INTRODUCTION — Obstructive sleep apnea (OSA) is a disorder that is characterized by obstructive apneas and hypopneas due to repetitive collapse of the upper airway during sleep. Continuous positive airway pressure (CPAP) is first-line therapy for most patients with OSA, while in select patients, surgery is an option. However, oral appliances are being increasingly used due to the limitations of CPAP (eg, frequent nonadherence) and challenges associated with surgical therapy.
The management of patients with OSA using an oral appliance is reviewed here. The treatment of OSA using CPAP and indications for surgery are discussed in detail elsewhere. (See "Management of obstructive sleep apnea in adults" and "Surgical treatment of obstructive sleep apnea in adults".)
DEVICE TYPES — Oral devices increase pharyngeal dimensions via protrusion of the mandible, thereby, reducing collapsibility of the upper airway during sleep. The two major types of oral appliances are mandibular advancement splints (MAS) and tongue-retaining devices (TRDs).
Mandibular advancement splints — MAS (also known as mandibular advancement devices or mandibular repositioning appliances) are the most commonly used oral appliances.
MAS are anchored to the teeth and induce mandibular advancement (ie, protrusion of the lower jaw), resulting in several beneficial anatomical changes to the upper airway during sleep. These changes can include anteroposterior and lateral retrolingual and retropalatal enlargement, resulting in increased upper airway cross-sectional area and volume (image 1). They cannot be used in edentulous patients.
The many available MAS differ in design. For example, they can be designed as a one- or two-piece device. The two-piece device has two parts that are separate rather than fixed together (as in the one-piece design); the two pieces then couple together using a variety of means to activate the advancement.
MAS also differ in size, material, degree of customization to a patient's dentition, coupling mechanism (ie, the method by which two pieces connect to produce mandibular advancement), occlusal coverage (ie, coverage of the surfaces of the teeth that contact each other when the mouth is closed), ability to titrate the mandibular advancement (only two-piece devices can be titrated without modifying the device), amount of mandibular mobility permitted, and amount of oral respiration permitted (picture 1 and picture 2):
Several factors need to be considered when selecting a device:
●Two-piece MAS allow more mandibular movement and have a greater range of settings than a one-piece MAS. As a result, they tend to be more comfortable and more effective.
●MAS that maintain mandibular advancement while permitting lateral jaw movement, jaw opening, or jaw closing may reduce the risk of complications and achieve better patient acceptance, although limited data suggest that the amount of vertical opening should be minimized [1].
●Custom-fitted MAS are preferable to self-administered over-the-counter prefabricated varieties because they appear to be more effective and comfortable, and are more likely to be retained by both the upper and lower teeth, ensuring that the lower jaw does not fall out of the appliance during sleep [2-4].
●Full occlusal coverage may be desirable to distribute the dental forces associated with mandibular advancement, thereby reducing the risk of tooth movements.
Tongue-retaining devices — TRDs use a suction cavity to pull the tongue out of the mouth, thus improving retrolingual dimensions (picture 3).
These devices have not been well studied. However, one clear advantage is that they can be used in edentulous patients or patients who cannot use MAS (eg, due to occlusal changes).
MULTIDISCIPLINARY AND ALGORITHMIC APPROACH — A multidisciplinary approach is required to assess and manage patients with OSA in whom an oral appliance is potentially indicated or used (algorithm 1).
●This begins with a medical assessment and review of the sleep study to confirm the diagnosis of OSA, determine whether treatment is indicated, and, if so, whether an oral appliance is an appropriate therapy [4,5]. (See 'Patient selection' below.)
●Dental evaluation by a qualified dentist or oral surgeon follows, which includes assessment of suitability for oral appliance therapy, device selection, fitting, and titration. (See 'Device selection and titration' below.)
●Once oral appliance therapy is initiated, the effectiveness should generally be evaluated by both the medical clinician and the dentist, and by objective testing, since subjective assessment alone is often unreliable. Long-term medical and dental follow-up is essential. (See 'Follow-up' below.)
PATIENT SELECTION — Once it has been confirmed that the patient has OSA and the severity determined, we assess whether treatment is indicated and, if so, whether an oral appliance is appropriate.
Criteria — We agree with the American Academy of Sleep Medicine and the American Academy of Dental Sleep Medicine and suggest that an oral appliance is appropriate when all of the following criteria exist [4-6]:
●Patients have a known diagnosis of OSA and treatment other than behavior modification is indicated (eg, weight loss, abstinence from alcohol, and avoidance of sleep in the supine position). (See 'Patient has indication for OSA treatment (review diagnosis, severity, symptoms)' below.)
●Patients with OSA are intolerant of or decline positive airway pressure (PAP) therapy. (See 'Patients intolerant of or decline positive airway pressure therapy' below.)
●Patients have no contraindications to oral device use. (See 'Absence of contraindications' below.)
Among patients who decline or fail PAP therapy, other options include upper airway surgery (hypoglossal nerve stimulation or other surgery). Surgery may be preferable to oral appliances in those who have an anatomic upper airway narrowing that is causing or exacerbating OSA and can be ameliorated surgically (eg, nasal obstruction, adenotonsillar hypertrophy) [5,6]. (See "Surgical treatment of obstructive sleep apnea in adults".)
Patient preference plays a role in selecting patients suitable for an oral device. As for all procedures, it is important that patients are fully informed about the adverse effects (particularly occlusal changes), alternative options (eg, continuous positive airway pressure [CPAP], surgery), and cost before commencing treatment. (See 'Evaluate adverse effects' below.)
While uncommon, some patients use both PAP therapy and an oral device. For example, simultaneously wearing an oral device during PAP therapy may allow a lowering of the PAP pressure requirement; other patients alternate between the two according to convenience (eg, an oral device when travelling and PAP use while at home).
The treatment of snoring using oral appliances in the absence of OSA is discussed separately. (See "Snoring in adults", section on 'Oral appliances'.)
Patient has indication for OSA treatment (review diagnosis, severity, symptoms) — Indications for the treatment of OSA include apnea-hypopnea index (AHI) ≥15 events per hour, AHI 6 to 14 events per hour with symptoms or sequalae of OSA or mission critical worker, AHI ≤5 events per hour with excessive daytime sleepiness and respiratory disturbance index ≥10. These criteria are discussed in detail separately (algorithm 2) [6,7]. (See "Management of obstructive sleep apnea in adults".)
●In most cases, the diagnosis of OSA is already in place. We review the data used to make the original diagnosis and assess the severity of OSA based on those data [5,6]. Diagnostic testing also provides a baseline from which to measure the effectiveness of therapy. The diagnostic approach to OSA in adults is described in detail separately and shown in the algorithm (algorithm 3). (See "Clinical presentation and diagnosis of obstructive sleep apnea in adults", section on 'Diagnostic evaluation' and "Clinical presentation and diagnosis of obstructive sleep apnea in adults", section on 'Classification of severity'.)
●We also assess current symptoms (eg, snoring, excessive daytime sleepiness) and sequalae of OSA (eg, cardiovascular complications) at this juncture. This also serves as a baseline against which a therapeutic effect can be measured. The clinical symptoms of OSA are discussed separately. (See "Clinical presentation and diagnosis of obstructive sleep apnea in adults", section on 'Clinical features'.)
Patients intolerant of or decline positive airway pressure therapy — While PAP (typically CPAP) therapy is the preferred therapy for most patients with moderate to severe OSA, some patients decline or are intolerant of such therapy. Patients may prefer oral appliances over PAP therapy because they are easier to use, more portable, quiet, and do not require a power source [7]. Oral appliances may also be a useful substitute for PAP during travel.
Although the traditional view is that ideal candidates for a mandibular advancement splint (MAS) are patients with mild to moderate OSA, there is growing evidence of efficacy among patients with severe OSA (ie, AHI>30 events per hour) [8,9].
Further details regarding management of patients who are nonadherent to PAP therapy are provided separately. (See "Assessing and managing nonadherence with continuous positive airway pressure (CPAP) for adults with obstructive sleep apnea".)
Absence of contraindications — There are several clinical situations in which an oral appliance should not be used. As examples:
●Rapid therapy required – Patients in whom rapid initiation of treatment is desirable (eg, patients with severe symptomatic OSA, sleepiness while driving) should be treated with PAP, which can be initiated quickly (and is also more effective). An oral appliance generally requires incremental advancement of the mandible over weeks to months to attain optimal efficacy and is therefore not suitable as initial therapy in such patients.
●Severe or prolonged oxygen desaturation – For patients with severe oxyhemoglobin desaturation during sleep (eg, nadir peripheral oxygen saturation [SpO2] <70 percent), caution is warranted as oral appliance therapy may not provide optimal improvement in oxygenation [7].
●Select dental conditions – Dental conditions such as temporomandibular joint disease, periodontal disease, insufficient dentition to support appliance retention in the mouth, and inadequate range of motion of the jaw are relative contraindications to an oral appliance [5,10], and require assessment by a qualified dentist. Similarly, patients who are undergoing dental realignment (eg, braces or retaining device) are not suitable candidates for an oral appliance.
●Central sleep apnea – Oral devices treat obstructive events only and cannot treat central forms of sleep apnea. (See "Central sleep apnea: Treatment".)
●Manual dexterity – Individuals must have sufficient manual dexterity to place and remove the device. Thus, patients with severe arthritis or neuromuscular disease may not be good candidates for an oral appliance, although a caretaker can be instructed on device use.
While in the past limited capacity for mandibular protrusion (<6 mm) was thought to be a contraindication, our experience suggests that many patients with limited protrusion can still achieve good results.
Possible predictors of benefit — It is not yet possible to reliably identify which patients are likely to benefit from therapy with an oral appliance. Further research should help clarify the phenotypes of an oral device responder compared with a nonresponder [11].
●Clinical factors associated with benefit – The following clinical factors are potential predictors of a better outcome, although none have been prospectively validated (table 1):
•Mild to moderate OSA – Patients with mild to moderate OSA may respond better to oral device therapy than those with severe OSA [12]. However, severity of OSA is an imperfect predictor since some patients with mild to moderate disease have a limited response, while some patients with severe OSA may have a remarkable response [8,9].
•Younger age and lower body mass index – Several studies have consistently shown that younger age (<60 years) and lower body mass index (<30 kg/m2) are predictors of a response to oral device therapy [12-14].
•OSA predominantly in the supine position – Supine OSA, defined as at least twice as many events occurring in the supine position compared with the nonsupine position, has been associated with treatment response in some studies [15,16], but not others [17,18].
•Others – Other predictors include female sex, smaller neck circumference, retracted maxilla and mandible, minimal mouth opening, and narrower airway [12,19].
●Imaging and rhinometric variables associated with benefit – Although variables including radiographic imaging (eg, cephalometry, computed tomography or magnetic resonance imaging scan), nasendoscopy, or rhinomanometry may predict benefit, we do not recommend performing them routinely until they are confirmed by prospective investigation to be valuable in patient selection for MAS therapy.
Potentially predictive factors include the following:
•Cephalometric variables such as short soft palate and decreased distance between mandibular plane and hyoid bone, either alone or in combination with other anthropomorphic and polysomnographic variables [8,9].
•Lower nasal resistance, as measured by posterior rhinomanometry [20].
•Positive effect of MAS on a simulation bite performed in maximal comfortable protrusion of the mandible during drug-induced sleep endoscopy [21].
●Predictors of a poor response - Predictors of a poor response include high therapeutic PAP [22,23]. This may be partly explained by severity and likely is a marker of the severity of airway collapsibility (which is not well reflected by the AHI). Absence of symptomatic benefit from PAP does not preclude a good response to MAS.
The cutoff value for defining high therapeutic pressure may vary by ethnicity. In a Japanese study, pressures >10.5 cm H2O were associated with poor response to subsequent oral appliance therapy [23], whereas in another study of primarily White individuals, pressures >13 cm H2O were predictive of a poor response [22].
DEVICE SELECTION AND TITRATION — For most patients with OSA in whom an oral appliance is indicated, we typically use a mandibular advancement splint (MAS). As an alternative in edentulous patients, a tongue-retaining device may be a suitable option. (See 'Device types' above.)
Referral to dental specialist or oral surgeon — Device selection is typically performed by a dentist or oral surgeon with experience in oral devices for patients with OSA. The dentist assesses oral health and jaw function (eg, clinical examination and intraoral imaging). If the patient is deemed suitable for MAS, the dentist proceeds with taking dental impressions and a protrusive bite, from which a customized MAS is manufactured (three-dimensional manufacturing may be used).
It is recommended that written informed consent is obtained from the patient, acknowledging the risk of tooth movements due to therapy.
We prefer custom-made devices rather than prefabricated devices (available over-the-counter), since the former is better tolerated, more comfortable, and more likely to be effective [24,25].
Once the device is made, the patient returns for a fitting. If comfortable and no adjustments are needed, the dentist instructs the patient about device titration.
Device titration — Once an oral device is ready, patients should undergo device titration. The dentist instructs the patient to sleep with the device in place and encourages nightly adherence for at least four or more hours per night. Over a period of weeks to months, the dentist or patient adjusts the degree of mandible protrusion to the maximum limit or degree tolerated by the patient.
There is no set titration protocol. Titration varies by dentist and also depends upon patient tolerance of titration. As a general rule of thumb, we often start patients at 60 percent of maximal protrusion allowed by the device, and then advance in 1 mm increments or less, every few weeks as tolerated, until they reach the maximum comfortable limit or device limit.
The amount of advancement required for a clinical response generally ranges from 50 to 90 percent of the maximum protrusion allowed by the device [26]. However, this can vary substantially among individuals, with some patients failing treatment regardless of maximum advancement, and others achieving a good response with minor advancement. Although the response tends to be dose dependent, the relationship is not linear [27,28].
Patient tolerance is a major determinant of the extent and speed of advancement that is feasible. For most patients, tolerance increases with time. It is advisable to have a process in place whereby patient progress is monitored to address any issues during titration. This can take a variety of forms, including scheduled clinic visits or telehealth approaches.
Single-night titration is a promising approach, the practical application of which has begun to enter clinical practice. It involves incrementally advancing the mandible under technician supervision while the patient sleeps in a sleep laboratory [29,30]. Two observational studies found that in most patients, single-night titration successfully identified the target amount of mandibular advancement [31,32]. In a randomized trial, single-night titration of an oral appliance followed by ongoing oral appliance therapy was compared with single-night titration of continuous positive airway pressure followed by ongoing positive airway pressure therapy [33]. Both approaches improved subjective and objective outcomes over two months, including sleepiness, neurocognitive function, and quality of life. In addition to predicting which individuals will have a successful treatment outcome, this approach may also be useful as a method for determining the target level of mandibular protrusion [31]. The feasibility of undertaking this method in an unattended home setting has also been reported [34]. The cost effectiveness of this approach warrants evaluation.
FOLLOW-UP — Patients receiving oral appliance therapy for OSA should be followed in the short- and long-term by both a medical clinician and a dentist (or oral surgeon) every six months for the first year and annually thereafter [5,6].
Evaluate symptoms and perform sleep testing — Once the dentist or oral surgeon has completed titration of oral appliance therapy, we assess the efficacy of treatment both clinically and objectively (ie, with sleep testing). We inquire about improved or resolved OSA symptoms and perform in-laboratory or home sleep apnea testing with the oral appliance in place [4-6,35]. Subjective measures alone are insufficient to assess efficacy, as residual OSA may persist despite symptom improvement [8,9]. (See "Home sleep apnea testing for obstructive sleep apnea in adults" and "Overview of polysomnography in adults".)
The goal of oral device therapy is similar to that for positive airway pressure (PAP; typically continuous PAP) therapy, which is to resolve signs and symptoms of OSA, improve sleep quality, and normalize the apnea-hypopnea index and oxyhemoglobin saturation levels. Additional goals during objective sleep testing are to resolve all apneas, hypopneas, snoring, and arousals related to these events, in all stages of sleep and in all sleep positions. Noteworthy is that even with PAP therapy, these goals are almost never completely achieved. Optimal goals of OSA therapy are discussed in more detail separately. (See "Titration of positive airway pressure therapy for adults with obstructive sleep apnea", section on 'Titration goals' and "Management of obstructive sleep apnea in adults".)
In general, we consider the following as reasonable:
●For patients who are well controlled, we continue therapy with the oral device and clinically assess patients intermittently every 6 to 12 months.
●For patients who are not well controlled, we assess the underlying reason(s) for inadequate control (eg, poor adherence, intolerable adverse effects, inadequate mandibular advancement, device wear and tear, weight gain), attempt to resolve it, and persist with oral device therapy. In some cases, consideration can be given to combining mandibular advancement splint (MAS) treatment with other options (eg, avoidance of sleep in the supine position, weight loss). (See 'Evaluate adherence' below.)
●For patients who fail despite optimizing oral device therapy, we consider alternate options (eg, repeat trials of PAP therapy, assess suitability for surgery or pharmacotherapy), which are discussed in detail separately. (See "Management of obstructive sleep apnea in adults".)
Over the long term, we follow patients indefinitely to monitor for recurrent symptoms of OSA as well as for adherence and adverse effects of the device. Studies suggest that the main reasons for long-term relapse of OSA appear to be appliance failure due to wear and tear, as well as weight gain [15,36]. (See 'Evaluate adverse effects' below.)
Evaluate adherence — We obtain a self-reported rate of adherence from the patient (and their sleep partner, if available). In addition, thermal chips are now commercially available and embedded in many modern devices for objective evidence of adherence.
Compared with PAP therapy, less is known about the incidence of adherence to oral appliances. Limited data suggest that rates of nonadherence range from 10 to 24 percent [15,37], which appear to be lower than that associated with PAP (which is approximately up to one-half of patients) [33,38]. In a prospective study of 51 patients with mild to moderate OSA undergoing treatment with an MAS, the discontinuation rate was 10 percent and the mean daily use rate was 6.4 hours per night, both measured objectively by a temperature microsensor embedded in the device [37]. (See "Assessing and managing nonadherence with continuous positive airway pressure (CPAP) for adults with obstructive sleep apnea", section on 'Prevalence'.)
Adherence patterns may be evident within the first 20 days of usage according to one study that classified patients as consistent users, inconsistent users, and nonusers based upon usage patterns downloaded from the device [39].
Adherence may wane over time. In one study, discontinuation rates at one year occurred in 24 percent of patients, mostly due to dental discomfort [15].
Reasons for nonadherence have not yet been identified but are assumed to be related to adverse effects.
Evaluate adverse effects — Adverse effects are usually minor and infrequently require discontinuation of the oral appliance. The decision to discontinue the appliance should balance the magnitude of the adverse effect, the severity of OSA, the response to therapy, and the desirability of treatment alternatives.
●Early side effects (first few weeks) – Most patients experience early side effects (table 2), particularly dental discomfort (usually of the upper and lower incisors). Other early side effects include temporomandibular joint pain, dry mouth or excessive salivation, gum irritation, and bruxism [40].
These side effects are generally mild to moderate in severity, usually last a few weeks or less, and tend to subside over time. Local anesthetic gels are not generally needed.
●Late side effects (occlusal changes; months to years) – Occlusal (bite) changes are the major long-term adverse effect of oral appliances [41]. Other rare late side effects include tooth loosening and device fracture, which have the potential to cause airway obstruction. Reduced efficacy due to device deterioration can also occur over time. These changes are usually monitored and managed by the dentist (or oral surgeon).
Occlusal changes are usually minor and most do not warrant cessation of treatment. In addition, not all are disadvantageous (eg, patients with an existing large overbite may improve with MAS). Changes are progressive over time, but importantly, patients are generally not aware of the changes [42,43]. Infrequently, some patients experience larger occlusal changes that may interfere with eating, necessitating readjustment of the device or a review of treatment alternatives such as PAP therapy.
There is considerable variation in the frequency, timing, and extent of occlusal changes between patients; MAS design and existing dental conditions likely explain this variation [42].
Occlusal changes are characterized by backward movement of the upper front teeth and forward movement of the lower front teeth and mandible, ranging from 0.4 to 3 mm [41,44,45]. The majority of patients develop a decreased overjet (horizontal distance between tips of upper and lower incisors) and overbite (vertical distance) during the first five years, and approximately one-third will experience an excess of 1 mm of change.
•In one observational study of 70 patients with an average follow-up of 7.4 years, occlusal change was identified in 86 percent [46].
•In a cohort of 77 patients with either snoring or mild to moderate OSA who were treated with an oral appliance for an average of 11 years, dental cast measurements demonstrated a significant reduction in overbite (2.3 mm), overjet (1.9 mm), and mandibular crowding (1.3 mm) [43]. An anterior crossbite (abnormal relationship between the labiolingual anatomy and incisors) of at least one tooth developed in 62 percent, and a posterior open bite (loss of occlusal contact on at least two posterior teeth) developed in 51 percent.
Bite changes have the potential to revert after cessation of the oral appliance. Rarely, permanent abnormalities requiring orthodontic treatment can occur.
EFFICACY AND OUTCOMES — Mandibular advancement splint (MAS) therapy appears to consistently improve indices of OSA including the apnea-hypopnea index (AHI), although positive airway pressure (PAP, typically continuous PAP [CPAP]) appears to be superior for this outcome. MAS also appears to improve both symptoms of sleepiness and blood pressure control to a degree that is similar to CPAP. (See 'Improved indices of obstructive sleep apnea' below and 'Impact on sleepiness' below and 'Impact on other outcomes (snoring, cardiovascular, neurocognitive, functional)' below.)
Most trials that evaluate oral appliance therapy are reflective of MAS since they are more commonly used than tongue-retaining devices (TRDs) (see 'Device types' above). Limited data suggest that MAS devices are better tolerated and are associated with greater rates of compliance, and possibly sleep indices, when compared with TRDs [47].
Improved indices of obstructive sleep apnea — The following data support the use of MAS therapy, particularly in patients with mild to moderate OSA (see 'Patient selection' above):
●Sleep indices compared with placebo – MAS therapy, compared with placebo, consistently reduces the frequency of arousals and respiratory events (eg, apneas and hypopneas) during sleep, while also improving oxyhemoglobin saturation [8,9,40,48,49]. As examples:
•In a cross-over trial that performed polysomnography on 28 patients with mild to severe OSA who had been randomly assigned to receive either an MAS or a control device [8], patients treated with an MAS had a lower AHI at one week (14 versus 30 events per hour). Also improved were minimal oxygen saturation level (91 versus 87 percent) and arousal index (27 versus 41 events per hour).
•Similarly, another randomized trial that compared MAS with placebo in 96 patients with mild to moderate OSA reported that the AHI was below five events per hour (ie, normalized) in one-half of patients using the oral appliance compared with only 11 percent in those using placebo [49]. The mean AHI fell from 15.6 to 6.7 events per hour in the oral appliance group compared with an increase from 15.3 to 16.3 events per hour in the placebo group.
Some studies suggest that complete resolution of OSA, defined as an AHI <5 events per hour during treatment, is more likely in patients with mild to moderate OSA (AHI 5 to 30 events per hour) than in patients with severe OSA (AHI >30 events per hour) [12]. However, this finding has not been universal [8,9].
Objective improvement of sleep apnea indices appears to persist over time, even up to 10 years [15,36,40,49-53].
●Sleep indices compared with PAP – Most clinical trials and several meta-analyses that compared oral appliances with PAP (usually CPAP) report that PAP is superior at improving the AHI and oxyhemoglobin saturation, but not the arousal index, or sleep architecture [7,33,54-63]. However, patients generally preferred and adhered better to the oral appliance.
●Sleep indices compared with surgery – Studies comparing oral appliances with surgical interventions are scant. In one trial, patients with OSA (AHI 5 to 25 events per hour) were randomly assigned to receive uvulopalatopharyngoplasty or an oral appliance that protruded the mandible to 50 percent of the maximum [53]. At one and four years, oral appliance therapy was more likely to normalize the AHI and achieve a 50 percent reduction in the apnea index.
●Sleep indices for TRDs – A meta-analysis of 16 studies involving 242 patients reported that TRDs reduced the AHI by 53 percent, increased oxygen saturation by 4 percent, decreased the oxygen desaturation index by 56 percent, and decreased Epworth sleepiness scale scores by 2.8 points [64].
Impact on sleepiness — A reduction in excessive daytime sleepiness has been reported with MAS [7,9,33,40,48,49,61,64,65]. As an example, a 2018 meta-analysis of 12 randomized trials reported that although CPAP was more effective at reducing the AHI than an oral appliance, both therapies resulted in similar post-treatment objective measures of daytime sleepiness, although differences compared with baseline favored CPAP [62].
Objective measures of sleepiness are discussed separately. (See "Quantifying sleepiness".)
Impact on other outcomes (snoring, cardiovascular, neurocognitive, functional) — The impact of MAS on a range of other outcome measures has been evaluated. Studies have reported improvement in the frequency and intensity of snoring, blood pressure, neurocognitive function, depressive symptoms, and quality of life [7,49,66-70]. Oral appliances have also been reported to improve driving simulator performance, with a magnitude of effect similar to that seen with CPAP [71].
The impact of MAS on blood pressure was illustrated by a cross-over trial that randomly assigned 61 patients with OSA (AHI ≥10 events per hour of sleep) to receive MAS therapy or a control device for four weeks [66]. MAS therapy reduced the awake mean systolic and diastolic blood pressures, with the peak effect (approximately 3 mmHg) noted during the late sleeping period and early morning.
The impact on blood pressure control appears to persist long-term [59,72,73] with two meta-analyses reporting a similar difference in the degree of blood pressure improvement in patients treated with CPAP or an oral appliance [72,73].
SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Sleep-related breathing disorders in adults".)
SUMMARY AND RECOMMENDATIONS
●Introduction and mechanism of action – Oral appliance therapy is increasingly used for the treatment of patients with OSA. Oral devices increase pharyngeal dimensions via protrusion of the mandible, thereby reducing collapsibility of the upper airway during sleep. The two major types of oral appliances are a mandibular advancement splint (MAS) and a tongue-retaining device. MAS is the most commonly used appliance. (See 'Introduction' above and 'Device types' above.)
●Assessment – A multidisciplinary and algorithmic approach is required to assess and manage patients with OSA who are potentially suitable for oral appliance therapy (algorithm 1). (See 'Multidisciplinary and algorithmic approach' above.)
•Patient selection – An oral appliance is one option when all of the following criteria exist (see 'Patient selection' above):
-Patients have a known diagnosis of OSA for which treatment is indicated (algorithm 3 and algorithm 2). (See 'Patient has indication for OSA treatment (review diagnosis, severity, symptoms)' above.)
-Patients are unable to tolerate or decline positive airway pressure (PAP) therapy. (See 'Patients intolerant of or decline positive airway pressure therapy' above.)
-Patients have no contraindications to oral device use (eg, immediate therapy required, prolonged and severe desaturations, dental conditions). (See 'Absence of contraindications' above.)
•Device selection – Once indicated, device selection, fitting, and titration are typically performed by a qualified dentist (or oral surgeon) with experience in oral devices for patients with OSA. For most patients, we suggest custom-made devices rather than prefabricated devices (Grade 2C). Custom-made devices appear to be better tolerated and more likely to be effective. Over a period of weeks to months, the degree of mandible protrusion is increased to the maximum limit or to that tolerated by the patient. (See 'Device selection and titration' above.)
●Follow-up – Following device titration, patients should be followed in the short- and long-term by both a medical clinician and a dentist (or oral surgeon) every six months for the first year and annually thereafter. (See 'Follow-up' above.)
•Clinical and objective assessment – We initially assess the efficacy of treatment both clinically, and objectively with sleep testing (eg, polysomnography or home sleep apnea test). The goal of oral device therapy is to resolve signs and symptoms of OSA, improve sleep quality, and normalize the apnea-hypopnea index (AHI) and oxyhemoglobin saturation levels. Over the long term, we follow patients indefinitely to monitor for recurrent symptoms of OSA (eg, due to weight gain) and signs of device deterioration and maladjustment. (See 'Evaluate symptoms and perform sleep testing' above.)
•Expected efficacy – Oral appliances are generally less effective than PAP at improving the AHI and oxyhemoglobin saturation, although there is no difference in the impact on symptoms (eg, subjective daytime sleepiness) or other health outcomes (eg, snoring, blood pressure, neurocognitive function, snoring). (See 'Efficacy and outcomes' above.)
•Adherence and adverse effects – To encourage compliance and maximize efficacy, we address nonadherence and any adverse effects. Rates of nonadherence appear to be lower than with continuous PAP (CPAP) and range from 10 to 24 percent. Adverse effects are usually minor (eg, dental discomfort) and infrequently require discontinuation of the oral appliance. Occlusal changes are the most common late adverse effect that requires dental expertise for assessment and management (eg, backward movement of the upper front teeth and forward movement of the lower front teeth and mandible). (See 'Evaluate adherence' above.)
●Outcomes – Oral appliance therapy improves indices of OSA on objective sleep testing, although PAP therapy appears to be superior for this outcome (specifically the AHI). Oral appliances also improve symptoms of sleepiness and blood pressure control to a degree that is similar to CPAP. (See 'Efficacy and outcomes' above.)
