OroSTIFF, also invented by Dr. Steven Barlow, measures non-participatory perioral stiffness in healthy adults for eventual application to patients with orofacial movement disorders associated with neuromotor disease, traumatic injury, or congenital clefts of the upper lip. The OroSTIFF device is face-referenced and avoids the complications associated with head-restraint. Real-time calculation of the perioral stiffness function demonstrated a significant quadratic relation between imposed interangle stretch and resultant force. This stiffness growth function also differed significantly between males and females. Studies demonstrate the OroSTIFF proof-of-concept for cost-effective, non-invasive stimulus generation and derivation of perioral stiffness in a group of healthy unrestrained adults. A case study illustrated the dose-dependent effects of Levodopa on perioral stiffness in an individual with advanced Parkinson’s disease who exhibited marked dyskinesia and rigidity.