Abstract
Orthodontic treatment in adult patients should ideally cause minimal clinical changes in alveolar bone levels while enhancing smile aesthetics. The aim of this study was to evaluate the changes in aesthetic parameters in patients undergoing maxillary expansion with the Invisalign system to determine the contribution of the orthodontic treatment to smile aesthetics, as well as to assess changes in alveolar bone levels. Retrospective data from 81 patients was analyzed. Aesthetic parameters such as smile line, lip curvature, smile index, and smile width were evaluated using pre- and post-treatment photographs. Alveolar bone level changes in the premolar regions were measured on panoramic radiographs using the Progressive Rate Index. The number of teeth visible in the smile increased significantly after treatment (p = 0.022). Although not statistically significant, improvements were observed in smile line values after treatment (p = 0.238). No significant changes were observed in upper lip curvature (p = 0.679) or smile index (p = 0.261). Percentage bone loss did not differ significantly between pre- and post-treatment measurements (p = 0.831). A non-significant increase in bone loss was observed with longer treatment durations (p = 0.071). Maxillary expansion treatment with Invisalign resulted in improvement in some aesthetic parameters with minimal changes in the bone.