The Study is a multi-center, prospective, open label, single-arm, three-month, long-term study of the Attune Sleep Apnea System for the treatment of obstructive sleep apnea (OSA). The objective of the study is to monitor long-term use of the Attune Sleep Apnea System.

Inclusion Criteria:

• Subject participated in the ATLAST Study, and completed the 28-day take-home period
• Subject understands the Study protocol and is willing and able to comply with Study requirements and sign the informed consent form.
• The study physician and investigator believe that study participation is appropriate for the subject.
• Subject has at least one molar in each of the four quadrants of the mouth (right upper, right lower, left upper, and left lower).

Exclusion Criteria:

• Female subjects who are pregnant or intend to become pregnant during the study period.
• Poor nasal patency as evidenced by the inability to breathe through the nose with the mouth closed.
• Oral cavity infection or any other oral or dental condition or problem that would limit subject use of the Attune Sleep Apnea System
• History of any OSA surgical treatment