Study On Arch Expansion Effect Using Digital Registration Method

To assess the clinical efficacy of clear aligner-assisted arch expansion for mild crowding using digital registration comparing designed versus actual outcomes. Thirty mild crowding patients underwent clear aligner expansion therapy. Digital models from treatment-stage plaster casts (scanned via D-station 3D-RI) and Clincheck-designed plans were imported into Geomagic Studio 2012. Arch width changes and expansion rates at first premolars/molars were measured, with digital registration quantifying buccolingual deviations. Data analysis utilized SPSS 27.0. Average expansion rates reached 87.26% (maxillary premolars), 86.57% (maxillary molars), 90.5% (mandibular premolars), and 89.88% (mandibular molars), showing significant design-actual discrepancies (P<0.01). Buccal deviations differed significantly between groups (maxilla: 0.40mm vs 0.59mm; mandible: 0.41mm vs 0.53mm, P<0.01), while lingual deviations showed no statistical difference (-0.36mm vs -0.39mm, P>0.05). Buccolingual displacement emerged as a valid treatment efficacy indicator. Digital registration effectively evaluates clear aligner performance. While effective for mild crowding, arch expansion demonstrates challenging buccal movement control with increased tipping tendency. Buccolingual displacement measurement serves as a reliable therapeutic assessment criterion.