Treatment with a mandibular advancement device (MAD) is recommended for mild obstructive sleep apnea (OSA), primary snoring and as a secondary option for Continuous Positive Airway Pressure, because it has better adherence and acceptance. However, edentulous patients do not have supports to hold the MAD. This study aimed to present a possible to OSA treatment with MAD in over complete upper and partial lower dentures. The patient, a 38-year-old female with mild OSA, was treated with a MAD. The respiratory parameter, such as apnea–hypopnea index, arousal index and oxyhemoglobin saturation was improved after treatment.