Introduction: Snoring and obstructive sleep apnea (OSA) are prevalent sleep-related breathing disorders with significant social and medical implications. Mandibular advancement devices (MADs) are a recognized treatment option for managing snoring and mild to moderate OSA; however, their impact on sleep architecture requires further investigation. Objective: This study aimed to evaluate the effects of MAD placement on total sleep duration, sleep stage distribution, and micro-awakenings. Methods: A total of 12 participants (66.67% male, 33.33% female) underwent polysomnography before and 60 days after MAD placement. Sleep duration in different stages and the frequency of micro-awakenings were analyzed. Descriptive and inferential statistical analyses were conducted using t stutends. Results: After MAD placement, total sleep duration increased, along with prolonged stage 2 and 3 NREM sleep (p > 0.05). However, the number of micro-awakenings, particularly those associated with respiratory events and snoring, also increased significantly (p < 0.05). Conclusion: The MAD contributed to an increase in total sleep duration and deeper sleep stages, which may indicate a beneficial effect on sleep architecture.