Bailey, Nicole2026-07-292026-07-292026-06-222026-06-222026-07-28http://hdl.handle.net/1993/39904ABSTRACT Objective: Assess the clinical outcomes of patients who have received expansion through the Invisalign Palatal Expander System. Methods and Materials: This study assessed 30 patients who met the inclusion criteria and were treated with an IPE. Pre- and post-expansion digital models were acquired and measurements for maxillary permanent intermolar width, intercanine width, tipping of the maxillary molar, presence of diastema and diastema width were collected. Data for intercanine and molar widths were compared to an existing data set (Torbaty et al., 2024) to assess how the IPE compared to controls, Hyrax expansion and Invisalign First. Results: Statistically significant (p<.001) increases occurred for all measurements after treatment with IPE. Intermolar and intercanine widths increased on average by 3.18mm (8.18%) and 1.46mm (4.76%) respectively. Diastema width increased an average 1.42mm, for 70% of patients. Compared to Torbaty et al., IPE performed better than Invisalign First for intermolar changes, but worse for intercanine changes. Hyrax expansion outperformed IPE for both intermolar and intercanine widths. Conclusions: - IPE increases intermolar and intercanine widths - Skeletal expansion with IPE is possible based on diastema development in 70% of subjects - IPE is less effective at increasing intercanine width than alternative expansion modalities - IPE is less effective than traditional rapid palatal expanders (e.g. Hyrax) at increasing interdental widthsengorthodonticsinvisalignexpansion