백서의 구개학대시 조직변화에 관한 조직학적 및 자기방사법적 연구

강정희(Kang Jeong-hee),국윤아(Yoon-A Kook),김상철(Sang-Cheol Kim) 대한치과교정학회 1992 대한치과교정학회지 Vol.22 No.2

The purpose of this study was to clarify the histologic changes in the expansion of midpalatal suture by the tensile forces. 39 Sprague-Dawley rats were divided into a control group (3 rats) and three experimental groups (36 rats)-group 1, pressured with a light force (50-75g), group 2, with a heavy force (250-300g) and group 3, with a heavy force (250-300g) plus laser irradiation. Autoradiographic and histopathologic observations were performed in 12, 24, 48 and 96 hours after force delivery. The results were as follows: 1. The anterior portion of midpalatal suture was more separated than the posterior portion in all experimental groups. Group 2 showed more separation than group 1 and no difference to group 3. 2. Ligament tearing appeared intensively in 24 hours, but the sutural matrices increased with times.: Group 2 showed more tearing than group 1, and active regeneration of sutural matrices was observed in group 3. 3. Vascular dilatation appeared intensively in 24 hours and decreased with times. : The anterior portion of midpalatal suture showed more dilatation than the posterior portion.: The changes was the greatest in group 3, group 2, group 1, in that order. 4. New bone formation and the new capillary prolieferation began to appear in 12 hours and increased with times.; Group 2 showed more changes than group 1 and no difference to group 3. 5. Infiltration of inflammatory cells was little observed and was the greatest in group 2, group 1, group 3, in that order. 6. Positive reaction of cells to [^³H] thymidine was the greatest in 24 hours, and decreased with times: The reaction was the greatest in group 3, group 2, group 1, in that order.

백서의 전치 이동시 초기 변화에 관한 조직학적 및 자기방사법적 연구

유기환(Ki-Whan Yoo),김상철(Sang-Cheol Kim),국윤아(Yoon-A Kook) 대한치과교정학회 1993 대한치과교정학회지 Vol.23 No.2

The purpose of this study was to quantify the biologic effects of the tensile forces from helical springs across the maxillary incisors on the periodontal tissues of rats. 39 Sprague-Dawlely rats were divided into a control group(3 rats) and three experimental groups(36 rats)-group 1, pressured with a light force(50?75g), group 2, with a heavy force(250-300g) and group 3, with a heavy force(250-300g) plus laser irradiation. Autoradiographic and histopathologic observations were performed in 12, 24, 48 and 96 hours after force application. The result were as follow : 1. Hyalinized zone of periodontal ligament began to appear at pressure side in 12 hours in group 2 and group 3 ; all decreased in 96 hours except in group 2. 2. Alveolar bone resorption began to appear in 12 hours in group 2 and group 3 ; Group 2 showed more resorption than group 1 and no difference to group 3. 3. Tearing of periodontal ligament and vascular dilatation began to appear at tension side in 12 hours in all groups ; Group 2 showed more changes than group 1 and no difference to group 3 ; Decrease began to appear in 96 hours. 4. New bone formation began to appear at tension side in 12 hours and increased more and more; No differences were shown of groups 5. New capillary proliferation began to appear at pressure side in 12 hours; The changes were the greatest in group 3, group 2, group 1, in that order. 6. Positive reaction of cells to [^³H]-thymidine was the greatest in 24 hours of all groups and decreased with times ; Group 2 showed more reaction than group 1 and no difference to group 3.

백서의 구개확대시 조직변화에 관한 조직학적 및 자기방사법적 연구

강정희(Kang, Jeong-hee),국윤아(Yoon-A Kook),김상철(Sang-Cheol Kim) 대한치과교정학회 1992 대한치과교정학회지 Vol.22 No.2

브라켓의 수직적 변위에 따른 마찰이 NiTi wire의 힘과 모멘트에 미치는 영향

박재범(Jea-Beom Park),유지아(Ji-A Yoo),모성서(Sung-Seo Mo),최광철(Kwangchul Choy),김윤지(Yoon-Ji Kim),한성호(Seong Ho Han),국윤아(Yoon-Ah Kook) 대한치과교정학회 2011 대한치과교정학회지 Vol.41 No.5

본 연구는 초탄성 니켈-타이타늄 wire로 수직적 높이 차이가 있는 치아의 leveling 과정을 재현하여 wire의 size와 결찰방법에 따른 force system의 변화를 알아보고 여기에 마찰력의 영향에 대해서 알아보고자 하였다. 브라켓은 0.018" slot의 standard twin bracket을 사용하였으며 교정용 wire는 0.014", 0.016" 그리고 0.016" × 0.022" NiTi를 이용하였고 수직적인 높이는 0에서 5 mm까지 1 mm 간격으로 부하와 탈부하 과정을 실험하여 다음과 같은 결론을 얻었다. 마찰력은 loading 시 wire의 stiffness를 증가시켰으며, 0.014" NiTi를 O-ring 결찰을 한 경우에 현저한 stiffness의 증가를 나타내었다. Light wire (0.014)는 수직적으로 5 mm 변위된 치아의 이동 시 2 mm, 0.016"는 3 mm, 0.016" × 0.022"는 4 mm까지의 이동에 유용한 것으로 분석되었다. 본 연구결과는 수직적 변위가 큰 경우에 light wire조차도 적절한 힘을 발휘하지 않은 것으로 나타났다. Objective: The purpose of this study was to evaluate the effect of force and moment produced by Nickel-titanium wires of different sizes at activation and deactivation according to differing vertical bracket displacement. Methods: Superelastic NiTi wires of 3 different sizes (0.014", 0.016", and 0.016" × 0.022") were tied with elastomeric or 0.009-inch stainless steel ligations in a twin-bracket, 0.018-inch slot. A testing machine recorded the effects of simulated activation of 5 distances from 1 to 5 mm and deactivation of 5 distances from 4 to 0 mm, in increments of 1 mm. Results: Frictional force increased the wire stiffness during loading. Ligation of 0.014-inch NiTi wire with O-ring resulted in a significant increase in the stiffness. On application of orthodontic force for 5 mm of vertical displacement of teeth, the effective displacement in the case of the 0.014", 0.016", and 0.016" × 0.022" NiTi wires was 2 mm, 3 mm, and 4 mm, respectively. Conclusions: Our results showed that movement of teeth with large vertical displacement was ineffective because of excessive friction. This finding might contribute to the understanding of the force system required for effective teeth movement and thereby facilitate the application of the appropriate light wire for leveling and alignment.

성견의 실험적 치아이동시 치주조직내 대식세포와 T-림파구의 활성에 관한 면역조직화학적 연구

박의웅(Eui-Woong Park),김상철(Sang-Cheol Kim),국윤아(Yoon-A Kook) 대한치과교정학회 1995 대한치과교정학회지 Vol.25 No.4

ABN각의 변화요인에 관한 연구

국윤아,김상철 원광대학교 치의학연구소 1993 圓光齒醫學 Vol.3 No.2

The purpose of this study was to investigate the factors which cause the variation of ANB angle. The cephalograms, taken from 150 subjects, 77 in Class Ⅰ malocclusions and 43 in Class Ⅱ malocclusions. 30 in Class Ⅲ malocclusions, were studied and analyzed statistically. The obtained results were as follows 1. The classification by the ANB angle agreed with the clinical classification by Angle's in 55.8% of Class I , 79.1% of Class Ⅱ, 100% of Class Ⅲ. 2. Multiple regression analysis showed that ANB angle was much influenced by SNA. SN-GoGn. in Class 1 (57.1%), SNA, SN-occlusal plane, SN-palatal plane in Class Ⅱ (56.3%), SNA, SN-GoGn, in Class Ⅲ (54.8%), SNA. SNGoGn, NSAr in total(51.9%). 3. Regression equation in Class Ⅰ was that ANB angle=0.417×(SNA angle)+0.270× (SN-GoGn)-40.608. In clinical orthodontics, the anteroposterior relationship of apical bases can be evaluated by comparing ANB angle calculated from regression equation with that angle directly measured from cephalogram.

전치 위치에 따른 측모 연조직의 변화에 관한 연구

남승규,국윤아,김상철 원광대학교 치의학연구소 1991 圓光齒醫學 Vol.1 No.2

The purpose of this study was to evaluate the influence of skeletodental element on the soft tissue profile, in orthodontic treatment. So the changes of soft tissue profile, related to skeletodental elements were examined in cases treated by four bicuspid extraction. Lateral cephalometric head films of 23 cases, before and after treatment, were traced and statistically analyzed. The obtained results were as follows 1. There were retraction in upper & lower incisor subsequent to orthodontic treatment, however lower lip retracted only and remarkable increment of upper lip thickness was shown. 2. There were significant correlations between the retraction of the upper incisor and that of lower lip and it's ratio was approximately 1.74 : 1

교정용 open coil spring의 역학적 특성에 관한 연구

박규찬,김상철,국윤아 원광대학교 치의학연구소 1992 圓光齒醫學 Vol.2 No.1

It was the purpose of this study to analyze and compare the mechanical properties of orthodontic open coil springs. Four variable facters were presented-wire diameter (.008〃, .009〃, .01〃), lumen size (.030〃, 032〃, .036〃), arch wire size and shape (.016〃found, .016〃×.022〃rect.) and alloy type (HiT Ⅱ, Elgiloy, Sentalloy). The total 104 specimens were divided into 13 groups, and compression test was performed on an Instron test machine. The load-deflection curve of each open coil spring was obtained, from which, the load-deflection relations, stifnesses, percent recoveries were computed statistically. The results were obtained as follows 1. When the lumen size of the coil spring remained constant, stiffness and percent recovery increased as the wire diameter increased. 2. When the wire diameter of the coil spring remained constant, stiffness and percent recovery decreased as the lumen size increased. 3. The effect of size and shape of arch wire on the coil spring was not statistically significant. 4. In alloy types, stiffness was the greatest in HiT Ⅱ(55.21), Elgiloy (42.61) and Sentalloy (7.74) in that order. Sentalloy exhibited superior percent recovery and long range of action.

3급 부정 교합자의 수직적 골격 요소에 관한 연구

임나원,김상철,국윤아 원광대학교 치의학연구소 1992 圓光齒醫學 Vol.2 No.2

The purpose of this study was to investigate the vertical skeletal pattern of Class Ⅲ malocclusion, and to identify the morphologic differences in relation to various facial patterns. 31 normal occlusions and 59 Class Ⅲ malocclusions were selected, and Class Ⅲ malocclusions were subdivided to horizontal group and vertical group by terms of facial height ratio. Cephalograms were measured and analyzed statistically for identification of the morphologic differences in groups. The results were as follows 1. FH-MP, PP-MP, and OP-MP angle in the vertical group were larger than those in the horizontal group. 2. AB-MP angle in the vertical group was smaller than that in the horizontal group. 3. AB-MP angle in skeletal CI Ⅲ malocclusion was smaller than that in normal occlusion. 4. OP-MP angle and (OP-MP)/(PP-MP) ratio in skeletal Cl Ⅲ malocclusion were larger than those in normal occlusion.

하악과두 전위로 인한 두부방사선계측의 변화에 관한 연구

김상철,국윤아,유기환 대한치과교정학회 1991 대한치과교정학회지 Vol.21 No.3

To determine the difference in cephalometric measurements between centric relation and centric occlusion, 60 patient-20 patients for each malocclusion group-were examined with the cephalograms in centric relation and in centric occlusion. The results are as follows: 1.There are differences in cephalometric measurements with the mandible in the two different position, and some measurements are statistically significant. 2.No clinically useful prediction may be made from cephalometric radiographs concerning the amount of mandibular deflection from centric relation to centric occlusion. 3.If, the large differences in the cephalometric measurements with the mandible in the two different position, the analysis with the cephalogram in centric occlusion is needed to be compensated with the other clinical approach.