편측성 후방연장 국소의치에서 직접유지장치의 설계와 지대치 골흡수에 따른 간접유지장치 지대치 주위조직에 발생하는 응력분석

이석현,이청희,조광헌,Lee, Suk-Hyun,Lee, Cheong-Hee,Jo, Kwang-Hun 대한치과보철학회 1998 대한치과보철학회지 Vol.36 No.1

For the purpose of evaluating the effect of both direct retainer design and bony absorption degree around abutment of indirect retainer on the supporting tissue of abutment of indirect retainer, dislodging force was transmitted to unilateral distal extension RPD bases. Analysis of stress distributed within the supporting tissue around abutment of indirect retainer was carried out. Using three-dimensional photoelastic stress analysis method and the conclusion is a follows. 1. According to the extent of force which the direct retainer of the most distal abutment tooth, the amount of force transmitted to the abutment tooth of indirect retainer was small. 2. Of all the cases, Mandibular first premolar which was used abutment tooth of indirect retainer, buccal, mesial and distal sides represented compression stress and lingual side represented tensile stress. 3. The more bone resorption of abutment tooth of indirect retainer, the more distortion of buccal and distal side of abutment tooth was existed and the extent of compression stress which was existed and distal side to abutment tooth was large. 4. When the alveolar bone around the abutment with indircet retainer is normal. The amount of force transmitted on abutment with indirect retainer was small in the order of Akers clasp, RPA clasp, RPI clasp. 5. When the alveolar bone around the abutment with indirect retainer has been absorbed 20% and 30%, the amount of force transmitted on abutment with indirect retainer was small in the order of RPA calsp, RPI clasp, Akers clasp. 6. When denture is displaced, shape of the direct retainer reciprocating abutment affect much the function of indirect retainer.

상악 가철식 보정장치인 circumferential comfortable retainer (CCR)에 대한 불편감 평가

최진휴(Jin-Hugh Choi),문철현(Cheol-Hyun Moon) 대한치과교정학회 2010 대한치과교정학회지 Vol.40 No.5

발음장애, 구토감 및 착용 불편감과 같은 보정장치에 대해 환자가 느끼는 불편감을 평가해보기 위해 고정식 교정장치로 교정치료를 받고 교정장치가 제거된 66명(남자 23명, 여자 43명; 평균연령 23.42 ± 10.19)의 교정환자를 대상으로 무작위로 두 군으로 배정한 후 고정식 교정장치를 제거한 다음 날 CWR 장착군에게는 구개를 완전히 덮는 구개 완전 피개형 보정장치인 conventional wraparound retainer (CWR)를 장착시키고 CCR 장착군에게는 구개를 말 발굽 모양으로 부분 피개하는 보정장치인 circumferential comfortable retainer (CCR)를 4주 동안 장착시킨 후 발음장애, 구토감 및 착용 불편감의 정도에 대해 100-mm visual analog scale (VAS)로 표시할 수 있도록 제작된 설문지를 통해 얻은 점수에 대해 통계적으로 비교 분석하였다. 연구결과 발음장애와 착용 불편감의 비교에서 CCR 장착군이 CWR 장착군에 비해 통계적으로 유의하게 낮았다 (p < 0.05). 구토감의 비교에서는 CCR 장착군이 CWR 장착군에 비해 낮은 점수를 보였지만 통계적으로는 유의한 차이를 보이지 않았다 (p = 0.146). 이상의 연구 결과로 circumferential comfortable retainer (CCR)는 발음장애를 감소시키고, 착용 불편감을 완화시킴으로써 환자의 협조도를 증진시켜 줄 수 있는바 고정식 교정장치를 이용한 교정치료 후 치료결과 유지에 도움이 될 수 있음을 시사하였다. (대치교정지 2010;40(5):325-333) Objective: The aim of this study was to illustrate the circumferential comfortable retainer (CCR) as a removable maxillary retainer with good potential patient compliance and to evaluate the discomfort of the retainers including distorted speech, gagging sensation and appliance discomfort. Methods: Sixty-six orthodontic patients (male, 23; female, 43; mean age, 23.42 ± 10.19 years) who received orthodontic treatment with fixed orthodontic appliances were randomly assigned to two groups after debonding, a conventional wraparound retainer (CWR) group that fully covers the palate with an acrylic plate and a highly polished surface, and a circumferential comfortable retainer (CCR) group which has a horseshoe shaped base plate with three folds on the anterior region. A questionnaire that had a visual analog scale (VAS) which consists of a 100-mm horizontal line with 2 end-points labeled “no discomfort” on the left and “worst discomfort” on the right, with regard to distorted speech, gagging sensation and discomfort, was administered to patients after 4 weeks of retainer wear. The Mann-Whitney test was used to test the hypothesis that there was no difference between the two retainers. Results: Comparing distorted speech and discomfort, the CCR group significantly had lower values than the CWR group (p < 0.05). Comparing gagging sensation, the CCR group had lower values than the CWR group but there were no statistically significant differences between groups (p = 0.146). Conclusions: In conclusion, the results suggest that the circumferential comfortable retainer (CCR) might facilitate patient compliance and thereby improve the maintenance of the fixed orthodontic treatment outcome. (Korean J Orthod 2010;40(5):325-333)

임진왜란기(壬辰倭亂期) 분조(分朝) 구성원의 행적에 관한 고찰

조인희,최윤오 역사실학회 2020 역사와실학 Vol.73 No.-

The purpose of this paper is to examine the specific activities of the members of Bunjo cabinet. For the research, examination on the selection of the meritorious retainer escorting Prince Gwanghae was made based on the Annals of Chosun dynasty and personal records. The following are the clues to the criteria for selecting the meritorious retainer escorting Prince Gwanghae and other meritorious retainers. 1 In the case of Hoseong meritorious retainer, he was recognized as a servant of King Seonjo or Gwanghaegun when he was ordered to leave due to official duties. This exception applies for Weesung meritorious retainers as well. Unlike Hoseong meritorious retainers, Weesung meritorious retainers could be selected as a meritorious subject even if it participated in only one of the first and second divisions. 3 Even if he participated in both the first and second divisions, he may not win the first prize. The figures who participated in the cabinet were treated as honored guests or received a considerable number of government posts related to the Prince Gwanghae's education. However not all of them were engaged in Bunjo cabinet or cited. Those who joined the group after the launch of Bunjo cabinet were not selected as the first meritorious retainers. In addition, even if they served Prince Gwanghae without resignation, they may not be selected as the No.1 contributor. 6 Even if it was due to official duties, they could not be selected as meritorious retainers if they were outside for too long time. It is not clear whether this condition applies to Weesung meritorious retainers. 7 If a person who has been obedient was sinned and deformed at the time of discussion on the selection of meritorious retainers, he could be demoted. 본고의 목적은 분조 구성원의 구체적인 행적에 대해 고찰해 보는 것에 있다. 이를 위해 본고에서는 호성선무청난공신도감의궤(扈聖宣武淸難功臣都監儀軌)와 실록, 개인 문집을 중심으로 위성공신(衛聖功臣)의 선정 과정에 대해 살펴보고자 하였다. 이를 통해 알아낼 수 있었던 위성공신 및 호성, 선무, 청난공신의 선정 기준에 대한 단서는 다음과 같다. ① 호성공신의 경우, 공무로 인해 명을 받고 선조나 광해군의 곁을 떠날 경우에는 종시호종으로 인정받았다. 이 예외 사항은 위성공신에도 동일하게 보는 것이 타당하다. ② 호성공신과 달리 위성공신은 1, 2차 분조 중 어느 한 곳에만 참여한 경우에도 공신으로 선정될 수 있었다. ③ 1, 2차 분조에 모두 참여했다 하더라도 반드시 1등 공신으로 선정됐던 것은 아니다. ④ 분조에 참여한 인물들은 빈객의 대우를 받거나, 세자시강원 관련 벼슬을 받는 경우가 상당히 많았다. 그러나 빈객이나 세자시강원 관련 벼슬을 받았다고 반드시 분조에서 업무에 종사했거나 공신에 선정됐던 것은 아니다. ⑤ 공신 선정에서 설령 공무로 인한 것이었다 하더라도 장기간(3달) 이탈을 할 경우 호성공신에 선정되지 못할 수 있었다. ⑥ 종시호종한 자가 공신 선정 논의 시점에서 죄를 지어 부처(付處)되고 탈고신(奪告神)된 경우에는 강등될 수 있었다.

A survey on retention practice among orthodontists in Malaysia

Norma Ab Rahman,Tze Fui Low,Nur Shaheera Idris 대한치과교정학회 2016 대한치과교정학회지 Vol.46 No.1

Objective: The aim of this study was to evaluate retention practices commonly employed by orthodontists. The objectives were to identify the types of retainer frequently used and to investigate the variations in retention practice. Methods: A total of 97 orthodontists were randomly selected, and a questionnaire consisting of 25 multiple-choice questions sent to them by mail. Upon receiving of the completed questionnaires, the data were statistically analyzed. Results: A total of 32 responses were received; among these, 59.4% of orthodontists’ practiced is in a government setting and 40.6% were in private practice. A vacuum-formed retainer was the most commonly used removable retainer for both maxillary (46.9%) and mandibular (46.9%) arches, followed by a Hawley retainer (maxilla, 43.8%; mandible, 37.5%), and a fixed retainer (maxilla, 3.1%; mandible, 9.4%). Of the responding orthodontists, 78.1% prescribed full-time wear (more than 20 h per day) for a duration of 3−9 months for a maxillary arch, compared to 71.9% for the mandibular arch. Only 18.8% of the orthodontists prescribed part-time wear of the retainer for the maxillary arch, compared to 21.9% for the mandibular arch. The majority of orthodontists did not instruct their patients to stop wearing removable retainers (71.9%) or fixed retainers (66.8%) at any specific time and they preferred their patients to continue wearing retainers. Conclusions: Vacuum-formed retainers are the most commonly used retainers among orthodontists. The majority of orthodontists prescribed full-time wear for more than 20 h per day with a duration of 3−9 months and preferred indefinite use of the retainer.

Innovative customized CAD/CAM nickel-titanium lingual retainer versus standard stainless-steel lingual retainer: A randomized controlled trial

Emilie Gelin,Laurence Seidel,Annick Bruwier,Adelin Albert,Carole Charavet 대한치과교정학회 2020 대한치과교정학회지 Vol.50 No.6

Objective: To compare computer-aided design and computer-aided manufacturing (CAD/CAM) customized nitinol retainers with standard stainless-steel fixed retainers over a 12-month study period. Methods: This randomized controlled trial (RCT) was conducted on 62 patients randomly allocated to a control group that received stainless-steel retainers or a test group that received customized CAD/CAM nickel-titanium retainers. Four time points were defined: retainer placement (T0) and 1-month (T1), 6-month (T2), and 12-month (T3) follow-up appointments. At each time point, Little’s irregularity index (LII) (primary endpoint) and dental stability measurements such as intercanine width were recorded in addition to assessment of periodontal parameters. Radiological measurements such as the incisor mandibular plane angle (IMPA) were recorded at T0 and T3. Failure events (wire integrity or debonding) were assessed at each time point. Results: From T0 to T3, LII and other dental measurements showed no significant differences between the two groups. The data for periodontal parameters remained stable over the study period, except for the gingival index, which was slightly, but significantly, higher in the test group at T3 (p = 0.039). The IMPA angle showed no intergroup difference. The two groups showed no significant difference in debonding events. Conclusions: This RCT conducted over a 12-month period demonstrated no significant difference between customized CAD/CAM nickel-titanium lingual retainers and standard stainless-steel lingual retainers in terms of dental anterior stability and retainer survival. Both retainers eventually appeared to be equally effective in maintaining periodontal health.

A simple and easily available nostril retainer using syringe

( Jungyoon Ohn ),( Yun Seon Choe ),( Jung Won Shin ),( Chang Hun Huh ) 대한피부과학회 2015 대한피부과학회 학술발표대회집 Vol.67 No.1

A 62-year-old Korean woman presented with waxy plaques with telangiectasia on left nasal ala of 6-month duration, histopathologic finding of which was basal cell carcinoma. Full-thickness excision was performed leaving defect of the ala and alar rim. This defect was reconstructed by Spear’s nasolabial flap. Nostril retainer was in situ for two weeks, which was made from a syringe by cutting it apart on bed-side. The subcutaneous pedicled nasolabial flap transferring skill was described as a useful method for reconstructing full-thickness defects of nasal ala by Spear et al. It is suitable for not only ensuring structural integrity but also preventing the “valve” movement without cartilage grafts. Also, additional usage of nostril retainer could aidthem. In this case, the barrel part of a syringe was used as a nostril retainer. It is made from a common medical supply, a syringe, not only easy to get but also very cheap (8 cents). In addition to its accessibility, it adequately performs its role, preventing “valve” effect of reconstructed nasal ala. In conclusion, this simple nasal retainer can be used as an alternative to ready-made products in ala reconstruction patient.

Flowable composite resin을 이용한 접착식 유지장치의 결합강도와 파절양상에 열순환이 미치는 영향

전재호,손우성 대한치과교정학회 2005 대한치과교정학회지 Vol.35 No.4

이 연구는 flowable composite resin을 이용한 접착식 유지장치를 열순환시킨 후 결합강도와 파절양상을 조사하여 flowable composite resin이 접착식 유지장치의 레진 접착제로서 유용한지를 알아보기 위해 시행되었다. 교정치료를 목적으로 발거한 160개의 치아로 80개의 시편을 제작하고 40개씩 두 군으로 나누어 접착식 유지장치를 제작하였다(Group G: 일반 복합레진인 CharmFil, Group F: flowable composite resin인 CharmFil Flow, wire: Tri-flex). 각 군을 20 개씩 2 개의 subgroup으로 나누었다(Subgroup 24: 생리식염수에 24시간 동안 보관, Subgroup T : 37℃ 생리식염수에 24 시간 동안 보관한 후 5 ± 2℃ ~55± 2℃ 수조에 500회 열순환). 유지장치의 wire 중점에 수직전단력을 주면서 파절되는 순간의 하중을 측정하여 비교하였으며, 광학입체 현미경으로 파절면을 관찰하여 파절양상을 비교하였다. 그 결과, 두 군의 전단결합강도 및 파절양상에는 통계학적으로 유의한 차이가 없었다. 따라서, 전달결합강도와 파절양상의 측면에서만 본다면 flowable composite resin을 유지장치의 레진 접착제로 충분히 적용시킬 수 있을 것으로 본다. The purpose of this study was to evaluate the effects of thermocycling on shear bond strength and mode of failure of orthodontic bonded retainer using flowable composite resin and to ascertain whether the flowable composite resin is useful for use as adhesive for orthodontic bonded retainers. One hundred and sixty freshly extracted human premolars were collected and eighty bonded retainer specimens were fabricated. They were randomly separated into 2 groups (Group G: general composite resin-CharmFil, Group F: flowable composite resin-CharmFil Flow, wire: Tri-flex). Each group was divided into 2 subgroups (Subgroup 24: stored in water at 37℃ for 24 hours for baseline data, Subgroup T: stored in water at 37℃ for 24 hours and thermocycled between 5 ± 2℃ and 55± 2℃ for 500 cycles before testing the in vitro shear bond strength). Shear bond strength was measured and mode of failure was evaluated with a stereomicroscope. There was no statistical difference in shear bond strength and mode of failure between the bonded retainer using general composite resin and flowable composite resin. Therefore, in considering shear bond strength and mode of failure, it is sufficient to use flowable composite resin as resin adhesives for bonded retainers.

국소의치 유지장치의 설계변화에 따른 지지조직의 3차원적 유한요소법 응력분석

김기숙,김광남,장익태,Kim, Ki-Sook,Kim, Kwang-Nam,Chang, Ik-Tae 대한치과보철학회 1995 대한치과보철학회지 Vol.33 No.3

The purpose of this study was to evaluate the stress distribution developed in the supporting structures by mandibular distal extension removable partial dentures with 2 different direct retainer designs and with or without indirect retainer and abutment splinting. The examined direct retainers on the second bicuspid abutment tooth were Akers clasp and RPA clasp, the indirect retainer was located on the mesial fossa of the first bicuspid, and the first and second bicuspid were splinted in case of tooth splinting. Total 8 cases were compared and analyzed with 3-dimensional finite element method. 150N were applied vertically on the artificial teeth of the removable partial denture, and then stress distribution patterns were analyzed and compared. The results were as follows : 1. The forces transmitted to the abutment tooth were primarily from the occlusal rests. 2. The abutment tooth was displaced distally when the force was applied. The compressive stress was observed at the distal root surface of the abutment tooth and the tensile stress, at the mesial root surface. 3. The denture base was displaced posteriorly and inferiorly when the force was applied. At the more distal portion of the denture base, the greater displacement was observed.And the anterior portion of the major connector was displaced superiorly. 4. The occlusal rest placed on the distal part of the abutment tooth tended to tip the tooth more posteriorly than did one on the mesial part of that tooth. 5. Severe superior displacement was observed at the anterior portion of the major connector in case of removable partial dentures without indirect retainer. 6. In case of tooth-splinting, the stress was distributed through all the root surface of both abuments. In case of no tooth-splinting, the stress was concentrated on the distal root surface of the primary abutment.

고속 볼베어링 리테이너 최적화를 위한 원심력 해석

김규복(Kyu Bok Kim),이운주(Woon Ju Lee) 대한기계학회 2017 대한기계학회 춘추학술대회 Vol.2017 No.11

In the case of high-speed ball bearings used for supporting high-speed motors of EV(Electric Vehicle) and HEV(Hybrid Electric Vehicle), high rotational speeds cause large centrifugal forces when the bearings operate. If a large centrifugal force is applied to the retainer, it causes deformation. This causes interference between the retainer and the rolling element, thereby accelerating the heating and wear of the retainer. This is a major cause of reduced fatigue life of high-speed ball bearings. Therefore, in this paper, in order to minimize retainer deformation by centrifugal force, the material and design of the retainer were changed. The deformation by centrifugal force was measured by FEA(Finite Element Analysis) and based on this, we devised optimum design of retainer.

Effects of a new type of clear overlay retainer on occlusal contacts

Kyoung Yeon Kim,Hyo-Won Ahn,Seong-Hun Kim,Gerald Nelson 대한치과교정학회 2017 대한치과교정학회지 Vol.47 No.3

The popularity of clear overlay retainers (CORs) has increased recently because of their advantages such as better esthetics, cost effectiveness, easy fabrication, and good compliance. However, a deficiency in posterior occlusal settling is a reported limitation of CORs. The aim of this study was to evaluate the posterior occlusal contact changes in a new type of clear orthodontic retainer called Oral-treaper (OTP), which consists of three layers and has stronger mechanical characteristics than do conventional retainers. Three patients who completed fixed orthodontic treatment received OTP as a removable retainer. Cast models were fabricated after the removal of fixed appliances (T1) and after 4 to 11 months of using the retainers (T2). We evaluated all the cast models to compare the post-orthodontic settling pattern during the use of the OTPs. The depth of occlusal contacts was evaluated using color maps. The OTP did not prevent vertical settling in all patients but resulted in an improvement in posterior occlusal contact points.