Comparative analysis of two custom-made mandibular advancement devices with varied designs for treating moderate to severe obstructive sleep apnea.

INTRODUCTION: Custom-made titratable mandibular advancement device (MAD) treatment can nowadays be considered a promising first-line treatment in patients with mild to severe obstructive sleep apnea (OSA). Specific manufacturing designs and titration mechanisms of MAD are on the market, characterized by their titration approach, vertical opening, and materials selection. The wing-designed MAD (SomnoDent® Flex™, SomnoMed Ltd, Sydney, Australia) has a lateral screw mechanism to advance the lower jaw in incremental steps of 0.1 up to 6.0 mm. The newer uniquely designed custom-made MAD with passive mouth closing (SomnoDent® Avant™ SomnoMed Ltd, Sydney, Australia) has a frontal exchangeable advancement strap of fixed lengths as a specific titration mechanism, all supporting freedom of lateral movement. We aimed to assess the associations between the type of MAD prescribed and OSA treatment outcome.

METHODS: Data from 209 patients (165 male, mean age 53.9 (±10.9) years, median baseline BMI and AHI 27.02 [24.8; 29.7] kg/m2 and 22.8 [17.7; 31.6]/hour sleep, respectively) were collected. Of this cohort, 91 patients with the traditional, wing-based SomnoDent® Flex™ and 118 patients with SomnoDent® Avant™. All patients were diagnosed with a type 1 polysomnography demonstrating moderate to severe OSA (15 ≤ AHI ≤65 per hour sleep). The selected MAD was fitted in the so-called maximal comfortable protrusion. After 3 months of subjective titration until resolution of subjective symptoms and/or achieving physical limits, a checkup with validated home sleep monitoring was conducted. Treatment success was defined as "AHI reduction ≥50% with MAD compared to baseline AHI and AHI with MAD <10 events per hour".

RESULTS: These real-world data set showed that 67% of patients achieved treatment success, with a statistically significant reduction in AHI from 22.8 [17.7; 31.6] to 7.45 [3.4; 15.0]/h sleep. The SomnoDent® Avant™ achieved 75% treatment success versus 56% for the traditional, wing-based SomnoDent® Flex™ (P < 0.05). Overall, AHI reduction was 70% for SomnoDent® Avant™ (P < 0.05) vs. 63% for SomnoDent® Flex™ (P < 0.05).

CONCLUSIONS: This study shows that choice of MAD design can impact the treatment outcome and could become an important consideration in selecting the type of MAD for personalized treatment for OSA patients. While the results of the traditional wing-based MAD design were comparable to the therapeutic outcome with other titratable, custom-made MADs, the MAD with the passive mouth closing feature showed significantly greater reduction in total AHI potentially due to encouraged nasal breathing, reduced mouth breathing and lesser vertical opening thereby decreasing the probability of tongue base collapse.