Mandibular advancements during tidal breathing, achieved through a stepped mouthpiece design, affect the size of the upper airways in subjects with and without Obstructive Sleep Apnea.

Inclusion Criteria:

• Subjects must provide written informed consent to participate in the study.
• Adult male or female subjects over 18 years of age who have or have not been diagnosed with OSA.
• Subjects claiming no history of OSA should take the Epworth questionnaire and obtain a result less than 10.
• Subjects must satisfy the study investigator about their fitness to participate in the study.
• Subjects must be available to complete the study.

Exclusion Criteria:

• Subjects not compliant with the instructions for use of the stepped mouthpiece and the study procedures.
• Subjects who have participated in a clinical trial in the previous month.

The study will be performed as an open investigation including 60 subjects. The 60 subjects will be stratified such that 30 subjects should have been diagnosed with OSA, and 30 subjects should not have been diagnosed with OSA.