Clinical Outcomes of Sequential Distalization with Clear Aligners: A Systematic Review and Meta-Analysis

Background/Objectives: Sequential distalization with clear aligners is increasingly used as a non-extraction approach for correcting Class II and selected Class III malocclusions. However, evidence remains heterogeneous regarding treatment protocols, anchorage strategies, and clinical outcomes. This systematic review and meta-analysis evaluated the clinical outcomes of sequential distalization with clear aligners, including achieved posterior tooth movement, predictability, biomechanical effects, and other clinically relevant outcomes. Methods: This systematic review was conducted according to PRISMA 2020 guidelines, and the protocol was prospectively registered in the Open Science Framework. PubMed, Embase, Scopus, Web of Science Core Collection, and the Cochrane Library were searched from inception through 1 July 2026. Eligible clinical studies evaluating sequential distalization with clear aligners were included. Random-effects meta-analyses were performed for sufficiently comparable outcomes, and certainty of evidence was assessed using GRADE. Results: Twenty-eight studies met the inclusion criteria. Pooled mean achieved distalization was 1.72 mm (95% CI, 1.02-2.42) for the maxillary first molar and 1.76 mm (95% CI, 1.12-2.40) for the maxillary second molar. Pooled distal tipping was 5.33° (95% CI, 1.37-9.30) for first molars and 5.77° (95% CI, -6.84-18.38) for second molars. First-molar intrusion was 0.58 mm (95% CI, 0.05-1.10). Movement predictability varied substantially across studies. Certainty of evidence was very low across clinically important domains. Conclusions: Sequential distalization with clear aligners may achieve moderate maxillary molar distalization but is accompanied by variable movement expression and biomechanical effects. Heterogeneous protocols and limited study quality restrict the certainty and generalizability of current estimates.