Molar distalization and stability following maxillary anterior teeth alignment with class II elastics and a 10-day aligner protocol

This study compares the anticipated maxillary anterior teeth alignment and molar distal movement with the actual results. The molar stability after anterior teeth alignment has also been investigated. The sample consisted of 30 individuals. Three digital models were obtained using an intra-oral scanner before treatment (T0), after maxillary molar distalization (T1), and at the treatment end, before refinement (T2). The digital models were registered over the palatal rugae area. 120 maxillary molars were investigated for distal movement and anchorage loss. Also, 180 upper anterior teeth were evaluated for anterior teeth alignment. After maxillary molar distalization, the predicted distalization of maxillary molars significantly differed from the actual clinical values (P < 0.001) with a mean percentage accuracy of 75.3% (T0-T1). During T0-T2 stage, anterior teeth showed a significant difference between the two variables except for the labial movement of the lateral incisor (p = 0.056) and canine (p = 0.167). Also, lingual torque of the lateral incisor (p = 0.190). For anterior tooth alignment, the overall mean accuracy was 54.79%. At the treatment end before refinement, the average percentage of posterior anchorage loss was 34.02% and the average percentage accuracy of molar distalization decreased to 48.25% (T0-T2). While clear aligners are an effective modality for maxillary molar distalization in non-growing adults, their accuracy in achieving anterior tooth alignment is limited. Clinicians should account for significant posterior anchorage loss and anticipate challenges in achieving precise lingual movement of the anterior teeth during treatment planning.