Lower Molar Distalization Using Clear Aligners: Bodily Movement or Uprighting? A Preliminary Study

Background: Lower molar distalization is considered to be one of the most difficult movements to obtain with clear aligners. The aim of this study was to evaluate the possibility to distalize the lower molars using clear aligners in adults without miniscrews. Material and methods: rx cephalograms of 16 patients (8 males, 8 females; mean age of 25.6 years), who underwent lower molar distalization, were analyzed. Cephalograms were taken before the beginning of treatment (T0) and after the end of treatment (T1). Dental and skeletal changes between T0 and T1 were evaluated. The level of significance was set at p < 0.05. Results: At T1, the lower second molar moved distally 2.47 mm, but there was a significant tipping (p = 0.027); the same result was found at the first molar, with a mean distal movement of 1.16 mm and a significant tipping (p = 0.003). No significant changes were detected on the sagittal and vertical skeletal variables. Conclusion: Clear aligner therapy can provide more distal tipping than bodily movement in the lower molars when a distalization is programmed. This movement could be sufficient to correct the initial malocclusion and gain a class I molar relationship.