Definition of self-ligation brackets (SLB)
Self-ligating brackets have an in-built metal/ ceramic face or metal jaws/clip, which can be opened and closed.
History and past failings of SLB
In reality, molar tubes and ligation with metal ligature were the first self-ligation system in orthodontics.
The Russell Lock edgewise attachment first described by Stolzenberg (Russell Lock edgewise attachment) in 1935 was the early examples of self-ligating brackets but were prone to breakages and inadvertent opening.
New designs continue to appear, with at least twenty four new brackets since 2000.
Classification of SLB
Passive SLB
Active or interactive SLB
"Claimed" benefits of SLB
A. Clinician-related benefits
Faster archwire removal and ligation: Chen et al. 2010 showed that this feature uses save 20 seconds per arch.
Price: No need for evidence
B. Patients-related benefits
Assist good oral hygiene: no significant difference between conventional ligation and SLB (Kaklamanos et al 2017, Baka et al in 2013, Uzuner et al 2014).
Patient comfortability: SLB is worse than conventional ligation (Fleming et al 2008, Scott et al 2009 and Bertl et al 2013).
Treatment efficiency: no significant difference between conventional ligation and SLB (Pandis et al 2008, O’Dywer et al 2016)
C. Treatment-related benefits
Speed of treatment during alignment: no significant difference between conventional ligation and SLB (Mills 2005 , Scott 2008, Fleming 2009, Pandis 2011, Eliades 2008)
Speed of treatment during canine retraction: no significant difference between conventional ligation and SLB (Mezomo 2011)
Speed of treatment during space closure: no significant difference between conventional ligation and SLB (Mills 2007)
Overall treatment duration: no significant difference between conventional ligation and SLB (Fleming 2010, DiBiase 2011, Johannson 2012)
Anchorage loss: no significant difference between conventional ligation and SLB (De Almeida et al in 2013, Monini et al 2014).
Arch expansion: it was reported by Fleming et al in 2009 that this feature belongs to the wide archwire not the SLB
Torque expression: no significant difference between conventional ligation and SLB (Pandis el at 2006, Fleming et al 2009, Pandis et al 2007, and Pandis et al 2010)
Finishing and occlusal outcomes: no significant difference between conventional ligation and SLB (DiBiase et al 2011, Johannson 2012)
Treatment stability: no significant difference between conventional ligation and SLB (Rahman et al in 2017)
Apical root resorption: no significant difference between conventional ligation and SLB (Pandis et al 2008)
Others.
Real advantages
Less chairside assistance.
Improved movement control by secure and robust ligation, hence, maximises the potential long range of action.
With the ceramic SLBs, there is no discoloured modules that are usually seen with conventional ceramic brackets.
Uncertainty
We are uncertain about the efficiency of ceramic SLB and whether the last benefit can justify the huge extra cost as ceramic SLBs are so expensive compared to the conventional one.
Update
Angle Orthodontists Journal in its January 2021 issue published a paper titled (Factors influencing treatment efficiency) to answer the before-mentioned uncertainty.
The paper was published by Min-Ho Jung from Seoul.
This paper is a two-armed prospective cohort study that recruited 134 consecutively patients who were treated using either ceramic self-ligating brackets (SBs) or ceramic conventional brackets (CBs).
Conclusion
The use of ceramic self-ligating brackets did not result in significant reduction in alignment efficiency or treatment duration in comparison to ceramic conventional brackets.
Patients complaince, and the severity of malocclusion significantly increased treatment duration.
Patient age was not associated with treatment duration.
Take home message
THE MAGIC TOOL IS THE HANDS OF THE ORTHODONTIST NOT “THE BRACKETS”.
Link to the paper
What do you think?