The Influence of Occlusal Adjustment on Long-term Post-treatment Stability of Orthodontic Treatment

This study aimed to compare the long-term occlusal stability in patients treated orthodontically with and without occlusal adjustment.

This observational study followed the STROBE guidelines. The sample comprised 77 patients with class I malocclusion treated without dental extractions and without signs and symptoms of temporomandibular joint dysfunction (TMD), divided into two groups. Group 1 with occlusal adjustment comprised 37 patients, 16 males and 21 females, with mean initial, final, and post-retention ages of 18.33 (s.d.=3.96), 20.99 (s.d.=3.33), and 25.79 years (s.d.=3.34), respectively. The treatment time was 2.66 years (s.d.=1.57), and the time of post-retention evaluation was 4.80 years (s.d.=1.10). Group 2, without occlusal adjustment involved 40 patients, 21 males and 19 females, with mean initial, final, and post-retention ages of 18.07 (s.d.=3.03), 20.75 (s.d.=3.54), and 25.89 (s.d.=3.73) years, respectively. The treatment time was 2.68 years (s.d.=1.09) and the time of post-retention evaluation was 5.14 years (s.d.=1.36). The PAR and Little irregularity indices were measured in the initial, final, and post-retention dental casts. Intergroup comparison was performed using the independent t-test.

There was no statistically significant difference observed in the intergroup comparison of the PAR and Little irregularity indexes in all phases and periods evaluated.

There was no significant difference found in the long-term post-treatment crowding and occlusal relapse between class I patients treated with orthodontic non-extraction with and without occlusal adjustment. The occlusal adjustment did not influence the alignment and occlusal post-retention stability.