Digital Orthodontics: Posterior crossbite correction and arch expansion with directly 3-dimensional printed clear aligners

Posterior crossbite correction and mandibular arch expansion have traditionally been managed with fixed appliances, while conventional thermoformed aligners have shown limited efficacy due to material properties and biomechanical constraints. This case report describes the management of bilateral premolar crossbite and mandibular constriction in a 26-year-old female using directly 3D-printed clear aligners (DPA) fabricated with a biocompatible resin. A complete digital workflow treatment planning was employed, and twenty-six aligners were produced using high-resolution LCD printing over a treatment period of thirty-one weeks. Posttreatment evaluation confirmed successful correction of the crossbite, stable arch expansion, and maintenance of posterior inclination control. Three-dimensional superimposition and colormap analysis demonstrated minimal relapse, less than 0.5 mm, at one-year follow-up. This report highlights the potential of DPA as a clinically effective alternative to thermoformed aligners for the correction of complex occlusal discrepancies.