Various designs of mandibular advancement appliances (MAAs) have been proposed for managing obstructive sleep apnea (OSA) in children. However, the difference in efficacy between various MAA designs remain unclear. A deeper understanding of the effectiveness of various MAA designs could help refine their design and improve treatment outcomes. This systematic review evaluates the efficacy of different available MAA designs. PubMed, EMBASE, and the Cochrane Library were searched for eligible studies published up to January 2025. A total of 1098 studies were initially identified, from which three randomized controlled trials (RCTs) and five Non-RCTs assessing the efficacy of MAAs in pediatric OSA patients were included. The results showed that MAAs were associated with increased minimal oxygen saturation (SpO2) (CI: 17.67 to -0.82, p=0.03) and mean SpO2 (CI: 1.07 to -0.09, p=0.02) in pediatric OSA patients. The Twin-block appliance did not significantly reduce the apnea-hypopnea index (AHI) (CI: 0.11 to 8.63, p=0.06), while the Mono-block appliance was found to reduce AHI significantly (CI:2.21 to 6.79, p=0.0001). Additionally, unlike the Twin-block appliance, the Mono-block appliance improved both minimal and mean SpO2. With limitation of selected studies, the impact of MAA design on pediatric OSA varied. However, it cannot be concluded that one specific MAA design is superior to others for managing pediatric OSA.