• Title/Summary/Keyword: Unilateral traction

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Arytenoid Adduction by Lateral Approach (측방접근법을 이용한 피열연골내전술)

  • Lee, Nak-Joon;Cho, Jungkyu;Kim, Han-Kyeol;Yun, Young-Sun;Son, Young-Ik
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.25 no.2
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    • pp.90-95
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    • 2014
  • Background and Objectives : Arytenoid adduction procedure is one of the main surgical options addressed for the correction of glottal incompetence in patients with unilateral vocal cord paralysis. Traditionally, a midline approach is used for identifying and suturing around the muscular process, which often needs over-traction of the thyroid cartilage and results in patient's discomfort as well as surgeon's distress. The authors investigated the advantage of a modified procedure, lateral approach, in which the arytenoid cartilage is exposed through the space between strap muscles and sternocleidomastoid muscle. Materials and Methods : Retrospective chart review was performed for 66 patients who received arytenoid adduction surgery at Samsung Medical Center, between the year 1997 and 2014. Operation time, types of anesthesia, voice outcomes and complications were compared between the midline (n=22) and the lateral (n=44) approach group. Results : Operation time was shorter in the lateral approach group ($125{\pm}24min$) than in the midline group ($144{\pm}24min$). Arytenoid adduction was proceeded under local anesthesia in 66% (n=29/44) and 14% (n=3/22) of patients with lateral and midline approach group, respectively. Voice outcomes and complication rates were comparable between the two groups. Injection laryngoplasty in conjunction with arytenoid adduction resulted in more favorable voice outcomes. Conclusion : A lateral approach for the arytenoid adduction procedure showed comparable voice outcomes and similar complication rates with those of a midline approach. However, lateral approach provided less discomfort to the patients and less distress to a surgeon, and therefore, shorter operation time was needed and local anesthesia could be more frequently applied for this modified procedure.

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A FEM comparison study about the force, displacement and initial stress distribution on the maxillary first molars by the application of Asymmetric Head-Gears with the different traction forces (Asymmetric Head-Gear의 견인력의 차이에 따른 상악 제 1 대구치에 나타나는 힘과 변위 및 초기 응력분포에 관한 유한요소법적 비교 연구)

  • Cha, Kyung-Suk
    • The korean journal of orthodontics
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    • v.31 no.3 s.86
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    • pp.311-323
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    • 2001
  • One of the various mechanics used to treat unilateral Class II malocclusion is head gear with asymmetric face bow. We made the finite element models of unilateral Class II maxillary dental arch and power arm asymmetric face bow. We designed this experiment to observe stress distribution of periodontal ligament, reaction force, and displacement and to understand force system, so to predict the therapeutic effect. On the basis of computerized tomograph of maxillary dental arch of 25 years old male with normal occlusion without extraction and orthodontic treatment history, we made finite element models of maxillary dental arch and periodontal ligament. Then we modified that model to unilateral maxillary Class II malocclusion model of which maxillary left molar displaced mesially. Also, We made finite element model of asymmetric face bow of which right outer bow shorter than left by 25mm(RMO, Penta-FormTM/Medium size, 0.045 inch iner bow, 0.072 inch outer bow). After that, retraction force of 250g, 300b, 350g were applied to maxillary first molar. We concluded as follow. 1. The Net force that both maxillary first molars were received increased as the retraction force increased. Mesially positioned tooth received more force than normally positioned tooth. But, both tooth were received distal force, so distal movement occured. 2. Both tooth received buccal lateral force. In analysis of force element, as the retraction force were increased, force of X-axis at mesially positioned tooth decreased, and force of X-axis at normally positioned tooth increased. so lateral force component moved to the side received less force from more force. 3. There were rotation, tipping with distal movement in maxillary first molar. As retraction force were increased, rotation and tipping also increased. More tipping and rotation occured at the side received more force, that is, mesially positioned tooth. Though it Is small change, displacement of same pattern occur in normally positioned tooth

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Factors that influence treatment duration for patients with palatally impacted maxillary canines (구개측으로 매복된 상악견치의 교정치료기간에 영향을 미치는 요소)

  • Jeong, Song-Hwa;Jo, Bong-Hye;Kim, Seong-Sik
    • The korean journal of orthodontics
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    • v.37 no.2 s.121
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    • pp.150-158
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    • 2007
  • Objective: The aim of this study was to determine the relationship between the status of a unilateral palatally impacted maxillary canine (as seen on the panoramic radiograph) and the orthodontic treatment duration. Methods: A total of 36 subjects were chosen (8 males and 28 females, $13.7{\pm}2.5$ years). All patients had undergone orthodontic traction of the impacted canine after a closed flap surgery. The position of impacted canine on the panoramic radiograph was traced and calculated with regard to the treatment duration. Results: The canine overlap over the lateral incisor (COGr) had significant statistical difference between the short-term and the long-term treatment duration groups (divided by average treatment time of 21 months) (p<0.05). Multiple regression indicated that the variables of significance (with treatment duration as the dependent variable) were the canine vertical height from the occlusal plane $(HCV,\;r^2=0.115;\;p<0.05)$ and the mandibular anterior width $(MnDW,\;r^2=0.142;\;p<0.05)$. The treatment duration, the canine angle to the incisor midline (CA), and HCV decreased from primary dentition (under 12 yrs) to permanent dentition (15 yrs). Howerer, these increased again at the adolescent ages (over 16 yrs). Conclusion: These findings suggested that orthodontic treatment of a palatally impacted canine would show good prognosis at an age of early permanent dentition with the canine showing smaller CA and HCV.