Effect of the Mandibular Repositioning Appliance (MARA) on Posterior Airway Space (PAS)

Aim of the study was to show the effect of skeletal Class II treatment with the mandibular anterior repositioning appliance (MARA) on the sagittal posterior airway space (PAS) diameter. A total of 53 patients were selected retrospectively: 26 male patients (median 13 years, age span 10-19 years) and 27 female patients (median 14 years, age span 11-47 years). All patients had lateral cephalograms taken at T1 (before MARA treatment) and at T2 (after MARA treatment). Average treatment took 13.1 +/- 7.5 months (Group 1) and 10.5 +/- 4.5 months (Group 2), respectively. The following PAS parameters were obtained at T1 and T2: TI (Tangent Point 1), Me/Gn (menton/gnathion), DW (dorsal wall). Additionally, Bjork's sum angle, SNA, SNB and ANB were determined. The male patients showed a higher increase in the anteroposterior diameter of the PAS (+27.5%) compared to female patients (+11.6%). Male participants had a significantly higher PAS (p = 0.006) than female participants (p = 0.09). Although not significantly, Bjork's sum angle decreased in both groups. In general, compared to female patients, male patients showed a greater decrease between T1 and T2. SNA and SNB exhibited varied behavior between T1 and T2, with some individuals reporting a decrease and others reporting an increase. SNA tended to decrease in general. In terms of ANB, the male participants displayed a decrease from T1 to T2. Treatment of a skeletal Class II malocclusion with the mandibular anterior repositioning appliance (MARA) caused an increase in the sagittal posterior airway space (PAS) diameter and, thereby, might be effective against obstructive sleep apnea.