Does the bracket-ligature combination affect the amount of orthodontic space closure over three months? A randomized controlled trial

The scientific evidence for pre-adjusted edgewise attachments and mechanics

Introduction Fixed orthodontic appliance systems continue to evolve with a wealth of evidence emerging to underpin these refinements.Aims To present the evidence from comparative prospective research informing the selection of fixed appliance design and mechanics.Design Detailed literature review.Materials and methods An electronic search to identify randomised controlled trials and clinical controlled trials was undertaken using pre-defined search terms.Results Based on high-level evidence, no one bracket system has been proven superior in terms of efficiency or outcome. Similarly, a clear advantage associated with one wire type or dimension has not been shown. The effect of lacebacks in terms of anchorage management appears to be limited, while elastomeric chain and nickel titanium closing coils are associated with similar rates of space closure.Discussion A wealth of high-quality recent evidence to support the selection of fixed appliance attachments, archwires and auxiliaries, including lacebacks and space closing mechanics, was identified.Conclusions There has been a considerable increase in the amount of high-quality evidence informing the choice of pre-adjusted edgewise mechanics in recent years. This information can be used to make evidence-based decisions in the selection and manipulation of fixed appliances during daily practice.

The Tip and Torque adjustable bracket as a new concept in design

OBJECTIVES

To test a new concept in bracket design-the tip and torque adjustable bracket (TTAB)-to identify its integral ability to change both tip and torque.

MATERIALS AND METHODS

The newly designed TTAB underwent independent testing using the orthodontic measurement and simulation system. The TTAB incorporated Roth tip and torque prescription values, with the unique quality of the bracket to enhance or reduce the innate prescribed values of tip (by either +10° or -10°) and torque (by either +7.5° or -7.5°). The TTAB was tested using both the incorporated standard Roth prescription on the rate of canine retraction (sliding mechanics), using 0.018-inch stainless-steel (SS) arch wire, and with alteration of tip values (-10° and +10°). Similarly, frictional measurements and torque evaluations using 0.019 × 0.025-inch SS arch wire were undertaken with the standard prescription and altered torque (+7.5° and -7.5°). In addition, a number of control investigations were performed. Differences were analyzed using analysis of variance.

RESULTS

The rate of observed tooth movement for the TTAB with its prescribed baseline values was comparable to that of the control brackets. Importantly, the alteration of TTAB tip to -10° and +10° significantly (P < .001) increased and reduced, respectively, the rates of canine retraction. In the alteration of torque, at +7.5° and -7.5°, the bracket delivered a moment of +9.3 (2.8) Nmm and -11.9 (3.8) Nmm, respectively, to the lateral incisor (P < .001).

CONCLUSIONS

This in vitro study demonstrates a new concept in preadjusted edgewise bracket design, offering adjustable tip and torque, with the potential for expanded clinical scope.

Effects of a ceramic active self-ligating bracket on retraction/tipping/ rotation of canine, premolar mesialization, and transverse arch dimensions: A preliminary single-blind split-mouth randomized clinical trial

BACKGROUND

There is no clinical study on ceramic self-ligating brackets (SLBs). Therefore, this preliminary study was conducted for the first time to address its effects.

MATERIALS AND METHODS

This split-mouth randomized trial was performed on 32 quadrants in 16 orthodontic patients needing extraction of maxillary premolars and distalization of canines. In each blinded patient, right/left sides were randomized into control (ceramic bracket) and experimental (ceramic SLB) groups. Dental stone models were taken before canine retraction and 3 months into retraction. Models were digitized as three-dimensional models. Changes were measured on superimposed models. Groups were compared using Wilcoxon signed-rank test (α = 0.05, β = 0.1).

RESULTS

Both bracket types caused significant changes after 3 months in terms of all assessed clinical outcomes (P ≤ 0.002). Compared to conventional ceramic brackets (control), ceramic SLBs reduced retraction rate (P = 0.001), canine rotation (P = 0.001), canine tipping (P = 0.002), and arch expansion at the canine site (P = 0.003). However, the extents of anchorage loss (P = 0.796) and arch constriction in the premolar area (P = 0.605) were not statistically different between the bracket types.

CONCLUSION

Compared to conventional metal-lined ceramic brackets, active ceramic SLB can increase the duration of canine distalization, while reducing canine rotation and tipping (inducing more bodily movements). The loss of anchorage with ceramic SLB was similar to that of conventional ceramic bracket after 3 months of treatment (considering the lower rate of SLB canine retraction during that time). Both brackets similarly constricted the arch at the premolar site. In the canine area, they expanded the arch, with the SLB causing smaller extents of expansion.

Is there any difference between conventional, passive and active self-ligating brackets? A systematic review and network meta-analysis

AIM

To test the null hypothesis that there was no difference in treatment efficiency between therapies undertaken with conventional (CBs), passive self-ligating (PSLBs) or active self-ligating (ASLBs) brackets.

MATERIALS AND METHODS

An electronic search was performed in 3 data bases (Pubmed, Web of Science, Cochrane Library) from their origin up to January 2019. Additional references were hand searched. Search was strictly restricted to randomized controlled trials (RCTs) and split-mouth design studies (SMDs). RCTs and SMDs were initially processed separately and subsequently combined in a network meta-analysis. The following variables were evaluated: treatment duration, number of visits, occlusal outcomes, alignment rate, transverse arch dimensional changes, incisor position modification, rate of space closure, anchorage loss, bond failure, root resorption, perception of discomfort during the initial phase of alignment, time to ligate in or to untie an archwire, periodontal variables, quality of life.

RESULTS

On 229 papers, 30 RCTs and 9 SMDs were finally included in this study. Out of 85 comparisons, 16 only revealed statistically significant differences. It was quicker to untie and ligate an 0.014 NiTi arch from/in 6 ASLBs anterior ceramic brackets compared to 6 ceramic CBs. It was also more painful to insert and remove an 0.019×0.025 SS wire in/from PSLB's brackets compared to CB's attachments. Compared to conventional brackets, there was less maxillary incisor proclination with PSLBs in non-extraction cases. Moreover, there was less bleeding on probing 4-5 weeks after bonding with PSLBs compared to CBs brackets. The only significant difference between ASLBs and PSLBs was that alignment was 10 days faster with active self-ligating braces compared with passive self-ligating braces even if treatment duration between ASLBs and PSLBs was not significantly different. The network meta-analysis revealed that IMPA was greater in extractions cases with CBs compared with both ASLBs (+2,5°) and PSLBs (+1,6°).

CONCLUSIONS

The vast majority of the studied variables did not show any significant differences between the three types of brackets. The most significant findings were that it was quicker to insert and remove archwires from ASLBs compared to CBs, and it was more painful to insert and remove an 0.019×0.025" stainless steel wire in/from PSLBs compared to CBs. The major difference between ASLBs and PSLBs was that alignment was 10 days faster with active self-ligating braces compared with passive self-ligating braces even if treatment duration between ASLBs and PSLBs was not significantly different. Most of the claims put forward by the suppliers were not substantiated by our network meta-analysis.

Comparison of orthodontic space closure using micro-osteoperforation and passive self-ligating appliances or conventional fixed appliances

OBJECTIVES

To examine the effect of micro-osteoperforation (MOP) on the space closure rate using passive self-ligating or conventional brackets.

MATERIALS AND METHODS

This was a two-arm parallel randomized controlled trial undertaken at the outpatient department of a dental college. There were 60 participants (30 women and 30 men) who fulfilled the inclusion criteria. Both the study and control groups were subjected to MOPs throughout the period of space closure. MOPs were repeated every 28 days. The experimental group (mean age 19.5 ± 1.66 years) was bonded with passive self-ligating brackets while the control group (mean age 19.9 ± 1.13 years) was bonded with conventional brackets. Both groups were examined and compared for rate of space closure. An evaluation was conducted for both groups until the entire extraction space was closed and confirmed by evaluation of a tight contact between the canine and the second premolar using a piece of dental floss.

RESULTS

Before the initiation of retraction, all initial criteria were similar between the two groups (P > .05). No difference was observed between the two groups in the rate of space closure (P > .05).

CONCLUSIONS

MOP in conjunction with passive self-ligation does not increase the rate of orthodontic space closure when compared with MOP used with conventional brackets.

Efficacy of elastic memory chains versus nickel-titanium coil springs in canine retraction: A two-center split-mouth randomized clinical trial

OBJECTIVE

The use of newly-introduced elastic memory chains (EMCs) in space closure is increasingly gaining popularity. However, no clinical studies have evaluated their efficacy. Therefore, this study was conducted.

METHODS

In this two-center split-mouth single-blind randomized controlled trial, 21 jaws were divided into 42 quadrants. The two treatments [canine retraction using EMCs versus nickel-titanium (NiTi) coil springs (as control)] were randomly assigned to two quadrants of each jaw. The premolar space was measured at the baseline, and in the 1st, 2nd, and 3rd months of canine retraction, by a blinded orthodontist. Space closure rates were compared using a paired t-test.

RESULTS

The rates of space closure using NiTi springs were 1.93±0.62, 1.71±0.75, and 1.36±0.51mm/month, during the 1st, 2nd, and 3rd months of treatment, respectively. The 3-month average rates of space closure were 1.67±0.39 and 1.89±0.36mm/month in the NiTi and elastic groups, respectively (faster in the elastic group, P=0.022).

CONCLUSIONS

The application of elastic memory chains is as effective as NiTi springs.

Therapeutic efficacy of self-ligating brackets: A systematic review

INTRODUCTION

Over the last few years, the use of self-ligating brackets in orthodontics has progressed considerably. These systems have been the subject of numerous studies with good levels of evidence making it possible to evaluate their efficacy and efficiency compared to conventional brackets. The aim of this study was to evaluate the therapeutic efficacy of self-ligating brackets by means of a systematic review of the scientific literature.

MATERIALS AND METHODS

A systematic study was undertaken in the form of a recent search of the electronic Pubmed database, oriented by the use of several keywords combined by Boolean operators relating to the therapeutic efficacy of self-ligating brackets through the study of tooth alignment, space closure, expansion, treatment duration and degree of discomfort. The search was limited to randomized controlled studies, and two independent readers identified studies corresponding to the selection criteria.

RESULTS AND DISCUSSION

The chosen articles comprised 20 randomized controlled trials. The studies analyzed revealed the absence of significant differences between the two types of system on the basis of the clinical criteria adopted, thereby refuting the hypothesis of the superiority of self-ligating brackets over conventional systems.