Susceptibility status and synergistic activity of DDT and Lambda-cyhalothrin on Anopheles gambiae and Aedes aegypti in Delta State, Nigeria.

The detection of insecticide resistance in male mosquitoes has been treated with less importance in monitoring insecticide resistance spread in mosquitoes. There are no studies on the susceptibility and synergistic activity of DDT and lambda-cyhalothrin on male Anopheles gambiae and Aedes aegypti in Delta State, Nigeria. Even though studies have extensively reported resistance in female mosquitoes, the susceptibility of male mosquitoes to insecticide classes should be ascertained. In this study, we tested the susceptibility status and synergistic activity of DDT and Lambda-cyhalothrin on An. gambiae and Ae. aegypti in Delta State, Nigeria, in order to ascertain the level of resistance and knockdown. In addition, we modelled the knockdown time using Probit analysis model. WHO bioassay method was used to expose two days old adult mosquitoes to 4% DDT and 0.05% lambda-cyhalothrin. The results showed that An. gambiae mosquitoes exposed to DDT and lambda-cyhalothrin were confirmed resistant (61% and 53% respectively). However, pre-exposing the resistant mosquito population to piperonyl butoxide (4%) showed an increase in mortality to 90% (possible resistance) in DDT and 98% (susceptible) in lambda-cyhalothrin. Ae. aegypti mosquitoes exposed to DDT were susceptible (98%) while those exposed to lambda-cyhalothrin were confirmed resistant (87%) and this increased to complete mortality (100%) in PBO+lambda-cyhalothrin population. Furthermore, the results showed that the knockdown time (KDT50 and KDT95) in An. gambiae exposed to DDT was 39.5-71.2 minutes and 124.5-146.4 minutes respectively, while that of lambda-cyhalothrin was 33.0-81.8 minutes and 64.0-124.4 minutes respectively. In Ae. aegypti, KDT50 and KDT95 was 23.9 and 61.7minutes for DDT exposure whereas it was 5.6-15.3 minutes and 36.1-72.3 minutes for lambda-cyhalothrin exposure. It can be concluded that male An. gambiae mosquitoes exposed to the insecticides were resistant and the causes may be linked to certain resistant genes in the mosquitoes. The chances of transferring resistance are possible in wild species and molecular-based studies on the resistant gene in male mosquitoes as well as the tendencies of transfer are required to establish this focus.

The orthodontic condition of children in England, Wales and Northern Ireland 2013.

Background The 2013 Children's Dental Health Survey is the fifth in a series of national surveys.Aims This paper reports the orthodontic condition of 12- and 15-year-olds and how they and their parents feel about the appearance of their teeth.Methodology A representative sample of children (5y, 8y, 12y, 15y) in England, Wales and Northern Ireland were invited to participate in dental examinations. A modified Index of Orthodontic Treatment Need (IOTN) was used as a measure of orthodontic treatment need for 12- and 15-year-olds. Children and parents were invited to complete a questionnaire about oral health behaviour and attitudes.Results Nine percent of 12-year-olds and 18% of 15-year-olds were undergoing orthodontic treatment at the time of the survey. Forty-four percent of 12-year-olds and 29% of 15-year-olds expressed a desire for straighter teeth, however over half of this group would not qualify for NHS treatment. Unmet treatment need was higher in children eligible for free school meals (P <0.05 at 15y).Conclusions Provision of and demand for orthodontic treatment is increasing, with a significant proportion of children who desire orthodontic care not eligible to receive it. Children from deprived backgrounds have greater unmet orthodontic treatment need.

Organ donation after circulatory death in a university teaching hospital.

Although organ transplantation is well established for end-stage organ failure, many patients die on waiting lists due to insufficient donor numbers. Recently, there has been renewed interest in donation after circulatory death (DCD). In a retrospective observational study we reviewed the screening of patients considered for DCD between March 2007 and December 2012 in our hospital. Overall, 148 patients were screened, 17 of whom were transferred from other hospitals. Ninety-three patients were excluded (53 immediately and 40 after review by donation staff). The 55 DCD patients were younger than those excluded (P=0.007) and they died from hypoxic brain injury (43.6%), intraparenchymal haemorrhage (21.8%) and subarachnoid haemorrhage (14.5%). Antemortem heparin administration and bronchoscopy occurred in 50/53 (94.3%) and 22/55 (40%) of cases, respectively. Forty-eight patients died within 90 minutes and proceeded to donation surgery. Associations with not dying in 90 minutes included spontaneous ventilation mode (P=0.022), absence of noradrenaline infusion (P=0.051) and higher PaO2:FiO2 ratio (P=0.052). The number of brain dead donors did not decrease over the study period. The time interval between admission and death was longer for DCD than for the 45 brain dead donors (5 [3-11] versus 2 [2-3] days; P<0.001), and 95 additional patients received organ transplants due to DCD. Introducing a DCD program can increase potential organ donors without reducing brain dead donors. Antemortem investigations appear to be acceptable to relatives when included in the consent process.

Adult Dental Health Survey 2009: implications of findings for clinical practice and oral health policy.

This is the final paper in a series reporting on the results of the 2009 Adult Dental Health Survey. Since 1968 national adult surveys have been repeated every decade with broadly similar methods providing a unique overview of trends in oral health over a 40-year period. This paper aims to explore the implications for dentists and oral health policy of the key results from the Adult Dental Health Survey 2009. Although repeat, cross-sectional, epidemiological surveys provide very valuable data on trends in disease patterns, they do not provide answers to test causal relationships and therefore cannot identify the causes for the significant improvements in oral health over the last 40 years. Evidence would indicate, however, that broad societal shifts in population norms and behaviours, combined with changes in clinical diagnostic criteria, treatment planning and clinical procedures are the main reasons for the changes that have taken place. Key implications of the survey results include the need to monitor, support and maintain the good state of oral health of the increasing proportion of younger adults with relatively simple treatment needs. A smaller number of young and middle aged adults but a significant proportion of older adults will have far more complex treatment needs requiring advanced restorative and periodontal care. Future oral health policy will need to address oral health inequalities, encourage skill mix and promote and facilitate the dental profession to deliver appropriate and high quality care relevant to the needs of their local population.

Adult Dental Health Survey 2009: transformations in British oral health 1968-2009.

This series of four papers reports and interprets the findings of the Adult Dental Health Survey (ADHS), 2009, published in early 2011. This is the fifth in a series of surveys repeated every decade since 1968. The evolution of the surveys and the way the supporting methodology has changed to meet the changing needs and circumstances over the last 40 years is described. In 1968, 37% of adults in England and Wales were edentate. By 2009, only 6% of the combined population of England, Wales and Northern Ireland were edentate. Among the dentate in 1968, there were a mean of 21.9 teeth. By 2009, not only had the dentate increased by 30 percentage points as a fraction of the population, but the number of teeth in this group had also increased by nearly four teeth on average to 25.7. There were significant variations in oral health according to geography and social variables and smaller differences according to sex. The retention of 21 or more teeth is widely used as a way of defining a minimum functional dentition. The proportion of adults with 21+ teeth increased from 73% in 1978 to 86% in 2009. Further huge improvements are projected as younger generations age, assuming future tooth loss continues at current low rates. We might expect that over 90% of those aged 35-44 in 2009 have a realistic prospect of retaining a functional natural dentition of 21 or more teeth by age 80.

A competing risk survival analysis model to assess the efficacy of filling carious primary teeth.

In recent years a strategy of selective, symptom-based intervention of carious primary teeth has been developed amongst some British general dental practitioners. Practice-based studies appear to provide evidence that policies of restoration of symptomless carious primary teeth do not confer any significant benefits above those associated with non-restorative care. However, results from these studies contrast with those of many clinical trials and prospective studies of primary molar restorations. In the current investigation, cohort study data from 5,168 carious primary molar teeth from 2,654 British children aged 4-5 years at baseline, augmented with Dental Practice Board treatment data, was utilised to assess the effect of restorative treatment on the likelihood of carious teeth subsequently progressing to either exfoliation or extraction. The effect of demographic and tooth level covariates on the fate of these teeth was also assessed. Multivariate multilevel parametric survival models were applied to the analysis of the carious-exfoliation and carious-extraction transitions to which the teeth were subject, assuming an underlying data hierarchy with teeth nested within individuals. Time of occurrence of caries affected survival experience, with teeth in which caries occurred later in life being associated with higher survival rates to extraction. Amongst filled teeth, later fillings were also associated with higher survival rates to extraction. Demographic and tooth level variables had a limited effect on survival experience. Treatment was found to be significantly associated with survival with respect to extraction, with survival rates of over 80% at 14 years, double those of untreated teeth.

Modelling childhood caries using parametric competing risks survival analysis methods for clustered data.

Caries in primary teeth is an ongoing issue in children's dental health. Its quantification is affected by clustering of data within children and the concurrent risk of exfoliation of primary teeth. This analysis of caries data of 103,776 primary molar tooth surfaces from a cohort study of 2,654 British children aged 4-5 years at baseline applied multilevel competing risks survival analysis methodology to identify factors significantly associated with caries occurrence in primary tooth surfaces in the presence of the concurrent risk of exfoliation, and assessed the effect of exfoliation on caries development. Multivariate multilevel parametric survival models were applied at surface level to the analysis of the sound-carious and sound-exfoliation transitions to which primary tooth surfaces are subject. Socio-economic class, fluoridation status and surface type were found to be the strongest predictors of primary caries, with the highest rates of occurrence and lowest median survival times associated with occlusal surfaces of children from poor socio-economic class living in non-fluoridated areas. The concurrent risk of exfoliation was shown to reduce the distinction in survival experience between different types of surfaces, and between surfaces of teeth from children of different socio-economic class or fluoridation status. Clustering of data had little effect on inferences of parameter significance.

Profile of the dentist in the oral healthcare team in countries with developed economies.

This paper confines itself to the description of the profile of a general dentist while outlining where the boundary between specialist and generalist may lie. The profile must reflect the need to recognize that oral health is part of general health. The epidemiological trends and disease variation of a country should inform the profile of the dentist. A particular tension between the provision of oral healthcare in publicly funded and private services may result in dentists practicing dentistry in different ways. However, the curriculum should equip the practitioner for either scenario. A dentist should work to standards appropriate to the needs of the individual and the population within the country's legal and ethical framework. He/she should have communication skills appropriate to ascertain the patient's beliefs and values. A dentist should work within the principles of equity and diversity and have the knowledge and clinical competence for independent general practice, including knowledge of health promotion and prevention. He/she should participate in life-long learning, which should result in a reflective practitioner whose clinical skills reflect the current evidence base, scientific breakthroughs and needs of their patients. Within the 4-5 years of a dental degree it is not possible for a student to achieve proficiency in all areas of dentistry. He/she needs to have the ability to know their own limitations and to access appropriate specialist advice for their patients while taking responsibility for the oral healthcare they provide. The dentist has the role of leader of the oral health team and, in this capacity; he/she is responsible for diagnosis, treatment planning and the quality control of the oral treatment. The dental student on graduation must therefore understand the principles and techniques which enable the dentist to act in this role. He/she should have the abilities to communicate, delegate and collaborate both within the dental team and with other health professionals, to the benefit of the patient. The profile of a dentist should encompass the points raised but will also be based upon competency lists which are published by a variety of countries and organizations. It is important that these lists are dynamic so that they are able to change in light of new evidence and technologies.

Analysing and presenting qualitative data.

This paper provides a pragmatic approach to analysing qualitative data, using actual data from a qualitative dental public health study for demonstration purposes. The paper also critically explores how computers can be used to facilitate this process, the debate about the verification (validation) of qualitative analyses and how to write up and present qualitative research studies.

Conducting qualitative interviews with school children in dental research.

This paper explores when and how to conduct qualitative research with children in dentistry, using research interviews as a method of data collection. Methodological guidance is also provided, based on research and a recent dental public health study in which 74 children from Years 2 (6-7-year-olds) and 6 (10-11-year-olds) were interviewed about their understanding of and attitudes to food.

Qualitative research in dentistry.

This paper is the first in a series of four that provides an overview of the key elements of qualitative research. In particular, it discusses issues such as what qualitative research is, when its use is appropriate, what it can offer dentistry and approaches to data collection and analysis. Where appropriate, examples of dental studies that have used qualitative methods are also provided for practical purposes.

Methods of data collection in qualitative research: interviews and focus groups.

This paper explores the most common methods of data collection used in qualitative research: interviews and focus groups. The paper examines each method in detail, focusing on how they work in practice, when their use is appropriate and what they can offer dentistry. Examples of empirical studies that have used interviews or focus groups are also provided.

Introducing a family case study to the dental undergraduate curriculum.

The 'Family Study' was introduced at Cardiff Dental School in the 2001/2 session. Students are paired with local families who they visit over three years to collect information about family structure, childhood development and health behaviours, which forms the basis of a major project in year 4. In this paper, data gained from the first cohort of students to complete the study are reviewed, together with a practical evaluation of the programme's delivery and teaching gains.

Sedation in Wales: a questionnaire.

AIM: To identify the current provision of sedation in primary dental care in Wales. DESIGN: Postal questionnaire survey. SETTING: Wales 2003. SUBJECTS AND MATERIALS: Questionnaires were sent to all dentists appearing on the Dentists Register with addresses in Wales (n = 1374). The questionnaires sought details on personal status, use of and training in conscious sedation techniques. RESULTS: In total 951 (69%) questionnaires were returned, 720 (90%) respondents worked in a primary dental care setting. Only 87 (12.1%) primary care dentists offered some form of sedation. CONCLUSIONS: The provision of conscious sedation services in primary dental care in Wales is poor.

Provision of prevention to adults in NHS dental practices and attitudes to prevention.

AIMS: To identify the number of claims reported by the Dental Practice Board (DPB) for the three adult preventive codes for the year ending October 2002 in Wales. To identify the attitudes of practitioners to the use of these codes. DESIGN: A cross-sectional study using routinely gathered DPB data and data generated by a postal questionnaire. SAMPLE: All DPB claims for the 12 months ending October 2002. A randomised sample of 400 dentists currently practising in Wales for the postal questionnaire. RESULTS: The DPB data showed great variation across Wales for: the number, type and distribution of preventive code claims; the age and payment status of patients prescribed these treatments; and the proportion of male versus female dentists claiming for the codes. The questionnaire response rate was 67% (n = 267). The results showed that most respondents were deterred by the restrictions on the codes, insufficient reimbursement and a perceived unwillingness of patients to pay for preventive care. CONCLUSION: Few dentists provide preventive care to adults under the existing remuneration system. Work is necessary to enable dentists to use effective preventive techniques for adult patients. These results can be considered to show the baseline provision of prevention and could facilitate the evaluation of any changes to the current system.

Primary care research: difficulties recruiting preschool children to clinical trials.

OBJECTIVES: The aims of the present study were to report difficulties experienced recruiting preschool children to a clinical trial and to report the acceptability of a dental intervention to their parents. DESIGN: The study was a randomized controlled trial (RCT). SETTING: The study took place in community dental clinics, health centres and patient homes. SAMPLE AND METHODS: Health visitors were used to recruit 508 children aged between 18 and 30 months from high caries areas of South Wales. Children with caries-free first primary molars were entered into a placebo-controlled individual RCT of fissure sealants. All children received a standard package of dental health education. Children in the test group had their first primary molars sealed with glass ionomer. All children were reviewed once. Families were asked to rate the acceptability of procedures. RESULTS: Health visitors referred 1228 children for screening, but only 547 were seen (44.5%) and 508 subjects were recruited to the trial. Of these, 449 (88.4%) were seen at follow-up. Some 667 children missed 1610 visits at baseline, and 373 of those recruited missed an appointment. At follow-up, 1056 appointments were staffed to review 449 children. Three-quarters of parents reported the examination to be very easy. CONCLUSIONS: Preschool children are difficult to access for community trials. Dental examinations and sealant placement were acceptable to the majority of families who were seen.

A randomised controlled trial to determine the effectiveness of glass ionomer sealants in pre-school children.

BACKGROUND: Caries levels in pre-school children remain high in some areas of the UK. Studies of glass ionomer fissure sealants show their potential for caries prevention in permanent teeth, but their use in primary teeth has not been reported. AIM: To determine whether a glass ionomer fissure sealant placed on primary molars in pre-school children at high risk of developing dental caries can decrease the incidence of dental caries. MATERIAL: 508 children aged 18-30 months from high caries areas of South Wales with caries-free first primary molars were recruited to the trial after informed consent. METHODS: This was a placebo-controlled individual randomised controlled trial (RCT). All children (n = 508) received a standard package of dental health education. Children in the test group (n = 241) had their first primary molars sealed with glass ionomer. All the children were re-examined once at varying intervals between 12 and 30 months. RESULTS: Analysis of the caries data revealed no significant difference between test and control groups for any of the parameters examined. Examination of the confidence intervals showed no indication that there might be a difference even if the sample size had been increased. CONCLUSION: There is no evidence that the intervention as used in this population had any effect on caries incidence and it cannot be recommended as a clinical procedure.

The York review--a systematic review of public water fluoridation: a commentary.

Following the election of the British government in May 1997, a policy document outlining proposals to improve the health of the nation was published. This document placed a major emphasis on reducing inequalities in health and recognised the continuing poor state of oral health in deprived communities. However, whilst acknowledging the benefits of water fluoridation as a caries preventive measure, the Department of Health suggested that most of the research had been carried out some years ago and furthermore, recognised that strong views were held both for and against fluoridation.