Mandibular Advancement Device and Changes in Nocturia

Inclusion Criteria: * English speaker * \>18 y/o * Obstructive sleep apnea diagnosis with AHI≥5 * ≥ 2 voiding/night at baseline * Upon clinical examination ≥ 8 teeth per arch, range of mandibular protrusion ≥5 mm * Consent to participate in the study. Exclusion Criteria: * Patients with concomitant diagnosed sleep disorders (i.e. insomnia, narcolepsy, restless legs syndrome, rapid eye movement sleep behavior disorder). * Prostate/kidney problems (urological disease: (eg overactive bladder, benign prostate hyperplasia) * Pregnancy * Heart failure, use of diuretics, diabetes, Parkinson's disease or dementia. * Patients using combination therapy for the management of obstructive sleep apnea (OSA) (i.e. positive airway pressure (PAP) therapy or positional therapy). * Upon clinical examination: periodontal disease (\>4 mm on periodontal probing, with bleeding on probing, visual signs of periodontal inflammation); tooth horizontal mobility \>1 mm, vertical mobility, and unfavorable crown to root ratio; open cavities, loose or fractured restorations, or patient undergoing restorative dental treatments. * Exaggerated gag reflex. * Lack of coordination or dexterity. * Inadequate English comprehension.