To solve transversal problems, multiple designs of expanders exist which can be used in treatments with or without SARPE. Nowadays, one of the most complicated issues is to achieve sufficient expansion, symmetrical expansion and the release of the pterygoid sutures, especially in cases of MARPE. For this reason, we have designed the Power Expander, a customised bone-borne expander manufactured with 3D technology. It allows a higher and more efficaceously exerted force to be applied on the maxilla. This article describes the fabrication of the Power Expander and the results obtained in a case report.