발치후 임프란트 매식 시기에 따른 골유착에 관한 연구 : Histomorphometric and Biomechanical Studies 조직형태계측학적 및 생역학적 연구

오희균,류선열 大韓顎顔面成形再建外科學會 1994 Maxillofacial Plastic Reconstructive Surgery Vol.16 No.4

The purpose of this study was to investigate the effect of timing of implant insertion on osseointegration after tooth extraction. Fifteen mongrel dogs, weighing 15kg or more, were used. The lower right 1st, 2nd, 3rd, 4th premolars and 1st molar were extracted under general anesthesia. Implants were inserted at 2, 4, and 8 weeks after extraction of the teeth, being designated as 2-, 4-, and 8-week groups, respectively. Results obtained were as follows. 1. Macroscopically there was neither an infection at the implant site nor an exposure of the implant. 2. Histologically the surrounding bone of the implant was less mature in the 2-week group than in the 4- and 8-week groups. 3. The implant-bone contact ranged from 75 to 82%, with no significant differences among the groups. No increase in the implant-bone contact was found with increasing healing periods from 4 to 12 weeks after implant insertions. 4. The average depth (0.64mm) of the fibrous connective tissue ingrowth in the 2-week group was slightly deeper than those in the 4- (0.51mm) and 8-week (0.53mm) groups at 12 weeks after implant insertion. 5. the implant-bone interfacial bond strengths were 73.05kgf in the 2-week group, 69.71 kgf in the 4-week group and 73.76 kgf in the 8-week group. No significant difference was noted in pullout force among the groups. The degree of confidence of interfacial bone strength was highest in the 8-week group, followed by the 4- and 2-week groups. These results indicate that at least 4 weeks of healing period will be required before implant is to be inserted following tooth extraction.

구내 신연장치를 이용한 치조골 신연에 미치는 잠복기의 영향

오유근,오희균,유선열 대한악안면성형재건외과학회 2001 Maxillofacial Plastic Reconstructive Surgery Vol.23 No.4

The present study was aimed to investigate the effects of latency period on alveolar ridge distraction using the intraoral distraction device, Nine adult mongrel dogs of either sex, weighing about 15kg, were used. They were divided into 3-day, 5-day, and 7-day groups according to the latency period. The left upper and lower premolars and first molars were extracted, Twelve weeks after the extraction, an osteotomy was performed and the distraction device was applied. After the latency period, the distraction was applied at a rate of 1.2mm for 8 days. The distraction device was left in place for 2 weeks to allow consolidation and was then removed. The animals were sacrified at 8 weeks after completion of distraction and were examined macroscopically, radiographically, and histologically. After completion of the distraction, the alveolar crest protruded prominently, showing the vertical augmentation of the alveolar bone. Soft tissues were broken down after the 6th day of distraction in 3-day latency group, and premature union occurred on the 7th day of distraction in the 7-day latency group. The average distance was 9.40±0.3mm in 3-day latency group, 9.35±0.1mm in 5-day latency group, and 8.85±0.1mm in 7-day latency group. In the radiograph taken at 8 weeks after distraction, there was slight bone resorption around the medial and distal edges of the alveolar bone segment, and a new bone deposition was observed in the neighboring alveolar crest area in all groups. Fibrous tissues were present in a part of the buccal cortical bone area of the distraction gap, and the woven and lamellar bones were observed in the distracted gap. There were bony bridges in the distraction gap in all animals examined. These results suggest that optimal time of latency period on alveolar ridge distraction using the intraoral distraction device is about 5 days in dogs, and about 7days in human beings.

통계적 방법을 이용한 MR 영상의 조직 분류

임희자,송주환,오병균 木浦大學校基礎科學硏究所 1998 基礎科學硏究誌 Vol.16 No.-

We describe a segmentation of head MR images using the statistical method. This comprises five stages, such as user interactive identification of tissue classes, calculation of a probability distribution for each tissues, segmentation of MR images using the probability distribution, interpolation of the segmented MR Images, and Rendering. We segment a head MR image into four sorts of tissues, such as air, face, brain, and CSF. MRI can generate three types of MR images, such as PD(proton density), T1(spin-lattice relaxation time), and T2(spin-spin relaxation time). We calculate mean, variance, correlation from sample point of two images among the three types of images, - in results, because PD and T2 correlation is the largest one of them, we use PD and T2 MR images -and we acquire the bivariate normal probability distribution for each tissues using those. MR images are segmented using the bivariate normal probability distribution into each tissues.

Human tissue-type plasminogen activator의 국소 세척 및 전신 투여가 미세혈관 혈전증에 미치는 영향

류승희,오희균 전남대학교 치의학연구소 2003 구강과학 Vol.15 No.3

The needs of microvascular anastomosis or vessel graft to reconstruct maxillofacial tissue defect has been increased and a variety of attempts to improve the rate of patency has been achieved. Thrombolytic agents has been advocated in order to decrease the failure rate of microvascular anastomosis and to prevent the need for reoperation. Older thrombolytic agents, such as streptokinase or urokinase, have a significant side effects such as allergy, hyperthermia, systemic bleeding complications. This study was performed to evaluate the effect of local irrigation and intravenous administration of human tissue-type plasminogen activator (t-PA), which is known as effective thrombolytic agent with less systemic side effects, on patency and thrombus formation of experimental microvascular anastomoses in the traumatized femoral vein of rabbit. Nine rabbits weighing about 2㎏ were used. After exposure of both femoral veins. the veins were crushed by the jaws of smooth needle holder in order to create a thrombosis model. Transectional incision was made in the vein. The animals were then divided into 3 groups: 1) Experimental Group Ⅰ, topical irrigation of lumen with t-PA saline solution (n=6); 2) Experimental Group 2, Intravenous administration of t-PA (0.75 ㎎/㎏) via the marginal ear vein for 3 days; 3) Control Group, topical irrigation of lumen with saline solution (n=6). The veins were anastomosed utilizing microvascular technique with 10-0 Ethilon. The patency was evaluated with empty-and-refill test 30 minutes and 3 days after microanastomosis. The thrombus formation was evaluated 3 days after microanastomosis by observing the thrombus with surgical microscope. The histologic findings were also evaluated. The results were as follows: 1. Thirty minutes after microvascular anastomosis, the patency of all Experimental Groups 1 and 2 was more improved than that of Control Group. However, there was no significant difference among groups. 2. Three days after microvascular anastomosis, the patency of all Experimental Groups was much more improved than that of Control Group (p<0.05). There was no significant difference between Experiment Group 1 and Experiment Group 2. 3. Three days after microvascular anastomosis, the amount of thrombus in all Experimental Groups was much less than that of Control Group (p<0.05). 4. In histologic findings, a lot of luminal thrombus were observed around sutured area in Control Group. Few luminal thrombus was observed in all Experimental Groups. The necrotic changes were was observed in the vessel wall of all specimens. These results indicate that topical irrigation and intravenous administration of t-PA are effective measures in improving patency and preventing thrombus formation after microvascular anastomosis.

미세혈관문합시 헤파린의 국소 및 전신 투여가 혈전 형성에 미치는 영향

김성열,오희균 전남대학교 치의학연구소 2003 구강과학 Vol.15 No.2

The need of microvascular anastomosis or vascular graft has been increased gradually to reconstruct the maxillofacial defects. Despite advances in microsurgical technique, instrumentation and experience gained in clinical microvascular surgery, thrombosis of small veins may lead to the failure of microvascular surgery. A variety of anticoagulant agents have been used in either experimental or clinical microvascular surgery in order to decrease the failure rate of microvascular anastomosis and to prevent the need of reoperation. Heparin, which has been known to be effective in preventing thrombosis and in improving patency after microvascular anastomosis, is used locally or systematically. However, their effects is controversial. This study was performed to evaluate the effect of topical and intravenous heparin on thrombosis and patency in the microvascular anastomosis of the traumatized veins. Nine white rabbits wishing about 2 kg were used. After exposure of both femoral veins, the veins were crushed by the jaws of smooth needle holder in order to create a thrombosis model. Transectional incision was made in the vein. The animals were then divided into 3 groups based on the administration method of heparin: 1) Experimental Group 1, topical irrigation of lumen with heparin saline solution (n=6); 2) Experimental Group 2, topical irrigation of lumen with heparin saline solution and intravenous injection of heparin (0.75 mg/kg) via the marginal ear vein for 3 days; 3) Control Group. topical irrigation of lumen with saline solution (n=6). The veins were anastomosed utilizing microvascular technique with 10-0 Ethilon. The vascular patency was evaluated with empty-and-refill test 30 minutes and 3 days after microvascular anastomosis. The amount of thrombus was evaulated by surgery microscope 3 days after microvascular anastomosis and histologic findings were observed. The results are as follows: 1. Thirty minutes after microvascular anastomosis, the patency of all Experimental Groups was better than Control group. However, there was no significant difference among groups. 2. Three days after anastomosis, the patency of all Experimental Groups was much more improved than that of Control Group (p<0.05). There was no significant difference between Experimental Group 1 and 2. 3. Three days after anastomosis, the amount of thrombus in all Experimental Groups was much less than that of Control Group (p<0.05). 4. In histologic findings a lot of luminal thrombus were observed around sutured area in Control Groups. Few luminal thrombus was observed in all Experimental Groups. Mild necrosis in the vessel wall was observed around sutured area in all specimens. These results indicate that topical irrigation of heparin may improve the patency and inhibit the formation thrombus in the microvascular anastomosis of the traumatized veins.

이하선 종양에 관한 임상적 연구

백승,오희균,박홍주,유선열,김원재 전남대학교 치의학연구소 2002 구강과학 Vol.14 No.3

This is a clinical study on 113 patients, who were treated for parotid tumors at Chonnam National University Hospital over a period of 5 years from January 1996 to December 2000. The results were as follow, 1. The mean ages were 42.6 years old (12~73 years) for benign parotid tumor patients and 43.9 years old (2~74 years) for malignant patients. 2. The ratio of male to female was 1:2 in malignant parotid tumors, but there was no difference in sex distribution of benign tumor. 3. There was no difference in mean mass size and duration of illness between benign and nalignant tumor patients. 4. The combined use of fine needle aspiration biopsy and computed tomograph was common as the diagnostic method of parotid tumor 5. The parotid tumors were commonly located in the superficial lobe(69%). 6. The ratio of benign and malignant tumors was 4:1. The most common benign tumor was pleomorphic adenoma (72% of benign tumor), followed by Warthin's tumor and monomorphic adenoma. The most common malignant tumor was rnucoeplderrnoid carcinoma(45% of malignant tumor). followed by adenoid cystic carnoma. carcinoma ex pleomorphic adenoma, and adenocarcinoma. 7. The most common operations were superficial parotidectomy (72%) for benign parotid tumor and total parotidectomy (45%) for malignant tumor 8. The most common postoperative complication was temporary facial nerve weakness (82%), followed by Frey's syndrome (14%) and permanent facial palsy (4%). 9. Postoperative radiation therapy was done in 12 patients and the mean radiation dose was 5550±620cGy. 10. Of 113 cases. tumor recurrence developed in 12 cases (10%). These results suggest that the successful management of parotid gland tumors needs adequate surgical treatment on the basis of knowledge of parotid gland anatomy and preoperative diagnosis.

원발성 두개강내종양 2,616례의 통계학적 연구(1976-1995)

황승균,정희원,오창완,양희진,남도현,이상형,정영섭,김동규,왕규창,한대희,최길수,조병규 대한신경외과학회 1997 Journal of Korean neurosurgical society Vol.26 No.7

가토 대퇴정맥에서 헤파린 국소 적용과 혈관냉동이 미세혈관문합부 혈전 형성에 미치는 영향

김지영,오희균,김선헌 전남대학교 치과대학 2000 전남치대논문집 Vol.12 No.1

The effect of topical heparin application and vascular freezing on thrombosis was evaluated in the femoral vein of rabbits. The femoral veins were crushed, incised transversely and treated by 4 different ways; 1) group 1, heparin treated only 2) group 2, frozen only 3) group 3, heparin treated and frozen 4) group 4, treated with saline as control. The patency was evaluated by empty-and-refill test and thrombus formation was judged by stereoscopic and SEM observation, The results obtained were as follows: 1. Thirty minutes after suture, the patency was more improved in the three groups than the control, but there was no significant difference among groups. 2. Three days after suture, the patency was more improved in the three groups than the control, and were prominent in group 1 and group 3(P<0.05). 3. Significantly reduced thrombus could be seen in most case of group 3. These results suggest that topical application of heparin and vascular freezing is effective in reducing thrombus formation in microsurgery of the vein.

가토 대퇴정맥에서 헤파린 국소 적용과 혈관냉동이 미세혈관문합부 혈전 형성에 미치는 영향

김지영,오희균,유선열,김선헌 대한악안면성형재건외과학회 2001 Maxillofacial Plastic Reconstructive Surgery Vol.23 No.2

The effect of topical heparin application and vascular freezing on thrombosis was evaluated in the femoral vein of rabbits. The femoral veins were crushed, incised transverersely and treated by 4 different ways; 1) group 1, heparin treated only, 2) group 2, frozen only, 3) group 3, heparin treated and frozen,4) group 4, treated with saline as control. The patency was evaluated by empty-and-refill test and thrombus formation was judged by stereoscopic and SEM observation. The results obtained were as follows : 1.Thirty minutes after suture, the patency was more improved in the three groups than the control, but there was no significant difference among groups. 2.Three days after suture, the patency was more improved in the three groups than the control, and was prominent in group 1 and group 3 (P<0.05). 3.Significantly reduced thrombus could be seen in most case of group 3. These results suggest that topical application of heparin and vascular freezing is effective in

악골에 발생한 악성 섬유성조직구종 2례

정종철,최홍란,오희균,박준아,류선열,이종호,김영운,정숭룡 大韓顎顔面成形再建外科學會 1995 Maxillofacial Plastic Reconstructive Surgery Vol.17 No.3

Malignant fibrous histiocytoma rarely occurs in the jaws. Although the histogenesis of this tumor remains controversal, it is best regarded as a primitive and pleomorphic nature reflected by collagen production and occasional phagocytosis. It is common for metastatic foci to appear in lung and regional lymph node. There are variable treatments such as radiotherapy, surgical excision or combination, therapy of surgical excision, chemotherapy and radiotherapy. With the review of literatures, the authors report the clinical study of two cases of malignant fibrous histiocytoma of the jaw.