Bu-Kyu Lee - Academia.edu (original) (raw)

Papers by Bu-Kyu Lee

Journal of the Korean Association of oral and maxillofacial surgeons/Journal of the Korean association of oral and maxillofacial surgeon/Daehan gu'gang ag'anmyeon oe'gwa haghoeji, Jun 30, 2024

Tissue Engineering Part C: Methods

Maxillofacial Plastic and Reconstructive Surgery

Background The use of beta-tricalcium phosphate (beta-TCP) in dental surgery is limited owing to ... more Background The use of beta-tricalcium phosphate (beta-TCP) in dental surgery is limited owing to its rapid absorption compared to mixed formulations of hydroxyapatite. However, newly developed pure beta-TCP crystals have demonstrated slow absorption; hence, they last longer within the defect and act as a scaffold until new bone formation. The oral environment is unique and can prove unfavorable for bone grafts due to the high infection rate in the oral cavity and the fragile condition of the oral mucosa. The aim of this study was to evaluate the feasibility of using pure beta-TCP bone grafts in various dental treatments. Methods Panoramic X-ray images of 25 patients who underwent bone grafting during dental surgery were analyzed. A specially treated pure beta-TCP crystal, Neo Bone® (Neo Bone®, SN Biologics Co., Ltd, Seoul, Korea), was used in this study. The bone density at the graft site was compared with that of the surrounding bone using the ImageJ software (Wayne Rasband, NIH US...

Korean Journal of Cleft Lip And Palate, 2006

Journal of The Korean Association of Oral and Maxillofacial Surgeons, 2004

Biomedical Materials, 2021

The onlay-graft, one of the most difficult graft conditions, is used for diverse clinical conditi... more The onlay-graft, one of the most difficult graft conditions, is used for diverse clinical conditions, including plastic and dental surgery. The graft should withstand continuous pressure from overlying tissues and have excellent bone formation capability in a limited bone contact situation. We recently developed a 3D printed Kagome-structured polycaprolactone (PCL) scaffold that has a stronger mechanical property. This study evaluated the clinical feasibility of this scaffold for onlay-graft use. The value of the scaffold containing recombinant human bone morphogenetic protein-2 in a hyaluronate-based hydrogel (rhBMP-2/HA) to enhance bone regeneration was also assessed. 3D-printed Kagome-PCL scaffolds alone (n = 12, group I) or loaded with rhBMP-2/HA (n = 12, group II) were grafted using a rat calvarial onlay-graft model. Following sacrifice at 2, 4, and 8 weeks, all 3D-printed Kagome-PCL scaffolds were accurately positioned and firmly integrated to the recipient bone. Micro-compute...

Bio-Design and Manufacturing

Journal of the American College of Surgeons, 2012

Background: Magnesium alloys have been receiving much attention for use in biodegradable metal im... more Background: Magnesium alloys have been receiving much attention for use in biodegradable metal implants because of their excellent mechanical properties and biocompatibility. However, their rapid breakdown and low bioactivity can cause the implant to lose mechanical integrity before the bone is completely healed. Moreover, hydrogen gas released during degradation can significantly delay the tissue regeneration process. To solve the instability of magnesium alloys, Zn and Ca can be added to improve the mechanical properties and biocompatibility. One other way to improve the mechanical properties of Mg is plasma electrolytic oxidation (PEO), which provides a dense, thick ceramic-like coating on the Mg surface. In this study, high-purity Mg was selected as the control, and Mg-1wt%Zn-0.1wt%Ca alloy and PEO-treated Mg-1wt%Zn-0.1wt%Ca alloy were selected as the test materials; the results of radiographic and histological analyses of their biocompatibility are reported herein. Materials an...

Maxillofacial plastic and reconstructive surgery, 2007

Sweet syndrome is characterized by acute onset of fever. neutrophilic leukocytosis, painful eryth... more Sweet syndrome is characterized by acute onset of fever. neutrophilic leukocytosis, painful erythematous plaque on the face and extremities, infiltration of mature neutrophils in the dermis. Cutaneous lesion and clinical symptoms rapidly improve after treatment with systemic corticosteroids. The cause of sweet syndrome is unknown but the associations with hypersensitivity to bacteria, virus, or tumor antigen have been reported. Sweet syndrome itself can be a premonitory manifestation of malignancy, so diagnostic work up for other internal malignancy is recommended. Because of fever and leukocytosis, cutaneous infections are important differentials. Sweet syndrome can be divided into 4 categories according to associated disease and symptom. (Idiopathic Sweet syndrome, Parainflammatory Sweet syndrome, Paraneoplastic Sweet syndrome, Pregnacy associated Sweet syndrome.) Sweet syndrome is relatively rare disease and the association with myelodisplastic syndrome has been reported. We repo...

Tissue Engineering and Regenerative Medicine, 2016

Journal of The Korean Association of Oral and Maxillofacial Surgeons, 2004

International Journal of Oral and Maxillofacial Surgery, 2004

The reconstruction of large defects after head and neck cancer resection often requires composite... more The reconstruction of large defects after head and neck cancer resection often requires composite tissue transfer to replace a combination of bone, muscle and mucosa. Thus, tissue engineering techniques may be useful for oral mucosal reconstructive surgery to prefabricate mucosal tissue on the muscle flap in vivo, instead of using conventional skin-bearing composite flaps. The aim of this study was to investigate whether autogenous pre-confluent oral keratinocytes (PCOK) cultured in vitro can create mucosal coverage on muscle in vivo, in a single grafting procedure. In 30 Wistar rats, with a small piece of oral mucosa (2 mm x 5 mm), oral keratinocytes were isolated and then seeded on a hydrophilic PTFE membrane (n = 50) in serum-free culture condition. After 48 h, the membrane, together with the PCOK, was transplanted onto the gracilis muscle to fabricate a mucosal flap in vivo. The wound bed was closed primarily until the time of examination. Biopsies were carried out 1, 2, 3, and 4 weeks, respectively, after transplantation and were evaluated immunohistochemically (AE1/AE3 anti-pancytokeratin, cytokeratin 5/6, collagen IV, laminin, lectin-specific labeling of N-acetylglucosamine oligomeres of endothelial cells) with relation to the following criteria: (1) graft acceptance; (2) inflammatory signs; (3) structural changes and keratinocyte lining; (4) expression of basement membrane components; and (5) vascularization. Ninety-one percent of the grafts showed uniform epithelial layers. The mean number of reconstructed epithelial cell layers was 1.7, 2.0, 1.85 and 2.7 at 1, 2, 3 and 4 weeks, respectively after transplantation (P = 0.342). Collagen IV, laminin and lectin-specific capillaries developed between the neoepithelium and the underlying muscular layer. Only two specimens showed signs of infection 2 weeks after transplantation. In conclusion, this experiment demonstrated that PCOK grafts on muscle in vivo can achieve uniform multi-layered oral epithelial coverage in a short period of time. This technique may be a useful alternative tool for oropharyngeal reconstructive surgery and is also worth considering for further clinical studies.

In vivo, 2008

BACKGROUND Recent studies have shown that matrix metalloproteinases (MMPs) from tumors influence ... more BACKGROUND Recent studies have shown that matrix metalloproteinases (MMPs) from tumors influence the host immune system to reduce antitumor activity. The aim of this study was to examine the influence of MMP-2 and MMP-9 on the natural killer (NK) cell. MATERIALS AND METHODS NK cells were pretreated with either MMP-2 or MMP-9 in the experimental group but not in the control group. NK cell cytotoxicity against oral squamous cell carcinoma cells (OSCC) were examined using the [Cr51] release assay and the expression levels of surface receptors on NK cells were measured by flow cytometry. RESULTS NK cell cytotoxicity was significantly reduced in the experimental group compared to the control group. Significant increases in KIR expression and decreases in NKG2D expression on the NK cells were observed in the experimental group. CONCLUSION This study suggests an additional role of MMP-2 and MMP-9 in an immune escape mechanism of OSCC.

Journal of korean dental science, 2019

Osteochondroma is generally known as osteocartilaginous exostosis and one of the most common beni... more Osteochondroma is generally known as osteocartilaginous exostosis and one of the most common benign tumors of long bones, accounting for about 35%~50% of benign tumors and 8%~15% of primary bone tumors. However it is very rare in the facial skeletal bone especially as a solitary type. Osteochondroma is formed as a result of endochondral ossification and increase in size via endochondral ossification from an abnormal cartilaginous epiphyseal growth plate tissue. In the craniofacial region, the most common sites of occurrence are the mandibular coronoid process and the condyle of mandible. J Korean Dent Sci. 2019;12(2):66-72 https://doi.org/10.5856/JKDS.2019.12.2.66 ISSN 2005-4742 CASE REPORT

Purpose: Platelet-rich plasma (PRP) is known to accelerate and/or enhance hard and soft tissue he... more Purpose: Platelet-rich plasma (PRP) is known to accelerate and/or enhance hard and soft tissue healing and regeneration. As such, PRP has been used in various clinical fields of surgery. Recently there have been several attempts to use PRP in the field of tissue engineering. However, some controversies still exist on exact mechanism and benefits of PRP. Therefore various animal experiments are necessary to reveal the effect of the PRP. However, even if animal experiment is performed, the efficacy of the experiment could not be validated due to absence of an animal PRP model. The purpose of this study is to establish rat PRP model by comparing several PRP fabricating methods, and to assay growth factor concentration in the PRP. Materials and methods: Rat blood samples were collected from nine SD rat (body weight: 600-800g). PRP was prepared using three different PRP fabricating methods according to previously reported literatures. (Method 1: 800 rpm, 15 minute, single centrifuge; Met...

Maxillofacial plastic and reconstructive surgery, 2009

Il Woong Cleft lip and palate foundation was founded in 1968 by Professor emeritus Byoung-Il Min.... more Il Woong Cleft lip and palate foundation was founded in 1968 by Professor emeritus Byoung-Il Min. Since then the foundation has operated numerous cleft lip and palate patients not only in Korea but also in under-developed countries such as Vietnam, China, and Cambodia. In December 2005, the foundation was allowed as an incorporated association by Ministry of Foreign affairs and Trade, so that it could have official status. From March 6th 2009 to March 14th 2009, we conductp,d charity cleft lip and palate operations of 23 patients in areas of Deozhou, China. Hereby we present the results of operations.

Applied Sciences, 2021

An alloplastic total joint replacement (TJR) is an effective and reliable treatment option in non... more An alloplastic total joint replacement (TJR) is an effective and reliable treatment option in non-salvageable end-stage temporomandibular joint (TMJ) disease. However, unilateral alloplastic TJR of the TMJ (TMJ TJR) could affect the other side natural joint because the physiologic action of both condyles is quite different during mandibular movement. In this study, we examined whether the unilaterally replaced alloplastic TMJ TJR affects the other side natural joint condition over long periods of time. Eight patients who received alloplastic TJR on one side were subjects in this study. All alloplastic TJR implants were stable in situ. The average maximum mouth opening was 37.5 mm (range 19–49 mm) pre-operatively and 44.1 mm (range 34–57 mm) post-operatively. This parameter gradually increased and reached the maximum at about twelve months after surgery. The post-operative change of pain level was significantly reduced from 3.5 to 0 on a pain scale of zero to ten. No significant comp...

Journal of the Korean Association of oral and maxillofacial surgeons/Journal of the Korean association of oral and maxillofacial surgeon/Daehan gu'gang ag'anmyeon oe'gwa haghoeji, Jun 30, 2024

Tissue Engineering Part C: Methods

Maxillofacial Plastic and Reconstructive Surgery

Background The use of beta-tricalcium phosphate (beta-TCP) in dental surgery is limited owing to ... more Background The use of beta-tricalcium phosphate (beta-TCP) in dental surgery is limited owing to its rapid absorption compared to mixed formulations of hydroxyapatite. However, newly developed pure beta-TCP crystals have demonstrated slow absorption; hence, they last longer within the defect and act as a scaffold until new bone formation. The oral environment is unique and can prove unfavorable for bone grafts due to the high infection rate in the oral cavity and the fragile condition of the oral mucosa. The aim of this study was to evaluate the feasibility of using pure beta-TCP bone grafts in various dental treatments. Methods Panoramic X-ray images of 25 patients who underwent bone grafting during dental surgery were analyzed. A specially treated pure beta-TCP crystal, Neo Bone® (Neo Bone®, SN Biologics Co., Ltd, Seoul, Korea), was used in this study. The bone density at the graft site was compared with that of the surrounding bone using the ImageJ software (Wayne Rasband, NIH US...

Korean Journal of Cleft Lip And Palate, 2006

Journal of The Korean Association of Oral and Maxillofacial Surgeons, 2004

Biomedical Materials, 2021

The onlay-graft, one of the most difficult graft conditions, is used for diverse clinical conditi... more The onlay-graft, one of the most difficult graft conditions, is used for diverse clinical conditions, including plastic and dental surgery. The graft should withstand continuous pressure from overlying tissues and have excellent bone formation capability in a limited bone contact situation. We recently developed a 3D printed Kagome-structured polycaprolactone (PCL) scaffold that has a stronger mechanical property. This study evaluated the clinical feasibility of this scaffold for onlay-graft use. The value of the scaffold containing recombinant human bone morphogenetic protein-2 in a hyaluronate-based hydrogel (rhBMP-2/HA) to enhance bone regeneration was also assessed. 3D-printed Kagome-PCL scaffolds alone (n = 12, group I) or loaded with rhBMP-2/HA (n = 12, group II) were grafted using a rat calvarial onlay-graft model. Following sacrifice at 2, 4, and 8 weeks, all 3D-printed Kagome-PCL scaffolds were accurately positioned and firmly integrated to the recipient bone. Micro-compute...

Bio-Design and Manufacturing

Journal of the American College of Surgeons, 2012

Background: Magnesium alloys have been receiving much attention for use in biodegradable metal im... more Background: Magnesium alloys have been receiving much attention for use in biodegradable metal implants because of their excellent mechanical properties and biocompatibility. However, their rapid breakdown and low bioactivity can cause the implant to lose mechanical integrity before the bone is completely healed. Moreover, hydrogen gas released during degradation can significantly delay the tissue regeneration process. To solve the instability of magnesium alloys, Zn and Ca can be added to improve the mechanical properties and biocompatibility. One other way to improve the mechanical properties of Mg is plasma electrolytic oxidation (PEO), which provides a dense, thick ceramic-like coating on the Mg surface. In this study, high-purity Mg was selected as the control, and Mg-1wt%Zn-0.1wt%Ca alloy and PEO-treated Mg-1wt%Zn-0.1wt%Ca alloy were selected as the test materials; the results of radiographic and histological analyses of their biocompatibility are reported herein. Materials an...

Maxillofacial plastic and reconstructive surgery, 2007

Sweet syndrome is characterized by acute onset of fever. neutrophilic leukocytosis, painful eryth... more Sweet syndrome is characterized by acute onset of fever. neutrophilic leukocytosis, painful erythematous plaque on the face and extremities, infiltration of mature neutrophils in the dermis. Cutaneous lesion and clinical symptoms rapidly improve after treatment with systemic corticosteroids. The cause of sweet syndrome is unknown but the associations with hypersensitivity to bacteria, virus, or tumor antigen have been reported. Sweet syndrome itself can be a premonitory manifestation of malignancy, so diagnostic work up for other internal malignancy is recommended. Because of fever and leukocytosis, cutaneous infections are important differentials. Sweet syndrome can be divided into 4 categories according to associated disease and symptom. (Idiopathic Sweet syndrome, Parainflammatory Sweet syndrome, Paraneoplastic Sweet syndrome, Pregnacy associated Sweet syndrome.) Sweet syndrome is relatively rare disease and the association with myelodisplastic syndrome has been reported. We repo...

Tissue Engineering and Regenerative Medicine, 2016

Journal of The Korean Association of Oral and Maxillofacial Surgeons, 2004

International Journal of Oral and Maxillofacial Surgery, 2004

The reconstruction of large defects after head and neck cancer resection often requires composite... more The reconstruction of large defects after head and neck cancer resection often requires composite tissue transfer to replace a combination of bone, muscle and mucosa. Thus, tissue engineering techniques may be useful for oral mucosal reconstructive surgery to prefabricate mucosal tissue on the muscle flap in vivo, instead of using conventional skin-bearing composite flaps. The aim of this study was to investigate whether autogenous pre-confluent oral keratinocytes (PCOK) cultured in vitro can create mucosal coverage on muscle in vivo, in a single grafting procedure. In 30 Wistar rats, with a small piece of oral mucosa (2 mm x 5 mm), oral keratinocytes were isolated and then seeded on a hydrophilic PTFE membrane (n = 50) in serum-free culture condition. After 48 h, the membrane, together with the PCOK, was transplanted onto the gracilis muscle to fabricate a mucosal flap in vivo. The wound bed was closed primarily until the time of examination. Biopsies were carried out 1, 2, 3, and 4 weeks, respectively, after transplantation and were evaluated immunohistochemically (AE1/AE3 anti-pancytokeratin, cytokeratin 5/6, collagen IV, laminin, lectin-specific labeling of N-acetylglucosamine oligomeres of endothelial cells) with relation to the following criteria: (1) graft acceptance; (2) inflammatory signs; (3) structural changes and keratinocyte lining; (4) expression of basement membrane components; and (5) vascularization. Ninety-one percent of the grafts showed uniform epithelial layers. The mean number of reconstructed epithelial cell layers was 1.7, 2.0, 1.85 and 2.7 at 1, 2, 3 and 4 weeks, respectively after transplantation (P = 0.342). Collagen IV, laminin and lectin-specific capillaries developed between the neoepithelium and the underlying muscular layer. Only two specimens showed signs of infection 2 weeks after transplantation. In conclusion, this experiment demonstrated that PCOK grafts on muscle in vivo can achieve uniform multi-layered oral epithelial coverage in a short period of time. This technique may be a useful alternative tool for oropharyngeal reconstructive surgery and is also worth considering for further clinical studies.

In vivo, 2008

BACKGROUND Recent studies have shown that matrix metalloproteinases (MMPs) from tumors influence ... more BACKGROUND Recent studies have shown that matrix metalloproteinases (MMPs) from tumors influence the host immune system to reduce antitumor activity. The aim of this study was to examine the influence of MMP-2 and MMP-9 on the natural killer (NK) cell. MATERIALS AND METHODS NK cells were pretreated with either MMP-2 or MMP-9 in the experimental group but not in the control group. NK cell cytotoxicity against oral squamous cell carcinoma cells (OSCC) were examined using the [Cr51] release assay and the expression levels of surface receptors on NK cells were measured by flow cytometry. RESULTS NK cell cytotoxicity was significantly reduced in the experimental group compared to the control group. Significant increases in KIR expression and decreases in NKG2D expression on the NK cells were observed in the experimental group. CONCLUSION This study suggests an additional role of MMP-2 and MMP-9 in an immune escape mechanism of OSCC.

Journal of korean dental science, 2019

Osteochondroma is generally known as osteocartilaginous exostosis and one of the most common beni... more Osteochondroma is generally known as osteocartilaginous exostosis and one of the most common benign tumors of long bones, accounting for about 35%~50% of benign tumors and 8%~15% of primary bone tumors. However it is very rare in the facial skeletal bone especially as a solitary type. Osteochondroma is formed as a result of endochondral ossification and increase in size via endochondral ossification from an abnormal cartilaginous epiphyseal growth plate tissue. In the craniofacial region, the most common sites of occurrence are the mandibular coronoid process and the condyle of mandible. J Korean Dent Sci. 2019;12(2):66-72 https://doi.org/10.5856/JKDS.2019.12.2.66 ISSN 2005-4742 CASE REPORT

Purpose: Platelet-rich plasma (PRP) is known to accelerate and/or enhance hard and soft tissue he... more Purpose: Platelet-rich plasma (PRP) is known to accelerate and/or enhance hard and soft tissue healing and regeneration. As such, PRP has been used in various clinical fields of surgery. Recently there have been several attempts to use PRP in the field of tissue engineering. However, some controversies still exist on exact mechanism and benefits of PRP. Therefore various animal experiments are necessary to reveal the effect of the PRP. However, even if animal experiment is performed, the efficacy of the experiment could not be validated due to absence of an animal PRP model. The purpose of this study is to establish rat PRP model by comparing several PRP fabricating methods, and to assay growth factor concentration in the PRP. Materials and methods: Rat blood samples were collected from nine SD rat (body weight: 600-800g). PRP was prepared using three different PRP fabricating methods according to previously reported literatures. (Method 1: 800 rpm, 15 minute, single centrifuge; Met...

Maxillofacial plastic and reconstructive surgery, 2009

Il Woong Cleft lip and palate foundation was founded in 1968 by Professor emeritus Byoung-Il Min.... more Il Woong Cleft lip and palate foundation was founded in 1968 by Professor emeritus Byoung-Il Min. Since then the foundation has operated numerous cleft lip and palate patients not only in Korea but also in under-developed countries such as Vietnam, China, and Cambodia. In December 2005, the foundation was allowed as an incorporated association by Ministry of Foreign affairs and Trade, so that it could have official status. From March 6th 2009 to March 14th 2009, we conductp,d charity cleft lip and palate operations of 23 patients in areas of Deozhou, China. Hereby we present the results of operations.

Applied Sciences, 2021

An alloplastic total joint replacement (TJR) is an effective and reliable treatment option in non... more An alloplastic total joint replacement (TJR) is an effective and reliable treatment option in non-salvageable end-stage temporomandibular joint (TMJ) disease. However, unilateral alloplastic TJR of the TMJ (TMJ TJR) could affect the other side natural joint because the physiologic action of both condyles is quite different during mandibular movement. In this study, we examined whether the unilaterally replaced alloplastic TMJ TJR affects the other side natural joint condition over long periods of time. Eight patients who received alloplastic TJR on one side were subjects in this study. All alloplastic TJR implants were stable in situ. The average maximum mouth opening was 37.5 mm (range 19–49 mm) pre-operatively and 44.1 mm (range 34–57 mm) post-operatively. This parameter gradually increased and reached the maximum at about twelve months after surgery. The post-operative change of pain level was significantly reduced from 3.5 to 0 on a pain scale of zero to ten. No significant comp...