Prospective multicenter cohort study of obstructive sleep apnea (OSA) patients treated with a custom-made mandibular repositioning device (MRD)

Notes from Dr. Norman Blumenstock
This recent French study shows the benefits of oral appliance therapy.

August 22, 2014 / By Marie-Françoise Vecchierini, MD

Editor’s note: Dr. Marie-Françoise Vecchierini is a recent recipient of an American Academy of Dental Sleep Medicine (AADSM) 2014 Clinical Excellence Award.
Obstructive Sleep Apnea (OSA) has numerous and significant comorbidities, so its treatment is essential. Mandibular Repositioning Devices (MRD) are recommended as primary treatment for patients with mild-to-moderate OSA. Because very few studies have specifically assessed the long-term efficacy of MRDs in OSA patients who are noncompliant with continuous positive airway pressure (CPAP), my research team conducted a study on 312 patients (71% men; 53+/-12 years old), offering MRD treatment and determining the long-term efficacy of a custom-made computer aided-design (CAD)/computer-aided manufacturing technology (CAM).
ADDITIONAL READING | ‘Captain, permission to come aboard’ — getting the team on-board with OSA therapy
Study participants
The inclusion criteria were severe OSA patients with an apnea-hypopnea index (AHI) >30 or patients with a 5<AHI<30 and severe sleepiness. All patients had no dental or articular contraindications, and no previous MRD treatment. From this criteria, three subgroups were identified according to AHI value (14% of patients with 5<AHI<15, 44% with 15<AHI<30, and 42% with AHI>30).
ADDITIONAL READING | Hidden dental dangers of undiagnosed obstructive sleep apnea
Research parameters
Successful treatment was defined as a decrease of at least 50% of the AHI and complete response was achieved for an AHI<5 or <10. Mean mandibular advancement was 7 +/- 2 cm, 75% of the maximum advancement, after 2+/-1 titration visits.
Results
In the three- to six-month follow-up, AHI decreased significantly from 29+/-15 to 11+/-10, 84% of patients had a ≥ 50% reduction in AHI, and AHI<10 was achieved in 63%. Among the patients with severe OSA, 60% were effectively treated and 40% were completely cured.
Additional results of the study are as follows:

• SpO2 parameters significantly improved in each subgroup of patients
• Epworth Sleepiness Scale decreased significantly from 12+/-5 to 8+/-5
• Clinical symptoms, including loud snoring, nocturnal polyuria, and libido disorders, were all improved
• Quality of life and fatigue scores improved significantly from the baselines scores
• No significant change in sleep duration but a slight improvement in sleep latency, slow wave sleep, and REM sleep duration
• The mean use of MRDs was 6.7 hours per night and 6.6 days per week
• Side effects were reported by 21% of the patients, including gum irritation or pain (9.5%), dental or periodontal pain (8%), and temporomandibular joint pain or stiffness (7%)
• The rate of occlusion change or mobility was low (2%), and 8% of the patients stopped the treatment early as a result of side effects
• By looking for predictive factors of treatment success through univariate and multivariate regression analysis, less abdominal obesity and Class II malocclusion were found among the patients
• Significant predictive factors for complete MRD effectiveness were lower AHI or higher maximal jaw protrusion capability

Conclusion
In conclusion, an MRD offers an excellent compliance rate among patients and provides significant improvement in patients’ OSA symptoms, AHI, and quality of sleep. A custom-made MRD is an effective therapy for patients with mild to severe OSA that can be used successfully in patients who refuse or are not compliant with CPAP.

Marie-Françoise Vecchierini, MD,
is a member of the American Academy of Dental Sleep Medicine (AADSM), the American Academy of Sleep Medicine (AASM), and past president of the French Sleep Medicine and Research Society. Dr. Vecchierini also received two awards at the 2013 AADSM Annual Meeting in Minneapolis for her study on the follow-up of a large cohort of OSA patients intolerant to CPAP and treated by MRD.