A systematic review and meta-analysis examined 15 studies involving growing patients with maxillary transverse deficiency. The research compared clear aligners, specifically the Invisalign First system, against conventional expansion appliances used in orthodontic practice. The analysis focused on how predictably each method moves the upper jaw bones.
The findings show that clear aligners produce significantly less skeletal transverse expansion than conventional expanders. Measurements of intermolar distance, total palatal volume, and arch perimeter all confirmed that traditional devices achieve greater skeletal and posterior changes. This difference was especially evident in patients with more pronounced transverse deficiencies.
The study notes that most current evidence comes from retrospective studies with a moderate risk of bias. Consequently, conclusions should be interpreted cautiously and confirmed by well-designed prospective research. Clear aligners appear capable of producing expansion, mainly through dentoalveolar changes in the anterior region and at the level of deciduous teeth.