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Objectives This study aimed to evaluate the splatter contamination generated by rotary instrumentation and irrigation during simulations of surgical extractions. Specifically, comparisons of the splatters generated were made between traditional assistant-based irrigation and self-irrigating drills, and between saline and hydrogen peroxide irrigant. Materials and Methods A fluorescein solution was infiltrated into the irrigation system of high-speed drills, and the surgical extraction procedures were performed on manikins with typodont teeth. Filter papers were placed at the predetermined locations around the operatory to absorb the fluorescein splatters; these samples underwent photographic image analysis. Results The patient chest showed the largest area of splatters, followed by the assistant’s face shield. Procedures using the hydrogen peroxide irrigant generated a larger area of splatter than those using the saline irrigant. There was no difference between the splatters produced by assistant irrigation and self-irrigating drill procedures. Conclusions Clinicians should observe and disinfect the locations contaminated by splatters to prevent the spread of infection, since using alternative irrigant or irrigation methods did not reduce the formation of splatters. Clinical Relevance: Oral surgery drills with irrigation generate aerosols and splatters, which have potential to spread airborne pathogens. It is important to understand the patterns of splatters to mitigate contamination.

This study uses a general formulation of integrated visual grading regression (IVGR) and applies it to cone beam computed tomography (CBCT) scan data related to anatomical landmarks for dental implantology. The aim was to assess and predict a minimum acceptable dose for diagnostic imaging and reporting. A skull phantom was imaged with a CBCT unit at various diagnostic exposures. Key anatomical landmarks within the images were independently reviewed by three trained observers. Each provided an overall image quality score. Statistical analysis was carried out to examine the acceptability of the images taken, using an IVGR analysis that was formulized as a three-stage protocol including defining an integrated score, development of an ordinal regression, and investigation of the possibility for dose reduction through estimated parameters. For a unit increase in the logarithm of radiation dose, the odds ratio that the integrated score for an image assessed by observers being rated in a higher category was 3.940 (95% confidence interval: 1.016-15.280). When assessed by the observers, the minimum dose required to achieve a 75% probability for an image to be classified as at least acceptable was 1346.91 mGy·cm

With a higher pH level and being unlikely to erode the tooth, bottled water has been considered a safe alternative to acidic beverages. However, recent studies have reported some bottled water products in different countries to be acidic. The present paper aimed to examine the pH values of 42 bottled waters commercially available in Australia, using a pH meter and probe, and classify their risks to cause erosive tooth wear in comparison with the critical pH of enamel and dentine. Of the 42 bottled water samples collected, 81.0 and 73.8% were considered erosive to tooth dentine and enamel, respectively. Flavoured waters were the most acidic, followed by sparkling waters, spring waters, artesian waters, mineral waters, and alkaline waters. All sparkling waters and flavoured waters showed an erosive risk to the enamel and dentine. A portion of spring waters and artesian waters was also acidic enough to erode tooth structures. The findings of this work were of concern given the risk of sustaining erosive tooth wear from consuming bottled waters. Health promotion strategies including public awareness and education on oral health consequences related to the consumption of bottled water are needed. Future epidemiological and in vivo investigations are also warranted.

This study aimed to investigate the prevalence of areca nut consumption and to identify social and behavioural determinants among a Taiwanese adolescent population.A random sample of 5,343 high school students aged between 15-18 years in Kaohsiung, Taiwan, participated in the study. Participants underwent a clinical dental examination and completed a self-administered questionnaire. Data analyses were performed using multivariate logistic regression to establish a relationship between areca nut consumption as well as social and behavioural characteristics.The prevalence of areca nut consumption was 3.0%. The chewing habit was more prevalent among older adolescents (p .001, OR = 1.50, 95% CI: 1.26, 1.78), males (p .001, OR = 17.91, 95% CI: 8.57, 37.40), pupils living with non-birth parent(s) (p = .003, OR = 2.13, 95% CI: 1.29, 3.50), children of family heads with primary (p = .001, OR = 2.90, 95% CI: 1.50, 5.59) or secondary level of education (p .001, OR = 2.78, 95% CI: 1.74, 4.46), frequent risk takers (p .001, OR = 1.35, 95% CI: 1.27, 1.43) and students of low physical fitness (p .001, OR = 3.65, 95% CI: 1.81, 7.35).Areca nut consumption has become an ongoing pertinent issue in adolescent health. Future investigations into neurocognitive influences of risk-taking behaviour on areca nut consumption and social dependence of the habit are indicated.

Surface enhanced Raman scattering (SERS) sensors have been fabricated by rapid thermal chemical vapor deposition of high-density nanoscale discrete graphene islands on copper foils followed by electroless chemical plating of discrete, closely spaced, and irregularly shaped silver nanoparticles on the copper surface where it is not covered by graphene islands. By fine tuning of the size and distribution of graphene islands and adjusting the deposition time for silver nanoparticles, nanoscale gaps between silver particles are fabricated. SERS sensors exhibiting Raman scattering signal enhancement factors as high as 1014 in reference to a bare copper have been demonstrated. Raman scattering signal has been measured from as low as 10−16 M of R6G molecules in water. This article reports effects and optimization process of size and distribution of graphene islands on desirable morphology of chemically plated silver nanoparticles. The density of nanoscale gaps of a few nanometers in distance between neighboring silver nanoparticles is optimized, resulting in the demonstration of SERS sensors with very low detection limits for R6G molecules.

PURPOSE: In response to COVID-19, dental educators have been tasked with maintaining the quality of education while reducing cost, increasing efficiency, and leveraging technology. METHODS: This collaborative, multisite virtual health policy course used the Staged Self-Directed Learning Model (SSDL) to lead a diverse group of students studying health policy. Twelve Core sessions were offered with three additional sessions in August or December for a total of 15 total synchronous Zoom sessions that covered policy issues on supply, demand, and need for dental care. RESULTS: Twenty-eight students, seven lead instructors, and two course directors from six schools reported positive feedback on the course format, use of technology and the SSDL model, and breadth of topics presented. Participation by universities in four states with differing health policies stimulated virtual classroom discussions. CONCLUSION: In conclusion, collaborative interinstitutional virtual teaching and learning is cost effective, efficient, and engaging for students. This model has the potential to continue even when institutions are no longer affected by COVID-19.

Background Non-nutritive sucking habits, bottle feeding and facial hyperdivergency have been suggested as the influencing factors of anterior open bite (AOB). There was inconsistent reporting of prevalence and a gap of knowledge in the literature. Aim The aim of this study was to investigate the prevalence of AOB in 7- to 12-year-olds, with a special interest to characterise the determinants of this malocclusion. Design A sample of 203 children aged 7 to 12 years were selected from a primary school in regional Australia. The legal guardian of each child completed a self-administered questionnaire. Data was assessed using methods of univariate statistics and neural analysis. Results The prevalence of AOB and thumb sucking was 24.1% and 23.2%, respectively. AOB was associated with the habit (correlation = 0.754) and duration (correlation = 0.574) of thumb sucking. Age, gender, birth order, feeding modality, sleep patterns, history of orthodontic treatment and tonsil, adenoid or grommet surgery, and parents' level of education were not related to AOB (correlation absolute value ≤ 0.474). Conclusions Thumb sucking, specifically for prolonged duration, increases the risk of development of AOB. Cessation of thumb sucking habits should be encouraged at an early age to avoid the development of AOB.

Additional file 1: SPIRIT 2013 Checklist: Recommended items to address in a clinical trial protocol and related documents*

Additional file 1: SPIRIT 2013 Checklist: Recommended items to address in a clinical trial protocol and related documents*

Additional file 2: Participant survey

Additional file 2: Participant survey

Background Despite great improvement in child oral health, some children subgroups still suffer from higher levels of dental caries. Geographic and socioeconomic barriers and the lack of access to dental care services are among common reasons for poor oral health in children. Historically in Australia, oral health therapists or dental therapists have been responsible for providing dental care for school children through the School Dental Services (SDS). The current SDS has been unable to provide sustainable dental care to all school children due to a reduction in workforce participation and limited resources. We propose a paradigm shift in the current service through the introduction of user-friendly technology to provide a foundation for sustainable dental care for school children. Methods/design We describe an ongoing parallel, two-armed, non-inferiority randomised controlled trial that compares routine and teledental pathway of dental care in children aged 4–15 years (n = 250). Participating schools in Western Australia will be randomly assigned to the control or teledental group, approximately three schools in each group with a maximum of 45 children in each school. All participants will first receive a standard dental examination to identify those who require urgent referrals and then their teeth will be photographed using a smartphone camera. At the baseline, children in the control group will receive screening results and advice on the pathway of dental care based on the visual dental screening while children in the teledental group will receive screening results based on the assessment of dental images. At 9 months follow-up, all participants will undergo a final visual dental screening. The primary outcomes include decay experience and proportion of children become caries active. The secondary outcomes include the diagnostic performance of photographic dental assessment and costs comparison of two pathways of dental care. Discussion The current project seeks to take advantage of mobile technology to acquire dental images from a child’s mouth at school settings and forwarding images electronically to an offsite dental practitioner to assess and prepare dental recommendations remotely. Such an approach will help to prioritise high-risk children and provide them with a quick treatment pathway and avoid unnecessary referrals or travel. Trial registration Australian New Zealand Clinical Trials Registry, ACTRN12619001233112. Registered 06 September 2019.

While the prevalence of supernumerary teeth (ST) is high in permanent dentition, the etiology of ST in humans remains unclear. However, multiple murine models of ST have elaborated on dated mechanisms traditionally ascribed to ST etiology: one involves the rescue of rudimental teeth, and the second considers the contribution of odontogenic epithelial stem cells. It remains unclear whether these mechanisms of ST formation in mice are applicable to humans. The third dentition is usually regressed apoptotic—that is, the teeth do not completely form in humans. Recently, it was suggested that ST result from the rescue of regression of the third dentition in humans. The present investigation evaluates the proportion of collected general ST cases that evinced a third dentition based on the clinical definition of ST derived from the third dentition. We also investigated the contribution of SOX2-positive odontogenic epithelial stem cells to ST formation in humans. We collected 215 general ST cases from 15,008 patients. We confirmed that the general characteristics of the collected ST cases were similar to the results from previous reports. Of the 215 cases, we narrowed our analysis to the 78 patients who had received a computed tomography scan. The frequency of ST considered to have been derived from the third dentition was 26 out of 78 cases. Evidence of a third dentition was especially apparent in the premolar region, was more common in men, and was more likely among patients with ≥3 ST. SOX2-positive odontogenic epithelial stem cells within the surrounding epithelial cells of developing ST were observed in non–third dentition cases and not in third dentition cases. In conclusion, the third dentition is the main cause of ST in humans. The odontogenic epithelial stem cells may contribute to ST formation in cases not caused by a third dentition.

Cleidocranial dysplasia (CCD) is a congenital autosomal dominant syndrome characterised by dental and osseous dysplasia that leads to multiple dental and craniofacial anomalies. Two-thirds of CCD cases are associated with mutations of the runt-related transcription factor 2 (RUNX2) gene which codes for a transcription factor that is responsible for differentiation of osteoblasts and osteoclasts and skeletal development. Multiple mutations have been identified in the Runx2 gene, primarily clustered in the Runt domain. Other genes such as CCAAT/enhancer-binding protein beta (Cebpb) and T-box transcription factor TBX1 (Tbx1) are under investigation. There are multiple clinical and radiological signs of CCD, e.g. brachycephaly, frontal and parietal bossing, open sutures and fontanelles, delayed closure of fontanelles, kyphosis, narrow sloping shoulders, multiple wormian bones, and delayed mineralisation of the skull. Although the signs present themselves in varying degrees, certain signs such as supernumerary teeth, frontal bossing, hypoplastic maxilla, and prognathic mandible are characteristic. However, many of them may not appear before the growth spurt in all cases. Early identification of CCD, especially prenatal ultrasound diagnosis, has a better prognosis as early orthodontic intervention can be commenced. Apart from clinical and radiographic analysis, identification of a RUNX2 mutation can serve as a diagnostic aid in families with a history of CCD. However, it is important to understand that only two-thirds of the people with CCD have RUNX2 mutation, so genetic analysis will not be of use in people without the mutations.

Objectives This study aimed to determine whether intraoral photographic assessment by mid-level dental providers (MLDPs) offers a valid and reliable means of dental caries screening. Methods A mobile teledentistry model was developed to facilitate the acquisition of dental images, and transmission and reviewing of data. One hundred regularly attending patients at a dental clinic participated in the study. Following an on-site clinical examination by a senior dentist, photographs of participants' teeth were taken by a teledental assistant, using a smartphone camera. These intraoral photographs were directly uploaded from an Android App to a cloud-based server, ‘Remote-i’, using an encrypted store-and-forward telemedicine technology. The photographic assessment carried out by two independent screeners (MLDPs), was compared to the visual oral examination scores of a benchmark examiner. Results The sensitivity and specificity values for the photographic assessment method (assessed by screeners) as compared to the direct visual examination ranged from 60% to 68%, and 97% to 98%, respectively. The intra-rater reliability for the photographic assessment was almost perfect, with a kappa score of 0.89. The inter-rater reliability between the photographic and visual oral assessments ranged from moderate to substantial agreement, with kappa scores ranging from 0.57 to 0.61. Conclusion A new smartphone-based mobile teledentistry model used by mid-level dental providers shows potential for remote screening of dental caries.

The aims of this work were to assess dental age using the Demirjian system and to evaluate the discrepancy between chronological and dental age among children residing in Western Australia. Forty panoramic radiographs of 5- to 11-year-old children taken at the paediatric clinic of a dental hospital in Western Australia were selected. The developmental stage of each left permanent mandibular tooth excluding the third molar was assessed by three trained examiners. Estimated dental age using the Demirjian system was compared with the chronological age of each child. The accuracy of the Demirjian system in this group of children was 42.5%. The difference between chronological age and dental age was significant (t = 4.066, df = 39, p < 0.001). Dental age estimation for Caucasian children had greater accuracy (χ2 = 5.013, df = 1, p = 0.025). Gender and orthodontic concerns were not related to the accuracy of the Demirjian system (p ≥ 0.481). The discrepancy between chronological and dental age using the Demirji...

Objective Fibrous dysplasia of bone (FD) is a benign developmental disorder of bone in which normal bone is replaced by fibrous tissue, containing trabeculae of immature woven bone. This disease has been classified into three types: monostotic (MFD), polyostotic (PFD), and McCune–Albright syndrome (MAS). Occurring in multiple adjacent craniofacial bones (craniofacial FD) is considered to be an MFD lesion. Surgical reduction is performed for form revision after having observed the progress until adulthood, but postoperative recurrence cases are not rare, there is a report of malignant progression to osteosarcoma, and the clinical phenotypes are generally various. This study aimed to identify the relationship between clinical futures of FD and expression of bone morphogenetic protein (BMP) subtypes. Methods We studied 10 cases (9 MFD cases and 1 McCune–Albright syndrome case) diagnosed with fibrous dysplasia in our hospital, and immunohistochemical examinations of the excised sample from each case with anti-BMP-2, 4, 6, and 7 antibodies were performed. Results 5 MFD cases and 1 MAS case underwent reoperation, and the case that had the most number of operations was 9 times in the MFD case. Malignant transformations were not identified. BMP-4, 6, and 7 expressions were positive in all cases, but the expression of BMP-2 was positive only in 6 MFD cases. BMP-2 negative cases tended to undergo reoperation. Conclusions The variable expression of BMP-2 demonstrated in the current study was suggested to be a useful indication for clinical activity and convalescence of the lesions.

Adult Cebpb KO mice incisors present amelogenin-positive epithelium pearls, enamel and dentin allopathic hyperplasia, fewer Sox2-positive cells in labial cervical loop epitheliums, and reduced Sox2 expression in enamel epithelial stem cells. Thus, Cebpb acts upstream of Sox2 to regulate stemness. In this study, Cebpb KO mice demonstrated cementum-like hard tissue in dental pulp, loss of polarity by ameloblasts, enamel matrix in ameloblastic layer, and increased expression of epithelial-mesenchymal transition (EMT) markers in a Cebpb knockdown mouse enamel epithelial stem cell line. Runx2 knockdown in the cell line presented a similar expression pattern. Therefore, the EMT enabled disengaged odontogenic epithelial stem cells to develop supernumerary teeth. Cebpb and Runx2 knockdown in the cell line revealed higher Biglycan and Decorin expression, and Decorin-positive staining in the periapical region, indicating their involvement in supernumerary tooth formation. Cebpb and Runx2 acted synergistically and played an important role in the formation of supernumerary teeth in adult incisors.

This study aimed to carry out a case-control research study to assess occurrence of clicking of the temporomandibular joint (TMJ) in order to establish the relationship between TMJ clicking and the genotype of “ANKH inorganic pyrophosphate transport regulator” (ANKH) polymorphisms. A sample of 41 first-year dental residents was selected. Each was examined using standard clinical procedures and genotyping techniques. The participation rate was 91.8 %. The prevalence of TMJ clicking was 51.2 % (95 % CI: 35.7–66.7 %). Occurrence of TMJ clicking was not related to age, gender and genotypes of ANKH-OR as well as ANKH-TR polymorphisms (p ≥ 0.165). A similar distribution of ANKH genotypes in TMJ clicking and asymptomatic individuals has been demonstrated by this study. A high percentage of TMJ clicking has been confirmed. Future investigations are indicated.

This study sought to evaluate the efficacy of a mobile teledentistry approach using a smartphone camera for remote screening of dental caries.An image acquisition Android App was created to facilitate the acquisition and transmission of dental images to a store-and-forward based telemedicine server. One hundred participants who were attending routine checkups at dental clinics were enrolled in 2014. Following a face-to-face oral screening by a screener (dentist), images of patients' teeth were obtained using a smartphone camera. These images, along with patient information, were then transmitted from the Android App to the server through the Internet for later independent assessment by two charters (off-site dentists). The assessments of these charters were then compared to the benchmark face-to-face caries assessment.Sensitivity values for the photographic method when compared to the benchmark face-to-face caries assessment were moderate, and ranged from 60% to 63%. Weighted kappa (K) as a measure of intragrader agreement for the photographic assessment was estimated as almost perfect (K = 0.84). The intergrader agreement for the photographic method compared to the face-to-face caries assessment ranged from moderate to substantial (K = 0.54-0.66).Despite some limitations, the mobile teledentistry approach has shown the potential to detect occlusal caries from photographs taken by a smartphone camera with an acceptable diagnostic performance compared to traditional face-to-face screening. This study suggests that telemedicine and cellular phone technology can be combined to create an inexpensive and reliable screening tool.

Background: This study aimed to investigate dentists’ supply and practice patterns following the implementation of the global budget system in Taiwan. Materials and Methods: Data of reimbursement claims, municipal socioeconomic status and dental manpower were collected from the National Health Insurance administration, the Ministry of Internal Affair, and the Ministry of Health and Welfare, respectively. A multivariate linear regression method was used for data analysis. Results: A municipality that reported a higher percentage of tertiary educated population ( t = 3.718, P < 0.001), a higher per capita income ( t = 6.172, P < 0.001), a higher population density ( t = 6.172, P < 0.001), or a lower percentage of elderly population ( t = −2.506, P = 0.014) was more likely to have a higher number of dentists per 100,000 population. A municipality that reported a higher Herfindahl‑Hirschman Index (HHI) value ( t = 2.880, P = 0.005) was more likely to show a higher move‑out rate among dentists. The rate was lower after the implementation of the global budget system ( t = −2.436, P = 0.018). A municipality that had a higher percentage of elderly population ( t = 3.628, P < 0.001), a lower percentage of young population ( t = −2.138, P = 0.035), or a higher rate of population growth ( t = 4.412, P < 0.001) was more likely to display a higher move‑in rate among dentists. The percentage of amalgam restorations in total claims reduced from 19.82% to 17.94%, while the percentage of tooth‑colored material restorations increased from 25.46% to 28.79%. Conclusion: This study has demonstrated a stabilizing effect of the global budget system on dynamics of dental manpower in Taiwan. A relationship between HHI and dentists’ move‑out rate has been found. The relationship between municipal socioeconomic status and the density of dentists has also been confirmed. In addition, reduced utilization of amalgam restorations was accompanied by increased utilization of tooth‑colored material restorations. Further investigations are indicated. Key Words: Amalgam, composite resins, dentist, global, budget, health insurance, Herfindahl-Hirschman Index

Objectives: Novel methods for preserving primary teeth can help to maintain their developmental, esthetic, and functional capabilities. The aim of this study was to assess the success of the repair of bony defects, caused by pre-treatment perforations, with a mixture of three antibiotics combined with simvastatin (3Mixtatin) compared to MTA in hopeless primary molars. Study design: In this randomized clinical trial, 80 teeth from 65 healthy children aged 3–6 years with interradicular or periapical root resorption and/or perforation in primary molars were treated either with 3Mixtatin or MTA before conventional pulpectomy and restoration. The subjects were followed up clinically and radiographically for 4, 6, 12 and 24 months after pulp treatment to evaluate and compare the healing process. The data were compared using chi-square test at a significance level of 0.05. Results: By the end of 24 months in 3Mixtatin group, 31 (96.8%) teeth revealed no clinical signs or symptoms with arrested resorption progress in radiographs. In MTA group, clinical signs and symptoms including pain, mobility and sinus tract were observed in 18 (48.6%) teeth with cessation of root/interradicular radiolucency in 7 (18.9%) teeth without bone repair. Conclusions: Radiographic and clinical healing occurred more successfully following 3Mixtatin treatment compared to treatment with MTA, it may lead to a paradigm shift in the pulpal treatment of primary teeth in the future.

Objective:To investigate dental appearance and cephalometric features, using a sample of orthognathic and/or orthodontic patients. A special interest was to identify the relationship of the Dental Aesthetic Index (DAI) with anteroposterior basal bone discrepancy (APBBD) and cephalometric indicators.Materials and Methods:A full sample of 159 patients in two Japanese hospitals was used. Each patient was assessed with a preorthodontic dental cast and cephalometric radiography.Results:Malocclusion with APBBD was more prevalent among high DAI subjects (P = .034, OR = 1.04, 95% CI: 1.00–1.08), Class III malocclusion patients (P = .048, OR = 2.32, 95% CI: 1.01–5.34) and male patients (P = .008, OR = 2.96, 95% CI: 1.33–6.61). Participants scoring 88 points (the highest score in this sample) of the DAI had 16.84 times the risk of APBBD of those who scored 17 points (the lowest score in this sample). Patients with APBBD presented with a greater adjusted ANB angle (t = −8.10, P < .001) and a larger adjusted A-B/NF appraisal (t = −9.65, P < .001). The SNA angle (P < .001), the SNB angle (P = .002), the adjusted ANB angle (P = .001), and the adjusted A-B/NF appraisal (P = .035) were associated with DAI scores in cubic regression models.Conclusion:This study has demonstrated a relationship between the DAI and APBBD. Feasibility of using the adjusted ANB angle and the adjusted A-B/NF appraisal to assess severity of APBBD has been confirmed. The DAI may provide a supportive method to evaluate orthognathic needs. Future investigations are indicated.

Objectives: This investigation aimed to conduct a case-control study of mandibular morphology and dental anomalies to propose a relationship between mandibular/dental phenotypes and deficiency of CCAAT/enhancer-binding protein beta (CEBPB). Materials and methods: Skulls of CEBPB(-/-) , CEBPB(+/-) and CEBPB(+/+) mice were inspected with micro-computed tomography. Mandibular morphology was assessed with a method of Euclidean distance matrix analysis. Results: Elongation of the coronoid process was identified in CEBPB(+/-) (P ≤ 0.046) and CEBPB(-/-) 12-month-olds (P ≤ 0.028) but not in 14-day-olds (P ≥ 0.217) and 0-day-olds (P ≥ 0.189) of either genotype. Formation of supernumerary teeth in CEBPB(-/-) adult mice was demonstrated (χ(2 ) =( ) 6.00, df = 1, P = 0.014). Conclusions: CEBPB deficiency was related to elongation of the coronoid process and formation of supernumerary teeth. The mandibular and dental phenotypes of CEBPB deficiency were unseen by the 14th day after birth. Future investigations into the influence of CEBPB on mandibular and dental development are needed.

Objectives: This study aimed to investigate dental undergraduate students' tobacco usage and social nicotine dependence in Australia. A special interest was to identify the role of factors such as age, gender, year of dental education and cohabitants' smoking status for social nicotine dependence. Materials and methods: A sample of 252, first-to-fifth year undergraduate students in an Australian dental school was used. Each completed a self-administered questionnaire. Results: The smoking rate was 4.8%. Current smokers displayed higher social nicotine dependence than those that had never smoked (t = 3.1, df = 244, P = 0.002). Dental undergraduate students that showed higher social nicotine dependence (P = 0.001, OR = 1.3, 95% CI: 1.1–1.6), or that had smoking cohabitants (P = 0.016, OR = 4.8, 95% CI: 1.3–17.0), were more likely to smoke. Students' social nicotine dependence increased with year of dental study (P = 0.043, β = 0.4, t = 2.0). Social nicotine dependence enhanced tobacco usage among Year-1-to-4 students (P = 0.005, OR = 1.4, 95% CI: 1.1–1.7) but not Year-5 undergraduates (P = 0.432). Conclusions: Social nicotine dependence has become a developing issue in dental education. Tobacco control should be highlighted in the dental curriculum. Future investigations into the effects of dental education on social nocotine dependence and tobacco usage are indicated.

The safety impact of differential speed limits (DSL) with a truck lane restriction was investigated on a 17 mile long elevated freeway segment over the Atchafalaya Basin in Louisiana that has been a subject of concern for the past decade due to sporadically occurring fatal crashes involving large trucks. Three before and after (B-A) methods were used in the current study: A naive B-A method, the improved B-A method, and the comparison group B-A method. The last two methods estimate the safety difference of a highway facility between, with, and without an intended treatment while taking into account other variables that may affect safety. Although all three methods show the reduction in truck and total crashes with DSL implementation, the naive method clearly underestimates the magnitude of the reductions in this case. Lack of traffic composition information makes the results from the comparison group B-A method less reliable than that by the improved B-A method. Based on the improved B-A method, that is m...

Background Wnt5a and Mrfzb1 genes are involved in the regulation of tooth size, and their expression levels are similar to that of Bmp7 during morphogenesis, including during the cap and early bell stages of tooth formation. We previously reported that Usag-1-deficient mice form supernumerary maxillary incisors. Thus, we hypothesized that BMP7 and USAG-1 signaling molecules may play important roles in tooth morphogenesis. In this study, we established double genetically modified mice to examine the in vivo inter-relationships between Bmp7 and Usag-1. Results We measured the volume and cross-sectional areas of the mandibular incisors using micro-computed tomography (micro-CT) in adult Bmp7- and Usag-1-LacZ knock-in mice and their F2 generation upon interbreeding. The mandibular incisors of adult Bmp7+/− mice were significantly larger than those of wild-type (WT) mice. The mandibular incisors of adult Usag-1−/− mice were the largest of all genotypes examined. In the F2 generation, the effects of these genes were additive; Bmp7+/− was most strongly associated with the increase in tooth size using generalized linear models, and the total area of mandibular supernumerary incisors of Usag-1−/−Bmp7+/− mice was significantly larger than that of Usag-1−/−Bmp7 +/+ mice. At embryonic day 15 (E15), BrdU assays demonstrated that the labeling index of Bmp7+/− embryos was significantly higher than that of WT embryos in the cervical loop. Additionally, the labeling index of Usag-1−/− embryos was significantly the highest of all genotypes examined in dental papilla. Conclusions Bmp7 heterozygous mice exhibited significantly increased tooth sizes, suggesting that tooth size was controlled by specific gene expression. Our findings may be useful in applications of regenerative medicine and dentistry.

Using a classification of homicides based on the victim–offender relationship, this research analyzes individual-level data from a local prosecutor's office in Taiwan with multinomial logistic regression to locate the more precise correlates of three different homicide relationship types. The results of the analyses provide further support for the hypothesis that such partitioning of homicides is fruitful in revealing the relationships otherwise obscured. They indicate that both sociodemographic variables and situational variables are important correlates of three different homicide relationships, but their strengths vary based on the particular homicide relationship type. Age and crime premises correlate with homicide differently based on the victim–offender relationship. Premeditation is related to acquaintance homicide but not to intimate homicide. In contrast, previous conviction is associated with intimate homicide but not with acquaintance homicide. The implication of the findings is discussed within the limitation of the data.

This multinational survey investigated the relationship between emotional intelligence (EI) and perceived stress (PS) in seven countries. First-year dental undergraduates attending a dental school in England, Greece, Romania, South Africa, Australia, and the United States and three schools in Malaysia were invited to complete a set of questionnaires on age, gender, academic background, satisfaction with career choice, EI, and PS. Of 860 questionnaires distributed, 596 were fully completed--a response rate of 69.3 percent. Mean EI score was 123.8 (95 percent CI 122.7-124.9), and mean PS score was 19.1 (95 percent CI 18.6-19.7). Significant differences in EI and PS scores were detected between different countries. Females (p

Objectives: This study aimed to assess behavioural and occlusal outcomes of non-orthodontic intervention (NOI) in a sample of children, 4–12 years of age, in Australia, in order to establish clinical relevance. Materials and methods: Data from 91 patient records of 4- to 12-year-old children reporting a habit of digit sucking, from two clinics in north-eastern Australia, were de-identified and used. Each patient had been examined at two visits, separated by an interval of 4 months, using standard clinical procedures. Results: Of the 77 children who received a 4-month NOI, 69 (89.6%) had ceased their digit sucking habit by the end of the NOI period [χ2 = 67.0, degrees of freedom (d.f.) = 1, P < 0.001]. Of the 72 subjects who had front teeth, the number with anterior open bite decreased from 37 (51.4%) to 12 (16.7%) upon completion of NOI (χ2 = 21.3, d.f. = 1, P < 0.001). Among the 32 patients with a measurable overjet, the mean overjet was found to decrease from 4.2 ± 2.4 mm to 3.1 ± 1.9 mm after implementation of NOI (t = 5.8, d.f. = 31, P < 0.001). Children who received NOI were more likely to quit the digit sucking habit in the 4-month period (P < 0.001, OR = 51.8, 95% CI: 9.8–273.9) and were more likely to appear without anterior open bite at a 4-month recall (P < 0.001, OR = 30.0, 95% CI: 5.9–151.6). Conclusions: This study demonstrated clinical relevance of NOI on the cessation of a digit sucking habit, closure of anterior open bite and reduction of overjet. Further investigations are indicated. Further investigations are indicated.

The highest absolute number of new HIV infections and AIDS cases still occur among men who have sex with men (MSM). Numerous theoretical approaches have been used to understand HIV risk behaviors among MSM; however, no theoretical model examines sexual risk behaviors in the context of gay identity and interpersonal violence. Using a model testing predictive correlational design, the theoretical relationships between childhood sexual abuse, adverse early life experiences, gay identity, substance use, battering, aversive emotions, HIV alienation, cue-to-action triggers, and HIV risk behaviors were empirically tested using confirmatory factor analysis and structural equation modeling. The relationships between these constructs are complex, yet childhood sexual abuse and gay identity were found to be theoretically associated with HIV risk behaviors. Also of importance, battering victimization was identified as a key mediating variable between childhood sexual abuse, gay identity, and adverse early life experiences and HIV risk behaviors among urban MSM.

Using Lehigh Longitudinal Study data (N = 457), the authors compare prospective parent self-reports and retrospective adolescent reports of early childhood physical abuse, exploring their correspondence, predictive equivalence, and outcomes associated with conflicting reports. Correspondence between prospective and retrospective reports of child maltreatment was moderate (Phi = 0.27). Concurrence rates were similar for males and females. Analyses of the relative predictive capacity of prospective and retrospective measures revealed both to be significant predictors of key outcomes in adolescence. Findings support the predictive validity of both measures of childhood maltreatment and underscore the methodological challenges of measuring this important construct. Given the abundance and salience of research on the consequences of childhood maltreatment, greater attention to such measurement issues is due.

A location-aware navigation system has been developed and implemented for the visually disabled or visually impaired; the system is designed to improve individuals' independent mobility. This self-contained, portable system integrates several technologies, including mobile personal digital assistants, voice synthesis, a geographic information system (GIS), and a differential Global Positioning System (DGPS). The system is meant to augment the various sensory inputs available to the visually impaired user. It provides the user with navigation assistance, making use of voice cues iterating contextual building and feature information at regular intervals, through automatic GPS readings and a GIS database. To improve the efficiency of the retrieval of contextual information, an indexing method based on road segmentation was developed to replace the exhaustive search method. Experimental results show that the performance of the system on searching the buildings, landmarks, and other features around a road has been significantly improved by using this indexing method.

At the macro level, little quantitative research exists about organizational determinants of the citizen complaint rate against police abuse of power regarding unlawful arrest/detention, illegal search or seizure, harassment and intimidation, misuse of authority, and improper language. The current study tested Wilson's professionalism control thesis and Lundman's organizational product thesis. Variables were identified and created from the data of Pate and Fridell. Tobit regression analyses of the data revealed the important correlates of citizen complaints and organizational characteristics. The theoretical implications of the findings are discussed within the limitations of the data.

Background. The expression term of the gene transfected in cells needs to belong enough inorder to make a gene therapy clinically effective. The controlled release of the transfected gene can be utilized. The new biodegradable hydrogel material created by 20 w/w% aldehyded dextran and 10 w/w%ε-poly(L-lysine) (ald-dex/PLL) was developed. We examined whether it could be as a nonviral carrier of the gene transfer.Methods. A plasmid (Lac-Z) was mixed with ald-dex/PLL. Anin vitrostudy was performed to assess the expression of Lac-Z with X-gal stain after gene transfer into the cultured 293 cells and bone marrow cells. As a control group, PLL was used as a cationic polymer.Results. We confirmed that the transfection efficiency of the ald-dex/PLL had a higher transfection efficiency than PLL in 293 cells (plasmid of 2 μg: ald-dex/PLL 1.1%, PLL 0.23%, plasmid of 16 μg: ald-dex/PLL 1.23%, PLL 0.48%). In bone marrow cells, we confirmed the expression of Lac-Z by changing the quantity of aldehyded dextran. In the groups using ald-dextran of the quantity of 1/4 and 1/12 of PLL, their transfection efficiency was 0.43% and 0.41%, respectively.Conclusions. This study suggested a potential of using ald-dex/PLL as a non-carrier for gene transfer.

Maxillofacial dysmorphogenesis is found in 5% of the population. To begin to understand the mechanisms required for maxillofacial morphogenesis, we employed the inhibitors of the differentiation 2 (Id2) knock-out mouse model, in which Id proteins, members of the regulator of basic helix-loop-helix (bHLH) transcription factors, modulate cell proliferation, apoptosis, and differentiation. We now report that spatially-restricted growth defects are localized at the skull base of Id2 KO mice. Curiously, at birth, neither the mutant Id2 KO nor wild-type (WT) mice differed, based upon cephalometric and histological analyses of cranial base synchondroses. In postnatal week 2, a narrower hypertrophic zone and an inhibited proliferative zone in presphenoid synchondrosis (PSS) and spheno-occipital synchondrosis (SOS) with maxillary hypoplasia were identified in the Id2 mutant mice. Complementary studies revealed that exogenous bone morphogenetic proteins (BMPs) enhanced cartilage growth, matrix deposition, and chondrocyte proliferation in the WT but not in the mutant model. Id2-deficient chondrocytes expressed more Smad7 transcripts. Based on our results, we assert that Id2 plays an essential role, acting downstream of BMP signaling, to regulate cartilage formation at the postnatal stage by enhancing BMP signals through inhibiting Smad7 expression. As a consequence, abnormal endochondral ossification was observed in cranial base synchondroses during the postnatal growth period, resulting in the clinical phenotype of maxillofacial dysmorphogenesis.

To determine first year dental students' perceptions of intimidation by instructors and bullying by fellow students.Data were collected through a cross-sectional survey of first year dental students from seven dental schools representing five countries; one each from Romania, South Africa, Australia and the U.S.A., and three from Malaysia. Self-report questionnaires were administered to participants at least six months after they had commenced their dental degree course during 2005-6.Over a third (34.6%) reported that they had been intimidated or badly treated by their tutors/instructors and 17% reported that they had been bullied or badly treated by their fellow students in the recent past. There were statistically significant differences in reports of intimidation by instructors between the different dental schools. Intimidation by instructors was associated with a history of medication use for stress, anxiety and depression, and perceived stress in the past month. There were no statistically significant variations in reports of bullying by fellow students between different dental schools. Bullying by fellow students was associated with dieting to lose weight, self-reported general health and perceived stress.This multi-national study highlights that intimidation and bullying is prevalent within dental teaching and training environments. Future research is needed to explore their impact on students' wellbeing and academic progress as well as on patient care.Dentists are the best recruiters for the profession. If the dental school experience is a negative one it can have significant impact on the future of the profession

This study investigates several factors as possible mediators of physical child abuse in the prediction of violence among adolescents. Prospective and retrospective measures of abuse are compared in mediation tests. Data are from the Lehigh Longitudinal Study, a prospective study of 457 children followed from preschool into adolescence. Structural equation models examined the degree to which abuse is mediated in the prediction of violence through youths' bonds to family, commitment to school, involvement with antisocial peers during adolescence, and attitudes about the use of violence. The model included measures of family socioeconomic status and youths' gender and age as controls on violence. Findings suggest that abuse (whether measured prospectively or retrospectively) is heavily mediated in its prediction of later violence and that a sizeable proportion of variance is accounted for in the violence outcome. A fuller pattern of mediation was shown when the retrospective abuse variable was modeled.

OBJECTIVE: To assess the activities related to the occurrence of traumatic dental injuries (TDI) in order to establish the relationship between gender, socio-economic status (SES) and major TDI related events, using classification and examination procedures suitable for epidemiological purposes, in a sample of 15- to 18-year-old students in Taiwan. METHODS: A random sample of 6312 15- to 18-year-old senior high school students in southern Taiwan was selected. Each was examined with standard clinical procedures and a questionnaire. RESULTS: The prevalence of TDI was 19.9%. The major TDI related events included sports and leisure activities (30.8%), eating (20.5%), falls (19.4%), traffic accidents (10.2%) and collisions (7.1%). Within TDI victims, sports and leisure related TDI were more prevalent among males (P = 0.001, OR = 1.640, 95% CI = 1.225, 2.195) and high SES adolescents (P = 0.014, OR = 1.991, 95% CI = 1.149, 3.449). The occurrence of non-accidental TDI was not related to age, gender and SES (P > or = 0.643). CONCLUSION: Traumatic dental injuries have become an important issue in public health and dentistry. Prevention and treatment of TDI should be emphasised to the public, the health professional and the policy maker. Future investigations into the relationship between TDI related events and their determinants are indicated. Language: en

Purpose The study investigated protective factors (school commitment/importance, parent/peer disapproval of antisocial behavior, positive future orientation, and religion) hypothesized to lower risk for antisocial behavior among adolescents who, as children, had been physically abused. Protective factors also were investigated for comparison, nonabused children, and for children at risk on abuse and other factors: low socioeconomic status and early antisocial behavior. Methods Analyses used a two-step hierarchical regression approach. In step 1, age, gender, and early antisocial behavior were entered as controls. In step 2, each protective factor was entered separately as a predictor. A final regression model in each case examined the additive (combined) effect of all protective factors on a given outcome. Tests of predictor-by-group interactions were used to examine group differences. Results Among abused and nonabused children, having a strong commitment to school, having parents and peers who disapprove of antisocial behavior, and being involved in a religious community lowered rates of lifetime violence, delinquency, and status offenses. Having a positive future orientation appeared less powerful as a protective influence. Exposure to an increasing number of protective factors was for each outcome associated with a diminution in risk for antisocial behavior. Conclusions Protective factors represent targets for preventive intervention that are viable for children as they enter adolescence. The fact that protective factors were predictive of lower antisocial behavior in both the abuse and comparison groups suggests that protective effects are more universal than they are unique to a given group of children.

Objectives: To identify the staining potential of acidulated phosphate fluoride (APF) foam on restorations in vitro. Materials and Methods: Two hundred ovine molars were used. Except 40 teeth remained unrestored as the controls, each was randomly selected to receive one of four restorative materials including preparation without restoration, glass ionomer cement (GIC), resin modified glass ionomer cement (RMGIC), or composite resin (CR). Following the procedure, topical APF was applied with a predetermined frequency. Staining formation was then evaluated. Results: APF-treated teeth and restorations appeared with a darker shade, an orange-colored surface and/or a brown margin. The staining rates on GIC, RMGIC, and CR were 50%, 27.5%, and 17.5%, respectively. GIC had a higher staining potential than RMGIC (χ2 = 4.266, df = 1, P = 0.039) and CR (χ2 = 9.448, df = 1, P = 0.002), whereas the difference between RMGIC and CR was indiscernible (χ2 = 1.147, df = 1, P = 0.284). Repeated applications of topical APF increased the risk of staining on RMGIC (χ2 = 8.436 df = 1, P = 0.004) and CR (χ2 = 6.873, df = 1, P = 0.009) but not on GIC (χ2 = 0, df = 1, P = 1) and the controls (χ2 = 4.051, df = 3, P = 0.256). Conclusions: APF-foam-related staining was confirmed in vitro. GIC was more susceptible to fluoride staining. This study suggested aesthetic implications when applying fluorides to restored teeth.

Bone morphogenetic proteins (BMPs) are highly conserved signaling molecules that are part of the transforming growth factor (TGF)-beta superfamily, and function in the patterning and morphogenesis of many organs including development of the dentition. The functions of the BMPs are controlled by certain classes of molecules that are recognized as BMP antagonists that inhibit BMP binding to their cognate receptors. In this study we tested the hypothesis that USAG-1 (uterine sensitization-associated gene-1) suppresses deciduous incisors by inhibition of BMP-7 function. We learned that USAG-1 and BMP-7 were expressed within odontogenic epithelium as well as mesenchyme during the late bud and early cap stages of tooth development. USAG-1 is a BMP antagonist, and also modulates Wnt signaling. USAG-1 abrogation rescued apoptotic elimination of odontogenic mesenchymal cells. BMP signaling in the rudimentary maxillary incisor, assessed by expressions of Msx1 and Dlx2 and the phosphorylation of Smad protein, was significantly enhanced. Using explant culture and subsequent subrenal capsule transplantation of E15 USAG-1 mutant maxillary incisor tooth primordia supplemented with BMP-7 demonstrated in USAG-1+/- as well as USAG-1-/- rescue and supernumerary tooth development. Based upon these results, we conclude that USAG-1 functions as an antagonist of BMP-7 in this model system. These results further suggest that the phenotypes of USAG-1 and BMP-7 mutant mice reported provide opportunities for regenerative medicine and dentistry.

Objectives: To assess the prevalence of traumatic dental injuries (TDI) in Taiwan, and to analyse the relationships between the occurrence of traumatic dental injuries and school type, age, gender, socio-economic status, family structure, overjet and lip morphology. Methods: A random sample of 6284 15–18-year-old academic and vocational senior high school students in southern Taiwan was selected. Each completed a questionnaire and was examined with standard clinical procedures. Results: Participation rate was 99.97%. The prevalence of TDI in Taiwan was 19.94% (95% C.I. 18.96%, 20.95%). Male adolescents (OR = 1.809, 95% C.I. 1.589, 2.058) attending private (OR = 1.158, 95% C.I. 1.004, 1.336) and/or vocational schools (OR = 1.200, 95% C.I. 1.030, 1.398), with an overjet greater than 5 mm (OR = 1.697, 95% C.I. 1.450, 1.985), inadequate lip morphology (OR = 1.350, 95% C.I. 1.189, 1.533), living with at least one nonbirth parent (OR = 1.274, 95% C.I. 1.013, 1.601), and/or having the middle educated chief guardian (OR = 1.210, 95% C.I. 1.039, 1.411), were found to be at greater risk of TDI. Conclusions: The prevalence of TDI in Taiwan was similar to that found in other countries. Correlates of TDI were gender, lip morphology, overjet, chief guardian's level of education, family structure and school type. Further investigation into the aetiology of TDI is indicated.

[Extract] Obesity has become an increasing problem in the paediatric population. An association between Body Mass Index (BMI) and saliva buffering capacity has had limited investigation. Previous studies have found that caries experience is correlated to obesity and also salivary buffering capacity. In addition, salivary buffering capacity is influenced by some medical conditions, such as Down syndrome and cystic fibrosis. As a consequence of these studies, it can be inferred that salivary buffering capacity may have a relationship to obesity. The aim of this study was to determine the relationship between and individual's BMI and the bufer capacity of their saliva in a 7-9 year age group. The relationships between salivary buffering capacity to salivary pH, age and gender were also evaluated.

[Extract] This study aimed to determine the nature of surface degradation for composite resins following the application of the fluoride in a simulated oral environment.

Although application of professionally applied Acidulated Phosphate fluoride (APF) gel is effective in prevention of dental caries, APF-induced discolouration and/or surface degradation of dental restorations has been reported. However, no publication has reported a dose-response effect of APF gel on Glass Ionomer Cement (GIC) restorations in vivo and/or human teeth. Therefore, this study aimed to examine the discolouration effect of APF gel at various concentration levels on GIC restorations of human teeth in vitro.Seventy extracted human teeth were used. Each was restored with GIC and then topically applied with a different dilution of APF gel. Change of shade and/or colour of restorations was assessed by a trained examiner.GIC discolouration was detected on 4 (5.71%) and 23 specimens (32.86%) after the first and the second APF applications, respectively. The discolouration rate increased with APF gel concentration on the second application (χ2=38.314, df=1, p0.001) but not the first ( χ2=2.352, df=1, p=0.125). Discolouration of GIC restorations was more likely to form under application of a higher concentration of APF gel (OR=1.099, 95%CI=1.052, 1.148), a higher concentration of fluoride (OR=1.001, 95%CI=1.000, 1.001) and/or a lower pH value (OR=0.002, 95%CI=0.000, 0.039).Discolouration of GIC was associated with concentration and frequency of APF gel application in extracted natural human teeth in vitro. Increasing discolouration rates were related to increased fluoride concentration and increasing acidity of APF gel. Further investigation is indicated.