Diffusion MRI for Quantitative Assessment of Myofascial Pain

Inclusion Criteria: * Men and women 18-65 years of age * Ability to give informed consent * Symptoms meeting criteria for normal or latent/active temporomandibular myofascial pain Exclusion Criteria: * Contraindications to MRI scanning including severe obesity or difficulty in laying in a supine position, intracranial clips, metal implants, external metallic devices/objects/clips within 10mm of the head, suspected or confirmed metal in the eyes (history of welding or similar activity), claustrophobia, cardiac pacemaker or pacing wires * Pregnancy or breast feeding * Traumatic injury of masticatory muscles or temporomandibular joint within last 12 months * Mandibular fracture within last 12 months * Initiation of additional treatment of myofascial pain within the past 1 month * Received masseter Botox within the last 4 months