The effectiveness of two types of MADS for OSA therapy

Periodontal effects of two Somnodent oral devices for the treatment of OSA: A finite element study

OBJECTIVE

The study aims to evaluate the stresses and the deformations generated at the periodontal level by two mandibular advancement devices (MADs) using finite element analysis.

METHODS

A three-dimensional digital model of the skull of a 29-year-old patient was created using a CBCT. The 3D models of two MADs (Somnodent FlexTM and Somnodent AvantTM) were reconstructed from scanning prototypes based on the patient's anatomy. The overall geometry was imported into software for the finite element study. A force of 11.18 N representing an advancement of 9.5 mm was applied to the devices. A finite element analysis wfas subsequently performed.

RESULTS

Somnodent FlexTM generates a peak of 3.27 kPa on periodontal ligaments and 287 kPa on teeth. For Somnodent AvantTM the maximum stress is 4.53 kPa on periodontal ligaments and 467 kPa on teeth.

CONCLUSION

Different activation mechanisms of the devices generate stresses of different entities.

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.

Comparisons of the effects of two types of titratable mandibular advancement devices on respiratory parameters and upper airway dimensions in patients with obstructive sleep apnea: a randomized controlled trial

OBJECTIVES

To compare the effects of two types of titratable mandibular advancement devices (MADs), namely MAD-H (allowing limited vertical opening) and MAD-S (allowing free vertical opening), on respiratory parameters and upper airway dimensions in patients with mild to moderate obstructive sleep apnea (OSA).

MATERIALS AND METHODS

Patients with mild to moderate OSA (5 ≤ apnea-hypopnea index (AHI) < 30 /h) were randomly assigned to two parallel MAD groups. All MADs were subjectively titrated according to a standardized protocol during a 3-month follow-up. Every patient underwent two polysomnographic recordings, and two cone beam computed tomography scans in supine position: one at baseline and another one after 3 months with the MAD in situ. The primary outcome variables were the AHI in supine position (AHI-supine) and the minimal cross-sectional area of the upper airway in supine position (CSAmin-supine).

RESULTS

A total of 49 patients were recruited, and 31 patients (21 men and 10 women) with a mean (± SD) age of 48.5 (± 13.9) years and a mean AHI of 16.6 (± 6.7) /h completed the study. In the per-protocol analysis, there was no significant difference between MAD-H (n = 16) and MAD-S (n = 15) in their effects on AHI-supine (P = 0.14) and CSAmin-supine (P = 0.59). Similar results were found in the intention-to-treat analysis (P = 0.47 and 0.57, respectively).

CONCLUSIONS

Within the limitations of this study, we conclude that there is no significant difference in the effects of an MAD allowing limited vertical opening and an MAD allowing free vertical opening on respiratory parameters and upper airway dimensions in patients with mild to moderate OSA.

CLINICAL RELEVANCE

MADs allowing limited vertical opening and allowing free vertical opening have similar effects on respiratory parameters and upper airway dimensions in patients with mild to moderate OSA.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02724865. https://clinicaltrials.gov/ct2/show/NCT02724865.

Mandibular advancement device design: A systematic review on outcomes in obstructive sleep apnea treatment

Obstructive Sleep Apnea (OSA) is often treated with Mandibular Advancement Devices (MADs). It is unclear whether particular design features are superior to others in terms of OSA alleviation. In order to facilitate clinical decision-making, this systematic review summarizes the objective and subjective outcomes of different available MAD designs. Studies comparing different MAD designs in OSA treatment were searched. After screening 1887 titles and abstracts, 20 original RCTs and six cohort studies were included. 14 articles were systematically reviewed in a meta-analysis. The decrease in AHI was significantly different between some of the MAD designs. The clinical relevance of the observed differences was however limited. Monoblock appliances performed more favorable, compared to bilateral thrust (effect size:-0.37; CI:-1.81 to 0.07). Midline traction appliances performed more favorable, compared to other designs. Custom appliances performed more favorable, compared to thermoplastic appliances (effect size:0.86; CI:-0.62 to 2.35). Furthermore, there were no clinically relevant differences between MAD designs in reduction of ESS, compliance, preference, side effects, and cost effectiveness. With respect to the included trials, presently there is not one superior custom MAD design in OSA treatment regarding the effect on AHI reduction, ESS improvement, compliance, preference, side effects, cost effectiveness, and other disease-related outcomes. We confirm custom MAD designs perform superior to thermoplastic MAD designs.

Use of mandibular advancement devices for the treatment of primary snoring with or without obstructive sleep apnea (OSA): A systematic review

The aim of this review was to systematically evaluate the available scientific evidence on the benefit of mandibular advancement devices (MADs) in the treatment of primary snoring (PS). From 905 initially identified articles, 18 were selected. Papers that provided indirect information regarding obstructive sleep apnea syndrome (OSAS) and/or sleep breathing disorders (SBD) were included. Information was obtained on monoblock and duoblock appliances from the selected studies. The devices were most commonly able to achieve 50%-70% of the maximum mandibular protrusion. The frequently used outcome measurements were the apnea-hypopnea index, Epworth sleepiness scale, and oxygen desaturation index, which all yielded positive post-treatment results. The most common side effects were temporomandibular joint pain and excessive salivation, which improved with time. Our findings indicated that the use of MADs, even with varying designs, improved outcomes in all the reported patient populations (PS, OSAS, and SBD). Despite the lack of studies on PS, the available evidence supports the use of MADs for treatment of PS. Snoring should be treated from a preventive and psychosocial perspective to avoid progression to more severe diseases that could have a significant medical and economic impact.

Mandibular advancement reveals long-term suppression of breathing discomfort in patients with obstructive sleep apnea syndrome

Obstructive sleep apnoea syndrome (OSAS) patients do not report breathing discomfort in spite of abnormal upper airway mechanics. We studied respiratory sensations in OSAS patients without and with mandibular advancement device (MAD). Fifty-seven moderate to severe non obese OSAS patients were asked about breathing discomfort using visual analogue scales (VAS) in the sitting position (VAS-1), after lying down (VAS-2), then with MAD (VAS-3). Awake critical closing pressure (awake Pcrit) was measured in 15 patients without then with MAD. None of the patients reported breathing discomfort when sitting but 19 patients (33%) did when lying (VAS-2: -20% or less). A feeling of "easier breathing" with MAD was observed and was more marked in patients reporting breathing discomfort when supine (VAS-3: +66.0% [49.0; 89.0]) than in those not doing so (VAS-3: +28.5% [1.0; 56.5], p = 0.007). MAD-induced change in awake Pcrit was correlated to VAS-3. In conclusion, MAD revealed "latent dyspnea" related to the severity of upper airways mechanics abnormalities in OSAS patients.