So-Youn An

Comparison of mesenchymal-like stem/progenitor cells derived from supernumerary teeth with stem cells from human exfoliated deciduous teeth

AIMS Dental tissue has been the focus of attention as an easily accessible postnatal tissue source of high-quality stem cells. Since the first report on the dental pulp stem cells (DPSCs) from permanent third molar teeth, stem cells from human exfoliated deciduous teeth (SHED) were identified as a population distinct from DPSCs. In this study, we compared DPSCs from supernumerary teeth and SHED in three age- and sex-matched patients. PATIENTS & METHODS Dental samples were obtained from the three patients, who were 6 years old and male, with the parental consent of the three donors, and then isolated cells from dental pulp for comparative analysis between supernumerary DPSCs and SHED. RESULTS Colony-forming unit fibroblast levels and the proliferation rate of supernumerary DPSCs were slightly lower than that of SHED. The expression of cell surface antigens in supernumerary DPSCs and SHED were almost identical. Cells were mainly expressing endogenous mesodermal and ectodermal lineage markers. Differentiation capacity to osteogenic, adipogenic and chondrogenic lineage was similar in the SHED and supernumerary DPSCs. Migration assay revealed that both supernumerary DPSCs and SHED rapidly migrated toward wounded areas. Supernumerary DPSCs were altered in cell growth after storage for 2 years. Specially, the population doubling time of supernumerary DPSCs increased while that of SHED remained nearly unchanged. CONCLUSION Both supernumerary teeth and deciduous teeth share many characteristics, such as highly proliferative clonogenic cells with a similar immunophenotype to that of mesenchymal stem cells, although they are inferior to SHED for long-term banking. Our findings suggest that supernumerary teeth are also easily accessible and noninvasive sources of postnatal stem cells with multipotency and regenerative capacity.

DENTAL FEAR AND ANXIETY OF JUVENILES IN SOME AREAS OF GYEONGGI PROVINCE

The objective of this study is to measure the fear and anxiety levels of some middle school students in Gyeonggi Province, to analyze the relevant factors, to seek how to alleviate such fear and anxiety and thus enable to make a comfortable and efficient oral management. Six hundred twenty two middle school students in Gyeonggi Province participated in the survey, which used the data of 614 respondents, i.e. 337 males and 277 females. A frequency analysis was conducted to determine the distribution of answers for each question, a crosstabulation analysis was performed to verify the gender differences in answer and an Mann-whitney U test was used to compare fear scores. According to the results patients feared even in unexpected circumstances. In addition, they feared when receiving direct treatment. In terms of gender, female students showed higher levels of fear than male ones (p

Dental fear & anxiety and dental pain in children and adolescents; a systemic review

Background There are few previous studies investigating the relationship of dental fear and anxiety (DFA) with dental pain among children and adolescents. To address this issue, we examined the literature published between November 1873 and May 2015 to evaluate the prevalence of DFA and dental pain among children and adolescents, and their relationships with age and sex. Methods We performed a broad search of the PubMed database using 3 combinations of the search terms dental fear, anxiety, and dental pain and prevalence. A large proportion of the identified articles could not be used for the review due to inadequate end points or measures, or because of poor study design. Thirty-two papers of acceptable quality were identified and reviewed. Results We found that the prevalence of DFA was estimated to be 10%, with a decrease in prevalence with age. It was more frequently seen in girls, and was related to dental pain. Conclusions We concluded that dental fear, anxiety, and pain are common, and several psychological factors are associated with their development. In order to better understand these relationships, further clinical evaluations and studies are required.

Dental Fear and the associated Factors of some Middle School Students in Cheongju-City

This study aims to examine the level of fear and the influential factors affecting their dental fear and to utilize the result as the basic materials in the dental management. The subjects were the students from a middle school located in Cheongju-City. The school was selected by convenient sampling and self-answered questionnaire was filled in by the students for a week from December 19th 2011. The survey result showed that 77 male students and 169 female students(total 246 students) answered `yes` to the question `Have you ever felt fear when you visited a dentist?` among 475 students who had visited a dentist in the past. The distribution of responses in each category of fear was examined by frequency analysis. The study results showed significant difference in the item of `causing irritation during the dental treatments` between male students and female students (p

ORAL HEALTH BEHAVIORS OF MOTHERS AND DENTAL CARIES IN CHILDREN FROM MULTICULTURAL FAMILIES

The objectives of this study were to evaluate oral health status of children in multicultural families and compare oral health behaviors of multicultural mothers with those of ordinary Korean families. The mothers` social characters, oral health behaviors and oral health status of children were investigated so that the data from this study can be utilized in developing programs for oral health care promotion especially designed for multicultural families. The subjects were 135 pairs of multicultural mothers and their children who participated in the community programs in suburban areas of Ik-san city and 168 pairs of ordinary Korean mothers and their children residing in Ik-san city. The results were as follows : 1. The dft index and dfs index of multicultural subjects were 4.17 and 6.67, respectively, while ordinary Korean subjects were found to have 2.69 and 4.63( >0.05).

Cytotoxic effects of one-step self-etching adhesives on an odontoblast cell line.

The aim of this study was to evaluate the cytotoxic effects of one-step self-etching adhesives. Cells from an immortalized mouse odontoblast cell line (MDPC-23) were cultured with six different dental adhesive systems (diluted to concentrations of 0.5% for 4 h): Adper Easy Bond (EB), Xeno V (XV), iBond (IB), AdheSE One (AO), Clearfil SE primer (CS), and Adper Single Bond 2 (SB). MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and flow cytometric apoptosis assays were used to evaluate cell viability and the rate of apoptosis. The odontoblasts were also examined under a scanning electron microscope. While all of the cultures with adhesives showed reduced viability, the viabilities in the IB and SB groups were not significantly different from the control group. Although increased apoptosis rates were observed in all of the cultures with adhesives, the rate in the SB group was not significantly different from the rate in the control. The control group showed the lowest apoptosis rate followed by the SB, AO, IB, EB, XV, and CS groups. When examined under a scanning electron microscope, control odontoblasts and the SB group exhibited relatively large cytoplasmic extensions. In contrast, in the EB and CS groups, fewer fibroblasts remained adhered to the plate surface. Cytoplasmic membrane shrinkage and cell-free areas with residual membrane fragments from dead cells were observed. In conclusion, all cultures with one-step self-etching adhesives showed increased apoptotic activity. SB, an etch-and-rinse adhesive, was comparable to the control group, and CS and EB showed the lowest odontoblast viabilities according to the MTT assay.

Use of three-dimensional computed tomography images in dental care of children and adolescents in Korea

Advances in computed tomography (CT) technology - from traditional CT to cone beam (CB) CT - have benefitted both the dentists and their young patients. We therefore wanted to determine the prevalence of CBCT use in pediatric dentistry in Korea. Our first approach was to conduct an institutional survey to evaluate the use of CBCT for diagnosing and evaluating dental problems in pediatric patients. Our second approach was to review any articles published during 2002-2011 in the Journal of the Korean Academy of Pediatric Dentistry that described clinical use of CBCT. The journal articles surveyed indicated that there were three areas in which CBCT was most useful. The most prevalent use was for diagnosis and monitoring of the growth of cystomas and other tumors in the mouth. The second most common use of CBCT was localization of impacted teeth and evaluation of their relations with adjacent teeth. The third use was to observe supernumerary teeth and evaluate their relations with the roots of adjacent teeth. Compared with traditional CT, CBCT has shorter acquisition times and causes less radiation exposure to the patient. There are fewer side effects with CBCT because its accuracy allows minimally invasive treatment for such problems as impacted and supernumerary teeth.

A SURVEY ON THE KNOWLEDGE AND AWARENESS OF TRAUMATIC DENTAL INJURIES IN A GROUP OF JEON-BUK PROVINCE ELEMENTARY SCHOOL TEACHERS

The purpose of this study was to evaluate the attitude and knowledge level of a group of elementary school teachers in management of traumatic dental injury. The sample consisted of 231 elementary school teachers in Jeon-Buk province, and data was collected by means of a self-administered questionnaire. The questionnaire surveyed the teachers`general information, attitude on the dental trauma education, knowledge of management of tooth fracture, luxation, avulsion and tooth storage media. Only 15.2% of the teachers had received dental first aid treatment education, but 97% were favorable to receiving education. Although there were differences among the questions, insufficient knowledge and awareness of the management of traumatic dental injury were shown in the majority of teachers. It is recommended that education strategies and programs for improving the awareness of immediate management of traumatic dental injuries are necessary for elementary school teachers in Jeon-Buk province.

Aspiration and Ingestion of Foreign Bodies in Dental Practice

Despite preventative efforts, aspiration and ingestion of foreign bodies during clinical dental procedures occasionally occur. Careful clinical and radiographic examination and prompt emergency management can prevent potentially serious consequences. In this report, we describe a case of accidental foreign body ingestion and discuss prevention and management of dental instrument aspiration and ingestion.

Retrospective Study of Association between Displacement of Maxillary Canine and Tooth Agenesis

OBJECTIVE The purpose of this study was to investigate the interrelationships between displacement of maxillary canine and tooth agenesis in age from 10 to 19 years. STUDY DESIGN The panoramic radiographs of 128 subjects with displacement of maxillary canine and 600 subjects without displacement of maxillary canine were examined. The panoramic radiographs taken between 2003 and 2013 were used for diagnosis other related dental anomalies, including permanent tooth agenesis and small maxillary lateral incisor. RESULTS Patients with maxillary canine displacement had a significantly higher prevalence rate of permanent tooth agenesis excluding of third molars (p < 0.05). Significant increase in occurrence of tooth agenesis of maxillary lateral incisor (p < 0.05), maxillary second premolar (p < 0.05) and small maxillary lateral incisor (p < 0.05). In contrast, the mandibular second premolar did not show any significant difference (p > 0.05). CONCLUSION This study indicates that there is positive relationship between displacement of maxillary canine, small maxillary lateral incisor and permanent tooth agenesis. Especially, maxillary lateral incisor and maxillary second premolar have strong association with maxillary canine displacement. Consequently, permanent tooth agenesis and small maxillary lateral incisor can be a predictor of maxillary canine displacement.