Temporary Anchorage Devices and Clear Aligner Therapy: A Systematic Review

Clear aligner therapy (CAT) has well-documented biomechanical limitations for demanding tooth movements, including molar distalization, posterior intrusion, and significant torque control. Temporary anchorage devices (TADs) provide a compliance-independent source of skeletal anchorage that may help overcome some of these limitations; however, the clinical evidence supporting their combined use with CAT remains incompletely characterized. This systematic review aimed to identify and critically appraise all available clinical evidence on the use of TADs in conjunction with CAT, synthesize findings according to clinical indication, evaluate methodological quality, and identify evidence gaps. Four electronic databases (PubMed, Cochrane Library, Web of Science, and Scopus) were searched from inception to April 2026, with an initial search conducted in May 2025 and an updated search performed in April 2026. Human clinical studies reporting orthodontic outcomes of combined TAD and CAT treatment were eligible for inclusion, while in vitro studies, reviews, and studies involving purely surgical applications of TADs were excluded. Study selection followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) 2020 guidelines. Methodological quality was assessed using the Joanna Briggs Institute (JBI) Critical Appraisal Checklists for case reports and case series and the Methodological Index for Nonrandomized Studies (MINORS) instrument for comparative and cohort studies. Fourteen studies published between 2009 and 2026, involving 109 patients, met the inclusion criteria, comprising five case reports, three case series, two prospective comparative studies, two retrospective comparative cohort studies, one retrospective observational cohort study, and one retrospective longitudinal study. No randomized controlled trials were identified. Clinical applications included maxillary molar distalization (six studies), mandibular molar distalization (three studies), vertical correction (two studies), transverse scissor-bite correction (one study), impacted canine management (two studies), and complex hybrid or surgery-first approaches (two studies). Across the available comparative studies, TAD anchorage was associated with reduced unwanted side effects, particularly anterior anchorage loss, molar tipping, and vertical adverse effects; however, distalization efficiency remained substantially below planned values, ranging from 32% to 71% in quantitative studies. Case reports and case series provided low-level evidence with substantial inherent bias, while comparative and cohort studies demonstrated moderate methodological limitations. Overall, the combination of TADs and CAT appears technically feasible and demonstrates proof of concept across a range of clinical applications, with the principal benefit being improved control of tooth movement rather than a proportional increase in the magnitude of achieved movement. Nevertheless, the overall certainty of evidence remains low, precluding definitive clinical recommendations. Well-designed randomized controlled trials incorporating standardized three-dimensional outcome measures are needed to establish the effectiveness of this treatment approach.