Mandibular Advancement Splints

Mandibular Advancement Splint Therapy

Mandibular advancement splint (MAS) therapy is the leading alternative to continuous positive airway pressure (CPAP) therapy for the treatment of obstructive sleep apnoea. A MAS is an oral appliance which advances the mandible in relation to the maxilla, thus increasing airway calibre and reducing collapsibility. Although it is less effective than CPAP in reducing the apnoea-hypopnoea index (AHI), it has demonstrated equivalence to CPAP in a number of key neurobehavioural and cardiovascular health outcomes, perhaps due to increased tolerability and patient adherence when compared to CPAP. However, response to MAS is variable, and reliable prediction tools for patients who respond best to MAS therapy have thus far been elusive; this is one of the key clinical barriers to wider uptake of MAS therapy. In addition, the most effective MAS devices are custom-made by a dentist specialising in the treatment of sleep disorders, which may present financial or accessibility barriers for some patients. MAS devices are generally well tolerated but may have side effects including temporomandibular joint (TMJ) dysfunction, hypersalivation, tooth pain and migration as well as occlusal changes. A patient-centred approach to treatment from a multidisciplinary team perspective is recommended. Evidence-based clinical practice points and areas of future research are summarised at the conclusion of the chapter.

Mandibular Advancement Device Treatment Efficacy Is Associated with Polysomnographic Endotypes

Rationale: Mandibular advancement device (MAD) treatment efficacy varies among patients with obstructive sleep apnea.Objectives: The current study aims to explain underlying individual differences in efficacy using obstructive sleep apnea endotypic traits calculated from baseline clinical polysomnography: collapsibility (airflow at normal ventilatory drive), loop gain (drive response to reduced airflow), arousal threshold (drive preceding arousal), compensation (increase in airflow as drive increases), and the ventilatory response to arousal (increase in drive explained by arousal). On the basis of previous research, we hypothesized that responders to MAD treatment have a lower loop gain and milder collapsibility.Methods: Thirty-six patients (median apnea-hypopnea index [AHI], 23.5 [interquartile range (IQR), 19.7-29.8] events/h) underwent baseline and 3-month follow-up full polysomnography, with MAD fixed at 75% of maximal protrusion. Traits were estimated using baseline polysomnography according to Sands and colleagues. Response was defined as an AHI reduction ≥ 50%.Results: MAD treatment significantly reduced AHI (49.7%_baseline [23.9-63.6], median [IQR]). Responders exhibited lower loop gain (mean [95% confidence interval], 0.53 [0.48-0.58] vs. 0.65 [0.57-0.73]; P = 0.020) at baseline than nonresponders, a difference that persisted after adjustment for baseline AHI and body mass index. Elevated loop gain remained associated with nonresponse after adjustment for collapsibility (odds ratio, 3.03 [1.16-7.88] per 1-standard deviation (SD) increase in loop gain [SD, 0.15]; P = 0.023).Conclusions: MAD nonresponders exhibit greater ventilatory instability, expressed as higher loop gain. Assessment of the baseline degree of ventilatory instability using this approach may improve upfront MAD treatment patient selection.Clinical trial registered with www.clinicaltrials.gov (NCT01532050).

Discriminating the severity of pharyngeal collapsibility in men using anthropometric and polysomnographic indices

STUDY OBJECTIVES

Although obstructive sleep apnea results from the combination of different pathophysiologic mechanisms, the degree of anatomical compromise remains the main responsible factor. The passive pharyngeal critical closing pressure (Pcrit) is a technique used to assess the collapsibility of the upper airway and is often used as a surrogate measure of this anatomical compromise. Patients with a low Pcrit (ie, less collapsible airway) are potential candidates for non-continuous positive airway pressure therapies. However, Pcrit determination is a technically complex method not available in clinical practice. We hypothesized that the discrimination between low and high Pcrit can be estimated from simple anthropometric and polysomnographic indices.

METHODS

Men with and without obstructive sleep apnea underwent Pcrit determination and full polysomnography. Receiver operating characteristics analysis was performed to select the best cutoff of each variable to predict a high Pcrit (Pcrit ≥ 2.5 cmH₂O). Multiple logistic regression analysis was performed to create a clinical score to predict a high Pcrit.

RESULTS

We studied 81 men, 48 ± 13 years of age, with an apnea-hypopnea index of 32 [14-60], range 1-96 events/h), and Pcrit of -0.7 ± 3.1 (range, -9.1 to +7.2 cmH₂O). A high and low Pcrit could be accurately identified by polysomnographic and anthropometric indices. A score to discriminate Pcrit showed good performance (area under the curve = 0.96; 95% confidence interval, 0.91-1.00) and included waist circumference, non-rapid eye movement obstructive apnea index/apnea-hypopnea index, mean obstructive apnea duration, and rapid eye movement apnea-hypopnea index.

CONCLUSIONS

A low Pcrit (less collapsible) can be estimated from a simple clinical score. This approach may identify candidates more likely to respond to non-continuous positive airway pressure therapies for obstructive sleep apnea.

Mandibular advancement splints for the treatment of obstructive sleep apnea

Introduction: Obstructive sleep apnea (OSA) is a chronic condition which requires a comprehensive chronic disease management model, rather than a device-focused approach, so as to achieve the best possible health outcomes. Oral appliances are the main alternative to continuous positive airway pressure (CPAP) for the treatment of OSA. There has been an expansion of the research evidence to support the use of oral appliances in clinical practice and the clinical use of oral appliances for the treatment of OSA has become a mainstream practice.Areas covered: This review summarizes the evidence base for the use of oral appliances for the treatment of OSA. The types of oral appliances; their mechanism of action and clinical efficacy for the treatment of OSA; adverse effects, and the impact on patient acceptability and treatment adherence; and clinical effectiveness and health outcomes are discussed.Expert opinion: Personalization of treatment is vitally important in OSA and is a pre-requisite for optimizing adherence with treatment which, in turn, is a key determinant of clinical effectiveness. Treatment of OSA with mandibular advancement splints could provide an equivalent health benefit to CPAP despite not achieving a complete normalization of polysomnographic indices, mediated by differences in adherence profiles.

Structure and severity of pharyngeal obstruction determine oral appliance efficacy in sleep apnoea

KEY POINTS

•Some patients with obstructive sleep apnoea (OSA) respond well to oral appliance therapy, whereas others do not for reasons that are unclear. •In the present study, we used gold-standard measurements to demonstrate that patients with a posteriorly-located tongue (natural sleep endoscopy) exhibit a preferential improvement in collapsibility (lowered critical closing pressure) with oral appliances. •We also show that patients with both posteriorly-located tongue and less severe collapsibility (predicted responder phenotype) exhibit greater improvements in severity of obstructive sleep apnoea (i.e. reduction in event frequency by 83%, in contrast to 48% in predicted non-responders). •The present study suggests that the structure and severity of pharyngeal obstruction determine the phenotype of sleep apnoea patients who benefit maximally from oral appliance efficacy.

ABSTRACT

A major limitation to the administration of oral appliance therapy for obstructive sleep apnoea (OSA) is that therapeutic responses remain unpredictable. In the present study, we tested the hypotheses that oral appliance therapy (i) reduces pharyngeal collapsibility preferentially in patients with posteriorly-located tongue and (ii) is most efficacious (reduction in apnoea-hypopnea index; AHI) in patients with a posteriorly-located tongue and less-severe baseline pharyngeal collapsibility. Twenty-five OSA patients underwent upper airway endoscopy during natural sleep to assess tongue position (type I: vallecula entirely visible; type II: vallecula obscured; type III: vallecula and glottis obscured), as well as obstruction as a result of other pharyngeal structures (e.g. epiglottis). Additional sleep studies with and without oral appliance were performed to measure collapsibility (critical closing pressure; Pcrit) and assess treatment efficacy. Overall, oral appliance therapy reduced Pcrit by 3.9 ± 2.4 cmH2 O (mean ± SD) and AHI by 69 ± 19%. Therapy lowered Pcrit by an additional 2.7 ± 0.9 cmH2 O in patients with posteriorly-located tongue (types II and III) compared to those without (type I) (P < 0.008). Posteriorly-located tongue (p = 0.03) and lower collapsibility (p = 0.04) at baseline were significant determinants of (greater-than-average) treatment efficacy. Predicted responders (type II and III and Pcrit < 1 cmH2 O) exhibited a greater reduction in the AHI (83 ± 9 vs. 48 ± 8% baseline, P < 0.001) and a lower treatment AHI (9 ± 6 vs. 32 ± 15 events h-1 , P < 0.001) than predicted non-responders. The site and severity of pharyngeal collapse combine to determine oral appliance efficacy. Specifically, patients with a posteriorly-located tongue plus less-severe collapsibility are the strongest candidates for oral appliance therapy.

Sleep Apnea Multilevel Surgery (SAMS) trial protocol: a multicenter randomized clinical trial of upper airway surgery for patients with obstructive sleep apnea who have failed continuous positive airway pressure

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) is a serious and costly public health problem. The main medical treatment, continuous positive airway pressure, is efficacious when used, but poorly tolerated in up to 50% of patients. Upper airway reconstructive surgery is available when medical treatments fail but randomized trial evidence supporting its use is limited. This protocol details a randomized controlled trial designed to assess the clinical effectiveness, safety, and cost-effectiveness of a multilevel upper airway surgical procedure for OSA.

METHODS

A prospective, parallel-group, open label, randomized, controlled, multicenter clinical trial in adults with moderate or severe OSA who have failed or refused medical therapies. Six clinical sites in Australia randomly allocated participants in a 1:1 ratio to receive either an upper airway surgical procedure consisting of a modified uvulopalatopharyngoplasty and minimally invasive tongue volume reduction, or to continue with ongoing medical management, and followed them for 6 months.

RESULTS

Primary outcomes: difference between groups in baseline-adjusted 6 month OSA severity (apnea-hypopnea index) and subjective sleepiness (Epworth Sleepiness Scale). Secondary outcomes: other OSA symptoms (e.g. snoring and objective sleepiness), other polysomnography parameters (e.g. arousal index and 4% oxygen desaturation index), quality of life, 24 hr ambulatory blood pressure, adverse events, and adherence to ongoing medical therapies (medical group).

CONCLUSIONS

The Sleep Apnea Multilevel Surgery (SAMS) trial is of global public health importance for testing the effectiveness and safety of a multilevel surgical procedure for patients with OSA who have failed medical treatment.

CLINICAL TRIAL REGISTRATION

Multilevel airway surgery in patients with moderate-severe Obstructive Sleep Apnea (OSA) who have failed medical management to assess change in OSA events and daytime sleepiness. https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=366019&isReview=true Australian New Zealand Clinical Trials Registry ACTRN12614000338662, prospectively registered on 31 March 2014.

Mandibular positioning techniques to improve sleep quality in patients with obstructive sleep apnea: current perspectives

The purpose of this article is to review 1) mandibular advancement device (MAD) - indication, treatment success, and side effects; 2) maxillomandibular advancement (MMA) surgery of the jaws - indication, treatment success, and side effects; and 3) current perspectives. Both MAD and MMA are administered to increase the upper airway volume and reduce the collapsibility of the upper airway. MAD is noninvasive and is indicated as a first-stage treatment in adult patients with mild-to-moderate obstructive sleep apnea (OSA) and in patients with severe OSA unable to adhere to continuous positive airway pressure (CPAP). MAD remains inferior to CPAP in reducing the apnea-hypopnea index (AHI) with a treatment success ranging between 24% and 72%. However, patient compliance to MAD is greater, and with regard to subjective sleepiness and health outcomes, MAD and CPAP have been found to be similarly effective. Short-term side effects of MAD are minor and often transient. Long-term side effects primarily appear as changes in the dental occlusion related to decreases in overjet and overbite. MMA is efficacious but highly invasive and indicated as a second-stage treatment in patients with moderate-to-severe OSA, with prior failure to other treatment modalities or with craniofacial abnormalities. The surgical success and cure rates are found to be 86.0% and 43.2%, respectively. Side effects may appear as postsurgical complications such as temporary facial paresthesia and compromised facial esthetics. However, most patients report satisfaction with their postsurgical appearance. Both treatment modalities require experienced clinicians and multidisciplinary approaches in order to efficaciously treat OSA patients. Some researchers do propose possible predictors of treatment success, but clear patient selection criteria and clinical predictive values for treatment success are still needed in both treatment modalities.

Oral Appliances for the Management of OSA: An Updated Review of the Literature

Oral appliances (OAs) are becoming increasingly recognized not only as an alternative to but also possibly as an adjunct treatment modality for OSA. Compared with CPAP, the gold standard therapy, OAs are less efficacious but are more accepted and tolerated by patients, which, in turn, may lead to a comparable level of therapeutic effectiveness. Different OA designs currently exist, and more are constantly emerging. Additionally, state-of-the-art technologies are being used in the fabrication of many; however, all the currently available OAs employ the same mechanism of action by targeting the anatomical component involved in the pathogenesis of the disease. Furthermore, the scope of use of OAs is expanding to include patients who are edentulous. For patients with OAs, the dentist is a member of an interdisciplinary team managing OSA, and constant communication and follow-up with the sleep physician and other team members is necessary for disease management.