In vitro comparison of contemporary radiographic imaging techniques for measurement of tooth length: reliability and radiation dose.

OBJECTIVES: To measure the reliability of tooth length measurements taken using dental pantomograms (DPT), long cone periapical radiographs (PR), and cone beam computed tomography (CBCT) and to compare their effective radiation dose. SUBJECTS AND METHODS: A model containing sixteen anterior teeth was used to simulate a patient undergoing fixed appliance treatment. PRs were taken at standardized vertical angulations to the occlusal plane (0, 5, 10, 15, and 20°) using conventional and digital techniques. DPT and CBCT images were also taken. Measurements of radiation dosages were used to estimate a risk benefit analysis for each of the techniques. RESULTS: DPT consistently overestimated tooth lengths by 2 mm or more [mean: 2·34 mm; 95% confidence interval (CI): 1·4-3·3 mm]. CBCT consistently underestimated tooth length (mean: -0·89 mm; 95% CI: -0·44 to -1·33 mm). PRs taken at 90° angulation closely resembled the actual tooth length (mean: -0·14 mm; 95% CI: -0·64 to 0·37 mm), but overestimation occurred with increasing PR film angulation. The radiation dosages ranged widely: DPT plus eight PRs that would be necessary to assess all teeth and root length of the upper and lower labial segments amounted to 23 µSv. Radiation dose from CBCT ranged from 17·8 to 60 µSv, depending on equipment and settings.

Protocol for the ADDITION-Plus study: a randomised controlled trial of an individually-tailored behaviour change intervention among people with recently diagnosed type 2 diabetes under intensive UK general practice care.

BACKGROUND: The increasing prevalence of type 2 diabetes poses both clinical and public health challenges. Cost-effective approaches to prevent progression of the disease in primary care are needed. Evidence suggests that intensive multifactorial interventions including medication and behaviour change can significantly reduce cardiovascular morbidity and mortality among patients with established type 2 diabetes, and that patient education in self-management can improve short-term outcomes. However, existing studies cannot isolate the effects of behavioural interventions promoting self-care from other aspects of intensive primary care management. The ADDITION-Plus trial was designed to address these issues among recently diagnosed patients in primary care over one year. METHODS/DESIGN: ADDITION-Plus is an explanatory randomised controlled trial of a facilitator-led, theory-based behaviour change intervention tailored to individuals with recently diagnosed type 2 diabetes. 34 practices in the East Anglia region participated. 478 patients with diabetes were individually randomised to receive (i) intensive treatment alone (n = 239), or (ii) intensive treatment plus the facilitator-led individual behaviour change intervention (n = 239). Facilitators taught patients key skills to facilitate change and maintenance of key behaviours (physical activity, dietary change, medication adherence and smoking), including goal setting, action planning, self-monitoring and building habits. The intervention was delivered over one year at the participant's surgery and included a one-hour introductory meeting followed by six 30-minute meetings and four brief telephone calls. Primary endpoints are physical activity energy expenditure (assessed by individually calibrated heart rate monitoring and movement sensing), change in objectively measured dietary intake (plasma vitamin C), medication adherence (plasma drug levels), and smoking status (plasma cotinine levels) at one year. We will undertake an intention-to-treat analysis of the effect of the intervention on these measures, an assessment of cost-effectiveness, and analyse predictors of behaviour change in the cohort. DISCUSSION: The ADDITION-Plus trial will establish the medium-term effectiveness and cost-effectiveness of adding an externally facilitated intervention tailored to support change in multiple behaviours among intensively-treated individuals with recently diagnosed type 2 diabetes in primary care. Results will inform policy recommendations concerning the management of patients early in the course of diabetes. Findings will also improve understanding of the factors influencing change in multiple behaviours, and their association with health outcomes.

Survival and success of maxillary canine autotransplantation: a retrospective investigation.

The aim of this study was to evaluate survival and success rates following autotransplantation of permanent maxillary canine teeth. Sixty-three cases of maxillary canine autotransplantation from 49 subjects (mean age at transplantation 21.8 years, range 13-42.1 years) undertaken between 1977 and 2003 were collected as part of an audit project of transplantation success. All maxillary canines had complete root development at the time of transplantation. The sample was divided into two groups, a matched case-control study to compare 27 unilateral transplanted canines with the non-transplanted canine on the contralateral side, and all 63 transplanted canines with no controls. Teeth were assessed clinically using established criteria for success: tooth presence for survival and resorption, mobility, probing pocket depth (PPD), gingival bleeding, vitality, and colour. Radiographic investigation for success assessed internal and external inflammatory resorption (including the amount) bone levels and any signs of pathology. Data were described with descriptive statistics and analytical tests were used to assess frequencies of occurrence. The survival rate was 83 per cent with an average duration of 14.5 years in situ. Thirty-eight per cent of the transplants were deemed successful. There were statistically significant associations between the transplanted and non-transplanted teeth in PPD (P = 0.006), gingival bleeding (P = 0.006), vitality (P = 0.004), and colour (P = 0.002). Autotransplantation of impacted maxillary canines can be successful in the long term and may be indicated in selected cases. Although the rate for complete success in this study was low (no signs of resorption, mobility, and sound periodontal tissues), the survival rate can be considered favourable when evaluating autotransplantation as a treatment option for grossly malpositioned canines with little scope for orthodontic alignment.

Efficacy of a theory-based behavioural intervention to increase physical activity in an at-risk group in primary care (ProActive UK): a randomised trial.

BACKGROUND: Declining physical activity is associated with a rising burden of global disease. Efforts to reverse this trend have not been successful. We aimed to assess the efficacy of a facilitated behavioural intervention to increase the physical activity of sedentary individuals at familial risk of diabetes. METHODS: We enrolled 365 sedentary adults who had a parental history of type 2 diabetes. They were recruited from either diabetes or family history registers at 20 general practice clinics in the UK. Eligible participants were randomly assigned to one of two intervention groups, or to a comparison group. All participants were posted a brief advice leaflet. One intervention group was offered a 1-year behaviour-change programme, to be delivered by trained facilitators in participants' homes, and the other the same programme by telephone. The programme was designed to alter behavioural determinants, as defined by the theory of planned behaviour, and to teach behaviour-change strategies. The principal outcome at 1 year was daytime physical activity, which was objectively measured as a ratio to resting energy expenditure. Analysis was by intention to treat. This study is registered as ISRCTN61323766. FINDINGS: Of 365 patients, we analysed primary endpoints for 321 (88%) for whom we had data after 1 year of follow-up. At 1 year, the physical-activity ratio of participants who received the intervention, by either delivery route, did not differ from the ratio in those who were given a brief advice leaflet. The mean difference in daytime physical-activity ratio, adjusted for baseline, was -0.04 (95% CI -0.16 to 0.08). The physical-activity ratio did not differ between participants who were delivered the intervention face-to-face or by telephone (mean difference -0.05; 95% CI -0.19 to 0.10). INTERPRETATION: A facilitated theory-based behavioural intervention was no more effective than an advice leaflet for promotion of physical activity in an at-risk group; therefore health-care providers should remain cautious about commissioning behavioural programmes into individual preventive health-care services.

Fidelity of delivery of a physical activity intervention: predictors and consequences.

Assessing fidelity of behavioural interventions is important, but demanding and rarely done. This study assessed adherence to behaviour change techniques used in an intervention to increase physical activity among sedentary adults ( ProActive ; N = 365). Transcripts of 108 sessions with a sub-sample of 27 participants were assessed. An independent assessor coded adherence of four 'facilitators' who delivered the intervention to 208 protocol-specified facilitator behaviours (e.g. 'elicit perceived advantages of becoming more active') in four key sessions. Four raters classified the 208 behaviours under 14 techniques (e.g., goal setting, use of rewards) to enable calculation of adherence to techniques. Observed adherence to techniques across participants was modest (median 44%, IQR 35-62%), and lower than that reported by facilitators. Adherence differed between facilitators (range: 26-63%) and decreased across the four sessions (mean drop 9% per session, 95% confidence interval 7-11%). In this small sample facilitator adherence was unrelated to (change in) participants' physical activity or its cognitive predictors: Attitudes, subjective norm, perceived behavioural control and intention. Future research should investigate causal pathways between fidelity indicators and outcomes in larger samples and develop and test less intensive measures of fidelity.

Investigating theoretical explanations for behaviour change: the case study of ProActive.

Developing more effective behavioural interventions requires an understanding of the mechanisms of behaviour change, and methods to rigorously test their theoretical basis. The delivery and theoretical basis of an intervention protocol were assessed in ProActive, a UK trial of an intervention to increase the physical activity of those at risk of Type 2 diabetes (N = 365). In 108 intervention sessions, behaviours of facilitators were mapped to four theories that informed intervention development and behaviours of participants were mapped to 17 theoretical components of these four theories. The theory base of the intervention specified by the protocol was different than that delivered by facilitators, and that received by participants. Of the intervention techniques delivered, 25% were associated with theory of planned behaviour (TPB), 42% with self-regulation theory (SRT), 24% with operant learning theory (OLT) and 9% with relapse prevention theory (RPT). The theoretical classification of participant talk showed a different pattern, with twice the proportion associated with OLT (48%), 21% associated with TPB, 31% with SRT and no talk associated with RPT. This study demonstrates one approach to assessing the extent to which the theories used to guide intervention development account for any changes observed.