1

Introduction

Intraoral mandibular advancement devices (MADs) have become an acceptable and common treatment for the signs and symptoms of obstructive sleep apnea (OSA) in the United States. Oral appliances can be employed as a first-line modality for OSA and primary snoring or in patients who are intolerant of or need concurrent treatments with other modalities. MADs are usually not as efficacious as positive airway pressure (PAP) for normalizing the respiratory parameters of OSA, but are often preferred by patients over PAP ( Table 10.1 ) and appear to have similar clinical effectiveness. Oral appliances may be fitted by a qualified dentist or otolaryngologist after appropriate history, physical examination, and sleep testing. Although there are no absolute criteria predictive for MAD success, there are some prerequisites and predictive features, including adequate number of stable dentition, jaw protrusion range, and the extent of pharyngeal dilation with jaw protrusion. Once a patient qualifies and elects oral appliance therapy, treatment may be performed using thermoplastic or custom-made MADs, with the latter being preferred. Dental impressions are obtained, followed by fitting and patient education. Follow-up of patients is needed for both assessment of treatment effectiveness and monitoring for side effects. Objective monitoring of adherence to therapy is now available and may promote greater acceptance and utilization of oral appliances.

2

Indications

Oral appliances that advance the mandible are recommended for the treatment of both primary snoring and OSA in the United States. The American Academy of Sleep Medicine (AASM) updated its recommendations for oral appliance therapy in 2015 to specify that oral appliances are a “standard” treatment option, rather than no treatment for adult OSA in patients who do not tolerate or who prefer them to PAP. Notably, the statement did not include a reference to Apnea/Hypopnea Index (AHI) severity criteria. At the same time, the AASM panel’s recommendation noted a preference for PAP over MADs, as PAP was “found to be superior to OAs (oral appliances) in reducing the AHI, arousal index, and oxygen desaturation index and improving oxygen saturation, and therefore should still generally be the first-line option for treating OSA.” In the United States, the Centers for Medicare and Medicaid Services (CMS) covers custom-fabricated MADs as durable medical equipment for patients with sleep study–documented OSA, but restricts application for severe OSA (AHI >30) to cases of PAP intolerance or contraindication and to provision by a dentist. However commercial insurance carriers in the United States generally do not restrict a physician from providing the MAD to the patient. In some countries, health systems still do not cover the treatment of OSA using MADs.

Although most studies focus on treatment of OSA by single modalities, in some patients, treatment may be sequential or concurrent treatment with multiple modalities. For example, oral appliances could be used concurrently with positional treatment. A patient with residual OSA postsurgery may be treated with an oral appliance postoperatively. Some patients may even be treated with a combination of PAP and MAD via separate or hybrid devices. It may be possible to lower treatment pressure using PAP with advancement of the mandible and potentially improve tolerance. Also, PAP comfort may be improved by anchoring the nasal interface to the oral appliance and thereby avoid the need for fixation using straps.

3

Effectiveness

Despite having lower overall efficacy for reducing the respiratory parameters of OSA compared with PAP, oral appliances appear to have similar clinical effectiveness. This may be explained by greater nightly and long-term adherence to treatment for MADs. PAP effectiveness is affected by an overall adherence rate of <50%, as reflected by a recent large study assessing secondary cardiovascular event prevention with PAP therapy. In the multicenter cohort study a cardiovascular benefit was not demonstrated, likely related to adherence of 4 hours or more/night in only 42% of subjects at 3 years follow-up. In addition, the AHI may not be normalized in all patients on PAP therapy at presumably optimal settings under the care of sleep physicians. AHI <10 was demonstrated in 61% of patients on PAP therapy when assessed independently. For MADs, AHI reduction to <10 may be 70%, but they are advantageous in that the rate of discontinuation of oral appliance therapy is half the rate for PAP therapy.

Improvements in cardiovascular measures and quality of life have been demonstrated for MADs. Cardiovascular mortality was similarly reduced by MAD and PAP therapy from an odds ratio of 2.1/100 person years to 0.61/100 person years in an observational study over a mean 79 months. Blood pressure reduction, including nocturnal dipping, and heart rate variability improved with MAD treatment in crossover and randomized controlled trial studies despite partial AHI response. Sleepiness is reduced and alertness is improved by MAD treatment using both subjective and objective measurements such as driving simulations, psychomotor vigilance testing, and multiple sleep latency testing, but effect is not always demonstrated. Quality-of-life improvement, as assessed by the Functional Outcomes of Sleep Questionnaire (FOSQ) and Short Form Health Survey (SF-36) questionnaires, has been demonstrated in a randomized study at a long-term follow-up of 2 years (mean). A recent systematic review shows the quality-of-life effectiveness of MADs is at least as good as PAP.

3

Effectiveness

Despite having lower overall efficacy for reducing the respiratory parameters of OSA compared with PAP, oral appliances appear to have similar clinical effectiveness. This may be explained by greater nightly and long-term adherence to treatment for MADs. PAP effectiveness is affected by an overall adherence rate of <50%, as reflected by a recent large study assessing secondary cardiovascular event prevention with PAP therapy. In the multicenter cohort study a cardiovascular benefit was not demonstrated, likely related to adherence of 4 hours or more/night in only 42% of subjects at 3 years follow-up. In addition, the AHI may not be normalized in all patients on PAP therapy at presumably optimal settings under the care of sleep physicians. AHI <10 was demonstrated in 61% of patients on PAP therapy when assessed independently. For MADs, AHI reduction to <10 may be 70%, but they are advantageous in that the rate of discontinuation of oral appliance therapy is half the rate for PAP therapy.

Improvements in cardiovascular measures and quality of life have been demonstrated for MADs. Cardiovascular mortality was similarly reduced by MAD and PAP therapy from an odds ratio of 2.1/100 person years to 0.61/100 person years in an observational study over a mean 79 months. Blood pressure reduction, including nocturnal dipping, and heart rate variability improved with MAD treatment in crossover and randomized controlled trial studies despite partial AHI response. Sleepiness is reduced and alertness is improved by MAD treatment using both subjective and objective measurements such as driving simulations, psychomotor vigilance testing, and multiple sleep latency testing, but effect is not always demonstrated. Quality-of-life improvement, as assessed by the Functional Outcomes of Sleep Questionnaire (FOSQ) and Short Form Health Survey (SF-36) questionnaires, has been demonstrated in a randomized study at a long-term follow-up of 2 years (mean). A recent systematic review shows the quality-of-life effectiveness of MADs is at least as good as PAP.