Systematic Review on Molar Distalization using Clear Aligner Therapy

AbstractBackground: Clear aligner therapy (CAT) has become a widely accepted alternative to fixed orthodontic appliances for non-extraction treatment. Sequential molar distalization is commonly used to correct Class II malocclusion and create arch space; however, its effectiveness and predictability remain uncertain. This systematic review evaluated the effectiveness, predictability, and biomechanical effects of molar distalization using CAT.Methods: A systematic literature search was conducted in PubMed, Scopus, and Web of Science for studies published between January 2016 and July 2026. Clinical studies, randomized clinical trials, retrospective and prospective studies, and case reports evaluating molar distalization with clear aligners were included. Study selection, data extraction, and quality assessment were performed according to PRISMA 2020 guidelines.Results: Eighteen studies met the inclusion criteria. Clear aligner therapy achieved clinically significant molar distalization of approximately 2-2.5 mm while maintaining satisfactory vertical control. However, achieved tooth movement was generally lower than the digitally planned movement, with distal crown tipping being the most frequently reported adverse effect. The use of optimized attachments, sequential distalization protocols, and temporary skeletal anchorage devices improved anchorage control and bodily tooth movement but did not consistently increase distalization efficiency.Conclusion: Clear aligner therapy is an effective non-extraction approach for achieving clinically meaningful molar distalization. Although treatment predictability remains lower than planned, careful biomechanical planning and appropriate adjunctive mechanics can improve clinical outcomes. Further high quality prospective studies and randomized clinical trials are required to strengthen the current evidence.