This purpose of this study is to evaluate the safety and efficacy of treatment with nasal CO2 in the treatment of pain and other symptoms related to temporomandibular disorder (TMD).

This is a randomized, controlled trial evaluating the safety and efficacy of nasal carbon dioxide for the treatment of pain and other symptoms related to temporomandibular disorders (TMD). Approximately 115 men and women ages 18 to 70 years old who have a history consistent with TMD-related pain for at least 3 months and meet all other eligibility criteria will be enrolled in this study. There may be up to two (2) visits to the clinic, screening and treatment. Screening and treatment may occur on the same day.

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"