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.

Objectives: To assess and compare treatment effects and treatment time in adolescents with crowded and displaced teeth during and after non‐extraction treatments using a passive self‐ligating bracket system (PSLB) and a conventional bracket system (CB).

Materials and Methods: Consecutive adolescents (12–17 years old) with crowded and displaced teeth were randomised through computer generated block randomisation in a two‐arm parallel‐group design, to non‐extraction fixed appliance treatment with either PSLB (Damon Q, n  = 62) or CB (Victory, n  = 70) at four orthodontic clinics. Study models and cephalograms were collected at baseline, post‐alignment and post‐treatment. Primary outcome was assessed with weighted Peer Assessment Rating index (wPAR) and secondary outcomes with Little's Irregularity Index (LII), and as transversal width (mm), incisor inclination (°), position (mm) and treatment time (months).

Results: Intergroup differences in wPAR with mean score reductions of −24.07 (CB) and −22.11 (PSLB), LII upper/lower arch reductions of −9.02/−5.96 (CB) and −8.44/−5.29 (PSLB), and mean treatment times of 21.74 (CB) and 24.35 (PSLB) months were non‐significant (NS). Lateral expansion was greater in the PSLB group during alignment; mean intergroup maxillary differences (MD) were 1.35 at inter‐canines, 1.21 mm at first inter‐premolars, and mandibular MD were 0.75 at first, 0.76 mm at second inter‐premolars ( p  ≤ 0.019). Greater incisor proclination was observed in the CB group (L1NB, MD = 2.28°; ILiML, MD = 2.23°) ( p  ≤ 0.016). Intergroup differences post‐treatment were NS.

Conclusion: Great occlusal treatment outcomes were observed in both groups with no significant difference in treatment time. Although the expansion patterns differed during alignment, no significant intergroup difference remained after treatment.

Trial Registration: The protocol is registered on ClinicalTrials.gov (NCT05664282)

Background: Unilateral posterior crossbite is a common malocclusion, and early treatment is recommended to enable normal growth. There are several possibilities regarding choice of appliances used for correcting this malocclusion; however, when treatment is financed by public funds the decision needs to be based not only on the effects but also on the effect in relation to the costs.

Objectives: The aim was to perform a cost-effectiveness analysis comparing quad helix (QH) and rapid maxillary expanders (RME; hyrax-type) in children in the early mixed dentition.

Material and methods: Seventy-two patients were randomized to treatment with either QH or RME, at two different centres. Data were collected from the patient's medical records regarding success rate, number of visits, total treatment time, emergency visits, and so forth, together with answers from patient questionnaires concerning absence from school and use of analgesics. A cost-effectiveness analysis with both an intention-to-treat (ITT) and a per-protocol approach was performed, as well as a deterministic sensitivity analysis.

Results: The success rate, one year after the completion of the expansion, was equal between groups according to the ITT approach. From a healthcare perspective, the mean cost difference between RME and QH was €32.05 in favour of QH (P = 0.583; NS). From a societal perspective, the mean cost difference was €32.61 in favour of QH (P = 0.742; NS). The total appliance cost alone was higher in the RME group €202.67 resp. €155.58 in the QH group (P = 0.001). The probability of RME having a higher cost was 71% from a healthcare perspective and 62.7% from a societal perspective. The total treatment time was 97 days longer in the QH group. In the deterministic sensitivity analysis, when using a higher valuation of the children's educational loss, the QH becomes €58 more costly than the RME. There was a statistically significant difference in chair time and visits between centres (P < 0.001).

Conclusion: The difference in costs between RME and QH is not statistically significant, however, there is a slightly higher probability that RME is more expensive than QH with a mean cost of an additional €32 per patient from a healthcare perspective. Different work procedures at different centres indicate that logistics around the patient's treatment is a more important aspect than appliance used to decrease the number of visits and save chair time and thereby also costs.

Objectives/aim To analyze and compare costs of different prosthetic rehabilitations for the edentulous maxilla. Materials and methods Patients with edentulous maxillae were rehabilitated with either of three implant-supported prosthetic protocols; removable overdenture supported by 2 implants (ISOD 2), fixed dental prostheses supported by 4 (ISFAFDP 4) or 6 (ISFAFDP 6) implants. Cost of treatment and costs during follow-up were registered and compared. Results Twenty-four patients were included: six patients received ISOD 2 treatment, eight patients received ISFADP 4 treatment and ten patients received ISFADP 6 treatment. Initial costs for ISFAFDP 6 were higher than costs for ISFAFDP 4 and ISOD 2, but there were no differences in cost for maintenance i.e., the ISOD treatment remained the least costly treatment alternative after 1-year follow-up. Discussion The lack of difference in cost for maintenance and repair over the first year suggests that implant-supported overdentures will remain the least costly treatment option for the edentulous maxilla, at least in a short-term perspective. Conclusions Removable maxillary overdentures supported by 2 implants may be a valid low cost treatment option.

Objectives: To evaluate the costs of quad-helix (QH) and removable expansion plate (EP) treatments performed either in specialist or general dentistry for the correction of unilateral posterior crossbite with functional shift in the mixed dentition. Trial design: Four-arm parallel group multicentre randomized controlled trial. Materials and methods: One hundred and ten patients with unilateral posterior crossbite with functional shift were recruited. The patients were randomized by an independent person not involved in the trial. The randomization used blocks of 20 and into the following four groups: QH treatments in specialist orthodontic clinics (QHS), QH treatments in general dentistry (QHG), EP treatments in specialist orthodontic clinics (EPS), and EP treatments in general dentistry (EPG). Blinding was accomplished of the outcome assessor and data analyst. A cost analysis was performed with reference to intention-to-treat (ITT), regarding direct costs, indirect costs, and societal costs (the sum of direct and indirect costs) for calculations of successful treatments alone and for retreatments when required. To determine which alternative has the lower cost, a cost-minimization analysis was undertaken, based on that the outcome of the treatment alternatives were broadly equivalent, so the difference between them reduces to a comparison of costs. Results: In the QHS group, 28 of 28 patients were successfully corrected compared to 23 of 27 in the QHG group. Treatment with expansion plate was less successful: 18 of 27 patients in the EPS group and 18 of 28 in the EPG group. QH treatment performed in specialist orthodontic clinics had significantly lower costs than QH or EP treatment accomplished in general dentistry as well as EP treatments in specialist orthodontic clinics. Limitations: Costs depend on local factors and should not be directly extrapolated to other locations. Conclusion: Treatment of unilateral posterior crossbite in the mixed dentition is recommended to be performed by a specialist orthodontist using the QH appliance. Trial registration: The trial was not registered.

OBJECTIVES: The objectives of this study were to assess the three-dimensional (3D) treatment changes (palatal surface area and volume) of forced unilateral posterior crossbite correction using either quad-helix or removable expansion plate appliances in the mixed dentition, and to compare the treatment changes with the three-dimensional changes occurring in age-matched untreated unilateral posterior crossbite patients as well as in subjects with normal occlusion and with no or mild orthodontic treatment need. TRIAL DESIGN: Six-arm parallel group multicentre randomized controlled trial. MATERIALS AND METHODS: One-hundred and thirty-five patients with unilateral posterior crossbite with functional shift were recruited. The patients were randomized by an independent person not involved in the trial. The randomization used blocks of 25, and the patients were randomized into the following five groups: quad-helix treatments in specialist orthodontic clinics (QHS), quad-helix treatments in general dentistry (QHG), removable expansion plate treatments in specialist orthodontic clinics (EPS), removable expansion plate treatments in general dentistry (EPG), and untreated crossbite (UC). Twenty-five patients with normal occlusion who served as normal controls were also included in the trial. Blinding of the outcome assessor and data analyst was accomplished. Data on all children were evaluated on an intention-to-treat basis, regarding 3D palatal surface area, palatal projection area, and palatal shell volume; two-dimensional linear measurements were registered at the same time. RESULTS: After treatment, the surface and projection area and shell volume increased in the four treatment groups (QHS, QHG, EPS, and EPG). QHS increased significantly more than EPG for the surface and projection area. The QHS and EPS had significantly higher mean difference for shell volume. LIMITATIONS: The trial considers a short-term evaluation. CONCLUSION: After treatment, there were no significant differences between the four treatment groups and the normal group, which implies that the surface and projection area together with the shell volume for the four treatment groups and the normal group were equivalent. TRIAL REGISTRATION: The trial was registered with https://www.researchweb.org/is/sverige, registration number: 220751.

Objective: To analyse cost-effectiveness of anchorage reinforcement with buccal miniscrews and with molar blocks. We hypothesized that anchorage with miniscrews is more cost-effective than anchorage with molar blocks. Trial design: A single-centre, two-arm parallel-group randomized controlled trial. Methods: Adolescents (age 11–19 years) in need of treatment with fixed appliance, premolar extractions, and en masse retraction were recruited from one Public Dental Health specialist centre. The intervention arm received anchorage reinforcement with buccal miniscrews during space closure. The active comparator received anchorage reinforcement with molar blocks during levelling/alignment and space closure. The primary outcome measure was societal costs defined as the sum of direct and indirect costs. Randomization was conducted as simple randomization stratified on gender. The patients, caregivers, and outcome assessors were not blinded. Results: Eighty patients were randomized into two groups. The trial is completed. All patients were included in the intention-to-treat analysis. The median societal costs for the miniscrew group were €4681 and for the molar block group were €3609. The median of the difference was €825 (95% confidence interval (CI) 431–1267). This difference was mainly caused by significantly higher direct costs consisting of material and chair time costs. Differences in chair time costs were related to longer treatment duration. No serious harms were detected, one screw fractured during insertion and three screws were lost during treatment. Generalizability and limitations: The monetary variables are calculated based on a number of local factors and assumptions and cannot necessarily be transferred to other countries. Variables such as chair time, number of appointments, and treatment duration are generalizable. Owing to the study protocol, the benefit of miniscrews as a stable anchorage has not been fully utilized. Conclusions: When only moderate anchorage reinforcement is needed, miniscrews are less cost-effective than molar blocks. The initial hypothesis was rejected. Miniscrews provide better anchorage reinforcement at a higher price. They should be used in cases where anchorage loss cannot be accepted. Trial registration: NCT02644811

Objective: To examine: (I) the current evidence of the impact of fixed orthodontic appliances on the development of halitosis in patients undergoing orthodontic treatment, and (II) the influence of different orthodontic bracket systems on halitosis. Material and methods: Three electronic databases (PubMed, Scopus, and Cochrane Library) were searched prior to March 15, 2018. The review was systematically conducted and reported according to the Cochrane Handbook and the PRISMA statement. Only Randomised Clinical Trials (RCTs) were considered. Selected full-text papers were independently assessed by four investigators and any disagreements were resolved by consensus. The Cochrane Handbook was used to grade the risk of bias and the quality of evidence was rated according to GRADE. Results: Out of 363 identified studies, three RCTs on halitosis and fixed orthodontic appliances met the inclusion criteria. The risk of bias in the three studies was rated as high and the quality of evidence was rated as very low. Conclusions/clinical implications: There is a lack of scientific evidence that subjects with fixed orthodontic appliances develop halitosis during treatment. Additional well-conducted RCTs with extended periods of assessment are needed as well as consensus concerning cut-off values for the diagnosis of halitosis.

Objectives: To compare Oral health-related quality of life (OHRQoL) among 9-year-old children with excessive overjet (EO) to children with unilateral posterior crossbite (UPC) and children with normal occlusion (NO). Materials and methods: The study sample sourced from 19 Public Dental Service Clinics in Sweden. Reported are baseline data originating from two controlled trials, one regarding UPC and the other focusing on EO. The NO children derive from the same trials. The UPC group comprised 93 children (45 boys and 48 girls), the EO group 71 children (36 boys and 35 girls), and the NO group 65 children (32 boys and 33 girls). In conjunction to a clinical examination, all children completed the Child Perceptions Questionnaire (CPQ8-10) for evaluation of OHRQoL. The CPQ8-10 comprises 25 questions grouped into four domains: oral symptoms, functional limitations, emotional, and social well-being. Validated questions about pain in the jaws and face were also included. Results: The total mean CPQ score was 5.1 for the UPC, 7.4 for the EO, and 4.4 for the NO group, showing a significant difference between the UPC and EO (P = 0.048) and between EO and NO group (P = 0.012). These differences remained when adjusted for the confounders' caries, trauma, enamel defects, and headache. No difference between UPC and NO was found. The EO children also reported significantly higher scores in the domains emotional and social well-being (P = 0.039 and P = 0.012). Limitations: The study would be strengthened if a longitudinal design had been performed. Conclusion: Children with EO reported significantly lower OHRQoL compared to children with UPC or NO. The children generally reported low CPQ scores that imply an overall fairly good OHRQoL.

OBJECTIVE: Economic evaluations provide an important basis for allocation of resources and health services planning. The aim of this study was to evaluate and compare the costs of correcting anterior crossbite with functional shift, using fixed or removable appliances (FA or RA) and to relate the costs to the effects, using cost-minimization analysis. DESIGN, SETTING, AND PARTICIPANTS: Sixty-two patients with anterior crossbite and functional shift were randomized in blocks of 10. Thirty-one patients were randomized to be treated with brackets and arch wire (FA) and 31 with an acrylic plate (RA). Duration of treatment and number and estimated length of appointments and cancellations were registered. Direct costs (premises, staff salaries, material, and laboratory costs) and indirect costs (the accompanying parents' loss of income while absent from work) were calculated and evaluated with reference to successful outcome alone, to successful and unsuccessful outcomes and to re-treatment when required. Societal costs were defined as the sum of direct and indirect costs. INTERVENTIONS: Treatment with FA or RA. RESULTS: There were no significant differences between FA and RA with respect to direct costs for treatment time, but both indirect costs and direct costs for material were significantly lower for FA. The total societal costs were lower for FA than for RA. LIMITATIONS: Costs depend on local factors and should not be directly extrapolated to other locations. CONCLUSION: The analysis disclosed significant economic benefits for FA over RA. Even when only successful outcomes were assessed, treatment with RA was more expensive. TRIAL REGISTRATION: This trial was not registered. PROTOCOL: The protocol was not published before trial commencement.