Sociocultural determinants of children's oral health among immigrants in Canada.

OBJECTIVE: A conceptual model was designed and tested to predict immigrant children's oral health in Canada by examining parental acculturation and perceived social support (PSS) using structural equation modelling. METHODS: A convenience sample of first-generation immigrant parents and their children aged 2-12 years were recruited by multilingual community workers in Edmonton, Canada. Parents completed a validated questionnaire on demographics, child's oral health (OH) behaviours, parental acculturation and PSS. Dental examinations determined children's dental caries rate using DMFT/dmft index. Structural equation modelling (SEM) was used to analyse the data. RESULTS: A total of 336 families participated in this study. The average parental acculturation level was 10.46 with a maximum of 15, and the average PSS was 63.27 with a maximum of 75. SEM showed that 77% of the variance of DMFT/dmft scores in children was explained by parental PSS, acculturation level, immigration-related variables, socioeconomic variables and children's OH behaviours. The direct effect of parental PSS was associated with a significantly reduced rate of dental caries (ß = -.076, p-value = .008) and lower sugar consumption (ß = -.17, p-value = .04). While the mediation effect of parental acculturation on PSS was associated with positive OH behaviours of children (e.g., toothbrushing frequency and dental care utilization), the indirect effect was negatively associated with caries rate (ß = .77, p-value = .00). CONCLUSIONS: The direct effect of Parental Perceived Stress Scale (PSS) was associated with more favourable oral health behaviours and a lower prevalence of dental caries, while the mediation effect of acculturation was linked to a higher prevalence of dental caries.

Direct-to-consumer orthodontics: Exploring laypeople's perception of orthodontic treatment complexity.

BACKGROUND: The authors aimed to explore the treatment preferences of laypeople regarding direct-to-consumer (DTC) orthodontics and to identify whether case complexity, as perceived by laypeople, is one of the factors influencing interest in DTC orthodontics. METHODS: An online cross-sectional survey was conducted. Data analysis was performed using logistic regression models. RESULTS: A total of 1,362 surveys were completed. A significant inverse association was identified between the complexity of an orthodontic case, as measured using the American Board of Orthodontics' discrepancy index (DI) score, and the likelihood of choosing DTC treatment over an orthodontist. Participants were 3.53 times more likely to choose DTC treatment for a mild case (DI score, 0-10) compared with a complex case (DI score, > 20), although the likelihood of choosing DTC treatment for a moderate case (DI score, 11-20) was only 1.79 times higher than for a complex case. CONCLUSIONS: When laypeople were asked to consider each case as if it were their own dentition, there was a significant inverse association between the complexity of an orthodontic case, as measured using the DI score, and the likelihood of choosing DTC treatment over an orthodontist. Laypeople were seemingly more likely to choose DTC orthodontics for dentitions that did not appear crowded and were well aligned within the arches. Laypeople seemed to have an understanding that there are some limitations to DTC orthodontics. PRACTICAL IMPLICATIONS: Orthodontists should better understand the factors influencing consumers' decisions to select DTC orthodontics and dental organizations should focus their educational campaigns on these factors.

Comparative assessment of dental and basal arch dimensions of passive and active self-ligating versus conventional appliances : A randomized clinical trial.

PURPOSE: In this parallel, three-arm, single-center randomized trial, the dental and basal arch dimensions after orthodontic treatment using conventional brackets and passive and active self-ligating (SL) brackets were compared. METHODS: Patients needing comprehensive orthodontic treatment were randomly allocated to the active SL, passive SL, or conventional brackets (control) group. All patients were treated with a standardized arch wires sequence. Eligibility criteria included class I malocclusion in the permanent dentition, crowding (4-6 mm), and adequate oral hygiene. The primary outcome was intermolar width, based on cone beam computed tomography (CBCT) scans. Secondary outcomes were maxillary and mandibular widths in the canines and premolars regions, dental arch depth, buccolingual inclination, and alignment duration. Blinding of outcome assessment was implemented. Patients were followed every 4 weeks until insertion of the stainless steel 0.019â€¯× 0.025 wire. Mean values were computed from CBCT sections, and data were analyzed using a one-way analysis of variance. RESULTS: In all, 66 patients (ages 18-25 years) were randomized into a 1:1:1 ratio; 7 patients dropped out before treatment initiation. Examining dental arch dimensions in the canine and premolar regions showed that expansion of the maxillary dental arch was greatest in the passive SL brackets group, less in the active SL brackets group, and lowest in the control group (P < 0.01). Changes in maxillary intermolar width between the three groups were not significant, and changes in basal arch dimensions, depth of dental and basal arches, buccolingual inclination, and alignment duration were similar in the three groups. CONCLUSIONS: Self-ligating brackets were not more effective than conventional brackets when examining intermolar width, basal transverse dimensions, depth of the arch, and alignment duration.

Immigrant Parents' Perceived Social Support and Their Children's Oral Health Behaviors and Caries Experience.

This study examined the associations between immigrant parents' perceived social support (PSS) and their children's oral health behaviors (OHB) and caries experience. We recruited immigrant parents and children aged 2−12 years. Data were collected on the sociodemographic and OHB information of the children. The parents' total PSS score and its dimensions were measured using the validated Personal Resource Questionnaire (PRQ2000). Dental examinations determined the children's caries experience using the DMFT/dmft index. A total of 336 parents and children were included in the study. Household income predicted the parents' PSS (B = −5.69; 95% CI −9.077, −2.32). Children of parents with higher PSS reported ≥2 toothbrushing/day (p ≤ 0.05). Among the PSS domains, parental education level predicted their social integration (B = −0.16; 95% CI −0.30, −0.02) and nurturance (B = −0.24; 95% CI −0.43, −0.06). Family income predicted social integration (B = −0.17; 95% CI −0.33 −0.01), worth (B = −0.23; 95% CI −0.39 −0.06), and assistance (B = −0.22; 95% CI −0.42 −0.01). Parents with higher scores of intimacy and social integration were more aware of their children's oral health (p = 0.01). The parental social integration mean scores were significantly higher among parents whose children consumed ≥1 sugary snack/day (p = 0.02). All five domain scores were significantly higher among parents of children who reported ≥2 toothbrushing/day compared with children who brushed <2/day (p < 0.05). The results demonstrated that parents' PSS only improved their children's toothbrushing frequency. Compared to other domains, social integration was significantly associated with children's OHB. Neither parental PSS total score nor domains were associated with DMFT/dmft.

Are Biases Related to Attrition, Missing Data, and the Use of Intention to Treat Related to the Magnitude of Treatment Effects in Physical Therapy Trials?: A Meta-Epidemiological Study.

ABSTRACT: The objective of this study was to determine the association between biases related to attrition, missing data, and the use of intention to treat and changes in effect size estimates in physical therapy randomized trials. A meta-epidemiological study was conducted. A random sample of randomized controlled trials included in meta-analyses in the physical therapy discipline were identified. Data extraction including assessments of the use of intention to treat principle, attrition-related bias, and missing data was conducted independently by two reviewers. To determine the association between these methodological issues and effect sizes, a two-level analysis was conducted using a meta-meta-analytic approach. Three hundred ninety-three trials included in 43 meta-analyses, analyzing 44,622 patients contributed to this study. Trials that did not use the intention-to-treat principle (effect size = -0.13, 95% confidence interval = -0.26 to 0.01) or that were assessed as having inappropriate control of incomplete outcome data tended to underestimate the treatment effect when compared with trials with adequate use of intention to treat and control of incomplete outcome data (effect size = -0.18, 95% confidence interval = -0.29 to -0.08).Researchers and clinicians should pay attention to these methodological issues because they could provide inaccurate effect estimates. Authors and editors should make sure that intention-to-treat and missing data are properly reported in trial reports.

Parental acculturation and oral health of children among immigrants.

OBJECTIVES: This cross-sectional study aimed to examine the associations between parental acculturation level and strategies and children's caries experience and oral health (OH) behaviors. METHODS: Participants were immigrant parents of children aged 2-12 years. Data were collected by validated questionnaires gathering information on socio-demographics, child's OH behaviors, and parents'; acculturation and dental examinations determining child's caries experience using DMFT/dmft index. Univariate and multivariate regression analyses were used. RESULTS: Three hundred and thirty-six parent/child dyads completed the study. Length of residency (B = 0.103; 95% CI: 0.064, 0.141) parents' education (B = 1.691; 95% CI: 1.228, 2.155), and household income (B = -0.959; 95% CI: -1.566, -0.352) significantly predicted acculturation level. Parents with high Canadian cultural knowledge reported higher frequency of children's toothbrushing (p-value = 0.015). Parents of children who consumed sugar >1/day had higher mean scores of acculturation to Canadian culture (p-value = 0.016), English language proficiency (p-value = 0.024), and Canadian food adoption (p-value = 0.046). Parents of children who visited the dentist within last 12 months had significantly higher assimilation and lower separation mean scores. Parents of children who visited dentist because of dental problems had higher marginalization mean score than those who went for check-ups (p-value = 0.046). Parental acculturation was not significantly correlated with their children's dmft/DMFT level. CONCLUSIONS: Children of highly acculturated parents reported higher toothbrushing frequency and were more likely to consume sugar than children of less acculturated parents. Assimilated parents reported more and marginalized parents reported less favorable OH behaviors than other categories. Parental acculturation level or strategy was not associated with children's caries experience.

Influence of Sponsorship Bias on Treatment Effect Size Estimates in Randomized Trials of Oral Health Interventions: A Meta-epidemiological Study.

BACKGROUND: In this meta-epidemiological study, we aimed to examine associations between treatment effect size estimates and sponsorship bias in oral health randomized clinical trials. METHODS: We selected oral health related meta-analyses that included a minimum of five randomized controlled trials. We extracted data, in duplicate, related to influence of sponsorship bias. We quantified the extent of bias associated with influence of sponsorship on the magnitude of effect size estimates of continuous variables using a two-level meta-meta-analytic approach with random-effects models to allow for intra- and inter-meta-analysis heterogeneity. RESULTS: We initially identified 540 randomized trials included in 64 meta-analyses. Risk of sponsorship bias was judged as being "unclear" in 72.8% (n = 393) of the trials, while it was assessed as "low" in 16.7% (n = 90) and as "high" in 10.6% (n = 57) of the trials. Using a meta-epidemiological analysis (37 meta-analyses, including 328 trials that analyzed 85,934 patients), we identified statistically significant larger treatment effect size estimates in trials that had "high or unclear" risk of sponsorship bias (difference in treatment effect size estimates=0.10; 95% confidence intervals: 0.02 to 0.19) than in trials that had "low" risk of sponsorship bias. CONCLUSIONS: We identified significant differences in treatment effect size estimates between dental trials based on sponsorship bias. Treatment effect size estimates were 0.10 larger in trials with "high or unclear" risk of sponsorship bias. PRACTICAL IMPLICATIONS: Clinicians should have an adequate knowledge of sponsorship bias in a clinical trial and be able to estimate the degree to which the conclusions of a systematic review are synthesized and interpreted, based on trials with low risk of sponsorship bias.

Direct to consumer orthodontics: Exploring patient demographic trends and preferences.

INTRODUCTION: This study aimed to evaluate market trends on the demographics most likely to select direct to consumer orthodontics and the reasoning behind their decisions. METHODS: An internet-based cross-sectional survey was conducted. Data analysis was carried out using logistic regression models. RESULTS: Total of 1573 surveys were completed. While 32.2% of those surveyed selected direct to consumer orthodontics over conventional orthodontics, 10.8% would select direct to consumer orthodontics for their children. Among parents who would seek direct to consumer orthodontics, only 27.8% would consider the same treatment for their children. The odds of seeking direct to consumer orthodontic treatment for divorced participants was 2.52 times higher than that for single participants, for participants with 4 children or more was 2 times higher than that for participant with no children, and in age group 46-59 years was 2.23 times higher than that for age group 18-26 years. Seventy three percent of consumers who selected direct to consumer orthodontics selected cost as an influencing factor. Convenience was also a major determining factor at 69.6%. CONCLUSIONS: Cost, convenience, and perceived simplicity all appear to factor into a consumer's consideration of direct to consumer orthodontics. As annual household income, age, and education increases consumers are more likely to consider direct to consumer orthodontic treatment.

Does Type of Sponsorship of Randomized Controlled Trials Influence Treatment Effect Size Estimates in Rehabilitation: A Meta-Epidemiological Study.

BACKGROUND: Sponsorship bias could affect research results to inform decision makers when using the results of these trials. The extent to which sponsorship bias affect results in the field of physical therapy has been unexplored in the literature. Therefore, the main aim of this study was to evaluate the influence of sponsorship bias on the treatment effects of randomized controlled trials in physical therapy area. METHODS: This was a meta-epidemiological study. A random sample of randomized controlled trials included in meta-analyses of physical therapy area were identified. Data extraction including assessments of appropriate influence of funders was conducted independently by two reviewers. To determine the association between biases related to sponsorship biases and effect sizes, a two-level analysis was conducted using a meta-meta-analytic approach. RESULTS: We analyzed 393 trials included in 43 meta-analyses. The most common sources of sponsorship for this sample of physical therapy trials were government (n = 205, 52%), followed by academic (n = 44, 11%) and industry (n = 39, 10%). The funding was not declared in a high percentage of the trials (n = 85, 22%). The influence of the trial sponsor was assessed as being appropriate in 246 trials (63%) and considered inappropriate/unclear in 147 (37%) of them. We have moderate evidence to say that trials with inappropriate/unclear influence of funders tended to have on average a larger effect size than those with appropriate influence of funding (effect size = 0.15; 95% confidence interval = -0.03 to 0.33). CONCLUSIONS: Based on our sample of physical therapy trials, it seems that most of the trials are funded by either government and academia and a small percentage are funded by the industry. Treatment effect size estimates were on average 0.15 larger in trials with lack of appropriate influence of funders as compared with trials with appropriate influence of funding. Contrarily to other fields, industry funding was relatively small and their influence perhaps less marked. All these results could be explained by the relative youth of the field and/or the absence of clear industry interests. In front of the call for action by the World Health Organization to strengthen rehabilitation in health systems, these results raise the issue of the need of public funding in the field.

Impact of social support on oral health among immigrants and ethnic minorities: A systematic review.

OBJECTIVE: Adaptation to social life changes after migration may be beneficial or detrimental to migrants' oral health outcomes and related behaviors. This systematic review aims to synthesize the scientific literature on the impact of social support on immigrants' and ethnic minorities' oral health status and/or behaviors. METHODS: A comprehensive electronic search, up to November 2018, was conducted using five electronic databases. We included cross-sectional and longitudinal quantitative studies that examine associations between social support and oral health outcomes among immigrants and ethnic minorities. Study selection, data extraction, and risk of bias assessment were completed in duplicate and the Newcastle-Ottawa checklist was used to appraise the methodological quality of the quantitative studies. RESULTS: A total of 26 studies met the eligibility criteria. Included studies examined multiple oral health outcomes such as dental care utilization, oral health behaviors, oral health problems, self-rated oral health, oral health knowledge, and oral health-related quality of life among immigrants and ethnic minorities. The social support level is assessed either by social support indicators or by adapting certain scales. Overall, social support was found to be positively associated with dental care utilization, number of carious teeth, periodontal disease, oral health behaviors, oral health knowledge, oral health-related quality of life, and self-rated oral health. CONCLUSION: Although immigrants and ethnic minorities encounter several challenges after migration to a new country that could affect their oral health, social support from their surrounding environment in the form of structural or functional support plays an important role in improving their oral health outcomes.

Impact of acculturation on oral health among immigrants and ethnic minorities: A systematic review.

OBJECTIVE: Cultural changes faced by immigrants and ethnic minorities after moving to a host country may have a detrimental or beneficial influence on their oral health and oral health-related behaviors. Therefore, this paper reviews the literature to see the impact of acculturation on immigrants and ethnic minorities' oral health outcomes. METHODS: We searched seven electronic databases up to January 2018. All cross-sectional and longitudinal quantitative studies that examined associations between acculturation and oral health status and/or oral health behaviors among ethnic minority and immigrant population[s] were included. Study selection, data extraction, and risk of bias assessment were completed in duplicate. The Newcastle-Ottawa checklist was used to appraise the methodological quality of the quantitative studies. A meta-analytic approach was not feasible. RESULTS: A total of 42 quantitative studies were identified. The studies showed a positive association between acculturation and oral health status/behaviors. The most frequently used acculturation indicators were language spoken by immigrant and ethnic minorities and length of stay at the host country. High-acculturated immigrant and ethnic minority groups demonstrated better oral health outcomes, oral health behaviors, dental care utilization, and dental knowledge. CONCLUSIONS: According to existing evidence, a positive effect of acculturation on oral health status and behaviors was found. PRACTICAL IMPLICATIONS: Dental practitioners should be culturally competent to provide the appropriate services and treatments to immigrant and ethnic minorities. Policymakers should also be sensitive to cultural diversities and properly address the unique needs of each group in order to maintain oral health equity.

Influence of blinding on treatment effect size estimate in randomized controlled trials of oral health interventions.

BACKGROUND: Recent methodologic evidence suggests that lack of blinding in randomized trials can result in under- or overestimation of the treatment effect size. The objective of this study is to quantify the extent of bias associated with blinding in randomized controlled trials of oral health interventions. METHODS: We selected all oral health meta-analyses that included a minimum of five randomized controlled trials. We extracted data, in duplicate, related to nine blinding-related criteria, namely: patient blinding, assessor blinding, care-provider blinding, investigator blinding, statistician blinding, blinding of both patients and assessors, study described as "double blind", blinding of patients, assessors, and care providers concurrently, and the appropriateness of blinding. We quantified the impact of bias associated with blinding on the magnitude of effect size using a two-level meta-meta-analytic approach with a random effects model to allow for intra- and inter-meta-analysis heterogeneity. RESULTS: We identified 540 randomized controlled trials, included in 64 meta-analyses, analyzing data from 137,957 patients. We identified significantly larger treatment effect size estimates in trials that had inadequate patient blinding (difference in treatment effect size = 0.12; 95% CI: 0.00 to 0.23), lack of blinding of both patients and assessors (difference = 0.19; 95% CI: 0.06 to 0.32), and lack of blinding of patients, assessors, and care-providers concurrently (difference = 0.14; 95% CI: 0.03 to 0.25). In contrast, assessor blinding (difference = 0.06; 95% CI: -0.06 to 0.18), caregiver blinding (difference = 0.02; 95% CI: -0.04 to 0.09), principal-investigator blinding (difference = - 0.02; 95% CI: -0.10 to 0.06), describing a trial as "double-blind" (difference = 0.09; 95% CI: -0.05 to 0.22), and lack of an appropriate method of blinding (difference = 0.06; 95% CI: -0.06 to 0.18) were not associated with over- or underestimated treatment effect size. CONCLUSIONS: We found significant differences in treatment effect size estimates between oral health trials based on lack of patient and assessor blinding. Treatment effect size estimates were 0.19 and 0.14 larger in trials with lack of blinding of both patients and assessors and blinding of patients, assessors, and care-providers concurrently. No significant differences were identified in other blinding criteria. Investigators of oral health systematic reviews should perform sensitivity analyses based on the adequacy of blinding in included trials.

Profile changes following extraction orthodontic treatment: A comparison of first versus second premolar extraction.

OBJECTIVE: To determine the change in the soft tissue profile following extraction orthodontic treatment with either first or second premolar extractions. METHODS: This was a retrospective clinical study of 81 consecutive orthodontic patients treated with extraction of four premolars. Patients were divided into two treatment groups according to whether four first premolar teeth (PM1 treatment group, n=48) or four second premolar teeth were removed (PM2 treatment group, n=33) during treatment. Changes in the nasolabial angle and the distance of the upper and lower lips to E-plane were compared pre- and post-treatment. Age, sex, upper lip thickness, facial convexity, facial axis, upper and lower arch crowding at pre-treatment, use of molar anchorage and the amount of retrusion of the maxillary and mandibular incisor teeth during treatment were used as explanatory variables. RESULTS: When facial convexity and facial axis at pre-treatment, the use of maxillary anchorage and the amount of retrusion of the maxillary and mandibular incisor teeth achieved as a consequence of treatment were taken into account, there was less than one degree (0.67°) difference between the change in the nasolabial angle in the PM1 treatment group compared to the PM2 treatment group (P>0.05). The mean change in the upper lip position relative to E-plane and the mean change in lower lip position relative to E-plane were also similar for the two groups. CONCLUSION: The change in soft tissue profile following orthodontic treatment was similar regardless of whether first premolar or second premolar teeth were removed.

Randomized clinical trials in dentistry: Risks of bias, risks of random errors, reporting quality, and methodologic quality over the years 1955-2013.

OBJECTIVES: To examine the risks of bias, risks of random errors, reporting quality, and methodological quality of randomized clinical trials of oral health interventions and the development of these aspects over time. METHODS: We included 540 randomized clinical trials from 64 selected systematic reviews. We extracted, in duplicate, details from each of the selected randomized clinical trials with respect to publication and trial characteristics, reporting and methodologic characteristics, and Cochrane risk of bias domains. We analyzed data using logistic regression and Chi-square statistics. RESULTS: Sequence generation was assessed to be inadequate (at unclear or high risk of bias) in 68% (n = 367) of the trials, while allocation concealment was inadequate in the majority of trials (n = 464; 85.9%). Blinding of participants and blinding of the outcome assessment were judged to be inadequate in 28.5% (n = 154) and 40.5% (n = 219) of the trials, respectively. A sample size calculation before the initiation of the study was not performed/reported in 79.1% (n = 427) of the trials, while the sample size was assessed as adequate in only 17.6% (n = 95) of the trials. Two thirds of the trials were not described as double blinded (n = 358; 66.3%), while the method of blinding was appropriate in 53% (n = 286) of the trials. We identified a significant decrease over time (1955-2013) in the proportion of trials assessed as having inadequately addressed methodological quality items (P < 0.05) in 30 out of the 40 quality criteria, or as being inadequate (at high or unclear risk of bias) in five domains of the Cochrane risk of bias tool: sequence generation, allocation concealment, incomplete outcome data, other sources of bias, and overall risk of bias. CONCLUSIONS: The risks of bias, risks of random errors, reporting quality, and methodological quality of randomized clinical trials of oral health interventions have improved over time; however, further efforts that contribute to the development of more stringent methodology and detailed reporting of trials are still needed.

Posterior cranial base natural growth and development: A systematic review.

OBJECTIVE: To provide a synthesis of the published studies evaluating the natural growth and development of the human posterior cranial base (S-Ba). MATERIALS AND METHODS: The search was performed on MEDLINE, Embase, PubMed, and all EBM Reviews electronic databases. In addition, reference lists of the included studies were hand-searched. Articles were included if they analyzed posterior cranial-base growth in humans specifically. Study selection, data extraction, and risk of bias assessment were completed in duplicate. A meta-analysis was not justified. RESULTS: Finally, 23 published studies were selected: 5 cross-sectional and 18 cohort studies. Articles were published between 1955 and 2015, and all were published in English. The sample sizes varied between 20 and 397 individuals and consisted of craniofacial measurements from either living or deceased human skulls. Validity of the measurements was not determined in any of the studies, while six papers reported some form of reliability assessment. All the articles included multiple time points within the same population or data from multiple age groups. Growth of S-Ba was generally agreed to be from spheno-occipital synchondrosis growth. Basion displaced downward and backward and sella turcica moved downward and backward during craniofacial growth. Timing of cessation of S-Ba growth was not conclusive due to limited identified evidence. CONCLUSIONS: Current evidence suggests that S-Ba is not totally stable, as its dimensions change throughout craniofacial growth and a minor dimensional change is observed even in late adulthood.

Effect of fluoride-releasing resin composite in white spot lesions prevention: a single-centre, split-mouth, randomized controlled trial.

INTRODUCTION: The objective of this two-arm split-mouth randomized trial, was to evaluate the ability of fluoride-releasing resin composite to prevent demineralization and white spot lesion (WSL) formation, during orthodontic treatment with fixed appliances. METHODS: Patients needing comprehensive orthodontic treatment were randomly allocated into two groups, according to the half split-mouth technique. This trial examined a total of 300 teeth in each group: the control group, in which brackets were fixed with a non-fluoride-containing adhesive resin; and the intervention group, in which brackets were fixed with a fluoride-containing adhesive resin. Eligibility criteria included Class I malocclusion in the permanent dentition, adequate oral hygiene and no missing teeth, active caries, enamel demineralization, fluorosis staining, or heavy restorations. The primary outcome was the formation of WSLs. Randomization was achieved using a computer-generated random number table; blinding of the patients, assessor, orthodontist and data analysist were achieved. The patients were followed for twelve months, during which time their teeth were checked every three months. To investigate the differences in frequencies and ranks of demineralization and WSL formation between the two groups, odds ratios were computed using mixed modelling (to compensate for the clustered nature of the data) with intervention as a fixed effect and patient as a random effect. RESULTS: Thirty-four patients (ages, 13-25 years; mean age, 17.6) were randomized into a 1:1 ratio, though four patients dropped out before the start of the treatment. The percentage of the teeth showing the effects of demineralization and WSL formation, increased from 6.3% to 15% for the control group after three and twelve months, respectively, and from 3% to 16.3% for the study group, after three to twelve months, respectively. There were no significant differences between the two groups and no interaction between time and treatment group in the visual inspections (OR 0.79; 95% CI 0.52, 1.21), in DIAGNOdent examinations (OR 0.68; 95% CI 0.43, 1.06), or in photographic images (OR 0.72; 95% CI 0.46, 1.11). No serious harm was observed during the trial. LIMITATIONS: This trial was a single-centre trial, and treatment was carried out by one orthodontist. CONCLUSIONS: Fluoride-containing resin adhesive does not have the desired preventive effect to prevent demineralization and WSL formation, during orthodontic treatment with fixed appliance. REGISTRATION AND PROTOCOL: This randomized trial was not registered, and the protocol was not published before patient recruitment. FUNDING: The University of Damascus funded this trial.

Blinding in Physical Therapy Trials and Its Association with Treatment Effects: A Meta-epidemiological Study.

OBJECTIVE: The aim of this study was to examine whether blinding of participants, assessors, health providers, and statisticians have an effect on treatment effect estimates in physical therapy (PT) trials. DESIGN: This was a meta-epidemiological study. Randomized controlled trials in PT were identified by searching the Cochrane Database of Systematic Reviews for meta-analyses of PT interventions. Assessments of blinding in PT trials were conducted independently following established guidelines. RESULTS: Three hundred ninety-three trials and 43 meta-analyses that included 44,622 patients contributed to this study. Only a quarter of the trials were adequately blinded (n = 80; 20%). Most individual components of blinding as well as what they were blinded to were also poorly reported. Although trials with inappropriate blinding of assessors and participants tended to underestimate treatment effects when compared with trials with appropriate blinding of assessors and participants, the difference was not statistically significant (effect size, -0.07; 95% confidence interval, -0.22 to 0.08; effect size, -0.12; 95% confidence interval, -0.30 to 0.06, respectively). CONCLUSIONS: The lack of statistical significance between blinding and effect sizes should not be interpreted as meaning that an impact of blinding on effect size is not present in PT. More empirical evidence in a larger sample is needed to determine which biases are likely to influence reported effect sizes of PT trials and under which conditions.