To evaluate the effectiveness of a new mandibular advancement device (MAD) (Prosomnus® [IA] Sleep Device, Prosomnus Sleep Technologies, Pleasanton CA) fitted with a compliance tracker as a first-line treatment in a population of patients with mild to severe obstructive sleep apnea (OSA). MethodsTreatment effectiveness was measured using pre and post-treatment home sleep testing (HST) and validated sleep and quality of life questionnaires. Mean disease alleviation (MDA) was calculated to compare the treatment effectiveness of MAD to historical continuous positive airway pressure (CPAP) effectiveness data. ResultsMAD was found to be an effective first-line treatment for patients with mild, moderate, and severe sleep apnea with excellent compliance rates, similar to or better than CPAP, and an equal or better MDA of 56.7% compared to literature values of 50% for CPAP. ConclusionsMAD should be considered an effective first-line treatment for patients with mild and moderate sleep apnea and for severe sleep apnea for patients who prefer, refuse, or are not candidates for CPAP.