Maxillary arch development with clear aligners: A comprehensive scoping review

OBJECTIVE: This scoping review aims to evaluate the efficacy and limitations of clear aligner therapy (CAT), particularly Invisalign, in the transverse development of the maxillary arch. With increasing demand for esthetic, removable orthodontic alternatives, clear aligners are used beyond mild crowding to manage arch expansion and crossbites. MATERIALS AND METHODS: A comprehensive search of PubMed, Scopus, Web of Science, Google Scholar, Elsevier, and National Center for Biotechnology Information was conducted to identify English-language studies published between 2020 and 2024. Keywords used included “maxillary arch development,” “CAT,” and “Invisalign.” After applying inclusion and exclusion criteria, eight studies were included from an initial 3,190 identified records. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) framework guided the selection process. RESULTS: The included studies demonstrated that clear aligners can achieve maxillary expansion primarily through buccal tipping of posterior teeth. However, bodily movement remains limited. The predictability of expansion outcomes varied, with cusp width changes being more reliable than root or gingival-level movements. One study found an expansion efficiency of over 90% at the first premolar cusp, while others noted discrepancies between planned and achieved outcomes. CONCLUSION: Clear aligners demonstrate moderate effectiveness for maxillary arch expansion through dental tipping, especially in mild to moderate cases. However, they are less predictable for bodily movement or large-scale skeletal changes. Further high-quality, controlled trials are required to validate these outcomes and optimize treatment protocols.