BACKGROUND: When assessing the effectiveness of interventions, randomized controlled trials (RCTs) are considered to generate the highest level of evidence. The CONSORT 2010 recommendations promote clear and transparent reporting of RCTs. However, to perform a complete analysis of methodological errors and risk of bias that RCTs may be subjected to, the Risk of Bias tool 2 (RoB 2) has been constructed.

OBJECTIVES: The aim of this systematic review was to assess the last 55 years of changes in methodological quality of orthodontic RCTs by using the RoB 2 tool.

SEARCH METHODS: The MEDLINE via Entrez PubMed, Web of Science, and Cochrane library databases were searched for orthodontic RCT publications from 1 January 1968 to 31 December 2024.

SELECTION CRITERIA: All RCTs on humans in the field of orthodontics were included. Non-randomized trials, animal studies, orthognathic surgery, syndrome patients, CLP patients, sleep apnea, and in vitro studies were excluded.

DATA COLLECTION AND ANALYSIS: The quality assessment of the studies was conducted using the Cochrane Risk of Bias Tool (RoB2). The RCTs were divided into three time periods, i.e. before CONSORT 2010, from 2011 to 2016, and from 2017 to 2024.

RESULTS: A total of 3135 RCTs were identified, and after excluding studies not fulfilling the criteria, 1231 RCTs were included in the quality assessment. Publications in the later or latest time-period had a larger number with low risk of bias than early ones. However, significant room for improvement remained since, in the latest time period there were relatively many RCTs with high risk of bias (67.6%). The main factors to high bias were unclear or missing information about 'who generated the random allocation sequence and enrolled participants' (selection bias), whether 'ITT or intention-to-treat' was used (attrition bias) as well as omitting reporting of 'all important harms or unintended effects' (other bias). Another factor was that baseline characteristics were missing (selection bias).

LIMITATIONS: The RoB2 tool is complex, and it requires trained individuals to use the tool.

CONCLUSIONS: There remains a need to enhance the quality of RCTs in orthodontics. To reduce the risk of bias, researchers should become well-acquainted with RoB2 before developing research protocols and plans. Specifically, use the 'signaling questions of RoB2' as extensively as possible to aid in designing the plans and protocols concerning the trial's conduct and progression.

REGISTRATION: PROSPERO: CRD42023390206.

Background: In Sweden, dental care for children and adolescents, including specialist orthodontic treatment, is publicly funded. This study aims to analyze the impact of sociodemographic factors on the distribution of publicly funded specialist orthodontic treatment in a mid-sized Swedish region. Methods: A registry-based cohort study was conducted in Region Östergötland, including individuals born between 2000 and 2003. Sociodemographic data were obtained from Statistics Sweden (SCB), while dental health information was sourced from The Swedish Quality Registry for Caries and Periodontal Disease (SKaPa). The primary outcome variable was initiation of specialist orthodontic treatment, extracted from dental records. Statistical analysis was performed using Stata v.18.1. Results: The cohort comprised 16 893 individuals, with 51.5% males and 48.5% females. Specialist orthodontic treatment was initiated for 25.7% of the population (n = 4 342), with most treatments involving fixed appliances. Several sociodemographic factors were significantly associated with the likelihood of receiving orthodontic treatment. Females had 1.74 times higher odds (95% CI: 1.63–1.87) of receiving treatment compared to males. Individuals born in Sweden had 1.42 times greater odds (95% CI: 1.18–1.72) of receiving treatment compared to those born abroad. Similarly, children with Swedish-born parents had 1.16 times increased odds (95% CI: 1.04–1.30) compared to children with foreign-born parents. Children of mothers with university/college education had an OR of 1.29 (95% CI: 1.12–1.48), while those whose fathers had a university/college education had an OR of 1.19 (95% CI: 1.05–1.34), compared to parents with primary/lower secondary education. Conclusions: Males, individuals born outside Sweden, those with foreign born parents, and whose parents had lower educational levels were less likely to receive orthodontic treatment within the publicly funded dental health services in Region Östergötland. These findings suggest that sociodemographic factors influenced the distribution of orthodontic care, though the role of treatment demand requires further investigation.

Background: Orthodontic patients are often instructed to use fluoride mouthrinses (FMR) to prevent caries during treatment with fixed orthodontic appliances (FOA). The aim of this study was to examine the caries preventive effect of FMR during FOA treatment based on randomized controlled trials. Methods: An information specialist searched five databases up to September 30, 2024. We included trials with parallel groups (intervention vs. control) and a minimum duration of six months. Based on the abstracts, the authors independently selected and reviewed full text papers, extracted key outcome data, and assessed the risk of bias. The primary outcome was incidence of enamel caries on subject level. We conducted a narrative synthesis and pooled comparable data in a random effects model. Results: We identified 22 studies of which seven, involving 704 patients, met the inclusion criteria. Five and two studies had moderate and high risk of bias, respectively. In all studies, FMR was additive to daily use of fluoride toothpaste. The intervention varied from twice daily to twice weekly and the duration ranged from six to 26 months. Five studies were included in a meta-analysis. The aggregated data showed a small risk difference of − 0.07 (95% CI -0.14; -0.01) in initial caries development adjacent to bracket base between the experimental and the control groups. Conclusion: This review found insufficient support for a general recommendation to use FMR during treatment with fixed orthodontic appliances in populations with regular use of fluoride toothpaste. This does not rule out the possibility that individual orthodontic patients may benefit from FMR after comprehensive risk assessment. Further investigations with standardized interventions and duration, reporting a core outcome set are required to clarify the effectiveness of fluoride mouthrinses in orthodontic patients.

Background: Orthodontic treatment need has commonly been assessed using treatment need indices during clinical examinations or using photographs in combination with plaster casts. Recently, the use of intraoral photographs alone to screen malocclusions has increased.

Objective: This study aimed to validate intraoral photographs for the assessment of orthodontic treatment need.

Materials and methods: The study sample consisted of case files from 30 pre-orthodontic patients aged 12-19 years. Each case file included intraoral photographs and casts. The cases were consecutively recruited from two orthodontic treatment waiting lists: 15 from the Department of Orthodontics at Folktandvården Eastmaninstitutet, Stockholm, Sweden and 15 from the Center for Orthodontics and Pediatric Dentistry, Norrköping, Public Dental Service Östergötland. Their orthodontic treatment need was assessed by four raters (calibrated orthodontists) using the indices IOTN-AC, IOTN-DHC, ICON, and DAI. The four raters individually assessed the 30 cases on three occasions: (1) photos only, (2) photos and casts, and (3) photos only. Finally, the four raters jointly made a consensus assessment using both photos and casts. For IOTN-AC and IOTN-DHC, interrater agreement was assessed with Fleiss' kappa, and validity with the Wilcoxon signed-rank test. For ICON and DAI, interrater agreement was assessed with Intra Class Correlation (ICC) (1, 2) and validity with a paired t-test.

Results: Interrater agreement for IOTN-AC was slight (0.14-0.18) and moderate for IOTN-DHC (0.51-0.57), regardless of whether photographs were used alone or combined with casts. ICON demonstrated moderate interrater agreement (0.57-0.72), while DAI showed moderate to excellent (0.70-0.91), similarly unaffected by the use of photographs alone or in combination with casts. The validity analysis, which compared the individual assessments to the consensus one, revealed equivalent differences whether the assessment involved intraoral photographs alone or in combination with casts.

Conclusion: Intraoral photographs are sufficient for assessing orthodontic treatment need because interrater agreement and validity are similar whether photos are used alone or with casts. However, interrater variability was substantial for both assessment methods.

Trial registration: ClinicalTrial.gov. identifier: NCT05038865.

OBJECTIVES: To evaluate treatment time and patient perception of two surgical methods to expose a palatally displaced canine (PDC) into the oral cavity.

MATERIAL AND METHODS: A total of 30 consecutive patients between 11 and 18 years, with maxillary displaced canines were recruited. After gaining informed consent from the patients and custodians, the patients were randomized into two groups by an independent person. Both groups received a chain attached to the crown of the canine: in group A (control group) the chain was placed under the mucoperiosteal flap to an incision on the alveolar crest and in group B (test group), the chain penetrated the mucoperiosteal flap inferiorly to the crown of the canine. Outcome measures where time to expose the PDC into the oral cavity and the patient's experience of pain and discomfort during the treatment.

RESULTS: Twenty-six patients full-filled the trial, mean age was 12.9 years, (SD 1.6 years). The time to expose the canines for the control group was 11.9 months (SD 6.5) and for the test group 6.7 months (SD 3.2) The conventional method showed less pain on the day of surgery.

CONCLUSION: The method used in the test group resulted in a 5-month shorter time to expose the canine compared to the control group, and higher pain level on the day of surgery. For generalizability of the results, larger studies are needed.

Objectives: To evaluate the cephalometric effects of premolar extraction on skeletal and dental parameters, and on the soft tissues, in patients subsequently treated with fixed appliances. Prevalence and severity of external apical root resorption due to premolar extraction were also examined.Materials and methods: The dental records of 79 patients treated with fixed appliances were retrieved (groups: extraction, n = 19; non-extraction, n = 60). Pre- and post-treatment statuses of skeletal, dentoalveolar, and soft tissue variables were analyzed on lateral cephalograms to determine change. Periapical radiographs of the maxillary incisors were assessed for external apical root resorption using the Levander & Malmgren index. The t-test, Mann-Whitney U test, chi-squared test, and Kruskal-Wallis test were used to analyze the data. Significance was set at p < .05.Results: Changes in the protrusion and proclination of the incisors and in lip position were significantly different between the groups. Prevalence of external apical root resorption in the two groups was similar.Conclusions: Our findings suggest that extraction therapy affects dentoalveolar traits but not jaw position, nor the risk of root resorption, in patients treated with fixed appliances

OBJECTIVES: To assess the success rate of spontaneous space closure after extraction of the first permanent molar (FPM) in the maxilla and the mandible, and to identify the factors that make spontaneous space closure most favorable in each.

MATERIALS AND METHODS: A retrospective records-based cohort study was conducted through a search of the database of the Public Dental Service, Stockholm County Council, Stockholm, for young adults born between 2000 and 2001, who underwent extraction of one or more FPM between 2006 and 2016. A total of 995 extracted teeth were identified, of which 203 teeth in 155 patients met the inclusion criteria.

RESULTS: Of the 203 extracted teeth, 166 (81.8%) did not receive any orthodontic treatment. The success rate for space closure in orthodontically treated patients was 91.9%. The success rate for spontaneous space closure was 84.3%. All unsuccessful spontaneous space closure in the maxilla occurred in patients older than 12 years. The dental developmental stage of the second permanent molar (SPM) had a statistically significant association with spontaneous space closure in the mandible (P < .001).

CONCLUSIONS: The success rate of spontaneous space closure was high (84.3%) and was higher in the maxilla (94.1%) than the mandible (74.1%). Age at time of extraction and dental developmental stage of the SPM were significant factors for successful spontaneous space closure in the maxilla and mandible, respectively.

BACKGROUND: Mouthwashes containing oral antiseptics or enzymes are suggested suitable for controlling biofilm accumulation in patients with fixed appliances and thereby limiting unwanted side effects during the orthodontic treatment.

OBJECTIVES: To evaluate the effect of an enzyme-based mouthwash on the amount of dental biofilm and the composition of the salivary microbiome in patients undergoing treatment with fixed orthodontic appliances.

TRIAL DESIGN: Randomized double-blind placebo-controlled trial.

MATERIAL AND METHODS: In total, 35 young adolescents (14-18 years) under treatment with fixed appliances were consecutively enrolled and randomly allocated to an experimental or a placebo group by opening a computer-generated numbered envelope. The subjects were instructed to rinse twice daily during an intervention period of 8 days with experimental mouthwash or placebo without active enzymes. Unstimulated whole saliva samples were collected at baseline and after 8 days. The participants and examiner were blinded for the allocation. The primary outcome was the Orthodontic Plaque Index (OPI) and the secondary was the composition of the salivary microbiome.

RESULTS: In total, 28 adolescents (21 females and 7 males) completed the trial and there were no differences in age, clinical, or microbial findings between the test (n = 14) and the placebo group (n = 14) at baseline. We found a decreased OPI in the test group after 8 days and the difference was statistically significant compared with the placebo group (P < 0.05). There were no significant treatment effects on the richness and global composition of the salivary microbiome.

HARMS: In total, one participant in the test group claimed nausea and abandoned the project. In total, two participants did not like the taste of the mouthwash but used it as instructed. No other adverse events or side effects were reported.

LIMITATIONS: Short-term pilot trials may by nature be sensitive for selection and performance biases and are not designed to unveil persisting effects.

CONCLUSION: Daily use of enzyme-containing mouthwash reduced the amount of dental biofilm in adolescents under treatment with the fixed orthodontic appliances, without affecting the composition of the salivary microbiota.

ETHICAL APPROVAL: Approved by the Regional Ethical Board, Lund, Sweden (Dnr 2020-05221).

CLINICAL TRIAL REGISTRATION: NCT05033015.

BACKGROUND: Malocclusions in adolescents might have a negative impact on oral health-related quality of life (OHRQoL). Potential confounding variables (confounders) such as age, gender, caries, and socioeconomic status may skew the real relationship between malocclusions and OHRQoL.

OBJECTIVES: To analyse the effect of malocclusions in adolescents on OHRQoL, when controlled for potential confounders.

SEARCH METHODS: Five databases (PubMed, Cochrane Library, Cinahl, Scopus, and Web of Science) were searched up to 15 June 2022.

SELECTION CRITERIA: Studies in which OHRQoL in 10-19-year olds with and without malocclusions were compared.

DATA COLLECTION AND ANALYSIS: Screening, data extraction, and quality assessments were performed by four investigators independently. Risk of bias was assessed according to the Swedish Agency for Health Technology Assessment and Assessment of Social Services (SBU) guidelines. To be included, studies had to control for confounders. Certainty of evidence was assessed with GRADE.

RESULTS: Thirteen cross-sectional studies with low and moderate risk of bias were included in the qualitative synthesis. Four of these were also included in the quantitative synthesis (meta-analysis). The 13 studies in the qualitative synthesis displayed a large variation among the indices used for malocclusion ratings, as well as in instruments measuring OHRQoL. There was moderate quality of evidence that malocclusions have a negative effect on OHRQoL. The four articles included in the quantitative synthesis (meta-analysis) measured malocclusions with DAI and OHRQoL with CPQ 11-14 short form. There was moderate quality of evidence that malocclusions have a negative effect on OHRQoL (RR/PR 1.15, 95% CI 1.12-1.18, 3672 participants).

CONCLUSIONS: There is moderate quality of evidence that malocclusions in adolescents have a negative impact on OHRQoL, after taking relevant confounders into consideration. Future studies should ideally use standardized measures for malocclusion ratings and OHRQoL.

REGISTRATION: PROSPERO. CRD42020186152.

Background Compliance is crucial for the treatment outcome with removable appliances. Previous studies on treatment with the Twin Block appliance have focused on effectiveness in relation to other treatment methods or wear-time. Studies on different check-up intervals to improve compliance seem to be lacking. Objectives To compare the impact of two different check-up prescriptions on patient compliance and treatment outcome during treatment with Twin Block. Trial Design Two-arm parallel group, single-centre, randomized controlled trial. Materials and Methods Seventy-three patients, 38 boys, and 35 girls, mean age 11.2 years, were included and block-randomized into two groups treated with a Twin Block appliance. Group 1 was called for check-up visit every sixth week and group 2 every fourth week. Compliance was evaluated with a TheraMon (R) microsensor, moulded into the appliance, measuring wear-time. Overjet, overbite, and molar relationships were assessed on study casts before and after treatment. The treatment outcomes were analysed on an intention-to-treat basis. Results In group 1, the reduction of overjet was 5.2 mm and the mean wear-time was 6.9 hours. In group 2, the reduction was 4.7 mm and the wear-time was 6.1 hours. Seventy-four per cent of the patients presented an overjet of 4 mm or less. Wear-time did not correlate to age, gender, or severity of malocclusion. Harms No harm was observed in any patient. Lateral open bites were registered during treatment but were normalized at the end of the treatment. Limitations The trial was a single-centre study and long-term effects were not evaluated. Conclusions During treatment with the Twin Block appliance, a 4-week check-up interval did not improve treatment outcome or increase wear-time, compared to a 6-week check-up interval. The mean wear-time was 6.5 hours per day, even if the recommendation was 12 hours.