All‐In‐One Iontronic Sensing Aligner for High‐Precision 3D Orthodontic Force Monitoring

Abstract Clear aligners offer aesthetic and comfort advantages in orthodontics, yet their ability to deliver effective forces relies heavily on empirical judgment or large‐scale optical scanning, lacking real‐time quantitative evaluation. Integrating pressure sensors into aligners is a promising solution, but challenges in miniaturization, multi‐dimensional sensing, measurement accuracy, and biocompatibility hinder clinical application. Here, an all‐in‐one Orthodontic Force Acquisition System (OFAS) is presented that enables real‐time, 3D force monitoring using a cross‐shaped iontronic sensing array and an origami‐inspired, wireless battery‐free readout circuit miniaturized for single‐tooth placement. The system employs a cross‐linked polyelectrolyte with low creep and high repeatability, achieving 1.14% measurement accuracy. A 15‐day in vivo study demonstrates that OFAS accurately captured dynamic force profiles with strong correlation to tooth displacement (R 2 > 0.99), confirming its feasibility for real‐time, quantitative orthodontic force measurement and enabling timely treatment adjustments.