## 4 Discussion  
A proper diagnosis of mild and moderate OSAS is essential to initiate adequate management. Symptoms such as frequent snoring, excessive daytime sleepiness, lack of concentration, and irritability, often overlooked or attributed to other causes, must be carefully evaluated to identify this condition. There is a strong correlation between sleep quality and work performance. Insufficient or poor quality sleep can negatively affect attention, memory, creativity, and decision-making ability, thus impairing productivity at work [25]. Overnight polysomnography and sleep studies are fundamental tools for accurate diagnosis and differentiation among various forms of OSAS. For patients presenting with simple snoring, also known as non-apneic snoring, the goal of therapy is to eliminate or significantly reduce the noise and risk of bruxism, as an association between sleep bruxism and simple snoring has been demonstrated, especially in the supine position [26]. Therapeutic options for mild and moderate OSAS include lifestyle changes and the use of Mandibular Advancement Devices (MADs) or Continuous Positive Airway Pressure (CPAP) therapy. According to a guideline released by the American Academy of Sleep Medicine in 1995, MADs were recommended as the primary treatment for mild OSA and as a secondary option for moderate to severe OSA [27]. In the literature, the effectiveness of CPAP and MAD therapy has been compared, and the results have certainly demonstrated that CPAP has a greater capacity to reduce AHI, improve nighttime oxygen saturation, and decrease the number of arousals. However, the results show overlapping outcomes between the two types of treatments regarding improvement in quality of life, perception of daytime sleepiness, driving performance, and blood pressure control [28; 29]. Therefore, we could say that CPAP exhibits high efficacy but low efficiency. On the contrary, thanks to comparative studies between the two types of therapies, it has been understood that MADs are better tolerated and preferred by patients, who show greater compliance with the long-term use of intraoral devices compared to the use of CPAP [30]. In this prospective study, the effects of applying the F22 MAD (Mandibular Advancement Device), an oral appliance designed by the Specialization School of Orthodontics at the University of Ferrara, were analyzed in 18 patients with mild or moderate OSAS and simple snoring, along with one patient with severe OSAS who did not accept CPAP therapy. \begin{table}
\begin{tabular}{c c c c} \hline \hline  & **T0** & **T1** & \(p\)**-Value** \\ \hline AHI & \(15.6\pm 10.7\) & \(5.7\pm 5.7\) & \(p<0.01\) \\ \hline ODI & \(13.4\pm 8.8\) & \(6.2\pm 5.2\) & \(p<0.05\) \\ \hline Snoring & \(30.7\pm 7\) & \(7.5\pm 10.8\) & \(p<0.01\) \\ \hline Supine sleep & \(44.6\pm 18.7\) & \(42.6\pm 21.1\) & \(p>0.10\) \\ \hline ESS & \(8.75\pm 3.7\) & \(6.11\pm 2\) & \(p<0.01\) \\ \hline \hline \end{tabular}
\end{table} 
Table 4: T0 and T1 parameters, and the \(p\)-values obtained from the \(t\)-test. From the comparison of polysomnographic outcomes before and after the application of the F22 MAD, the device has proven to be effective in reducing AHI (Apnea-Hypopnea Index), ODI (Oxygen Desaturation Index), and the snoring index. By analyzing each parameter in detail, we can observe that the mean value of the initial AHI compared to the mean value of the final AHI has significantly reduced (\(p<0.01\)). In particular, the success of the therapy can be confirmed by adhering to the Kushida criteria: with the MAD in place, there should be a reduction in AHI \(<5\) or AHI \(<10\) (in moderate OSAS), or a reduction in AHI \(>50\%\) compared to the initial value, with clinically noticeable symptom improvement [31]. In particular, [PERSON] et al., in 1994, compared the results of polysomnography before and after the application of MAD and observed a statistically significant reduction in AHI of approximately 50% post-treatment compared to pre-treatment values [32].