How to succeed with high quality randomised clinical trials in clinical orthodontic research

One goal of producing relevant clinical research is to ensure that evidence-based research results are transformed into everyday clinical practice that help clinicians deliver high quality care. It also involves ensuring that the individual patient receives the most effective and least risky treatment, ultimately leading to an optimal treatment outcome both in the short and long term. Some fundamentals of evidence-based dentistry are highlighted with focus on performing orthodontic randomised controlled trials

Intraoral maxillary molar distalization

OBJECTIVE: To evaluate the maxillary molar distalization and anchorage loss in two groups, one before (MD 1 group) and one after (MD 2 group) eruption of second maxillary molars. MATERIALS AND METHODS: After a sample size calculation, 20 patients were recruited for each group from patients who fulfilled the following criteria: no orthodontic treatment before distal molar movement, Class II molar relationship defined by at least end-to-end molar relationship, space deficiency in the maxilla, and use of an intra-arch NiTi coil appliance with a Nance appliance to provide anchorage. Patients in the MD 1 group were without any erupted second molars during the distalization period, whereas in the MD 2 group both the first and second molars were in occlusion at start of treatment. The main outcome measures to be assessed were: treatment time, ie, time in months to achieve a normal molar relation, distal movement of maxillary first molars, and anterior movement of maxillary incisors (anchorage loss). The mean age in the MD 1 group was 11.4 years; in the MD 2 group, 14.6 years. RESULTS: The amount of distal movement of the first molars was significantly greater (P < .01) and the anchorage loss was significantly lower (P < .01) in the group with no second molars erupted. The molar distalization time was also significantly shorter (P < .001) in this group, and thus the movement rate was two times higher. CONCLUSIONS: It is more effective to distalize the first maxillary molars before the second molars have erupted

Randomized controlled trial : the gold standard or an unobtainable fallacy?

Background: This article is the result of a debate at the European Journal of Orthodontics Open Session in 2013 in Reykjavik, Iceland. Objective: The aim of this article is to highlight some of the strengths and weakness of clinical orthodontic research, with particular emphasis on randomized controlled trials (RCT). The ultimate aim of improving clinical orthodontic research in general. Design: This article is organized into two sections with arguments for and against RCTs. The backgrounds to evidence-based evaluation and the level or quality of evidence in trials are discussed. The article emphasises what makes high quality clinical research, and gives practical advice including examples of tips and potential pitfalls for those undertaking clinical research. Results and Conclusion: The overriding message is constructive and it is hoped that the article serves as an aid in evaluating, designing, conducting, and reporting clinical research

The bite-type malocclusion classification - An extended Angle-method. Is the new classification reliable?

Objectives: As part in appraising the usefulness of the new bite-type method, a reliability assessment of the classification system was performed. Materials and Methods: Eighty-five selected dental casts were appraised by six operators and compared to a "Gold Standard." The reliability of the bite-type method was assessed by double registrations of each of the nine bite-type classes by every operator. Results: An overall acceptable bite-type classification of all examiners existed. Correct assessments were found in 75-90% of the dental casts. Thus, the bite-type classification is a reliable method for categorizing sagittal malocclusions. Conclusion: The procedure could favorably replace the angle classification as it is more precise and detailed, without losing the strength of the basic angle system as an uncomplicated communication tool

Anchorage capacity of osseointegrated and conventional anchorage systems : a randomized controlled trial

INTRODUCTION: Our aim in this investigation was to evaluate and compare orthodontic anchorage capacity of 4 anchorage systems during leveling/aligning and space closure after maxillary premolar extractions. METHODS: One hundred twenty patients (60 girls, 60 boys; mean age, 14.3 years; SD 1.73) were recruited and randomized into 4 anchorage systems: Onplant (Nobel Biocare, Gothenburg, Sweden), Orthosystem implant (Institut Straumann AG, Basel, Switzerland), headgear, and transpalatal bar. The main outcome measures were cephalometric analysis of maxillary first molar and incisor movement, sagittal growth changes of the maxilla, and treatment time. The results were also analyzed on an intention-to-treat basis. RESULTS: The maxillary molars were stable during the leveling/aligning in the Onplant, Orthosystem implant, and headgear groups, but the transpalatal bar group had anchorage loss (mean, 1.0 mm; P <.001). During the space-closure phase, the molars were still stable in the Onplant and Orthosystem groups, whereas the headgear and transpalatal bar groups had anchorage loss (means, 1.6 and 1.0 mm, respectively; P <.001). Thus, the Onplant and the Orthosystem implant groups had significantly higher success rates for anchorage than did the headgear and transpalatal bar groups. Compared with the Orthosystem implant, there were more technical problems with the Onplant. CONCLUSIONS: If maximum anchorage is required, the Orthosystem implant is the system of choice

Anchorage Provided during Intra-arch Distal Molar Movement : a Comparison between the Nance Appliance and a Fixed Frontal Bite Plane

The aim of this retrospective study was to evaluate and compare the anchorage provided with the Nance appliance (NA) and the fixed frontal bite plane (FBP) during intra-arch distal molar movement. After a sample size calculation, 20 patients were recruited and randomly selected for each group from patients who fulfilled the following criteria: use of an intra-arch Ni-Ti coil appliance with either NA or FBP to provide anchorage during a six-month molar distalization period, no orthodontic treatment before molar distalization, and first and second maxillary molars in occlusion. The outcome measures assessed were anchorage loss, ie, anterior movement of maxillary central incisors, distal movement of maxillary molars, and bite opening effect. The mean age in the NA group was 14.7 years (SD 1.09) and in the FBP group 15.0 years (SD 0.99). The data revealed that the maxillary central incisors moved anteriorly 1.4 mm in the NA group and 1.9 mm in the FBP group. The difference in anchorage loss was not significant. The mean amount of molar distalization within the maxilla was 1.7 mm in the NA group and 1.8 mm in the FBP group. In both groups, the overbite was significantly reduced and the overbite was decreased significantly more in the FBP group. Because neither the NA nor FBP provided stable anchorage, a second treatment phase is recommended to reverse the anchorage loss after distal molar movement. If molar distalization is planned in deep bite cases, the FBP is the anchorage system of choice

Management of ectopic maxillary canines : variations among orthodontists

OBJECTIVE: To document and analyze factors involved in decision-making by orthodontists in managing disturbances of eruption of maxillary canines. MATERIAL AND METHODS: The participants comprised orthodontic specialists and active members of the Swedish Orthodontic Society. Those selected for the study sample were under 65 years of age or younger and had been treating orthodontic patients for at least 1 year as a specialist. Three typical cases were presented for treatment proposals. The case notes, including radiographs and specific background data, were sent to the 182 selected orthodontists. The orthodontists were also requested to complete a questionnaire about practice profile, comprising eight questions. RESULTS: The response rate was 86.3%; yielding 157 participants (mean age 53.8 years, SD 8.12). Analysis disclosed no differences between responders and nonresponders regarding age, gender, and years of specialist practice. For treatment plans based on panoramic radiographs, intraoral radiographs, and status and anamnesis, there was general consensus. However, when supplementary information from computer tomography (CT) was provided, disclosing root resorption half-way to the pulp or more on the lateral incisor, the orthodontists' treatment proposals varied. Gender, age, and practice profile of the orthodontists had little association with the decision-making. CONCLUSIONS: Supplementary CT information led to variations in decision-making with respect to treatment of eruption disturbances of maxillary canines. This lack of consensus among specialist orthodontists can have negative implications for patients