prevent postoperative tracheal ischemic symptom.

SBR 가황물의 회복 거동에 미치는 스티렌 함량의 영향 (Influence of Styrene Contents on Retraction Behaviors of SBR Vulcanizates)

  • 최성신;우창수;장동호
    • Elastomers and Composites
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    • 제40권4호
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    • pp.237-241
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    • 2005
  • 스티렌 함량이 SBR 가황물의 회복 거동에 미치는 영향에 대해 연구하였다. 스티렌 함량이 15와 21 wt%인 SBR을 사용하였다. 스티렌 함량이 적은 가황물이 스티렌 함량이 많은 가황물에 비해 더 낮은 온도에서 회복하기 시작하였으며, 스티렌 함량이 적은 가황물의 회복 속도가 스티렌 함량이 많은 가황물보다 느렸다. 두 가황물 간의 회복 차이는 카본블랙으로 보강된 가황물이 실리카로 보강된 것보다 컸다. 실험 결과는 유리전이온도와 모듈러스로 설명하였다.

Antiplatelet Effect of Cudraxanthone L Isolated from Cudrania tricuspidata via Inhibition of Phosphoproteins

  • Shin, Jung-Hae;Rhee, Man Hee;Kwon, Hyuk-Woo
    • Natural Product Sciences
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    • 제26권4호
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    • pp.295-302
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    • 2020
  • Cudrania tricuspidata (C. tricuspidata) is a deciduous tree found in Japan, China and Korea. The root, stems, bark and fruit of C. tricuspidata has been used as traditional herbal remedies such as eczema, mumps, acute arthritis and tuberculosis. In this study, we investigated the potential efficacies of this natural compound by focusing on the inhibitory effect of cudraxanthone L (CXL) isolated from the roots of C. tricuspidata on human platelet aggregation. Our study focused on the action of CXL on collagen-stimulated human platelet aggregation, inhibition of platelet signaling molecules such as fibrinogen binding, intracellular calcium mobilization, fibronectin adhesion, dense granule secretion, and thromboxane A2 secretion. In addition, we investigated the inhibitory effect of CXL on thrombin-induced clot retraction. Our results showed that CXL inhibited collagen-induced human platelet aggregation, intracellular calcium mobilization, fibrinogen binding, fibronectin adhesion and clot retraction without cytotoxicity. Therefore, we confirmed that CXL has inhibitory effects on human platelet activities and has potential value as a natural substance for preventing thrombosis.

RETRACTED: Design of LEO Constellations with Inter-Satellite Connects Based on the Performance Evaluation of the Three Constellations SpaceX, OneWeb and Telesat

  • Peng Zong;Saeid Kohani
    • 대한원격탐사학회지
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    • 제40권3호
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    • pp.317-317
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    • 2024
  • Notice: This article has been retracted as a result of the review (on May 14, 2024) by the Research Ethics Committee of the Korean Society of Remote Sensing, which confirmed research misconduct (plagiarism). The Korean Journal of Remote Sensing (KJRS) Editorial Office received a report alleging plagiarism in a paper published in KJRS authored by Zong and Kohani (2021). Following a thorough investigation by our Research Ethics Committee, we found significant similarities between the original paper (Lee and Mortari, 2017) and the paper (Zong and Kohani, 2021) published in KJRS. The scope of the plagiarism included a number of identical figures, tables, and equations, as well as textual content. As a result, the Research Ethics Committee of the Korean Society of Remote Sensing has decided to retract the paper (Zong and Kohani. 2021) for deliberately using the ideas, research content, and results of others without proper approval or citation. To preserve academic integrity, we take responsibility for enforcing ethical policies and proceeding with the follow-up actions: 1. Disclosure and preservation of the facts and reasons for the retraction of the plagiarized paper, 2. Prohibition of submissions for the next three years for the authors of the plagiarized paper, 3. Notification to the authors’ affiliated institution of the retraction of the plagiarized paper. We deeply regret to report for retraction of the article and apologize to the readers of KJRS and to the authors of the original work for any inconvenience caused.

Pharmacological actions of morusinol on modulation of platelet functions via integrin αIIb/β3 signaling

  • Hyuk-Woo Kwon
    • Journal of Applied Biological Chemistry
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    • 제66권
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    • pp.171-178
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    • 2023
  • Morus alba, a popular medicinal plant belonging to the family Moraceae, has long been used commonly in traditional medicine and has various physiological activities, including antidiabetic, anti-microbial, diuretic, anti-oxidant, and anti-cancer activities. Morusinol was isolated from the root bark of M. alba; however, its biological effects have not yet been reported. Therefore, we examined the inhibitory effects of morusinol on human platelet aggregation, Ca2+ mobilization, and αIIb/β3 activity. Our data showed that collagen-induced human platelet aggregation was inhibited by morusinol without cytotoxicity. In this study, we examined whether morusinol inhibits platelet aggregation through the regulation of integrin αIIb/β3 and its associated signaling molecules. We observed that morusinol inhibited αIIb/β3 activation by regulating vasodilator-stimulated phosphoprotein, phosphatidylinositol-3 kinase, Akt (protein kinase B), and glycogen synthase kinase-3α/β. These results show that morusinol inhibited fibronectin adhesion, fibrinogen binding, and clot retraction. Taken together, morusinol shows strong antiplatelet and anti-clot retraction effects and is a potential therapeutic drug candidate to prevent platelet-related thrombosis and cardiovascular disease.