• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제32권5호
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• pp.436-446
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• 2006

The purpose of this study was to isolate and identify the bacteria in chronic maxillary sinusitis (CMS) lesions from 3 patients and to determine the antimicrobial susceptibility of them against 10 antibiotics. One of them was odontogenic origin and the others were non-odontogenic origin. Pus samples were collected by needle aspiration from the lesions and examined by culture method. Bacterial culture was performed in three culture systems (anaerobic, CO2, and aerobic incubator). Identification of the bacteria was performed by 16S rRNA gene (16S rDNA) nucleotide sequencing method. To test the sensitivity of the bacteria isolated from the maxillary sinusitis lesions against seven antibiotics, penicillin G, amoxicillin, tetracycline, ciprofloxacin, cefuroxime, erythromycin, clindamycin, and vancomycin, minimum inhibitory concentration (MIC) was performed using broth dilution assay. Our data showed that enterobacteria such as Enterobacter aerogenes (30%), Klebsiella pneumoniae (25%), and Serratia marcescens (15%) were predominately isolated from the lesion of non-odontogenic CMS of senile patient (70 year old). Streptococcus spp. (40.3%), Actinomyces spp. (27.4%), P. nigrescens, M. micros, and P. anaerobius strains were isolated in the lesion of odontogenic CMS. In the lesion of non-odontogenic CMS, Streptococcus spp. (68.4%), Rothia spp. (13.2%), and Actinomyces sp. (10.5%) were isolated. The susceptibility pattern of 10 antibiotics was determined according to the host of the bacteria strains ratter than the kinds of bacterial species. Even though the number of CMS was limited as three, these results indicate that antibiotic susceptibility test must be accompanied with treatment of CMS. The combined treatment of two or more antibiotics is better than single antibiotic treatment in the presence of multidrug-resistant bacteria in the CMS lesions.

• International Journal of Oral Biology
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• 제30권1호
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• pp.23-30
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• 2005

Bone remodeling is a process controlled by the action of two major bone cells; the bone forming osteoblast and the bone resorbing osteoclast. In the process of osteoclastogenesis, stromal cells and osteoblast produce RANKL, OPG, and M-CSF, which in turn regulate the osteoclastogenesis. During the bone resorption by activated osteoclasts, extracellular $Ca^{2+}/{PO_4}^{2-}$ concentration and degraded organic materials goes up, providing the hypertonic microenvironment. In this study, we tested the effects of hypertonicity due to the degraded organic materials on osteoclastogenesis in co-culture system. It was examined the cellular response of osteoblastic cell in terms of osteoclastogenesis by applying the sucrose, and mannitol, as a substitute of degraded organic materials to co-culture system. Apart from the sucrose, mannitol, and NaCl was tested to be compared to the effect of organic osmotic particles. The addition of sucrose and mannitol (25, 50, 100, 150, or 200 mM) to co-culture medium inhibited the number of tartrate-resistant acid phosphatase (TRAP) positive multinucleated cells induced by 10 nM $1{\alpha},25(OH)_2vitaminD_3$ ($1{\alpha},25(OH)_2D_3$). However, NaCl did exert harmful effect upon the cells in this co-culture system, which is attributed to DNA damage in high concentration of NaCl. To further investigate the mechanism by which hypertonicity inhibits $1{\alpha},25(OH)_2D_3$-induced osteoclastogenesis, the mRNA expressions of receptor activator of nuclear factor (NF)-kB ligand (RANKL) and osteoprotegerin (OPG) were monitored by RT-PCR. In the presence of sucrose (50 mM), RANKL mRNA expression was decreased in a dose-dependent manner, while the change in OPG and M-CSF mRNA were not occurred in significantly. The RANKL mRNA expression was inhibited for 48 hours in the presence of sucrose (50 mM), but such a decrement recovered after 72 hours. However, there were no considerable changes in the expression of OPG and M-CSF mRNA. Conclusively, these findings strongly suggest that hypertonic stress down-regulates $1{\alpha},25(OH)_2D_3$-induced osteoclastogenesis via RANKL signal pathway in osteoblastic cell, and may playa pivotal role as a regulator that modulates osteoclastogenesis.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권6호
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• pp.602-605
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• 2000

Human alveolar bone cells were isolated from alveolar bone fragments obtained from normal individual undergoing third molar extractions. Alveolar bone fragments were cultured as explant. Cells began to migrate in the first $5{\sim}7$ day and were confluent in $5{\sim}7$ week. Matrix mineralization was observed by 4 week. Our studies utilize established protocols for the characterization of these cells as osteoblasts by means of alkaline phosphatase activity determination, identification of osteocalcin antigens, establishing the presence of cells expressing type I collagen and determining the ability of cells to produce calcification. Transmission electron microscopic observations confirmed the presence of a collagen matrix undergoing a mineralization process. This new model, using human alveolar bone cells, may provide a tool to investigate alveolar bone development and physiology and to set up new therapeutic approaches.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제48권2호
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• pp.71-78
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• 2022

This study was conducted to review the efficacy of different sources of stem cells in bone regeneration of cleft palate patients. The majority of previous studies focused on the transplantation of bone marrow mesenchymal stem cells. However, other sources of stem cells have also gained considerable attention, and dental stem cells have shown especially favorable outcomes. Additionally, approaches that apply the co-culture and co-transplantation of stem cells have shown promising results. The use of different types of stem cells, based on their accessibility and efficacy in bone regeneration, is a promising method in cleft palate bone regeneration. In this regard, dental stem cells may be an ideal choice due to their efficacy and accessibility. In conclusion, stem cells, despite the lengthy procedures required for culture and preparation, are a suitable alternative to conventional bone grafting techniques.

• International Journal of Advanced Culture Technology
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• 제8권1호
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• pp.1-12
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• 2020

Pierre Robin syndrome is characterized by micrognathia, glossoptosis, and cleft palate. Infants with Pierre Robin syndrome causes feeding difficulty, upper airway obstruction, and other symptoms. This study aims to examine the effects of applying dysphagia treatment to infants with Pierre Robin syndrome. The study participant was an infant who was born four weeks premature and referred for dysphagia treatment approximately 100 days after birth. At the initial assessment, the infant showed oral sensory sensitivity, a high level of facial and masticatory muscle tension, and a low stability of the chin and cheeks with almost no normal "sucking-swallowing-breathing" pattern. We set the baseline period and intervention period using the AB design. During the baseline period, non-nutritive sucking training using a rubber nipple was conducted without implementing an oral stimulation intervention. During the intervention period, non-nutritive sucking training and an oral stimulation intervention were performed. After the intervention period, the infant's daily oral intake and oral intake per time significantly increased compared to that during the baseline period. We observed that the oral intake time of the infant decreased during the intervention period compared to that in the baseline period, which indicated an improvement in control over the chin, tongue, and lip movements, a change in muscular tension, and stabilization of the "sucking-swallowing-breathing" pattern. We provided dysphagia treatment before breastfeeding, it was positive effects such as normal development of the infant, transition from tube feeding to bottle feeding, and enhancement of overall oral motor function.

• 치위생과학회지
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• 제19권2호
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• pp.86-95
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• 2019

The modern era of microbial genome analysis began in earnest in the 2000s with the generalization of metagenomics and gene sequencing techniques. Studying complex microbial community such as oral cavity and colon by a pure culture is considerably ineffective in terms of cost and time. Therefore, various techniques for genomic analysis have been developed to overcome the limitation of the culture method and to explore microbial communities existing in the natural environment at the gene level. Among these, DNA fingerprinting analysis and microarray chip have been used extensively; however, the most recent method of analysis is metagenomics. The study summarily examined the overview of metagenomics analysis techniques, as well as domestic and foreign studies on disease genomics and cluster analysis related to oral metagenome. The composition of oral bacteria also varies across different individuals, and it would become possible to analyze what change occurs in the human body depending on the activity of bacteria living in the oral cavity and what causality it has with diseases. Identification, isolation, metabolism, and presence of functional genes of microorganisms are being identified for correlation analysis based on oral microbial genome sequencing. For precise diagnosis and treatment of diseases based on microbiome, greater effort is needed for finding not only the causative microorganisms, but also indicators at gene level. Up to now, oral microbial studies have mostly involved metagenomics, but if metatranscriptomic, metaproteomic, and metabolomic approaches can be taken together for assessment of microbial genes and proteins that are expressed under specific conditions, then doing so can be more helpful for gaining comprehensive understanding.

• Journal of Microbiology and Biotechnology
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• 제32권10호
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• pp.1234-1244
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• 2022

Oral streptococci are considered as an opportunistic pathogen associated with initiation and progression of various oral diseases. However, since the currently-available treatments often accompany adverse effects, alternative strategy is demanded to control streptococci. In the current study, we investigated whether short-chain fatty acids (SCFAs), including sodium acetate (NaA), sodium propionate (NaP), and sodium butyrate (NaB), can inhibit the growth of oral streptococci. Among the tested SCFAs, NaP most potently inhibited the growth of laboratory and clinically isolated strains of Streptococcus gordonii under anaerobic culture conditions. However, the growth inhibitory effect of NaP on six different species of other oral streptococci was different depending on their culture conditions. Metabolic changes such as alteration of methionine biosynthesis can affect bacterial growth. Indeed, NaP enhanced intracellular methionine levels of oral streptococci as well as the mRNA expression level of methionine biosynthesis-related genes. Collectively, these results suggest that NaP has an inhibitory effect on the growth of oral streptococci, which might be due to alteration of methionine biosynthesis. Thus, NaP can be used an effective bacteriostatic agent for the prevention of oral infectious diseases caused by oral streptococci.

• International Journal of Oral Biology
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• 제39권1호
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• pp.35-40
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• 2014

Halitosis is caused by consumption of certain foods or drinks and production of volatile sulfur compounds (VSCs) by periodontopathogens. VSCs-related halitosis is not easily removed using mechanical or chemical therapies such as dental floss, plaque control and mouth rinse. Lactobacillus are known to be probiotics and stimulate immune systems of human. Furthermore, L. casei ATCC 334 and L. rhamnosus GG have an effect on protection of dental caries in vitro studies. The aim of this study was to investigate effect of Lactobacillus on halitosis by Fusobacterium nucleatum- and Porphyromonas gingivalis-producing VSCs and to analyze inhibitory mechanism. The periodontopathogens were cultivated in the presence or the absence Lactobacillus, and the level of VSCs was measured by gas chromatograph. For analysis of inhibitory mechanisms, the susceptibility assay of the spent culture medium of Lactobacillus against F. nucleatum and P. gingivalis was investigated. Also, the spent culture medium of Lactobacillus and periodontopathogens were mixed, and the emission of VSCs from the spent culture medium was measured by gas chromatograph. L. casei and L. rhamnosus significantly reduced production of VSCs. L. casei and L. rhamnosus exhibited strong antibacterial activity against F. nucleatum and P. gingivalis. The spent culture medium of L. casei inhibited to emit gaseous hydrogen sulfide, methyl mercaptan and dimethyl sulfide from the spent culture medium of periodontopathogens. However, the spent medium of L. rhamnosus repressed only dimethyl sulfide. L. casei ATCC 334 may improve halitosis by growth inhibition of periodontopathogens and reduction of VSCs emission.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제31권1호
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• pp.31-38
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• 2005

Thorough screening of donors medical and social history, extensive serological and bacterial screening combined with developed processing and sterilization methods have improved the safety of the allogeneic tissues in recent decades. The risk of bacterial infection through allogenic tissue transplantation is one of the major problems facing tissue banks. The purpose study is to report the contamination rate in 358 retrieved tissues obtained strictly aseptic conditions, between 2001 and 2002 in Korea Tissue Bank. Samples from 9 donors(total 13 donors) were used in blood culture, and in 7 donors the blood culture were negative. Of the 358 tissues cultured in their entirety, 186(52%) were initially culture negative and 177(48%) were positive. Organism low pathogenicity were cultures from 20.2% of the tissues. To minimize the bacterial load, donors should be obtain in operating rooms, using aseptic techniques with only a few personnel for procurement. The procurement cultures from donors and retrieved tissues with multiple should be carefully interpreted. Blood cultures should be taken account, since these can help to find contamination not detect swab culture. A prospective cohort study is needed to determine which of the varied processing and sterilization methodologies gives the best quality.

• 디지털융복합연구
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• 제13권8호
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• pp.21-31
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• 2015

최근 음성인식기술의 향상은 세계를 새로운 구비문화의 시대로 이끌 것이다. 그것은 문자를 기반으로 하는 존재하지 않았던 말문화의 시대이며 문화적 혁명이 될 수 있다. 본 연구는 언어와 문자의 기반에 뿌리를 두고 인간을 탐구하는 인문학의 입장에서 이러한 말과 글의 상보적 관계가 야기할 수 있는 미래의 문화적 문제에 대응하는 것을 목표로 한다. 이를 위해 먼저 최근 변화되고 있는 글문화에서 말문화의 양상을 논의하고, 음성인식기술의 변화에 대해 점검한 이후, 그것이 야기할 수 있는 문화적 변동의 가능성과 문제성을 논의하게 될 것이다. 이에 대한 예상 가능성으로는 말하기와 쓰기의 상보성, 사적 문화의 공적문화로의 확대, 동시적 병행성의 가능성 등을 논하고, 문제점으로는 음성의 새로운 기호화 필요성, 생활세계로의 확대에 대한 준비, 그리고 한국문화의 글로벌 기업 종속에 저항해야 할 필요성들을 논의하였다. 본 연구는 새로운 음성인식기술과 문화변동의 가능성에 대한 단초적 연구로서, 이후 구체적이고 세분화된 후속연구들을 여는데 유용하게 활용될 수 있을 것으로 기대한다.