Cortical Bone Thickness for Mini-implant Placement in Korean

김흥중 KOREAN ACADAMY OF ORAL BIOLOGY 2011 International Journal of Oral Biology Vol.36 No.2

Recently, mini-implant is popular in the orthodontic treatment due to its simplicity and convenient surgical procedure. The objective of this study is to provide the anatomical guideline for mini-implant placement by analysing the cortical bone thickness in Korean. Hemi-sections of sixteen maxillae and twenty-two mandibles with normal teeth were used. Interdental areas between the 1st premolar and the 2nd premolar (Group 1), the 2nd premolar and the 1st molar (Gruop 2), and the 1st molar and the 2nd molar (Group 3) were sectioned and then scanned. After setting the axis of teeth, the cortical bone thickness was measured at the distance of 2 mm, 4mm, 6 mm, and 8 mm from alveolar crest. The mean thickness of cortical bone in the maxilla according to distance from alveolar crest was 1.30 ± 0.63 mm (2 mm), 1.49 ± 0.62 mm (4mm), 1.72 ± 0.64 mm (6mm), and 1.90 ± 0.90 mm (8 mm) at the buccal side and 1.33 ± 0.47 mm, 1.31 ± 0.45 mm, 1.37 ± 0.55 mm, and 1.39 ± 0.58 mm at the palatal side. In the mandible, that was 3.14 ± 1.71 mm, 4.31 ± 2.22 mm, 4.23 ± 1.94 mm, and 4.30 ± 1.57 mm at the buccal side and 1.98 ± 0.88 mm, 2.79 ± 1.01 mm, 3.35 ± 1.27 mm, and 3.93 ± 1.38 mm at the lingual side. The buccal cortical bone thickness in the maxilla was decreased from Group 1 to Group 3, while the thickness of palatal side was no change. In the mandible, it did not show a tendency at the buccal side and it was decreased from Group 1 to Group 3 without significant difference at the lingual side. Therefore, the buccal side of the Group 1 and Group 2 in both the maxilla and mandible seems to be the most appropriate site for a mini-implant placement with taking the stability and retention.

Molecular Identification of Bacterial Species Present on Toothbrushes

Ye Won Kwon,Si Young Lee KOREAN ACADAMY OF ORAL BIOLOGY 2014 International Journal of Oral Biology Vol.39 No.4

Toothbrushes play an essential role in oral hygiene. However, they can be significant in microbial transmission and can increase the risk of infection, since they can serve as a reservoir for microorganisms in healthy, oral-diseased and medically ill adults. This study was conducted to evaluate toothbrush contamination in six toothbrushes donated from four people. Two participants each supplied two toothbrushes . one used in the bathroom and one used in the workplace. The other two people each donated two toothbrushes used in the workplace. Polymerase chain reaction was used to construct a 16S rRNA clone library. Sequences of cloned DNA were compared with those from the reference organisms provided by GenBank. A total 120 clones, representing 20 clones for each toothbrush, were analyzed. They are composed of six pylum, 46 genera and 79 species. The most dominant species were Streptococcus oralis, Streptococcus parasanguinis and Haemophilus parainfluenzae. Enterobacter and Escherichia were recovered from toothbrushes used domestically. Toothbrushes used in the workplace did not contain Enterobacteria.

Oral Microbiota Comparison between Healthy volunteers, Periodontitis patients and Oral cancer patients

Hee Sam Na,Seyeon Kim,Yoon Hee Choi,Ju-Yeon Lee,Jin Chung KOREAN ACADAMY OF ORAL BIOLOGY 2013 International Journal of Oral Biology Vol.38 No.4

The presence of distinct bacterial species is found to be dependent on age, diet, and disease. We compared the detection rate of several oral bacterial strains in a cohort of 36 subjects including healthy volunteers, periodontal patients, and oral cancer patients. Gargling samples were obtained from these subjects from which DNA was then extracted. Specific primers for 29 bacterial species were used for PCR detection. In the oral cancer patients, Capnocytophaga ochracea, Gemella morbillorum, and Streptococcus salivarius were detected more frequently compared with the healthy volunteers and periodontitis patients. Fusobacterium nucleatum/ polymorphym and Prevotella nigrescens were significantly less prevalent in oral cancer patients than the other groups. In periodontitis patients, Porphyromonas gingivalis and Treponema denticola were more frequently found compared with the healthy volunteers. In the healthy volunteer group, Peptostreptococcus anaerobius was more frequently found than the other groups. The detection rate of several oral bacterial species was thus found to differ between healthy volunteers, periodontitis patients and oral cancer patients.

Effects of Microbial Communication on The Growth of Periodontopathogens

Chung-Koo Lee,Dong-Heon Baek KOREAN ACADAMY OF ORAL BIOLOGY 2010 International Journal of Oral Biology Vol.35 No.4

Most oral microorganisms exist as biofilms which initiate formation via the attachment of an early colonizer to host proteins on the tooth surface. Fusobacterium nucleatum act as a bridge between early and late colonizers. Dental biofilms eventually comprise dental pathogens such as Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia. To evaluate the effects of mutual interactions between oral bacteria on the growth of biofilms, periodontopathogens were co-cultured with a 0.4 μm barrier. Streptococcus gordonii inhibited the growth of F. nucleatum and periodontopathogens. However, F. nucleatum, P. gingivalis and T. denticola activated the growth of other bacteria. A co-culture system of early and late colonizers could be a useful tool to further understand bacterial interactions during the development of dental biofilm.

Inhibitory Effect of Pentose on Biofilm Formation by Oral Bacteria

Young-Jong Lee,Dong-Heon Baek KOREAN ACADAMY OF ORAL BIOLOGY 2010 International Journal of Oral Biology Vol.35 No.4

A number of bacterial species coexist in oral cavities as a biofilm rather than a planktonic arrangement. By forming an oral biofilm with quorum sensing properties, microorganisms can develop a higher pathogenic potential and stronger resistance to the host immune system and antibiotics. Hence, the inhibition of biofilm formation has become a major research issue for the future prevention and treatment of oral diseases. In this study, we investigated the effects of pentose on biofilm formation and phenotypic changes using wild type oral bacteria obtained from healthy human saliva. D-ribose and D-arabinose were found to inhibit biofilm formation, but have no effects on the growth of each oral bacterium tested. Pentoses may thus be good candidate biofilm inhibitors without growth-inhibition activity and be employed for the future prevention or treatment of oral diseases.

Recombinant Azurin from Pseudomonas aeruginosa Induces Apoptotic Cell Death in Oral Squamous Carcinoma Cells

Uk-Kyu Kim,Hyun-Jun Jeon,Moo-Hyung Lee KOREAN ACADAMY OF ORAL BIOLOGY 2010 International Journal of Oral Biology Vol.35 No.2

The use of bacteria in the treatment of cancer has a long and interesting history. The use of live bacteria in this way however has a number of potential problems including toxicity. Purified low molecular weight bacterial proteins have therefore been tested as anticancer agents to avoid such complications. Oral cancer is a widely occurring disease around the world and these lesions are typically very resistant to anticancer agents. In our present study we investigated the effects of purified recombinant azurin from Pseudomonas (P.) aeruginosa against YD-9 (p53-positive) human oral squamous carcinoma cells. Azurin showed cytotoxic effects against these cells in a dose dependent manner. The cell death accompanied by this treatment was found to be characterized by chromatin condensation and apoptotic bodies. Azurin treatment was further found to increase the expression of p53 The stabilization of p53 and induction of apoptosis in YD-9 cells by azurin suggests that it has potentially very strong anticancer properties in oral squamous carcinoma.

Ethanol Extracts of Angelica decursiva Induces Apoptosis in Human Oral Cancer Cells

Myoung-Hwa Lee,Myung Mi Kim,Joong-Ki Kook,Do Kyung Kim,Hye Ryun Kim,Heung-Joong Kim,Chun Sung Kim KOREAN ACADAMY OF ORAL BIOLOGY 2010 International Journal of Oral Biology Vol.35 No.4

Angelica decursiva has been used in Korean traditional medicine as an antitussive, an analgesic, an antipyretic and a cough remedy. However, its anti-cancer properties have not yet been well defined. In our current study, we report the cytotoxic activity and the mechanism of cell death induced by ethanol extracts of Angelica decursiva (EEAD) against the human oral cancer cell line, KB. Treatment of KB cells with EEAD induced apoptotic cell death in both a dose- and time-dependent manner as determined by MTT assay and DNA fragmentation. However, no cytotoxic effects of EEAD against human normal oral keratinocytes (HNOK) were evident. By western blot analysis, we found that apoptosis in KB cells is associated with a decrease in procaspase-7 and -9. In addition, the activation of caspase-7 was detectable in living KB cells by fluorescence microscopy. These results suggest that EEAD exhibits anti-cancer activity in KB cells via apoptosis and thus has potential as an anticancer agent in future drug development strategies.

MicroRNA Analysis in Normal Human Oral Keratinocytes and YD-38 Human Oral Cancer Cells

Hye Ryun Kim,Euteum Park,Kwang-Hee Cho,Do Kyung Kim KOREAN ACADAMY OF ORAL BIOLOGY 2011 International Journal of Oral Biology Vol.36 No.4

MicroRNAs (miRNAs) are small non-coding RNAs that mediate gene expression at the post-transcriptional level by degrading or repressing targeted mRNAs. These molecules are about 21-25 nucleotides in length and exert their effects by binding to partially complementary sites in mRNAs, predominantly in the 3’-untranslated region (3’-UTR). Recent evidence has demonstrated that miRNAs can function as oncogenes or tumor suppressors through the modulation of multiple oncogenic cellular processes in cancer development, including initiation, cell proliferation, apoptosis, invasion and metastasis. In our present study, we examined the expression profile of miRNAs related to oral cancer cell growth inhibition using normal human oral keratinocytes (NHOK) and YD-38 human oral cancer cells. By miRNA microassay analysis, 40 and 31 miRNAs among the 1,769 examined were found to be up- and down-regulated in YD-38 cells compared with NHOK cells, respectively. Using qRTPCR analysis, the expression levels of miR-30a and miR-1246 were found to be increased in YD-38 cells compared with NHOK cells, whereas miR-203 and miR-125a were observed to be decreased. Importantly, the overexpression of miR-203 and miR-125a significantly inhibited the growth of YD-38 cells. This finding and the microarray data indicate the involvement of specific miRNAs in the development and progression of oral cancer.

Antimicrobial Effects of Oleanolic Acid against Streptococcus mutans and Streptococcus sobrinus Isolated from a Korean Population

Min Jung Kim,Chun Sung Kim,Woo-Hyung Ha,Byung-Hoon Kim,Yun Kyong Lim,Soon-Nang Park,Yu Jin Cho,Myungmi Kim,Jang-Hyuk Ko,Soon-Sung Kwon,Yeong-Mu Ko,Joong-Ki Kook KOREAN ACADAMY OF ORAL BIOLOGY 2010 International Journal of Oral Biology Vol.35 No.4

Oleanolic acid is a natural triterpenoid that exists widely in foods and some medicinal herbs. The purpose of this study was to determine the antimicrobial activity of oleanolic acid against Streptococcus mutans strains isolated from a Korean population. Antimicrobial activity against these bacteria was evaluated by minimal inhibitory concentration (MIC) and time kill curves. The tolerance of human gingival fibroblasts and human periodontal ligaments to oleanolic acid was tested using a methyl thiazolyl tetrazolium (MTT) assay. The MIC90 value of oleanolic acid for both S. mutans and S. sobrinus isolated from Koreans was 8 μg/ml. Oleanolic acid showed bactericidal effects against S. mutans ATCC 25175 T and S. sobrinus ATCC 33478 T at 1 × MIC (8 μg/ml) and had no cytotoxic effects against KB cells at this dose. The results suggest that oleanolic acid could be useful in the future development of oral hygiene products for the prevention of dental caries.

Comparison of Three Antibiotic Susceptibility Tests for Viridans Group Streptococci

Yeon-Hee Kim,Si Young Lee KOREAN ACADAMY OF ORAL BIOLOGY 2011 International Journal of Oral Biology Vol.36 No.4

Oral viridans streptococci are recognized as one of the etiological agents of a variety of infectious diseases such as dental caries and infective endocarditis. Although antimicrobial susceptibility tests for these fastidious bacterial species are now established and standardized, a comparison between the broth microdilution and broth macrodilution tests has not previously been performed. This comparison was performed in the present study using the tests adopted by the Clinical and Laboratory Standards Institute (CLSI) and seven clinical isolates of oral viridans streptococcal strains. A modified broth macrodilution susceptibility test method was also included in this analysis, in which the media was not supplemented with horse blood. The susceptibility interpretation category agreements were measured at 83% (broth microdilution versus broth macrodilution) and 71% (broth microdilution versus modified broth macrodilution). The interpretation category agreement between the broth macrodilution and modified broth macrodilution tests was also 83%. These data indicate that the interpretation of antibiotic susceptibility test results for oral viridans streptococci are influenced by the methods used.