Perception of Pain Intensity and Quality in Patients Treated with Conventional Fixed Orthodontic Appliances Versus Clear Removable Aligners: A Pilot Study

The main objective of this study was to compare the perception of pain intensity between patients treated with fixed orthodontic appliances and those treated with clear removable aligners. The secondary objective was to investigate the pattern and quantities of analgesics use immediately after orthodontic adjustment visits and correlate this with the intensity and quality of the perceived pain.

Two hundred participants, 100 treated with fixed orthodontic appliances (G1) and 100 with clear removable aligners (G2), filled the Short-form McGill Pain Questionnaire (SF-MPQ), the Numeric Pain Rating scale (NPRS), and the Present Pain Index (PPI) at baseline (before orthodontic adjustment or changing to a new aligner) and 24-hours post-adjustment visit.

The mean change in the NPRS values from baseline to 24-hour post-adjustment showed significantly higher pain intensity in G1 (3.15±2.47) compared to G2 (1.58±1.74) (p<0.0001). There was also a statistically significant difference in the frequency of reporting of SF-MPQ pain descriptors between G1 and G2, with more pain associated with G1. The PPI 24-hours post-adjustment showed that 94% of G1 reported some form of pain compared to only 79% in G2. At the 24-hour post-adjustment visit, 34 participants in G1 and only 8 participants in G2 reported the use of analgesic medications (p<0.0001).

Overall, patients treated with fixed orthodontic appliances reported higher pain perception compared to patients treated with clear removable aligners during the first 24 hours following the adjustment visit.