Introduction: Obstructive sleep apnea (OSA) is a condition in which there is repetitive and intermittent occlusion of the upper airway (UA) during sleep. OSA can be treated through; continuous positive airway pressure (CPAP), surgery, or oral appliances. Mandibular Advancement Appliance (MAA) is considered a valid alternative, which can be the first choice in simple snorers and mild-moderate OSA. MAA can be either custom-made or non-custom-made, one-piece or two-piece, titratable or non-titratable. While Monoblock designs permit no mouth opening, two-piece appliances vary in permissible lateral jaw movement and in the coupling mechanisms which attach the two plates together.
Objectives: measuring the change in UA volume after the use of two different designs of MAA (Monoblock and Biblock)
Materials and methods: Twenty patients with diagnosed OSA were divided randomly into two equal groups: Monoblock group ; received Monoblock MAA fabricated using CAD/CAM technique at different advancement levels; 50% then 75% of maximum advancement, Biblock group; received Biblock MAA fabricated using CAD/CAM technique at different advancement levels; 50% then 75% of maximum advancement. UA volume of all patients were evaluated after three months of acclimatization of each stage of advancement through Cone-Beam Computed Tomography (CBCT).
Results: Biblock group showed statistically significant increase in UA volume at 75% mandibular advancement level, compared to Monoblock group (p=.001). There was statistically significant increase in UA volume percentage change from baseline to 50% advancement (p=.016), and also from baseline to 75% advancement (p=.001) in favor to Biblock MAA.
Conclusions: Both Monoblock and Biblock MAA produced statistically significant increase in UA volume of OSA patients. Biblock MAA with elastics presented statistically significant favorable increase in UA volume in relation to Monoblock MAA.