Nasal Carbon Dioxide (CO2)for the Treatment of Temporomandibular Disorders (TMD)Related Pain

Key Inclusion Criteria: * Have a history consistent with TMD-related pain for at least 3 months prior to screening * Agree not to use certain medications prior to randomization within the study specified * Females of childbearing potential must commit to using an acceptable method of birth control and have a negative pregnancy test. Key Exclusion Criteria: * Have recent history of alcohol or drug abuse within 2 years prior to randomization * Current major psychiatric disorder such as suicidal ideation, bipolar, panic disorder, schizophrenic, or psychoses * History of asthma (other than mild or intermittent) * Have an existing serious unstable systemic disease (such as severe emphysema, other respiratory diseases, heart disease, etc.) that precludes participation in the study * Clinically significant nasal disorder (such as deviated septum, presence of polyps, evidence of significant congestion, rhinitis, or other nasal abnormalities) * Current diagnosis of fibromyalgia * History or clear clinical evidence of osteoarthritis of temporomandibular joint (TMJ) * A TMD diagnosis of disc displacement without reduction, "locking"