The Effectiveness Of Anterior Torque Control By Clear Aligners In Extraction And Non-extraction Cases : Systematic Review
Introduction: Clear aligner treatment has gained popularity in recent years. Accurate torque expression of the upper incisors is crucial for orthodontic treatment outcomes but remains challenging in invisible orthodontic treatment. Objectives: This systematic review aims to evaluate the existing literature and critically assess the clinical effectiveness of aligners in controlling anterior torque or bucco-lingual root inclination, in both extraction and non-extraction cases. Methods: A systematic search of Scopus, PubMed, Web of Science, Ebsco, and the Cochrane Library was conducted for peer-reviewed articles published between 2014 and March 2025. A total of 257 records were identified (Scopus: 32; Web of Science: 87; PubMed: 96; Cochrane: 23; Ebsco: 19). After screening and eligibility assessment, 10 studies were included. Inclusion criteria comprised clinical studies evaluating anterior torque or bucco-lingual inclination achieved with clear aligners. Study selection and data extraction were performed according to predefined criteria. Results: Ten studies involving a total of 412 patients were included. In non-extraction cases, planned torque movements greater than 10° showed moderate predictability, ranging from 35.21% to 42%, whereas movements below 10° exhibited low predictability, reaching only 21.2%. Notably, one study using the Novela system reported an accuracy range of 48% to 98% across all anterior teeth. In premolar extraction cases, treatment with aligners was associated with increased lingual crown inclination and a tendency toward greater overbite. Conclusion: Torque changes _10° show only moderate predictability in non-extraction cases, and even less for smaller planned changes. In extraction cases, torque control is further reduced, often resulting in increased lingual crown inclination and deeper overbite. These findings should be interpreted with caution due to the heterogeneity of study designs, measurement methods, and patient characteristics in the included studies.