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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.

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.

Anterior open bite (AOB) is one of the most complex malocclusions to manage. AOB is caused by either by skeletal, genetic or environmental factors. Numerous treatment options are currently utilised to manage AOB. These vary from non-invasive behavioural shaping to orthodontic and surgical interventions. This paper reviews the available orthodontic and non-orthodontic interventions used in the management of AOB. The literature review was carried out using the PubMed search engine from the first of January 2000 to the first of June 2017. Two major keywords (open bite and anterior open bite) were used in addition to 23 minor keywords in the review. AOB is one of the most complex malocclusions to treat with high relapse rates. Long term outcome in treatments of patients with AOB was substantially low. Relapse rates were not taken into consideration for some of the literature reviewed. Despite limitations of the literature, it is recommended that orofacial myofunctional therapy (OMT) and non-orthodontic intervention (NOI) be used in conjunction as an effective treatment option for Anterior Open Bite. Keywords: Anterior open bite, Non-orthodontic intervention, Children, Malocclusion

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.

Background. Dental students have reported a high prevalence of psychological stress and the causes are associated with the challenging dental environmental and demographic factors. This study aimed to conduct a preliminary investigation on dental students' stress status, using a sample of first-to-third-year Bachelor of Dental Surgery students in an Australian university. Special interests included causes of dental environmental stress and access to help services. Methods. A sample of 145 students was surveyed with a modified Dental Environmental Survey and Depression Anxiety Stress Scale in 2014. The participants' demographic information was also collected. Results. The response rate was 95.4%. Second-year (P = 0.042), third-year (P < 0.001) and employed students (P = 0.027) were more likely to report stress resulting from transition to clinical learning. Third-year students were more often stressed about communicating and approaching staff (P = 0.023) as well as different opinions between staff (P < 0.001) and reduced holidays (P < 0.001). Students that were younger than 21 years of age (P = 0.001), that were first years (P < 0.001), and that were not in a relationship (P = 0.010) more often found difficulty of course work stressful. Students who were not in a relationship more often considered learning manual dexterity a source of stress (P = 0.034). Students previously seeking professional help were more likely to be stressed (P = 0.010). Conclusion. Causes of dental environment stress varied among years of study and demographic backgrounds. Professional support to stressed students should be enhanced. Further investigation is indicated.

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.

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 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...

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.

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.

[Extract] The tooth is a complex organ that consists of enamel, dentin, cementum, and pulp. Missing teeth is frequently occurring problem in aging populations. To treat these defects, the current approach involves prostheses, autotransplantation, and dental implants. The exploration of new strategies for tooth replacement has become a hot topic. Using the foundations of experimental embryology, developmental and molecular biology, tooth regeneration is becoming realistic possibility. Several different methods have been proposed to achieve biological tooth replacement. These include scaffold-based tooth regeneration, cell pellet engineering, stimulation of the formation of a third dentition, and gene-manipulated tooth regeneration. The idea that a third dentition might be locally induced to replace missing teeth is an attractive concept (Young et al., 2005; Edward & Mason, 2006; Takahashi et al., 2008, 2013). This approach is generally presented in terms of adding molecules to induce de novo tooth initiation in the mouth. Tooth development is the result of reciprocal and reiterative signaling between oral ectoderm-derived dental epithelium and cranial neural crest cell-derived dental mesenchyme under genetic control (Thesleff, 2006). More than 200 genes are known to be expressed during tooth development (http://bite-it.helsinki.fi/). A number of mouse mutants are now starting to provide some insights into the mechanisms of supernumerary tooth formation. Multiple supernumerary teeth may have genetic components in their etiology and partially represent the third dentition in humans. Such candidate molecules might be those that are involved in embryonic tooth induction, in successional tooth formation, or in the control of the number of teeth. This means that it may be possible to induce de novo tooth formation by the in situ repression or activation of a single candidate molecule. In this review, we provide an overview of the collective knowledge of tooth regeneration, especially regarding the control of the number of teeth for molecularly targeted therapy by the stimulation of a third dentition.

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.

[Extract] The tooth is a complex biological organ that consists of multiple tissues, including enamel, dentin, cementum, and pulp. Missing teeth is a common and frequently occurring problem in aging populations. To treat these defects, the current approach involves fixed or removable prostheses, autotransplantation, and dental implants. The exploration of new strategies for tooth replacement has become a hot topic. Using the foundations of experimental embryology, developmental and molecular biology, and the principles of biomimetics, tooth regeneration is becoming a realistic possibility. Several different methods have been proposed to achieve biological tooth replacement[1-8]. These include scaffold-based tooth regeneration, cell pellet engineering, chimeric tooth engineering, stimulation of the formation of a third dentition, and gene-manipulated tooth regeneration. The idea that a third dentition might be locally induced to replace missing teeth is an attractive concept[5,8,9]. This approach is generally presented in terms of adding molecules to induce de novo tooth initiation in the mouth. It might be combined with gene-manipulated tooth regeneration; that is, endogenous dental cells in situ can be activated or repressed by a gene-delivery technique to produce a tooth. Tooth development is the result of reciprocal and reiterative signaling between oral ectoderm-derived dental epithelium and cranial neural crest cell-derived dental mesenchyme under genetic control [10-12]. More than 200 genes are known to be expressed during tooth development (http://bite-it.helsinki.fi/). A number of mouse mutants are now starting to provide some insights into the mechanisms of supernumerary tooth formation. Multiple supernumerary teeth may have genetic components in their etiology and partially represent the third dentition in humans. Such candidate molecules or genes might be those that are involved in embryonic tooth induction, in successional tooth formation, or in the control of the number of teeth. This means that it may be possible to induce de novo tooth formation by the in situ repression or activation of a single candidate gene. In this review, we present an overview of the collective knowledge of tooth regeneration, especially regarding the control of the number of teeth for gene therapy by the stimulation of a third dentition.

Objectives: This study aimed to carry out a histological examination of the temporomandibular joint (TMJ) in ank mutant mice and to identify polymorphisms of the human ANKH gene in order to establish the relationship between the type of temporomandibular disorders (TMD) and ANKH polymorphisms. Materials and Methods: Specimens from the TMJ of ank mutant and wild-type mice were inspected with a haematoxylin and eosin staining method. A sample of 55 TMD patients were selected. Each was examined with standard clinical procedures and genotyping techniques. Results: The major histological finding in ank mutant mice was joint space narrowing. Within TMD patients, closed lock was more prevalent among ANKH-OR homozygotes (p = 0.011, OR = 7.7, 95% CI 1.6–36.5) and the elder (p = 0.005, OR = 2.4, 95% CI 1.3–4.3). Conclusions: Fibrous ankylosis was identified in the TMJ of ank mutant mice. In the human sample, ANKH-OR polymorphism was found to be a genetic marker associated with TMJ closed lock. Future investigations correlating genetic polymorphism to TMD are indicated.

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

Objective. We surveyed American Indian/Alaska Native (AIAN) women in New York City to determine the prevalence of 3 types of interpersonal violence among urban AIAN women and the behavioral health and mental health factors associated with this violence. Methods. Using a survey, we questioned 112 adult AIAN women in New York City about their experiences with interpersonal violence, mental health, HIV risk behaviors, and help-seeking. The sampling plan utilized a multiple-wave approach with modified respondent-driven sampling, chain referral, and target sampling. Results. Among respondents, over 65% had experienced some form of interpersonal violence, of which 28% reported childhood physical abuse, 48% reported rape, 40% reported a history of domestic violence, and 40% reported multiple victimization experiences. Overwhelmingly, women experienced high levels of emotional trauma related to these events. A history of interpersonal violence was associated with depression, dysphoria, help-seeking behaviors, and an increase in high–HIV risk sexual behaviors. Conclusions. AIAN women experience high rates of interpersonal violence and trauma that are associated with a host of health problems and have important implications for health and mental health professionals.

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.

Objectives. This study measured the prevalence of battering victimization (i.e., experience of psychological/symbolic, physical, and sexual battering) among men who have sex with men (MSM) and identified characteristics of these men. Methods. A probability-based sample of 2881 MSM living in 4 cities completed telephone interviews between 1996 and 1998. Results. Prevalence estimates were 34% for psychological/symbolic battering, 22% for physical battering, and 5% for sexual battering. The strongest demographic correlate independently associated with all forms of battering was age 40 or younger, whereas education and HIV serostatus were associated with physical and psychological/symbolic violence. Conclusions. Rates of battering victimization among urban MSM are substantially higher than among heterosexual men and possibly heterosexual women. Public health efforts directed toward addressing intimate partner battering among these men are needed.

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.