ABSTRACT Panoramic X-ray is well known to cause DNA damage and induces cellular death. The aim of the present study was to evaluate the cytotoxicity of radiation exposure from panoramic radiography on human buccal mucosa cells by assessing the cell viability using the simple-trypan blue exclusion test. The genotoxicity effect was evaluated by assessing comet assay score. This research included a total of 20 healthy patients who had panoramic radiography for a routine dental examination. Buccal mucosa cells were collected from all participants before X-ray exposure and at 30 min or 24 h after exposure in Groups 1 and 2, respectively, and subjected to a comet assay and trypan blue exclusion test to assess cell viability and DNA damage. Cell viability was calculated as the ratio of live (translucent) to total counted cells. Comet assay output images were analysed using OpenComet software and a visual score by measuring the percentages of tail DNA and summing the visual score, respectively. A statistically significant (p < 0.05) reduce in cell viability was observed at 30 min after exposure, furthermore there is no more reduction after 24 h. Both comet assay measurements showed a significant (p < 0.05) increase in the percentage of tail DNA and visual score at 30 min after exposure, then tend to decrease after 24 h of exposure, although it was not significant (p > 0.05). The results showed that panoramic radiography interfered cell viability and induced DNA damage in buccal mucosa cells within 30 min after exposure, but these effects were ceased after 24 h.
Mouth Mucosa--cytology ; Radiography, Panoramic

OBJECTIVE: To evaluate the feasibility of STR genotyping from trace epithelial cells on fountain pen and to discuss the impact of conservation time on DNA typing. METHODS: Seven fountain pens were separately used by each of the 17 volunteers 20 minutes per day for a month and then were preserved on day 1, 3, 5, 7, 14, 21, and 28. DNA was extracted from the epithelial cells on fountain pen by silicon bead and was genotyped by Identifier kit. The corresponding control samples were buccal swabs of the above volunteers. The detectable numbers of loci were counted for assessment. RESULTS: There were statistically significant differences in the DNA genotyping by detectable numbers of gene loci between buccal swabs and epithelial cells on fountain pen of different conservation times (P < 0.01). The differences of detectable numbers of loci between the epithelial cells on fountain pen preserved on day 1, 3, 5, 7, 14, 21, 28 and the corresponding oral swabs were also statistically significant (P < 0.01). More than 12 loci could be successfully genotyped in 41.2% samples from the epithelial cells on fountain pen if the tests were performed within 24 hours. CONCLUSION The trace epithelial cells on fountain pen can be used as biological samples for personal identification, but the conservation time would have influence on the results of DNA genotyping.
Epithelial Cells/metabolism* ; Forensic Medicine ; Genotype ; Humans ; Microsatellite Repeats/genetics* ; Mouth Mucosa/cytology* ; Skin/cytology*

OBJECTIVEAt present, blood and skin biopsy tissues are used in the fluorescent in situ hybridization (FISH) test for the diagnosis of Down's syndrome, however, the samples are usually obtained invasively. This study explores the value of oral mucosa cast-off cells in the FISH test, as samples obtained non-invasively, for the diagnosis of this disorder.

METHODSPeripheral blood and oral mucosa cast-off cells were sampled for the FISH test in 16 children with suspected Down's syndrome between March 2010 and March 2011. Chromosomal karyotype analysis of peripheral blood lymphocytes ("gold standard" for the diagnosis of Down's syndrome) was also conducted.

RESULTSThe FISH test, in which both peripheral blood and oral mucosa cast-off cells were examined, showed that 14 children had 21-trosomy syndrome and the other 2 children had normal numbers of cromosome 21. The results of the FISH test were the same as the results of the chromosomal karyotype analysis.

CONCLUSIONSUse of the FISH method to test samples of oral musoca cast-off cells is non-invasive and reliable for the diagnosis of Down's syndrome in children, and is hence worthy of recommendation.

Down Syndrome ; diagnosis ; Female ; Humans ; In Situ Hybridization, Fluorescence ; methods ; Infant ; Infant, Newborn ; Male ; Mouth Mucosa ; cytology

OBJECTIVETo investigate the expression of cytokeratins (CK) in the normal human gingival epithelium and to explore the difference between junctional epithelium (JE), oral epithelium (OE) and sulcular epithelium (SE).

METHODSTeeth specimens with gingival tissue were collected from 5 people. Paraffin-embedded sections were stained with monoclonal antibodies responded respectively to human CK5/6, 7, 8/18, 10/13, 16, 17, 19, 20.

RESULTSCK7 and 17 was not expressed in all strata of JE, OE and SE. CK5/6 and 20 were weekly or moderately expressed in the suprabasal, and not expressed in the basal layer of all three epithelia. CK10/13 and 16 were positive in all strata of JE and in the suprabasal layers of OE and SE. CK10/13 was moderately to strongly expressed and CK16 was weekly to moderately expressed. The staining for CK19 was intense in all strata of JE and the basal layer of OE and SE. There was a remarkable demarcation between JE and SE. The pattern of CK8/18 expression was similar to that of CK19, but was weaker. Besides the basal layer, some suprabasal layers close to the basal layer were stained.

CONCLUSIONSJE is an unique non-differentiated stratified epithelium different from OE and SE. CK19 would be a histological marker and CK10/13, 16 would be the cellular markers to differentiate JE from OE and SE.

Epithelial Attachment ; cytology ; metabolism ; Gingiva ; metabolism ; Humans ; Keratins ; metabolism ; Mouth Mucosa ; metabolism

OBJECTIVETo investigate the origin of myofibroblasts in oral submucous fibrosis.

METHODSThe oral keratinocytes and fibroblasts were isolated and cultured. The expression of the alpha-smooth muscle actin in the fibroblasts was examined by immunohistochemistry and reverse transcriptase polymerase chain reaction (RT-PCR).

RESULTSNo difference was found in expression of alpha-smooth muscle actin between the fibroblasts that were directly stimulated by arecoline and the control. The expression of alpha-smooth muscle actin in the keratinocyte and fibroblast-cocultured group was higher than in the control group, and higher in fibroblasts cocultured with keratinocytes preprocessed by arecoline than in fibroblasts cocultured with keratinocytes without preprocessed by arecoline.

CONCLUSIONSThe differentiation of myofibroblasts from fibroblasts in oral submucous fibrosis might be induced by the interaction of arecoline and keratinocyte.

Actins ; metabolism ; Arecoline ; pharmacology ; Cell Differentiation ; drug effects ; Cells, Cultured ; Coculture Techniques ; Fibroblasts ; cytology ; metabolism ; Humans ; Keratinocytes ; cytology ; Mouth Mucosa ; cytology ; Oral Submucous Fibrosis ; metabolism ; pathology

OBJECTIVE: To seek simple and cost-effective extraction technique to improve multiplex STR amplification from minimal oral epithelial cell samples. METHODS: One hundred DNA samples of oral epithelial cells extracted by mini system Chelex-100 method were quantitated by ABI 7500 Real Time System and were then typed with Identifiler system in ABI 3130 Genetic Analyzer. RESULTS: The DNA contents of different categories of samples were as followings: suck pipes (0.72-116.78 ng), cup edges (2.15-142.5 ng), mouths of drink bottle (1-34.65 ng), chopsticks (3.35-26.6 ng), fruit cores (0.294-21.4 ng), and poultry bones (0.88-5.88 ng). The mean successful typing rate for gender and more than 9 STR loci was about 59.38%. Except the addition or no addition of proteinase K to the samples, all other factors-C users' variation, sample extraction methods, and qualities and properties of the samples had considerable effects on the contents of extracted DNA. CONCLUSION Successful STR typing can be achieved in about 60% minimal oral epithelial cell DNA samples extracted by mini Chelex system.
DNA/analysis* ; Epithelial Cells/metabolism* ; Forensic Medicine/methods* ; Humans ; Microsatellite Repeats ; Mouth Mucosa/cytology* ; Polymerase Chain Reaction

OBJECTIVE: To establish a method for DNA examination on mouth mucosa exfoliative cells from toothbrush bristles. METHODS: Slough-off mouth mucosa exfoliative cells were collected by bristles extracted method and direct washing method. The DNA of exfoliative cells was extracted with Chelex-100 method and DNA IQTM kit. Then all the extracted DNA took PCR amplification and STR analysis. RESULTS: There was a significant difference between the groups with bristles extracted method and with direct washing method at the success rates of over 9 STR loci detected (P<0.05). However, there was no statistical significance between Chelex-100 method and DNA IQTM kit (P>0.05). CONCLUSION It is demonstrated that mouth mucosa exfoliative cells collected by bristles extracted method is more available than that with direct washing method.
DNA/analysis* ; Epithelial Cells/metabolism* ; Forensic Genetics ; Humans ; Microsatellite Repeats/genetics* ; Mouth Mucosa/cytology* ; Polymerase Chain Reaction ; Toothbrushing

Animals ; Bone Regeneration ; physiology ; Cell Differentiation ; Dental Enamel Proteins ; pharmacology ; Dental Pulp ; cytology ; Fibroblasts ; cytology ; Gingiva ; cytology ; Guided Tissue Regeneration, Periodontal ; methods ; Humans ; Induced Pluripotent Stem Cells ; cytology ; physiology ; Mouth Mucosa ; cytology ; Periodontal Ligament ; cytology ; Tissue Engineering ; methods

The identification and characterization of stem cells is a major focus of developmental biology and regenerative medicine. The advent of genetic inducible fate mapping techniques has made it possible to precisely label specific cell populations and to follow their progeny over time. When combined with advanced mathematical and statistical methods, stem cell division dynamics can be studied in new and exciting ways. Despite advances in a number of tissues, relatively little attention has been paid to stem cells in the oral epithelium. This review will focus on current knowledge about adult oral epithelial stem cells, paradigms in other epithelial stem cell systems that could facilitate new discoveries in this area and the potential roles of epithelial stem cells in oral disease.
Adult Stem Cells ; cytology ; physiology ; Animals ; Asymmetric Cell Division ; Biomarkers ; Cell Proliferation ; Clone Cells ; Epithelial Cells ; cytology ; Genetic Drift ; Humans ; Mouth Mucosa ; cytology ; Mouth Neoplasms ; pathology ; Neoplastic Stem Cells

OBJECTIVETo purpose of study aimed at investigating the technique of culturing oral epithelia in vitro and to set up an experimental model for further reconstructing oral mucosa in vitro.

METHODSThe oral mucosa was taken from young New Zealand rabbits, and the mucosa was digested with enzyme and suspended in liquid to form cellular suspension. Being seeded, the cells were cultured motionlessly. The medium was changed regularly and the cells were subcultured.

RESULTSThe cultured cells were all epithelial cells without fibroblasts, and they were proved to be diploid cells. The cells were subcultured in 1-13 generations which survived for 50-60 days.

CONCLUSIONThe oral epithelium of young New Zealand rabbit can be cultured in vitro, maintaining the ability to proliferate in a certain period. It is a pilot study to reconstruct oral tissue in vitro.

Animals ; Animals, Newborn ; Cells, Cultured ; Coculture Techniques ; Epithelial Cells ; cytology ; Female ; L Cells (Cell Line) ; Male ; Mice ; Mouth Mucosa ; cytology ; Rabbits ; Tissue Engineering