Temporomandibular disorders substantially affect and impair jaw functions and thus the quality of life. Yet, powered assistance for jaw rehabilitation remains widely unexplored despite advances in exoskeletons for other extremities. To the best of our knowledge, this work presents the first comprehensive computational framework for hybrid rigid-soft jaw exoskeletons, integrating a biomechanically validated 24-muscle jaw model with deformable finite element soft-body dynamics in MuJoCo. The proposed four-tendon system combines a rigid chin cup for force transmission with a compliant facial mask for user comfort. Simulation-based evaluation under six configurations (TPU/Silicone materials, muscles-only/tendons-only/combined actuation) demonstrates effective trajectory tracking with mean errors of 4.60-6.42 mm while maintaining safe interface pressures and material stresses. Critical findings reveal fundamental performance-comfort trade-offs: TPU enables efficient force transmission with lower mean strain (11.49 % vs 14.06 %) but higher mean pressure (12.02 kPa vs 9.89 kPa) than silicone. Mean tendon forces of 24.63-35.46 N in tendons-only mode achieve effective assistance, yet combined actuation paradoxically increases biological muscle loading by 6-10 % despite improved tracking, guiding future control strategies toward biomechanical- and metabolically-aware algorithms. This validated open-source computational framework establishes essential safety constraints and design prerequisites for physical prototyping, providing a systematic path toward safe, wearable robot-assisted therapy for temporomandibular disorders.
Müller et al. (Thu,) studied this question.