Effect of print layer height and printer type on the accuracy of 3-dimensional printed orthodontic models.

INTRODUCTION: Three-dimensional (3D) printing technologies enable production of orthodontic models from digital files; yet a range of variables associated with the process could impact the accuracy and clinical utility of the models. The objective of this study was to investigate the effect of print layer height on the accuracy of orthodontic models printed 3 dimensionally using a stereolithography format printer and to compare the accuracy of orthodontic models fabricated with several commercially available 3D printers. METHODS: Thirty-six identical models were produced with a stereolithography-based 3D printer using 3 layer heights (n = 12 per group): 25, 50, and 100 µm. Forty-eight additional models were printed using 4 commercially available 3D printers (n = 12 per group). Each printed model was digitally scanned and compared with the input file via superimposition analysis using a best-fit algorithm to assess accuracy. RESULTS: Statistically significant differences were found in the average overall deviations of models printed at each layer height, with the 25-µm and 100-µm layer height groups having the greatest and least deviations, respectively. Statistically significant differences were also found in the average overall deviations of models produced using the various 3D printer models, but all values fell within clinically acceptable limits. CONCLUSIONS: The print layer height and printer model can affect the accuracy of a 3D printed orthodontic model, but the impact should be considered with respect to the clinical tolerances associated with the envisioned application.

Diabetes knowledge in young adults: associations with hemoglobin A1C.

The purpose of this study was to quantify associations between hemoglobin A1C (A1C) and diabetes knowledge score using an assessment tool developed to evaluate the level of diabetes knowledge in young adults with Type 1 diabetes (T1DM) and their parent/primary caregiver. Seventy-five participants with T1DM, ages 15-22 years, completed questionnaires. Two 25-item questionnaires were developed: one for patient and one for caregiver. Linear regression quantified associations between correct items on the tools and participant A1C and demographic characteristics. Mean age of participants was 16.7 ± 1.7 years, diabetes duration 5.9 ± 4.2 years, 46.7% male, 74.7% Caucasian, 69.3% on multiple daily injections, and 30.7% on continuous subcutaneous insulin infusion therapy; 78.7% of parents/caregivers completed the questionnaire. A significant interaction was observed between patient and caregiver scores with A1C by diabetes duration. Among patients with diabetes <6 years, higher patient and caregiver scores were associated with lower A1C (-0.25 ± 0.11, p = .03 and -0.59 ± 0.19, p = .005, respectively) accounting for age, gender, race, therapy, and insurance. Neither patient nor caregiver score was associated with A1C in patients with diabetes duration ≥6 years. Better performance on a diabetes knowledge assessment (for both patient and the caregiver) was found to be associated with more favorable levels of glycemic control among young adults with diabetes <6 years. Additional evaluation of these questionnaires and novel interventions to enhance knowledge in this population are needed.

Interventions for motor vehicle crashes among Indigenous communities: strategies to inform Canadian initiatives.

OBJECTIVES: Motor vehicle crashes (MVCs) are a leading cause of death for Canadian Aboriginal peoples; developing effective interventions should be a public health priority. While intervention research has been conducted outside of Canada, few formal program evaluations have been conducted in Canada. We reviewed Canadian and non-Canadian Indigenous road safety initiatives to inform future program development in Canada. METHODS: A systematic review of the published and grey literature examining MVC intervention programs in Indigenous communities was performed. Studies published after 1980 reporting pre-post comparisons of MVC interventions in Indigenous communities were included in the review. These studies were assessed using a modified Participatory Action Research quality assessment tool. Haddon's Matrix of injury epidemiology and prevention was used to categorize crash-related risk factors targeted in the MVC interventions. SYNTHESIS: A total of 11 studies met inclusion criteria, including 1 Canadian study and 10 non-Canadian studies. Successful intervention components included focus groups, training community members, educational activities, distribution of safety devices, collaboration with local law officials to enhance enforcement, driver-licensing courses, and incentive programs. Potential barriers to successful implementation and evaluation involved lack of incorporation of cultural and contextual factors, enforcement factors, and methodological limitations. CONCLUSION: Several effective strategies to reduce MVCs can be adapted and implemented at the community and national levels. Future directions might include using multiple intervention components and incorporating a collaborative, culturally and contextually appropriate approach, while promoting evaluation initiatives and widespread dissemination of findings.

Perseveration moderates the relationship between perfectionism and binge eating: a multi-method daily diary study.

Theory and evidence suggest perfectionism is associated with binge eating. Few studies test conditions under which this association is particularly strong. To better understand the perfectionism-binge eating connection, the present study introduced perseveration as a moderator. A sample of 317 undergraduates completed a computerized Stroop task, baseline self-report measures of perfectionism (i.e., doubts about actions) and binge eating, and self-report daily diary measures of binge eating. Perseveration was defined in terms of reaction time difficulties when consecutive trials required a change of response relative to consecutive trials not requiring a change. Results indicated high levels of doubts about actions were especially related to high levels of binge eating for participants high (versus low) in perseveration. Findings suggest perfectionistic, nagging self-doubts, combined with a tendency to get stuck on thoughts or behaviors, may contribute to increased binge eating-a habitual behavior linked with difficulties in self-regulation.

Motor vehicle crashes among Canadian Aboriginal people: a review of the literature.

INTRODUCTION: Aboriginal people are substantially more likely to be injured or die in motor vehicle crashes (MVCs) than the general population. However, research examining MVCs among Canadian Aboriginal populations is limited. We examine trends and gaps in the Canadian literature and suggest priorities for future research. METHODS: We conducted a systematic review of the published and grey literature on MVCs involving Canadian Aboriginal people. We used the Haddon matrix of injury epidemiology and prevention to identify trends in crash-related risk factors. RESULTS: We reviewed 20 studies, which consisted of research at both national and provincial levels. We identified various risk factors related to human (e.g., male sex, substance use), vehicle and equipment (e.g., driving an older vehicle, driving a car [v. other types of vehicles]), and physical environment (e.g., occurring on-reserve, muddy and loose-gravel road conditions) variables. However, we did not find research that examined risk factors related to the social environment, such as perspectives related to MVCs. CONCLUSION: This review indicates that rates of death, hospital admission and injury related to MVCs are twice as high among Aboriginal populations than the general Canadian population, which highlights a major public health concern. Priorities for future research should include examination of the social environment, more rigorous methods and collaborative research in partnership with Aboriginal communities.

Infantile amnesia across the years: a 2-year follow-up of children's earliest memories.

Although infantile amnesia has been investigated for many years in adults, only recently has it been investigated in children. This study was a 2-year follow-up and extension of an earlier study. Children (4-13 years old) were asked initially and 2 years later for their earliest 3 memories. At follow-up, their age at the time of these memories shifted to several months later, with younger children unlikely to provide the same memories. Moreover, when given cues about memories recalled 2 years previously, many were still not recalled. In contrast, older children were more likely to recall the same memories, and cues to former memories were successful. Thus, older children were becoming consistent in terms of recalling very early memories.