골신장술시 반복적인 압축과 신장 방법이 골형성에 미치는 영향

윤병욱,김여갑,오정환,Yoon, Byung-Wook,Kim, Yeo-Gab,Oh, Jung-Hwan 대한악안면성형재건외과학회 2008 Maxillofacial Plastic Reconstructive Surgery Vol.30 No.5

Purpose: The aim of the present study is to evaluate the effect of repetitive distraction and compression on new bone formation during distraction period. Materials and methods: Sixteen healthy rabbits, weighing about 2.5kg, were used in this experiment. A unilateral mandibular osteotomy was performed in the left mandible and the distractor(Track 1 $plus^{(R)}$, Gebruder Martin $GmbH^{(R)}$, Germany) was fixed with four screws (Cross driver screw $TI^{(R)}$, Gebruder Martin $GmbH^{(R)}$, Germany). After 4 days, the mandibles were distracted at a rate of 0.6mm/day for 10 days to obtain the amount of 6mm distraction in the control group(n=4). In the experimental group A(n=6), they were distracted at a rate of 1.2mm/day for 5 days and then compression of 0.6mm length and distraction of 0.6mm per 12 hours were carried out as counter direction for 5 days, relatively. In the experimental group B(n=6), distraction of 1.2mm length and compression of 0.6mm length per 12 hours were repeated for 10 days to obtain the amount of 6mm distraction finally. The experimental animals were sacrificed at 2 and 4 weeks after surgery and block specimens were obtained. With histologic and histomorphometric analysis, we observed the histologic changes of the cells and bone formation after H-E and Masson- Trichrome staining and then, measured Bone Deposition Rate with TOMORO $ScopeEye^{TM}$ ver. 3.5(Olympus, Japan), Results: Histologically, new bone formation was examined in all experimental groups and the control. But, the ability of bone formation of the experimental group A was somewhat better than any other groups. On the histomorphometric analysis, Bone Deposition Rate was higher in the experimental group A$(50.67{\pm}4.36%)$ than in the control group$(45.94{\pm}3.97%)$ and in the experimental group B$(42.68{\pm}5.70%)$. These data showed significant differences statistically(p<0.05). Conclusion: These results show that the distraction osteogenesis using repetitive compression and distraction force in the early consolidation period may be effective for new bone formation.

Bisphosphonate, 구강악안면외과 영역의 새로운 위험 요소인가?

권용대,윤병욱,Kwon, Yong-Dae,Yoon, Byung-Wook,Walter, Christian 대한악안면성형재건외과학회 2007 Maxillofacial Plastic Reconstructive Surgery Vol.29 No.5

Since the first description of bisphosphonate related osteonecrosis of the jaw (BRONJ) in 2002, the number of report on the disease has rapidly been increasing. Now, BRONJ is considered as a new entity, which is emerging problem in oral and maxillofacial surgery. Bisphosphonates (BPs) can be categorized into 2 groups: nitrogen-containing and non-nitrogen containing, and nitrogen-containing BPs are considered to have more efficacy and toxicity possibly. It is unusual for osteonecrosis to occur in the maxilla but BRONJ is found in both the mandible and the maxilla, which is one of the special features of BRONJ compared with common infectious osteomyelitis of the jaws. Intravenous BPs are usually more likely to cause BRONJ than oral BPs which are frequently prescribed for osteoporosis and osteopenia. Nonetheless, the use of intravenous BPs cannot be prevented because of systemic condition of the patients. Although it is rare that oral BPs cause BRONJ in osteoporosis/osteopenia patients, we should be aware of BRONJ since the population of the patients is exceedingly increasing with the prolonging of life expectancy. So, we'd like to enlighten upon the problems and solutions of BRONJ.

후생유전학 (Epigenetics)과 DNA methylation의 이해

오정환,권용대,윤병욱,최병준,Oh, Jung-Hwan,Kwon, Young-Dae,Yoon, Byung-Wook,Choi, Byung-Jun 대한악안면성형재건외과학회 2008 Maxillofacial Plastic Reconstructive Surgery Vol.30 No.3

DNA 메틸화는 histone modification과 함께 DNA의 염기서열이 유지되면서 유전기능이 변화되고 자손까지 전달 될 수 있는 후생 유전의 중요한 한 부분이다. DNA 메틸화는 크로마틴의 구조를 변경시키는 과정을 통하여 유전자와 repetitive sequence의 표현을 억제시킬 수 있다. DNA 메틸화는 X-불활성화, 유전체 각인, 유전자 발현조절, 암 생성 등에 중요한 역할을 하는 것으로 밝혀졌고, DNA 메틸화 표지자 (DNA methylation marker)들은 종양의 진단과 치료에 대한 반응을 예측하는 지표로 활용되고 있다. 지금까지 많은 연구 성과에도 불구하고 DNA메틸화, 메틸화에 의한 gene silencing, DNA 메틸화의 표적부위 등에 대한 명확한 기전이 아직도 밝혀지지 않고 있어 향후 더 많은 기초적 연구가 필요할 것이다. 최근에는 후생 유전적 변화는 가역적이기 때문에 종양억제유전자를 억압하는 후생 유전적 변화를 제거한다면 그 종양억제유전자를 다시 활성화시킬 수 있다는 개념의 후생유전 치료법 연구로 DNA 메틸화 억제제와 histone deacetyaltion에 관여하는 HDAC의 억제제들이 항암제로서 개발되어 사용되고 있는데 향후 더 많은 약제 개발과 임상적 연구가 진행되어야 할 것이다. Epigenetic is usually referring to heritable traits that do not involve changes to the underlying DNA sequence. DNA methylation is known to serve as cellular memory. and is one of the most important mechanism of epigenetic. DNA methylation is a covalent modification in which the target molecules for methylation in mammalian DNA are cytosine bases in CpG dinucleotides. The 5' position of cytosine is methylated in a reaction catalyzed by DNA methyltransferases; DNMTl, DNMT3a, and DNMT3b. There are two different regions in the context of DNA methylation: CpG poor regions and CpG islands. The intergenic and the intronic region is considered to be CpG poor, and CpG islands are discrete CpG-rich regions which are often found in promoter regions. Normally, CpG poor regions are usually methylated whereas CpG islands are generally hypomethylated. DNA methylation is involved in various biological processes such as tissue-specific gene expression, genomic imprinting, and X chromosome inactivation. In general. cancer cells are characterized by global genomic hypomethylation and focal hypermethylation of CpG islands, which are generally unmethylated in normal cells. Gene silencing by CpG hypermethylation at the promotors of tumor suppressor genes is probably the most common mechanism of tumor suppressor inactivation in cancer.

수면 결핍과 스트레스에 의한 술후 조증 삽화에 대한 증례보고

공준하,이백수,김여갑,권용대,윤병욱,최병준,Kong, Jun-Ha,Lee, Baek-Soo,Kim, Yeo-Gab,Kwon, Yong-Dae,Yoon, Byung-Wook,Choi, Byung-Joon 대한악안면성형재건외과학회 2008 Maxillofacial Plastic Reconstructive Surgery Vol.30 No.1

Mania in psychiatry describes not only the state of temporary elation of the mood but also of the general mental function such as contents of a thought, thinking process, motivation, enthusiasm, interest, behavior, slumber and physical activities. The time of period when the above changes of mood, mental and behavioral disorder appear is called a manic episode. Postoperative mania is very rare and it has been reported only 5 times in english literature. It's an extremely rare case which has not yet been reported in Oral and Maxillofacial surgery. Patients normally deny the symptoms and it is easy to miss the diagnosis since the patient tends to seem content and happy. Patients show the following initial symptoms of mania - postoperative insomnia, atypical gregariousness, euphoria and unstability. Patients who are not disaffected with insomnia can also be included.

인간 게놈의 단일염기변형 (Single Nucleotide Polymorphism; SNP)에 대한 이해

오정환(Jung-Hwan Oh),윤병욱(Byung-Wook Yoon) 대한구강악안면외과학회 2008 대한구강악안면외과학회지 Vol.34 No.4

A Single Nucleotide Polymorphism (SNP) is a small genetic change or variation that can occur within a DNA sequence. It’s the difference of one base at specific base pair position. SNP variation occurs when a single nucleotide, such as an A, replaces one of the other three nucleotide letters-C, G, or T. On average, SNP occur in the human population more than 1 percent of the time. They occur once in every 300 nucleotides on average, which means there are roughly 10 million SNPs in the human genome. Because SNPs occur frequently throughout the genome and tend to be relatively stable genetically, they serve as excellent biological markers. They can help scientists locate genes that are associated with disease such as heart disease, cancer, diabetes. They can also be used to track the inheritance of disease genes within families. SNPs may also be associated with absorbance and clearance of therapeutic agents. In the future, the most appropriate drug for an individual could be determined in advance of treatment by analyzing a patient’s SNP profile. This pharmacogenetic strategy heralds an era in which the choice of drugs for a particular patient will be based on evidence rather than trial and error (so called“ personalized medicine”).

DNA 염기손상 치유유전자의 변이와 두경부암 발생 위험성

오정환(Jung-Hwan Oh),윤병욱(Byung-Wook Yoon),최병준(Byung-Jun Choi) 대한구강악안면외과학회 2008 대한구강악안면외과학회지 Vol.34 No.5

DNA damage accumulates in cells as a result of exposure to exogenous agents such as benzopyrene, cigarette smoke, ultraviolet light, X-ray, and endogenous chemicals including reactive oxygen species produced from normal metabolic byproducts. DNA damage can also occur during aberrant DNA processing reactions such as DNA replication, recombination, and repair. The major of DNA damage affects the primary structure of the double helix; that is, the bases are chemically modified. These modification can disrupt the molecules’regular helical structure by introducing non-native chemical bonds or bulky adducts that do not fit in the standard double helix. DNA repair genes and proteins scan the global genome to detect and remove DNA damage and damage to single nucleotides. Direct reversal of DNA damage, base excision repair, double strand break. DNA repair are known relevant DNA repair mechanisms. Four different mechanisms are distinguished within excision repair: direct reversal, base excision repair, nucleotide excision repair, and mismatch repair. Genetic variation in DNA repair genes can modulate DNA repair capacity and alter cancer risk. The instability of a cell to properly regulate its proliferation in the presence of DNA damage increase risk of gene mutation and carcinogenesis. This article aimed to review mechanism of excision repair and to understand the relationship between genetic variation of excision repair genes and head and neck cancer.

치조골 신장술 후 발생한 문제점의 해결책 및 예방법 : 증례보고

김영란,김여갑,이백수,권용대,윤병욱,최병준,유용재,오정환,Kim, Young-Ran,Kim, Yeo-Gab,Lee, Baek-Soo,Kwon, Yong-Dae,Yoon, Byung-Wook,Choi, Byung-Joon,Yu, Yong-Jae,Oh, Jung-Hwan 대한악안면성형재건외과학회 2008 Maxillofacial Plastic Reconstructive Surgery Vol.30 No.5

For the successful placement of dental implants, adequate alveolar bone height and width are required. Alveolar distraction osteogenesis is an effective method that resolves insufficient alveolar bone height for dental implant placement, and thus has been clinically applied with satisfactory results. But, minor and major problems may occur during the treatment. In the following report, we studied for such problematic cases. The problems are as follows: 1) sharp edges of the transport segment, 2) infection, 3) soft tissue dehiscence, 4) limitation of distraction, 5) numbness, 6) insufficient bone formation. But, most of them were answered by simple solutions and did not jeopardize the final outcomes. Distraction osteogenesis can be considered a safe and predictable procedure for lengthening the alveolar bone.

임프란트 식립시 이식된 탈회골기질을 함유한 이식재의 골형성에 대한 연구

김여갑(Yeo-Gab Kim),윤병욱(Byung-Wook Yoon),류동목(Dong-Mok Ryu),이백수(Baek-Soo Lee),오정환(Jung-Hwan Oh),권용대(Yong-Dae Kwon) 대한구강악안면외과학회 2005 대한구강악안면외과학회지 Vol.31 No.6

Purpose: The aim of the present study is to evaluate the effect of autogenous bone and allograft material coverd with a bioresorbable membrane on bone regeneration after a simultaneous installation of implant. Materials and methods: Twelve healthy rabbits, weighing about 3~4 kg, were used in this experiment. Following impalnt(with 3.25 mm diameter and 8 mm length) site preparation by surgical protocol of Oraltronics, artificial bony defect, 5mm sized in height and depth, was created on femoral condyle using trephine drill(with 5 mm diameter and 5 mm length). Then implant was inserted. In the experimental group A, the bony defect was filled with autogenous particulated bone and coverd with Lyoplant resorbable membrane. In the experimental group B, the bony defect was filled with allograft material(Orthoblast II) containing demineralized bone matrix and covered with Lyoplant. In the control group, without any graft materials, the bony defect was covered with Lyoplant. The experimental group A and B were divided into each 9 cases and control group into 3 cases. The experimental animals were sacrificed at 3, 6 and 8 weeks after surgery and block specimens were obtained. With histologic and histomorphometric analysis, we observed the histologic changes of the cells and bone formation after H-E staining and then, measured BIC and bone density with KAPPA Image Base system. Results: As a result of this experiment, bone formation and active remodeling process were examined in all experimental groups and the control. But, the ability of bone formation of the experimental group A was somewhat better than any other groups. Especially bone to-implant contact fraction ranged from 12.7% to 43.45% in the autogenous bone group and from 9.02% to 29.83% in DBM group, at 3 and 8 weeks. But, bone density ranged from 15.67% to 23.17% in the autogenous bone group and from 25.95% to 46.06% in DBM group at 3 and 6 weeks, respectively. Although the bone density of DBM group was better than that of autogenous bone group at 3 and 6weeks, the latter was better than the former at 8 weeks, 54.3% and 45.1%, respectively. Therefore these results showed that DBM enhanced the density of newly formed bone at least initially.

TMS320C32를 이용한 한시 과전류 계전기의 구현

유성록(Sung-Rok Yoo),윤병욱(Byung-Wook Yoon),박병우(Byung-woo Park),최창영(Chang Yung choi),강상희(Sang-Hee Kang) 대한전기학회 2009 대한전기학회 학술대회 논문집 Vol.2009 No.7

A digital over current relay(OCR) is realized by using TMS320C32 microprocessor. Fourier Transform is used to obtain the phasor of a current signal and a 2nd low pass filter is adopted to prevent aliasing error. H/W test shows almost same results with those of the S/W test. It could be possible that confirm simularity between H/W and S/W test in this paper

짧은 길이의 거친 표면 임프란트에 대한 후향적 연구

공준하,이백수,김여갑,권용대,윤병욱,최병준,Kong, Jun-Ha,Lee, Baek-Soo,Kim, Yeo-Gab,Kwon, Yong-Dae,Yoon, Byung-Wook,Choi, Byung-Joon 대한악안면성형재건외과학회 2009 Maxillofacial Plastic Reconstructive Surgery Vol.31 No.1

Background: Reduced bone height is one of the major problems faced in restoring tooth loss with implants. By the use of short implants, it is possible to reduce complicated and invasive treatment such as bone graft, allowing more simple surgery. But short implants are generally considered to have lower success rates than that of standard implants. Purpose: To assess the results of short Straumann implants by a retrospective study of short Straumann implants with TPS(titanium plasma-sprayed) and SLA(sandblasted, large grit, acid etched) surfaces. Materials and methods: 173 implants in 106 patients who received short Straumann implant surgery(${\le}8\;mm$) in the department of oral and maxillofacial surgery, Kyunghee Dental Hospital, from February 1996 to October 2006 were selected and studied. All of the implants were followed up after prosthetic rehabilitation. The average follow-up period was 34 months with 119 months as the longest follow up period. The average follow-up period after prosthetic rehabilitation was 31 months. 64 females(60.4%) and 42 males(39.6%) participated in the research with the age range of 19 to 85(mean age 47). 20 patients(18.9%) were under 40, 85 patients(80.2%) were over 40 and under 70, and only one patient(0.9%) was over 70 years old. Results: 27 implants(15.6%) had TPS surface while 146 implants(84.4%) had SLA surface. 9 implants(5.2%) were 3.3, 108 implans(62.4%) were 4.1mm and 56 implants(32.4%) were 4.8mm in diameter. 167 implants(96.5%) were 8mm and 6 implants(3.5%) were 6mm in length. There were 24 implants(13.9%) on the maxillas and 149 implants(68.8%) on the mandibles. 119 implants(68.8%) were rehabilitated with FPD(fixed partial denture), 47 implants(27.2%) with single crowns and 4 implants(2.3%) with overdentures. Among the fixed partial dentures, 30 of them were splinted with short implants only. After over an year of follow-up period, 139 implants(96.5%) out of 144 implants showed marginal bone loss of less than 1mm. 3 out of 173 implants failed showing 98.27% survival rate. Conclusions: The use of short Straumann implants(${\le}8mm$) can be a simple and reliable treatment method in minimal residual bone height.