Which way forward? Fixed or removable lower retainers.

Area of Science:

• Orthodontics
• Dental Materials Science
• Periodontology

Background:

• Maintaining orthodontic treatment results is crucial.
• Relapse of lower labial segment alignment is a common concern post-fixed appliance therapy.
• Both fixed and removable retainers are used to prevent relapse.

Purpose of the Study:

• To compare the efficacy of bonded lower canine-to-canine multistrand retainers versus Hawley-type removable retainers in preventing lower labial segment relapse.
• To assess changes in lower incisor alignment over at least one year post-debonding.

Main Methods:

• Two groups of 29 patients were studied, one with bonded retainers and one with removable Hawley retainers.
• Study models were collected at debonding (T1) and at least one year post-debonding (T2).
• Changes in Little's Index were measured using a reflex microscope to quantify alignment changes.

Main Results:

• Statistically significant changes in Little's Index (alignment) were observed in both groups over the study period (P = .001).
• No statistically significant difference in the amount of relapse was found between the bonded and removable retainer groups (P = .13).
• Bonded retainers were more frequently placed in older patients (P = .02).

Conclusions:

• Relapse of lower labial segment alignment can occur despite the use of either fixed bonded or removable Hawley retainers.
• The degree of relapse observed with both types of retainers was not statistically significantly different.
• Orthodontic relapse is a possibility regardless of the retainer type used.