A Skin-Adhesive Bimodal Sensing Patch for Decoding Occlusal Dysfunction

Occlusal dysfunction is a prevalent orofacial disorder characterized by aberrant occlusal force transmission and dysregulated masticatory muscle activity. Currently, objective functional assessment remains limited in clinical practice. In this study, we propose a skin-interfaced bimodal sensing patch that integrates serpentine-structured piezoelectric poly(vinylidene fluoride) (PVDF) films with conductive hydrogel electrodes for simultaneous monitoring of occlusal mechanics and muscle electrophysiology. An island-serpentine design ensures high mechanical compliance while preserving stable electromechanical performance over more than 12,000 loading cycles. The hydrogel interface serves not only as an adhesive layer enabling conformal adhesion of the PVDF film to the skin but also functions as a low-impedance electrode, facilitating high-fidelity surface electromyography (sEMG) with a signal-to-noise ratio of ~ 30 dB. Through combined analysis of piezoelectric and sEMG signals, the system distinguishes distinct functional occlusal phenotypes, including normal occlusion, deep overbite, crossbite, and mandibular deviation. This bimodal framework establishes a noninvasive strategy for early screening, objective phenotyping, and quantitative therapeutic evaluation of occlusal dysfunction.