Use and Adverse Effects of Vacuum-Formed Retainers - Comparison of the Experiences of Orthodontists in Croatia and North Macedonia.

Objective

To investigate experiences with vacuum-formed retainers (VFR), possible adverse effects and problems associated with their use among Croatian and Macedonian orthodontists. Subjects and

Methods

In 2023, a questionnaire on retention protocols was distributed by e-mail to 150 orthodontists in North Macedonia (78% of practicing orthodontists), with a response rate of 58%, and to 185 orthodontists in Croatia (85% of practicing orthodontists), with a response rate of 75%.

Results

VFR were the more frequently used retention appliance in Croatia than North Macedonia, both in maxilla (79 vs. 53%, p<0.001) and mandible (66 vs. 44%, p=0.001) mostly because of the availability of the appliance (66% in Croatia vs. 53% in North Macedonia; p=0.056). The most used foil thickness for the VFRs was the 1 mm (71% in Croatia vs. 59% in North Macedonia; p=0.019). The expected duration of the VFRs was 1-2 years (60% in Croatia vs. 47% in North Macedonia; p=0.015), however, less than 25% of the patients agreed to make new VFRs in both countries. Clinicians had rarely observed adverse reactions to VFRs (3% in Croatia and none in North Macedonia). Reasons for changing the VFR material were more often costs in North Macedonia than in Croatia (62 vs. 2%; p<0.001).

Conclusion

VFRs are preferred retention appliances among Croatian and North Macedonian orthodontists, mostly because of their availability. Patients tolerate them well, but failures mostly occur after 1-2 years and only ¼ of patients decide to make new retainers which can impose problems regarding relapse.