Characterization of the Temporo-masseteric Nerve Block (TMNB) in Healthy Subjects

Inclusion Criteria: * 18-64 years of age * All ethnicity * Male and female sex * Fluent in written/spoken English * Never been diagnosed with TMD * No significant history of orofacial pain * \<5 headaches/month in the 3 months before enrollment * No reported use of a nightguard or occlusal splint 'No' to all questions on self-administered questionnaire for TMD screening: * Pain in jaw or temple on either side of the face in the last 30 days * Stiffness or pain in jaw upon awakening in the last 30 days * Any pain increase/reduction in the jaw/temple region during the last 30 days with * Chewing hard or tough food * Opening mouth or moving jaw forward or to the side * Hold teeth together/clenching/grinding/chewing gum * Using the jaw during activities such as talking, kissing or yawning Exclusion Criteria: * Traumatic injury/ surgery on face or jaw \< 6 months * current orthodontic treatment * pregnant or nursing, * kidney failure or renal dialysis, * heart disease or heart failure, * uncontrolled chronic respiratory disease/ hypertension/ diabetes * history of * seizures * hyperthyroidism * drug or alcohol abuse * psychiatric disorder/conditions requiring hospitalization * chemotherapy/radiation