Aims: To evaluate the effect of three different palatal expanders (Hyrax, Quad-Helix and W-Arch) on maxillary 1st premolar, 2nd premolar and 1st molar width changes. Materials and Methods: The sample consisted of three groups, the Hyrax (N=10), the Quad-Helix (N=10) and the W-Arch (N=10). Images were taken before and after expansion; analysis were made using Autodesk AutoCAD© program. One-way ANOVA and Duncan's multiple range tests were used (P ≤ 0.05). Results: Significant difference was found in the maxillary 1st premolar, 2nd premolar and 1st molar width changes between the Hyrax and the other two expanders, while there was no significant difference between the Quad-Helix and the W-Arch expanders. Conclusion: Maxillary arch width increases more consistently with the Hyrax expanders.