The following prospective study has the aim of evaluating the efficiency of the F22 MAD (mandibular advancement device), a new oral device for the treatment of OSAS (Obstructive Sleep Apnea Syndrome) and snoring. Methods: AHI (apnea-hypopnea index), ODI (Oxygen Desaturation Index), snoring percentage, time spent in the supine position, and Epworth Sleepiness Scale score were evaluated in 19 patients with snoring, mild to moderate OSAS, or severe OSAS who declined CPAP (Continuous Positive Air Pressure) treatment, before and after the application of the F22 MAD. Results: The median value of AHI varied from 15.6 ± 10.7 to 5.7 ± 5.7; the median value of ODI varied from 13.4 ± 8.8 to 6.2 ± 5.2; the median value of the percentage of snoring varied from 30.7 ± 7 to 7.5 ± 10.8, except for the patient who has severe OSAS who increased their value. The value obtained by the self-completion of the ESS questionnaire (Epworth Sleepiness Scale) underwent a statistically significant variation, while clinically significant for 13\19 patients who obtained a reduction of the value >/= of 2 points. Conclusions: It is possible to conclude that the F22 MAD is effective in the treatment of patients with mild and moderate OSAS or simple snoring, reducing the polysomnographic outcomes with statistically and clinically significant results in terms of reduction of AHI, ODI and percentage of snoring.