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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... 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...
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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... 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...
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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... 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...
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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... 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...
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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... 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.
Research Interests: Dentistry, Medicine, Cell separation, Cell Culture, Keratinocytes, and 15 moreBasement Membrane, Head and Neck Cancer, Animals, Male, Oral Mucosa, Epithelial cells, Mouth mucosa, Endothelial cell, In vitro culture, Clinical Study, Oral mucositis, Biocompatible Materials, Collagen Type IV, Keratins, and Laminin
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... 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.
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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... 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
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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... 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...
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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... 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.
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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... 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...
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Clear aligner technology has become the preferred choice of orthodontic treatment for malocclusions for most adult patients due to their esthetic appeal and comfortability. However, limitations exist for aligner technology, such as... more
Clear aligner technology has become the preferred choice of orthodontic treatment for malocclusions for most adult patients due to their esthetic appeal and comfortability. However, limitations exist for aligner technology, such as corrections involving complex force systems. Composite attachments on the tooth surface are intended to enable active control of tooth movements. However, unintended tooth movements still occur. In this study, we present an effective attachment design of an attachment that can efficiently induce tooth movement by comparing and analyzing the movement and rotation of teeth between a general attachment and an overhanging attachment. The 3D finite element modes were constructed from CBCT data and used to analyze the distal displacement of the central incisor using 0.5- and 0.75-mm-thick aligners without an attachment, and with general and overhanging attachments. The results show that the aligner with the overhanging attachment can effectively reduce crown ti...
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INTRODUCTION AND OBJECTIVE:Treatment of muscle function loss due to traumatic injury, congenital defects, or tumor ablations is clinically challenging. The current treatment standard is grafting of...
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BACKGROUND Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a severe sequela caused by bisphosphonates (BPs), which are widely used to treat osteoporosis or other malignancies. However, the mechanism underlying BRONJ remains... more
BACKGROUND Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a severe sequela caused by bisphosphonates (BPs), which are widely used to treat osteoporosis or other malignancies. However, the mechanism underlying BRONJ remains unclear. Recently, human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) have been studied for treatment of diverse diseases and injuries. This study aimed to investigate the therapeutic effects of hUC-MSCs in BRONJ. METHODS The therapeutic effects of hUC-MSCs were examined in rat bone marrow (rBM)-derived cells using cell viability, colony-forming, and real-time PCR assays and FACS for analyzing essential proinflammatory and bone regeneration markers in vitro. To demonstrate the in vivo therapeutic and adverse effects of transfused hUC-MSCs, micro-CT, H&E staining, IHC (Angiogenesis marker gene expression) staining, and parathyroid hormone (PTH)/calcium assay were conducted in a BRONJ-induced animal model. RESULTS BP-induced cytotoxicity and inflammation in rBM-derived cells decreased, after co-culture with hUC-MSCs. The expression levels of bone regeneration markers (RUNX2, OSX, and BMP-2) significantly increased in BP-treated rBM-derived cells, after co-culture with hUC-MSCs. The BP-induced abnormal shift in RANKL/OPG expression ratio in rBM-derived cells was normalized by hUC-MSCs. Consistent with these in vitro results, transfused hUC-MSCs markedly decreased BRONJ and significantly healed injured mucosa in the BRONJ-induced animal model. The animals exhibited serious destruction of the kidney structure and increases in serum PTH and calcium levels, which were significantly normalized by hUC-MSC transfusion. CONCLUSION hUC-MSCs exerted therapeutic effects on BRONJ in vitro and in vivo through their anti-cytotoxicity, anti-inflammatory activity and ability to recover bone regeneration.
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Research Interests: Dentistry, Biology, Medicine, Humans, Female, and 9 moreSarcoma, Differential Diagnosis, Fibrosarcoma, Maxilla, CD, Aged, Vimentin, Keratins, and Odontogenic tumors
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Research Interests: Engineering, Biomedical Engineering, Hydrogels, Gene expression, Biological Sciences, and 15 moreCell Differentiation, Humans, Biomedical Materials, Polymerase Chain Reaction, Bone Tissue Engineering, Poly Ethylene Glycol, Membrane Integrity, Bone Substitutes, Cell Survival, Bone and Bones, Mesenchymal Stromal Cells, Polyethylene Glycols, Human Mesenchymal Stem Cells, reverse transcriptase polymerase chain reaction, and In Vitro Techniques
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... 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 ...
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Timely innervation of muscle tissue is critical in the recovery of function, and this time-sensitive process relies heavily on the host tissue microenvironment after implantation. However, restoration of muscle tissue mass and function... more
Timely innervation of muscle tissue is critical in the recovery of function, and this time-sensitive process relies heavily on the host tissue microenvironment after implantation. However, restoration of muscle tissue mass and function has been a challenge. We investigated whether pre-forming acetylcholine receptor (AChR) clusters on engineered muscle fibers using an AChR cluster-inducing factor (agrin) prior to implantation would facilitate established contacts between implanted muscle tissues and nerves and result in rapid innervation of engineered muscle in vivo. We showed that agrin treatment significantly increased the formation of AChR clusters on culture differentiated myotubes (C2C12), enhanced contacts with nerves in vitro and in vivo, and increased angiogenesis. Pre-fabrication of AChR clusters on engineered skeletal muscle using a released neurotrophic factor can accelerate innervations following implantation in vivo. This technique has considerable potential for enhancing muscle tissue function.
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Background Arthrocentesis of the temporomandibular joint (TMJ) is an easy, highly efficient, minimally invasive procedure for treating temporomandibular joint disorders (TMDs). However, in some cases of mouth opening limitation (MOL),... more
Background Arthrocentesis of the temporomandibular joint (TMJ) is an easy, highly efficient, minimally invasive procedure for treating temporomandibular joint disorders (TMDs). However, in some cases of mouth opening limitation (MOL), routine arthrocentesis is ineffective due to severe fibrotic adhesion in the superior joint space of the TMJ. In this condition, mechanical lysis of the adhesions might be needed to resolve the MOL, as well as other symptoms, such as chronic pain. Currently, this can be achieved by arthroscopic surgery or open TMJ surgery. The objective of this study was to introduce and evaluate our trial of the adhesion lysis procedure during arthrocentesis of the TMJ using normal 18-gauge needles. Results In this study, 40 patients with MOL due to disc derangement underwent conventional arthrocentesis at first and then physical detachment was conducted using the same needle. The change in maximum mouth opening (MMO) and the pain at the TMJ were recorded before, duri...
Background Dental studies of precocious puberty have focused on examination of jaw and dentition growth. The aim of the study was to analyze the relationship between precocious puberty and maxillary dental developmental abnormalities... more
Background Dental studies of precocious puberty have focused on examination of jaw and dentition growth. The aim of the study was to analyze the relationship between precocious puberty and maxillary dental developmental abnormalities (DDAs). Methods This retrospective study was conducted on the Korean patients in whom dental panoramic and hand-wrist radiographs had been taken before they were 15 years of age. The maxillary DDAs were assessed as mesiodens, congenital missing teeth, peg-shape lateral incisors, or impacted teeth. The chronological ages of the control group members were within the normal range of the hand-wrist bone age. Others with a peak luteinizing hormone of ≥ 5 and < 5 IU/L were allocated to central precocious puberty (CPP) and peripheral precocious puberty (PPP), respectively. Results Of the enrolled 270 patients, 195, 52, and 23 were allocated to the control, CPP, and PPP groups, respectively. The maxillary DDAs were significantly more prevalent in the CPP gro...
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Background The purpose of this study is to introduce our modified disc plication technique using MITEK mini anchors and to evaluate the clinical outcome for patients with internal derangement (ID) of the temporomandibular joint (TMJ).... more
Background The purpose of this study is to introduce our modified disc plication technique using MITEK mini anchors and to evaluate the clinical outcome for patients with internal derangement (ID) of the temporomandibular joint (TMJ). Patients and methods We evaluated 65 joints in 46 patients, comprised 32 women and 14 men, who first visited the Asan Medical Center from December 2012 to December 2016. The age of the patients ranged from 14 to 79 years, with a mean age of 36.6 years. The patients presented with joint problems including pain, joint noise, and mouth opening limitation (MOL). Patients who met our inclusion criteria underwent unilateral or bilateral disc repositioning surgery with our minimally invasive disc plication technique using MITEK mini anchors and No. 2-0 Ethibond® braided polyester sutures. The variables taken into account in this study were the range of maximum mouth opening (MMO), painful symptoms (evaluated with the visual analog scale, VAS), and the type of...
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Osteoarthritis (OA) is a degenerative condition of the temporomandibular joint (TMJ) characterised by chronic inflammation and damage to joint structures. Because of the complexity of TMJ-OA, only symptomatic treatments are currently... more
Osteoarthritis (OA) is a degenerative condition of the temporomandibular joint (TMJ) characterised by chronic inflammation and damage to joint structures. Because of the complexity of TMJ-OA, only symptomatic treatments are currently available. Recent reports have shown that many of stem cells can exert anti-inflammatory and tissue-regenerating effects. In this study, we investigated the potential cartilage-regenerating and anti-inflammatory effects of human umbilical cord matrix-mesenchymal stem cells (hUCM-MSCs) for the treatment of TMJ-OA. hUCM-MSC lines, isolated from different donors, which showed different activities in vitro. Using a selected cell line, we used different concentrations of hUCM-MSCs to assess therapeutic effects in a rabbit model of monosodium iodoacetate-induced TMJ-OA. Compared with the untreated control group, the potential regenerative result and anti-inflammatory effects of hUCM-MSCs were evident at all the tested concentrations in rabbits with induced TM...