A comparison of fixation methods using three-dimensional finite element analysis following anterior segmental osteotomy

Kyoung In Yun,Min-Kyu Park,Myung-Kyun Park,Je Uk Park 대한구강악안면외과학회 2012 대한구강악안면외과학회지 Vol.38 No.6

Objectives: This study sought to evaluate fixation methods and determine the best method for the postoperative stabilization of maxillary osteotomy. For our analysis we performed a three-dimensional finite element analysis of stress distribution on the plate, screw, and surrounding bone, as well as displacement onto the plate. Materials and Methods: We generated a model using synthetic skull scan data; an initital surface model was changed to a solid model using software. Modified anterior segmental osteotomy (using Park’s method) was made using the program, and four different types of fixation methods were used. An anterior load of 100 N was applied on the palatal surface of two central incisors. Results: The Type 1 (L-shaped) fixation method gave stresses of 187.8 MPa at the plate, 45.8 MPa at the screw, and 15.4 MPa at the bone around the plate. The Type 2 (I-shaped) fixation method gave stresses of 186.6 MPa at the plate, 75.7 MPa at the screw, and 13.8 MPa at the bone around the plate. The Type 3 (inverted L-shaped) fixation method gave stresses of 28.6 MPa at the plate, 29.9 MPa at the screw, and 15.3 MPa at the bone around the plate. The Type 4 (I-shaped) fixation method gave stresses of 34.8 MPa at the plate, 36.9 MPa at the screw, and 14.9 MPa at the bone around the plate. The deflection of the plates for the four fixation methods was 0.014 mm, 0.022 mm, 0.017 mm, and 0.018 mm, respectively. Conclusion: The Type 3 (inverted L-shaped) fixation method offers more stability than the other fixation methods. We therefore recommend this method for the postoperative stabilization of maxillary osteotomy.

MMPI를 이용한 악교정 수술환자의 인성에 관한 연구

박우경,박재억,박수병 대한치과교정학회 1998 대한치과교정학회지 Vol.28 No.5

이 연구에서는 악교정 수술환자의 술전, 술후 인서의 특성 및 술후 변화를 알아보기 위해 실시되었으며 객관적인 인성검사의 한가지인 MMPI를 이용하였다. 악교정 수술환자들의 수술동기와 술후 만족도는 질문지를 통하여 조사하였다. 연구대상은 술전교정 중인 환자 50명과 악교정 수술을 받은 환자 22명으로 이루어졌다. 이 연구에서 얻은 결과는 다음과 같다. 1. 술전 환자군에서 K 척도를 제외한 모든 T-scores는 정상적인 범주에 놓여 있었다. K 척도값은 57.7이었으며 이것은 이 환자들이 다소 스트레스를 많이 받고 있음을 보여주었다. 2. 술후 환자군은 모든 척도에서 정상범주에 놓여 있었다. 3. 술전, 술후 환자군을 비교했을 때, 단지, T-score만이 수술 후에 통계학적으로 유의성있는 증가를 보였다.(P<0.05) 4. 남성환자는 술전 K 척도를 제외한 모든 척도에서 정상적이었으며, 술후에 K, Hs 척도에서 통계학적으로 유의성있는 증가를 보였다.(P<0.05) 5. 여성환자는 모든 T-score기 정상적인 범주에 놓여 있었다. 6. 수술동기는 크게 심미적, 기능적, 악관절문제, 정신사회학적 동기로 나눌 수 있었으며, 각각 28.2, 32.1, 9.0, 30.7%였다. 7. 수술 후 수술 동기에 대한 만족도는 매우 만족하는 환자가 전체의 14.3%, 만족하는 환자가 71.4%, 그저그렇다고 답한 환자가 9.5%였으며, 매우 불만족스러움을 답한 환자가 4.8%였다. This study was designed to evaluated the personality characteristics of orthognathic surgery patients preoperatively and postoperatively through the MMPI. Comparison was made between the personality characteristics of preoperative and postoperative groups. Motivation for undergoing orthognatic surgery and postoperative satisfaction were examined trough the questionnaire. Subjects used in this study consisted 50 patients under presurgical orthodontic treatment and 22 patients who had received orthognathic surgery. From this study, the results were followings. 1. In preoperative patients group, all T-scores were within the normal range except for K-scale. The T-score of K-scale is 57.7, this showed that these patients underwent some of less stress. 2. In postoperative patients group, all T-scores were within the normal range. 3. Only in K-scale, there was statistically significant increase after surgery(P<0.05). 4. In male patients group, all T-scores were within the normal range except for that of preoperative K-scale. Postoperatively, there were statistically significant increase in K and Hs scales(P<0.05). 5. In female patients group, all T-scores were within the normal range. 6. Motivation for undergoing orthognathic surgery could be divided into 4 categories.:esthetic goal(28.2%), functional goal(32.1%), TMJ problem(9.0%), and psychosocial reason(30.7%). 7. The degree of postoperative satisfaction was quite high(85.7%). 14.3% of all patients were very satisfied, 71.4% were satisfied, 9.5% were neither satisfied or dissatisfied, and 4.8% were very dissatisfied.

30% 과산화수소를 함유한 전문가 미백제의 효용성 평가

김신영,박재억,김창현,양성은 大韓齒科保存學會 2010 Restorative Dentistry & Endodontics Vol.35 No.1

30% 과산화수소를 함유한 전문가 미백제인 레메화이트(Remewhite, Remedent Inc., Deurle, Belgium)를 시험군 피험자 31명, 시험용 미백제에서 과산화수소를 제외한 동일한 제재를 대조약으로 대조군 피험자 31명에게 1일 3회씩, 2차례에 걸쳐서 시행하였다. 미백의 임상적 효용성은 Colorimeter, Vitapan classical shade guide를 이용하여 전체 색변화량(□E*)을 측정하였다. 14주 후와 26주 후의 색변화량을 측정하여 군 간 색변화량을 비교하였고, 각 군 내에서의 색변화량도 비교하여 다음과 같은 결론을 얻었다. 1. Colohmeter를 이용한 평가시에 시험군에서 전체 색변화량(□E*)은 대조군에 비해 통계적으로 유의한 차이를 보였고, Vitapan classical shade guide를 이용한 평가시에는 통계적으로 유의한 차이를 나타내지 않았다(p < 0.05). 2. 시간이 지남에 따라 색 복원 현상이 나타남에도 불구하고 미백 시행 14주 후와 26주 후에도 미백의 효과가 유지된다고 할수 있다. 3. Colohmeter를 이용한 평가시에 Vitapan classical shade guide를 이용한 평가시보다 작은 색변화량을 더 정확하게 측정할 수 있다. This study evaluated the efficacy of an office bleaching gel (RemeWhite, Remedent Inc., Deurle, Belgium) containing 30% hydrogen peroxide. 31 volunteers were recieved office bleaching with the RemeWhite for 3 times at one visit, total 2 visits. As control group, the same gel in which hydrogen peroxide was not included was applied to 31 volunteers with the same protocol. The shade change (□E*, color difference) of 12 anterior teeth was measured using Colorimerter and Vitapan classical shade guide. The shade change of overall teeth in the experimental group was significantly greater than that in the control group which was measured using Colorimeter. There was also a significant difference between baseline and 14 weeks or 26 weeks though color rebounding phenomenon occurred as time went by. Small shade change difference can be measured accurately using Colorimeter than using Vitapan classical shade guide.

하악골 신연술 후 생성된 신생골의 조직학적 및 면역화학적 소견

윤경인,박재억 대한악안면성형재건외과학회 2001 Maxillofacial Plastic Reconstructive Surgery Vol.23 No.3

Distraction osteogenesis(DO) can be performed in the bony defect associated with trauma, anomaly, and various kinds of disease. The gap generated by DO is filled with growing callus : during the period of distraction, the osteogenesis is continued. However, there have been few reports about expression pattern of growth factors in newly formed bone during the consolidation periods. We performed DO in the mandibular defect case and studied the expressed pattern of growth factors. Its pattern was compared to that of the same patient. BMP-2 and -4 were strongly expressed in the DO site. Particularly, BMP-4 was not expressed in the normal mature bone, but expressed in new bone in DO. However, there was no difference in the FGF-7 expression between the sites. Therefore, strong expression of BMP-4 are related to new bone formation in DO and they may not be related to the normal homeostasis in human bone. Though FGF-7 is related to the growth of keratinocyte, it may have minimal role in the DO and normal mature bone.

골격성 Ⅲ급 부정교합자의 두개안면형태에 대한 하악이부의 형태 및 하악절치의 위치에 대한 연구

김성식,박재억,손우성 대한치과교정학회 1998 대한치과교정학회지 Vol.28 No.5

골격성 Ⅲ급 부정교합자의 두개안면골격형태가 하악이부형태와 하악전치의 위치에 미치는 영향을 알아보고자 연구를 시행하였다. 전후방적인 악골부조화가 나타나지 않고 교정치료의 경험이 없는 만 20세 이상의 성인남녀(정상군)와, 하악전돌의 악골부조화를 보이며 교정치료의 경험이 없는 만 20세 이상의 성인남녀(하악전돌군)를 비교하여, 두개안면골격형태에 따른 하악이부형태와 하악전치의 위치에 관하여 다음과 같은 결론을 얻었다. 1. 두개안면골격형태의 비교에서 하악에 관련된 ∠SN-Mn, ∠FMA, ∠Pal-Mn, ∠LFH은 하악전돌군이 정상군에 비하여 크게 나타났지만, (p<0.05) 상악에 관련된 항목은 차이를 나타내지 아니하였다(p>0.05). 2. 하악전치를 둘러 싸고 있는 치조돌기는 하악전돌군이 정상군에 비해서 수평적으로 좁고, 수직적으로 긴 형태를 나타내었다(p<0.05). 하악이부의 형태에서도 수평적으로는 하악전돌군이 정상군에 비해서 좁게 나타났으나, 수직적으로는 차이를 나타내지 아니하였다(p>0.05). 3. 하악전돌군의 두개안면골격형태와 이부계측항목과의 상관관계에서 두개저와 하악하연에 기인하는 수직적인 악골부조화가 증가할수록 LaABH, LiACBW, LaACBW, LiABBW, SW, ∠LISA가 감소하는 역상관계를 나타냈지만(p<0.05), 전후반적인 악골부조화와는 별다른 상관관계가 나타나지 않았다(p>0.05). 4. 하악전돌군에서 수직적인 두개안면골격형태를 나타내는 ∠SN-Mn, ∠FMA, ∠Pal_Mn, ∠LFH와 하악이부의 계측항목인 ∠LiACBW. LiaBBW, SW, ∠LISA사이에 높은 상관관계가 존재하여, 수직적인 악골부조화로 하악이부의 형태와 하악전치의 경사도를 예측할 수 있었다(p<0.001). The purpose of this study was to evaluate the morphology of mandibular symphysis and location of lower incisor under the influence of the craniofacial skeleton in skeletal Class III malocclusion. The sample consisted of 132 adults who have severe Class III malocclusion (prognathism group, 33 males and 33 females), and who have normal occlusion (normal group, 33 males and 33 females). They had not received any orthodontic treatment or orthognathic surgery. The lateral cephalograms were evaluated. The results were as follows: 1. Prognathism group were larger than normal group in comparison of facial skeleton (p<0.05) with the exception of ∠FH-Pal, ∠SNA. 2. In the morphology of symphysis, measurements of anteroposterior width(LaABBW, LiABBW, SW) of prognathism group were significantly less than that of normal group(p<0.001). 3. In the correlative analysis between the craniofacial skeleton and symphysis measurements of prognathism group, vertical measurements in relation with cranial base and mandibular plane showed reverse correlationship with anteroposterior with of symphysis(LiACBW, LaACBW, LiABBW, SW)(p<0.05). But, there was not distinct difference between horizontal skeletal measurements and symphysis measurements(p>0.05). 4. The probability by regression test between vertical measurements(∠SN-Mn, ∠FMA, ∠Pal-Mn, ∠LFH) and symphysis measurements(LiACBW, LiABBW, SW, ∠LISA)were very high(p<0.001).

Evaluation of Soft Tissue Change after Segmental Osteotomy in Korean

Park, Je-Uk 대한치과교정학회 1998 대한치과교정학회지 Vol.28 No.6

하악 전치부 근첨하 골전단술을 동반한 상악 변형 분절골 절단술 목적은 양치조성 혹은 양악 전돌 환자로부터 가장 좋은 치료 결과를 얻은 것이다. 본 연구에서는 두부방사선 계측 분석과 정면 사진을 비교 분석해 술 후 연조직 변화를 조사하였다. 구순 전돌이 효과적으로 감소되었으며 비순각은 증가하였다. 코가 약간 넓어졌으나 결과는 비교적 양호하였다. 절단된 골분절의 혈액공급은 잘 유지되었다. 이것은 많은 환자에게 적용할 수 있는 비교적 간단한 수술법이다. Our Goal of modified segmental osteotomy on maxilla accompanied by mandibular anterior subapical osteotomy was to get the best results from patients of bi-alveolar or bi-maxillary protrusion. In this study, cephalometric and photo(en face, profile) analysis have been compared to define the soft tissue change after surgery. Lip protrusion was efficiently reduced and nasolabial angle was much obtused. Although nose was a little widened, it was quite acceptable. Blood circulation on osteotomized segment was well maintained. This relatively simple methods could be successfully applied to many patients.

Gain of a New Exon by a Lineage-Specific Alu Element-Integration Event in the BCS1L Gene during Primate Evolution

Park, Sang-Je,Kim, Young-Hyun,Lee, Sang-Rae,Choe, Se-Hee,Kim, Myung-Jin,Kim, Sun-Uk,Kim, Ji-Su,Sim, Bo-Woong,Song, Bong-Seok,Jeong, Kang-Jin,Jin, Yeung-Bae,Lee, Youngjeon,Park, Young-Ho,Park, Young Il Korean Society for Molecular and Cellular Biology 2015 Molecules and cells Vol.38 No.11

BCS1L gene encodes mitochondrial protein and is a member of conserved AAA protein family. This gene is involved in the incorporation of Rieske FeS and Qcr10p into complex III of respiratory chain. In our previous study, AluYRa2-derived alternative transcript in rhesus monkey genome was identified. However, this transcript has not been reported in human genome. In present study, we conducted evolutionary analysis of AluYRa2-exonized transcript with various primate genomic DNAs and cDNAs from humans, rhesus monkeys, and crabeating monkeys. Remarkably, our results show that AluYRa2 element has only been integrated into genomes of Macaca species. This Macaca lineage-specific integration of AluYRa2 element led to exonization event in the first intron region of BCS1L gene by producing a conserved 3' splice site. Intriguingly, in rhesus and crabeating monkeys, more diverse transcript variants by alternative splicing (AS) events, including exon skipping and different 5' splice sites from humans, were identified. Alignment of amino acid sequences revealed that AluYRa2-exonized transcript has short N-terminal peptides. Therefore, AS events play a major role in the generation of various transcripts and proteins during primate evolution. In particular, lineage-specific integration of Alu elements and species-specific Alu-derived exonization events could be important sources of gene diversification in primates.

A variation in wrinkle structures of UV-cured films with chemical structures of prepolymers

Park, Seung Koo,Kwark, Young-Je,Nam, Saekwang,Moon, Jaehyun,Kim, Dong Wook,Park, Suntak,Park, Bongje,Yun, Sungryul,Lee, Jeong-Ik,Yu, Byounggon,Kyung, Ki-Uk Elsevier 2017 Materials letters Vol.199 No.-

<P>Spontaneously wrinkled films can be easily obtained from UV-crosslinkable liquid prepolymers under special UV-curing conditions. They vary wrinkle structures of the UV-cured films and, however, cannot be precisely controlled. Here, five different UV-crosslinkable prepolymers are synthesized to study the chemical structure effect of prepolymers on wrinkle formation and modulation of the UV-cured films irrespective of the UV-curing conditions. Both wavelength and amplitude of the wrinkles are tuned with the different liquid prepolymers from 4.10 to 5.63 mu m and from 1.00 to 1.66 mu m, respectively. The wrinkle structures of the UV-cured films are faded by adding a solid prepolymer to a liquid prepolymer due to interference from it in the shrinkage of the liquid prepolymer layer. The wrinkles completely disappear in the UV-cured films fabricated from the formulated prepolymers containing over 50 wt% of the solid prepolymer. (C) 2017 Elsevier B.V. All rights reserved.</P>

Thin film display based on polymer waveguides.

Park, Suntak,Park, Bong Je,Yun, Sungryul,Nam, Saekwang,Park, Seung Koo,Kyung, Ki-Uk Optical Society of America 2014 Optics express Vol.22 No.19

<P>This paper reports thin, transparent, and soft displays based on polymer waveguides that are compliant with curvilinear interfaces. In order to prove a feasibility of optical waveguide for a flexible display, we suggest the waveguide fabricated by a multi-step lithography process using two photo-curable pre-polymers with different refractive index. The displays are composed of light sources, polymer waveguides, and scatter patterns. The light signal propagating through the waveguides forms images of the scatter patterns by deflecting the light signals to outer surface. The scatter patterns are configured to a seven-segment. The seven-segment design with a switching methodology of the light sources contributes to selectively representing all decimal numbers from 0 to 9 by combination of activated segments. For a large area display based on the proposed methodology, a single light source interconnected to multi-waveguide section is integrated with a QWERTY key pad design. The display shows high transparency and flexibility without visual distortion.</P>

Evaluation of Soft Tissue Change after Segmental Osteotomy in Korean

Je-Uk Park(박재억) 대한치과교정학회 1998 대한치과교정학회지 Vol.28 No.6