A questionnaire-based study of Paediatric Dentists' knowledge of teething signs, symptoms and management.

INTRODUCTION: Signs and symptoms attributed to erupting primary teeth are commonly known as "teething". Its existence is controversial with concern that overusing this term might mask other illnesses and some treatments may be unnecessary or harmful. Parents/carers can access over-the-counter remedies and may seek professional advice. This survey-based investigation explored gaps in knowledge, training, perceptions and experiences of UK Paediatric Dentists (PDs) regarding teething in young children. METHOD: Cross-sectional study with a convenience sample of PDs with different training levels, accessed through the British Society for Paediatric Dentistry membership lists. A 10-item questionnaire explored participants' knowledge of teething-related issues and management. Responses are presented using descriptive statistics. RESULTS: Of 80 responding PDs (response rate 27%), 62-74% suggested drooling, irritability, oral fixation and flushed cheeks were attributed to primary tooth eruption. Fifty-eight (72%) participants were unaware of guidelines, yet 53 (66%) felt guidance was needed. CONCLUSION: Signs and symptoms of teething might mask underlying conditions so it should be a diagnosis of exclusion. PDs attributed similar signs and symptoms to teething, as have been reported in the literature, although some commented that they did not think teething was a condition. There was a lack of awareness over guidelines.

Teething products may be harmful to health.

Introduction An internet search identified teething powders licensed in the UK containing sucrose and alcohol.Aims To identify current UK guidance on teething and potentially harmful ingredients in teething products.Methods Internet searches identified UK national guidance on teething and evidence on teething interventions. The Medicines and Healthcare products Regulatory Agency was asked to provide information on the sugar and alcohol content of UK-licensed teething products. The internet search also highlighted concerns about 2% lidocaine teething product use in the USA. Information on lidocaine content was extracted from product information leaflets.Results A clinical knowledge summary notes the lack of evidence of effectiveness of teething powders, granules, pills or gels. Of 14 licensed teething products, two contain sucrose, six contain alcohol and six contain lidocaine, all potentially harmful ingredients. There is an opportunity to develop some new UK guidance drawing on extant teething guidance and the clinical knowledge summary.Conclusions Despite a lack of evidence of effectiveness for teething products, of the 14 licensed products in the UK, nine contain one or more of sucrose, alcohol or lidocaine. There is an opportunity to develop new guidance to steer health professionals and the public away from these potentially harmful products.

Genomic Evidence of Widespread Admixture from Polar Bears into Brown Bears during the Last Ice Age.

Recent genomic analyses have provided substantial evidence for past periods of gene flow from polar bears (Ursus maritimus) into Alaskan brown bears (Ursus arctos), with some analyses suggesting a link between climate change and genomic introgression. However, because it has mainly been possible to sample bears from the present day, the timing, frequency, and evolutionary significance of this admixture remains unknown. Here, we analyze genomic DNA from three additional and geographically distinct brown bear populations, including two that lived temporally close to the peak of the last ice age. We find evidence of admixture in all three populations, suggesting that admixture between these species has been common in their recent evolutionary history. In addition, analyses of ten fossil bears from the now-extinct Irish population indicate that admixture peaked during the last ice age, whereas brown bear and polar bear ranges overlapped. Following this peak, the proportion of polar bear ancestry in Irish brown bears declined rapidly until their extinction. Our results support a model in which ice age climate change created geographically widespread conditions conducive to admixture between polar bears and brown bears, as is again occurring today. We postulate that this model will be informative for many admixing species pairs impacted by climate change. Our results highlight the power of paleogenomics to reveal patterns of evolutionary change that are otherwise masked in contemporary data.

Dentist skill and setting to address dental treatment needs of care home residents in Wales.

OBJECTIVE: To explore the relationship between treatment plans, complexity anticipated in delivering those plans, and the special care dental skills and settings identified as appropriate. BACKGROUND: In older adults, many factors may complicate dental treatment including health and disability problems. Assessment of dental treatment needs amongst care home residents provides information about clinical care required and clinical experience needed for this population. MATERIAL AND METHODS: Analysis of dental data collected in a 2010 Welsh survey. Data analysed included treatment plan information, complexity assessment and dental expertise and settings required to deliver the treatment plans. RESULTS: The majority of participating residents needed simple dentistry, that is examinations, oral hygiene instruction, scaling of teeth, fillings, new dentures and fluoride application. Additional time was the commonest complexity factor. A large proportion of participants required dental treatment within a domiciliary setting. A similar proportion required care within a primary care setting (typically with care from a general dental practitioner) or a special care clinic (typically with care from a dentist with special care experience). Treatment plans involving specialists were more likely to be associated with poor general health, higher levels of interventional treatment and greater complexity. CONCLUSION: Most treatment need in care homes is basic restorative, periodontal and preventive care. Half of this could be managed by general dentists, some on a domiciliary basis and the rest in primary care dental clinics. The commonest complexity was additional time. More complex treatments were associated with care in clinics, skills in special care dentistry and multidisciplinary care.

Growth in fossil and extant deer and implications for body size and life history evolution.

BACKGROUND: Body size variation within clades of mammals is widespread, but the developmental and life-history mechanisms by which this variation is achieved are poorly understood, especially in extinct forms. An illustrative case study is that of the dwarfed morphotypes of Candiacervus from the Pleistocene of Crete versus the giant deer Megaloceros giganteus, both in a clade together with Dama dama among extant species. Histological analyses of long bones and teeth in a phylogenetic context have been shown to provide reliable estimates of growth and life history patterns in extant and extinct mammals. RESULTS: Similarity of bone tissue types across the eight species examined indicates a comparable mode of growth in deer, with long bones mainly possessing primary plexiform fibrolamellar bone. Low absolute growth rates characterize dwarf Candiacervus sp. II and C. ropalophorus compared to Megaloceros giganteus displaying high rates, whereas Dama dama is characterized by intermediate to low growth rates. The lowest recorded rates are those of the Miocene small stem cervid Procervulus praelucidus. Skeletal maturity estimates indicate late attainment in sampled Candiacervus and Procervulus praelucidus. Tooth cementum analysis of first molars of two senile Megaloceros giganteus specimens revealed ages of 16 and 19 years whereas two old dwarf Candiacervus specimens gave ages of 12 and 18 years. CONCLUSIONS: There is a rich histological record of growth across deer species recorded in long bones and teeth, which can be used to understand ontogenetic patterns within species and phylogenetic ones across species. Growth rates sensu Sander & Tückmantel plotted against the anteroposterior bone diameter as a proxy for body mass indicate three groups: one with high growth rates including Megaloceros, Cervus, Alces, and Dama; an intermediate group with Capreolus and Muntiacus; and a group showing low growth rates, including dwarf Candiacervus and Procervulus. Dwarf Candiacervus, in an allometric context, show an extended lifespan compared to other deer of similar body size such as Mazama which has a maximum longevity of 12 years in the wild. Comparison with other clades of mammals reveals that changes in size and life history in evolution have occurred in parallel, with various modes of skeletal tissue modification.

Ancient hybridization and an Irish origin for the modern polar bear matriline.

BACKGROUND: Polar bears (Ursus maritimus) are among those species most susceptible to the rapidly changing arctic climate, and their survival is of global concern. Despite this, little is known about polar bear species history. Future conservation strategies would significantly benefit from an understanding of basic evolutionary information, such as the timing and conditions of their initial divergence from brown bears (U. arctos) or their response to previous environmental change. RESULTS: We used a spatially explicit phylogeographic model to estimate the dynamics of 242 brown bear and polar bear matrilines sampled throughout the last 120,000 years and across their present and past geographic ranges. Our results show that the present distribution of these matrilines was shaped by a combination of regional stability and rapid, long-distance dispersal from ice-age refugia. In addition, hybridization between polar bears and brown bears may have occurred multiple times throughout the Late Pleistocene. CONCLUSIONS: The reconstructed matrilineal history of brown and polar bears has two striking features. First, it is punctuated by dramatic and discrete climate-driven dispersal events. Second, opportunistic mating between these two species as their ranges overlapped has left a strong genetic imprint. In particular, a likely genetic exchange with extinct Irish brown bears forms the origin of the modern polar bear matriline. This suggests that interspecific hybridization not only may be more common than previously considered but may be a mechanism by which species deal with marginal habitats during periods of environmental deterioration.