Are orthodontic randomised controlled trials justified with a citation of an appropriate systematic review?

Clinical evaluation of marketed and non-marketed orthodontic products: are researchers now ahead of the times? A meta-epidemiological study

BACKGROUND

The advertisement and adoption of untested orthodontic products is common. This study aimed to provide an update regarding the prevalence of clinical trials in orthodontics evaluating commercially marketed products. Associations between marketed/non-marketed products and study characteristics such as direction of effect, declaration of conflict of interest and industry sponsorship were evaluated. In addition, within the marketed products associations between direction of effect and study characteristics were explored.

MATERIAL AND METHODS

Electronic searching of a single database (Medline via PubMed) was undertaken to identify Randomized controlled trials (RCTs) published over a 5-year period (1st January 2017 to 31st December 2021). Descriptive statistics and associations between trial characteristics were explored.

RESULTS

196 RCTs were analysed. RCTs were frequently published in Angle Orthodontist (18.4%), American Journal of Orthodontics and Dentofacial Orthopedics (14.8%) and European Journal of Orthodontics (13.3%). 65.3% (128/196) of trials assessed marketed products after their introduction. The majority of trials assessed interventions to improve treatment efficiency (33.7%). Growth modification appliances were typically analysed in non-marketed compared to marketed products. An association between the type of product (marketed vs non-marketed) and both the declaration of conflict of interest and industry sponsorship was detected. For individual RCTs assessing marketed products either a positive effect (45.3%) or equivalence between interventions or between intervention and untreated control (47.7%) was evident. In 27% of these trials either no conflict of interest or industry funding was not clearly declared. Within the marketed products, no association between the direction of the effect and conflict of interest or funding was detected.

CONCLUSIONS

The analysis of marketed orthodontic products after their introduction is still common practice. To reduce research waste, collaboration prior to the licensing and marketing of orthodontic products between researchers, industry and manufacturers is recommended.

Interventions to facilitate the successful eruption of impacted maxillary incisor teeth due to the presence of a supernumerary: A systematic review and meta-analysis

INTRODUCTION

A failure of maxillary incisor eruption is commonly attributed to the presence of a supernumerary tooth. This systematic review aimed to assess the percentage of impacted maxillary incisors that successfully erupt after surgical removal of supernumerary teeth with or without other interventions.

METHODS

Systematic literature searches without restrictions were undertaken in 8 databases for studies reporting any intervention aimed at facilitating incisor eruption, including surgical removal of the supernumerary alone or in conjunction with additional interventions published up to September 2022. After duplicate study selection, data extraction, and risk of bias assessment according to the risk of bias in nonrandomized studies of interventions and Newcastle-Ottawa scale, random-effects meta-analyses of aggregate data were conducted.

RESULTS

Fifteen studies (14 retrospective and 1 prospective) were included with 1058 participants (68.9% male; mean age, 9.1 years). The pooled eruption prevalence for removal of the supernumerary tooth with space creation or removal of the supernumerary tooth with orthodontic traction was significantly higher at 82.4% (95% confidence interval [CI], 65.5-93.2) and 96.9% (95% CI, 83.8-99.9) respectively, compared with removal of an associated supernumerary only (57.6%; 95% CI, 47.8-67.0). The odds of successful eruption of an impacted maxillary incisor after removal of a supernumerary were more favorable if the obstruction was removed in the deciduous dentition (odds ratio [OR], 0.42; 95% CI, 0.20-0.90; P = 0.02); if the supernumeraries were conical (OR, 2.91; 95% CI, 1.98-4.28; P <0.001); if the incisor was in the correct position (OR, 2.19; 95% CI, 1.14-4.20; P = 0.02), at the level of the gingival third (OR 0.07; 95% CI, <0.01-0.97; P = 0.04) and had incomplete root formation (OR, 9.02; 95% CI, 2.04-39.78; P = 0.004). Delaying removal of the supernumerary tooth 12 months after the expected eruption time of the maxillary incisor (OR, 0.33; 95% CI, 0.10-1.03; P = 0.05) and waiting >6 months for spontaneous eruption after removal of the obstacle (OR, 0.13; 95% CI, 0.03-0.50; P = 0.003) was associated with worse odds for eruption.

CONCLUSIONS

Limited evidence indicated that the adjunctive use of orthodontic measures and removal of supernumerary teeth might be associated with greater odds of successfull impacted incisor eruption than removal of the supernumerary tooth alone. Certain characteristics related to supernumerary type and the position or developmental stage of the incisor may also influence successful eruption after removal of the supernumerary. However, these findings should be viewed with caution as our certainty is very low to low because of bias and heterogeneity. Further well-conducted and reported studies are required. The results of this systematic review have been used to inform and justify the iMAC Trial.

Survival of conventionally bonded mandibular retainers with or without enamel sandblasting in orthodontic patients over a 12-month period. A single-centre, split-mouth randomized clinical trial

BACKGROUND

The aim of this trial was to assess the effect of enamel sandblasting in addition to the acid-etch technique in reducing first-time failures of fixed mandibular retainers placed over a 12-month period.

MATERIALS AND METHODS

Ethical approval was obtained. Participants were recruited in a single private practice. The primary outcome of this study was any first-time failure of the mandibular fixed retainer assessed at three timepoints over a 12-month period. Three consecutive teeth either on the left or right side (from lower canine-lower central incisor) were randomly allocated to the intervention (sandblasting) and the control (non-sandblasted). Randomization was performed using a centralized randomization service. The patients were randomized in blocks of four and eight with allocation concealment secured by contacting the sequence generator for group assignment. Blinding of either the patient or clinicians was not possible at time of placement of the mandibular retainer.

RESULTS

One hundred and ninety-seven participants were randomized to receive enamel sandblasting (intervention) and non-sandblasting (control) in the region of the six anterior mandibular teeth in a split-mouth fashion. Participants were recruited between December 2018 to October 2020. The data for all participants were analysed resulting in 394 observations. Overall, the risk of first-time failure was 11.4%. No difference in first-time failures was observed between the intervention (sandblasting) and control (non-sandblasting) groups [hazard ratio (HR), 1.05; 95% confidence interval (CI), 0.59, 1.88, P = 0.88]. Males had a higher instant probability of first-time failures (HR, 3.18; 95% CI, 1.65-6.14; P < 0.01). Participants with a fair level of co-operation had a lower instant probability of first-time failures (HR, 0.37; 95% CI, 0.16-0.86; P = 0.02). There were no harms reported to either the participant or their dentition.

CONCLUSIONS

No difference in the first-time failures of mandibular bonded retainers placed with conventional etch-bond technique with or without enamel sandblasting was observed. The overall risk of first-time failure was 11.4%.

REGISTRATION

This trial was not registered prior to trial commencement.

Scoping reviews in orthodontics: are they justified?

BACKGROUND

Scoping Reviews (ScRs) have emerged in the orthodontic literature as a new methodological perspective to collate and summarize scientific evidence. The aim of the present study was to identify and record the proportion of Scoping Reviews in orthodontics that have been clearly and adequately justified, based on the methodological framework of such types of reviews. Associations with a number of publication characteristics were also sought. Three major databases, namely PubMed, Scopus and Web of Science Core Collection, as well as 11 specialty orthodontic journals were electronically sought from inception until August 1, 2022, for ScRs. The primary outcome pertained to whether the published reports of the ScRs included an appropriate justification and explanation for the selection of this kind of knowledge synthesis methodology. Potential association with year, journal, continent of authorship, number of authors, methodologist involvement, appropriate reporting guidelines and registration practices followed were explored.

RESULTS

A total of 40 ScRs were eligible for inclusion, with the majority not being adequately justified (22/40; 55.0%). The majority of studies were published from 2020 onward (32/40; 80.0%). The regression model did not reveal any significant association between justification of ScRs and a number of publication characteristics (p > 0.05 at all levels).

CONCLUSIONS

Less than half of the included ScRs were adequately justified in terms of selection of the appropriate synthesis methodology. Awareness should be raised in the scientific community regarding the correctness of the use of this newly emerging type of study in orthodontics, to safeguard against any trace of research waste.