A Clinical and Histological Evaluation for Healing of Dehiscence Defects Filled with an Absorbable Atelocollagen Sponge in Dogs

( Sang Joun Yu ),( Sang Sik Moon ),( Hyun Seon Jang ),( Kyung Yoon Han ),( Kwang Se Hwang ),( Seong Ho Choi ),( Young Hyuk Kwon ),( Byung Ock Kim ) 한국조직공학·재생의학회 2012 조직공학과 재생의학 Vol.9 No.6

The objective of this study was to evaluate the effect of absorbable atelocollagen sponge on healing of hard tissue of buccal dehiscence defects in mongrel dogs. The mandibular second and fourth premolars of 12 dogs were extracted. Group 1 and Group 2 consisted of dogs without and with an inserted atelocollagen sponge after extraction with buccal plate preservation ; Group 3 and Group 4 consisted of dogs without and with an inserted atelocollagen sponge after removing two thirds of the buccal wall. At 10 weeks, Group 4 presented a significantly greater increase in the height of the alveolar bone crest than that of Group 3. Histologically, Group 2 and Group 4 showed better new bone formation ability than Groups 1, 3 at 6 weeks after extraction. The new bone formation ability of Group 3 was the poorest at 10 weeks. The results showed that the transplantation of absorbable atelocollagen sponge in the extraction socket can promote new bone formation and compensate marginal ridge reconstruction.

The increase of keratinized and attached gingiva using collagen wound dressing in dogs: A clinical and histomorphometric comparative study

( Sang Joun Yu ),( In Chae Na ),( Han Wook Jang ),( Moon Jin Jung ),( Byung Ock Kim ) 조선대학교 치의학연구원 2015 Oral Biology Research (Oral Biol Res) Vol.39 No.1

Purpose: This study examined the width of keratinized gingiva and attached gingiva after an apically repositioned flap (APF group), APF combined with free gingival grafts (FGG group), and APF combined with collagen wound dressing (Collatape® group), both clinically and histomorphometrically. Materials and Methods: The right and left maxillary canine areas of eight mongrel dogs were used (16 surgical sites). In the maxilla, the canine areas were used as experimental sites. Three different surgical techniques were performed on the sixteen canine areas(apically repositioned flap; APF group, APF combined with free gingival grafts; FGG group, and APF combined with collagen wound dressing; Collatape® group). After 6 weeks, clinical and histomorphometric evaluation were done. Results: The FGG group showed more attached gingiva and a more favorable physiological appearance than the other groups. However, there was no significant difference in keratinized gingiva and attached gingiva among the three groups. According to the results of the histomorphometric examination, keratinized gingiva were formed in all groups. The FGG group showed thicker epithelium and connective tissue than the APF group. Collatape® group showed thicker connective tissue than the APF group. Conclusion: The clinical and histomorphometric results suggested that APF combined with collagen wound dressing promotes more favorable healing of the keratinized and attached gingiva.

Effect of fibroblast growth factor on injured periodontal ligament and cementum after tooth replantation in dogs

Yu, Sang-Joun,Lee, Jung-Seok,Jung, Ui-Won,Park, Joo-Cheol,Kim, Byung-Ock,Choi, Seong-Ho Korean Academy of Periodontology 2015 Journal of Periodontal & Implant Science Vol.45 No.3

Purpose: The purpose of this animal study was to perform a histological and histomorphometric analysis in order to elucidate the effect of fibroblast growth factor-2 (FGF-2) on injured periodontal ligament (PDL) and cementum after tooth replantation in dogs. Methods: The roots of 36 mandibular premolars from six mongrel dogs were used in this study. The roots were randomly divided into three groups: (1) a positive control group (n=12), in which the PDL was retained; (2) a negative control group (n=12), in which the PDL and the cementum between the notches were removed; and (3) an experimental group (n=12), in which the PDL and the cementum between the notches were removed and the roots were soaked in an FGF-2 solution ($30{\mu}g/0.1mL$). After treating the root surfaces, the extracted roots were replanted into extraction sockets. The animals were sacrificed four and eight weeks after surgery for histologic and histomorphometric evaluation. Results: At four and eight weeks, normal PDLs covered the roots in the positive control group. In the negative control group, most replanted roots showed signs of replacement resorption. In the experimental group, new PDL-like tissue and cementum-like tissue were observed to partially occupy the region between the root surfaces and the newly formed bone. Histomorphometric analysis showed that the mean length of the newly formed cementum-like tissue on the roots treated with FGF-2 was significantly greater than that of the tissue on the roots in the negative control group (four weeks, P=0.008; eight weeks, P=0.042). However, no significant differences were observed between the roots treated with FGF-2 and the negative control roots with respect to newly formed PDL-like tissue. Conclusions: The results of this study suggest that use of FGF-2 on injured root surfaces promotes cementogenesis after tooth replacement in dogs.

Dark-state Color Shift and Gray Scale Inversion in an In-plane Switching Liquid Crystal Display Device

Sung Il Park,Kyoung-Ho Park,Joun-Ho Lee,Jeong Hwan Yoon,Byeong Koo Kim,Byeong-Hun Yu,Ki-Han Kim,윤태훈 한국광학회 2012 Current Optics and Photonics Vol.16 No.4

Off-axis color shift in the dark state and gray scale inversion in an in-plane switching (IPS) liquid crystal display (LCD) device were investigated. Analyses were performed using the Poincaré sphere representation. The results show that color shift in the dark state and gray scale inversion in an IPS LCD can be reduced by using a biaxial film. We confirmed the extent of these improvements by measuring the optical performance of a fabricated IPS LCD.

임플란트식립을 위한 치조제증대술

유상준(Sang-Joun Yu) 대한치과의사협회 2019 대한치과의사협회지 Vol.57 No.12

Alveolar bone resorption are unpredictable and always occur after tooth extraction. Such bone resorption causes insufficient alveolar ridge which make implant placement difficult. There are many techniques to increase the alveolar ridge. Representative procedures include ridge split, guided bone regeneration, bone graft using autogenous block bone, and alveolar distraction. In each procedure, there are indications and complications. Depending on the shape and the width of bone defects, we can choose procedures for horizontal bone augmentation and vertical bone augmentation.

Effect of Garcinia mangostana L. and propolis extracts on the inhibition of inflammation and alveolar bone loss in ligature-induced periodontitis in rats

Se-Jin Sung,Kyung-Min Kang,Kyung-Hyun Lee,So-Young Yoo,Joong-Ki Kook,Dae Sung Lee,Sang-Joun Yu 대한구강생물학회 2019 International Journal of Oral Biology Vol.44 No.2

The purpose of this study was to evaluate the effect of mangosteen extract complex (MEC; Garcinia mangostana L. and propolis extracts) on the inhibition of inflammation and prevention of alveolar bone loss using a ligature-induced periodontitis model. Rat molars were ligatured with silk, and 1 μg/mL of lipopolysaccharide of Porphyromonas gingivalis was injected into the buccal and palatal gingivae of the teeth with or without treatment with the MEC. Changes in the expression levels of prostaglandin E 2 (PGE 2 ), interleukin-8 (IL-8), inducible nitric oxide synthase (iNOS), matrix metalloproteinase-8 (MMP-8), cyclooxygenase (COX)-1, and COX-2 in gingival tissues were evaluated using enzyme-linked immunosorbent assays. Alveolar bone loss around the ligated molars was examined using micro-computed tomography. The expression levels of PGE 2 , IL-8, iNOS, MMP-8, COX-1, and COX-2 in gingival tissues were significantly reduced in the group treated with a mixture of 16 µg of mangosteen extract powder and 544 µg of propolis extract powder (ligation [Lig] + lipopolysaccharide extracted from P. gingivalis KCOM 2804 [L] + MEC 1:34). Additionally, alveolar bone loss was significantly reduced in the Lig + L + MEC 1:34 group compared with that in other groups. These results indicate that the MEC could be useful in preventing and treating periodontitis.

A retrospective study on survival rates of dental implants in elderly patients

Hee-Jong Shin,Sang-Joun Yu,Byung-Ock Kim 대한치과의사협회 2015 대한치과의사협회지 Vol.53 No.5

목적: 노인 환자에서 식립된 임플란트의 생존율을 조사하고 다양한 요인에 따라 생존율에 미치는 영향을 후향적으로 평가하고자 하였다. 재료 및 방법: 2001년 1월부터 2007년 12월까지 조선대학교 치과병원 치주과에 내원한 65세 이상 노인 환자 56명에게 식립된 138개의 임플란트를 대상으로 하였다.(남자 38명, 여자 18명, 평균 연령69.38 ± 3.91세) 임플란트 생존율은 환자 성별 및 연령, 전신질환 유무, 치아 상실 원인, 식립 위치, 임플란트 직경 및 길이, 골질, 골이식 여부, 상부 보철물 유형에 따라 조사되었다. Kaplan-Meier survival analysis을 통해 각 요인에 따른 누적 생존율을 조사하였고, chi-square test를 통해 누적 생존율과 각각의 요인 간의 통계학적 유의성을 평가하였다. 결과: 보철물 시적 후 5 ~ 140개월 간 추적 관찰을 시행하였다. 65세 이상 노인 환자 56명에게 식립된 총 138개의 임플란트 중 추적 관찰 기간 동안 5개의 임플란트가 실패하였다. 그 중 63개의 임플란트는 환자가 정기적인 내원 약속에 응하지 않아 도중에 조사대상에서 제외되었으며, 결과적으로5년간 누적 생존율은 94.9%였다. 임플란트 생존율에 영향을 미치는 다양한 요인 중 골질 (P=0.037) 및 상부 보철물 유형 (P=0.015) 간에 누적 생존율이 통계적으로 유의한 차이가 있었다. 그외 연령, 성별, 전신질환 유무, 치아상실 원인, 식립 위치, 임플란트 직경 및 길이, 골이식 유무 관련 요인과 누적 생존율 사이에는 통계적으로 유의한 차이가 없었다. 결론: 여러 한계가 있었지만 노인 환자의 무치악 부위에 있어 임플란트는 장기간에 걸쳐 예지성 있고 받아들여질 만한 치료이면서 적은 합병증과 실패율을 가진다.

Treatment of excessive gingival display using modified lip repositioning technique with esthetic crown lengthening: Case reports

( Gwi-hyeon Min ),( Sang-joun Yu ),( Byung-ock Kim ),( Won-pyo Lee ) 조선대학교 구강생물학연구소 2018 Oral Biology Research (Oral Biol Res) Vol.42 No.2

Excessive gingival display that can be seen when a person smiles can cause non-esthetic problem. This gummy smile is mainly caused by an altered passive eruption, bony maxillary excess, and excessive maxillary lip mobility. Thus far, an altered passive eruption has been successfully treated using esthetic crown lengthening. Recently, an alternative to orthognathic surgery has been proposed for the treatment of a gummy smile. Studies using a lip repositioning procedure have actively been performed. In this report, we present three cases of treatment for excessive gingival display using the modified lip repositioning technique associated with esthetic crown lengthening.

A retrospective study on survival rates of dental implants in elderly patients

Shin, Hee-Jong,Yu, Sang-Joun,Kim, Byung-Ock The Korean Dental Association 2015 대한치과의사협회지 Vol.53 No.5

목적: 노인 환자에서 식립된 임플란트의 생존율을 조사하고 다양한 요인에 따라 생존율에 미치는 영향을 후향적으로 평가하고자 하였다. 재료 및 방법: 2001년 1월부터 2007년 12월까지 조선대학교 치과병원 치주과에 내원한 65세 이상 노인 환자 56명에게 식립된 138개의 임플란트를 대상으로 하였다.(남자 38명, 여자 18명, 평균 연령$69.38{\pm}3.91$세) 임플란트 생존율은 환자 성별 및 연령, 전신질환 유무, 치아 상실 원인, 식립 위치, 임플란트 직경 및 길이, 골질, 골이식 여부, 상부 보철물 유형에 따라 조사되었다. Kaplan-Meier survival analysis을 통해 각 요인에 따른 누적 생존율을 조사하였고, chi-square test를 통해 누적 생존율과 각각의 요인 간의 통계학적 유의성을 평가하였다. 결과: 보철물 시적 후 5 ~ 140개월 간 추적 관찰을 시행하였다. 65세 이상 노인 환자 56명에게 식립된 총 138개의 임플란트 중 추적 관찰 기간 동안 5개의 임플란트가 실패하였다. 그 중 63개의 임플란트는 환자가 정기적인 내원 약속에 응하지 않아 도중에 조사대상에서 제외되었으며, 결과적으로 5년간 누적 생존율은 94.9%였다. 임플란트 생존율에 영향을 미치는 다양한 요인 중 골질 (P=0.037) 및 상부 보철물 유형 (P=0.015) 간에 누적 생존율이 통계적으로 유의한 차이가 있었다. 그외 연령, 성별, 전신질환 유무, 치아상실 원인, 식립 위치, 임플란트 직경 및 길이, 골이식 유무 관련 요인과 누적 생존율 사이에는 통계적으로 유의한 차이가 없었다. 결론: 여러 한계가 있었지만 노인 환자의 무치악 부위에 있어 임플란트는 장기간에 걸쳐 예지성 있고 받아들여질 만한 치료이면서 적은 합병증과 실패율을 가진다.

미니돼지에서 Acellular dermal matrix에 배양된 치주인대섬유모세포을 이용한 자가치아이식술: 치주인대로써의 잠재력에 대한 조직학적 평가

유상준,김병욱,박주철,장현선,Yu, Sang-Joun,Kim, Byung-Ock,Park, Joo-Cheol,Jang, Hyun-Seon 대한치주과학회 2007 Journal of Periodontal & Implant Science Vol.37 No.1

The aim of this study was to examine the possibility of periodontal ligament regeneration when autotransplantation was used by the periodontal ligament fibroblasts cultured on the acellular dermal matrix in teeth without a periodontal ligament. One minipig was used in this study. The mandibular and maxillary permanent incisors were ex-tracted for the culture of the periodontal ligament cells. The roots of the unextracted teeth were classified into a positive control group, in which the normal periodontal ligament was preserved. The roots of the extracted teeth were divided into the following two groups: The negative control group, in which the periodontal ligament had been removed and the acellular dermal matrix was not applied; and an experimental group, in which the periodontal ligament had been removed and periodontal ligament fibroblast cultured on an acellular dermal matrix was applied. The prepared teeth were transplanted, and completely submerged using physical barrier membranes. The animal was sacrificed 4 weeks after the autotransplant. The transplanted teeth were examined histologically. In this study, the periodontal ligament was normal in the positive control group, and ankylosis was discovered on the denuded root surface in the negative control group. Periodontal ligament-like connective tissue was found adjacent to the denuded root and the new cementum-like layer of hard tissue was formed in the experimental group. These results suggest that the periodontal ligament fibroblasts cultured on the acellular dermal matrix may play a role in regenerating the periodontal ligament-like tissue with new cememtum-like tissue formation.