Mandibular Advancement Splint vs. CPAP: Which Sleep Apnoea Treatment Is Right for You? product guide

Frequently Asked Questions

What is a mandibular advancement splint (MAS): A dental appliance worn during sleep to treat OSA

What is CPAP: A machine delivering pressurised air through a mask to prevent airway collapse

How does CPAP keep the airway open: By creating pneumatic pressure that acts as a pneumatic splint

How does MAS keep the airway open: By moving the lower jaw forward to increase space behind the tongue

Is CPAP or MAS more effective at reducing AHI: CPAP reduces AHI more effectively

By how much does CPAP outperform MAS on AHI reduction: Mean difference of -5.83 events/hour (Pattipati et al., 2022)

How much does long-term MAS use reduce AHI: Approximately 16.8 events/hour (2023 meta-analysis)

Is MAS clinically ineffective: No, its AHI reductions are clinically significant

What percentage of MAS patients achieve complete response (AHI < 5): Approximately 35%

What percentage of MAS patients achieve greater than 50% AHI reduction: Approximately two-thirds

What percentage of MAS patients do not achieve greater than 50% AHI reduction: Approximately one-third

What is CPAP's long-term adherence rate: 30–60%

What is MAS adherence at one year: 76% of patients continue using their device

What is MAS adherence at four years: 62% of patients continue using their device

What is MAS adherence among five-year users: Over 90% report use more than 4 nights per week

Does higher MAS compliance offset its lower AHI efficacy: Yes, real-world effectiveness becomes comparable to CPAP

What did the Phillips et al. 2013 trial find about health outcomes: Important health outcomes were similar after one month of optimal MAS and CPAP treatment

Are daytime sleepiness improvements equivalent between MAS and CPAP: Yes, no statistically significant difference in ESS scores

Is quality of life improvement equivalent between MAS and CPAP: Yes, broadly equivalent across most measures

Does MAS outperform CPAP on any quality-of-life measures: Yes, MAS was superior on four general quality-of-life domains

Do patients prefer MAS or CPAP when they have tried both: Patients consistently prefer MAS

What fraction of crossover study patients preferred MAS over CPAP: 17 of 21 patients who completed both treatments

Is CPAP the first-line treatment for severe OSA: Yes, for AHI ≥ 30 events/hour

What AHI threshold defines severe OSA: 30 or more events per hour

Is MAS a first-line option for mild-to-moderate OSA: Yes

Is MAS appropriate when CPAP cannot be tolerated: Yes, it is the evidence-based alternative

Is MAS effective in non-obese CPAP-intolerant patients: Yes, particularly effective in non-obese individuals

Can MAS be used for central sleep apnoea: No, MAS is not indicated for central sleep apnoea

Is MAS suitable for patients with active periodontal disease: No

Is MAS suitable for patients with insufficient natural teeth: No, adequate dentition is required to anchor the device

Is severe TMJ dysfunction a contraindication for MAS: Yes

Does mild-to-moderate TMD automatically preclude MAS use: No

Can MAS address bruxism and OSA simultaneously: Yes, a single device can treat both conditions

Is CPAP noisy: Yes, machine noise is present during operation

Is MAS silent during use: Yes

Does CPAP require electricity: Yes

Does MAS require electricity: No, it is fully portable

Is MAS suitable for frequent travellers: Yes, due to full portability and no power requirement

Can established CPAP users use MAS while travelling: Yes, MAS is widely used as a travel alternative

Can MAS and CPAP be combined: Yes, combination therapy is a valid clinical strategy

Why might combination MAS and CPAP therapy be used: To reduce the CPAP pressure required to treat severe OSA

Does combining MAS with CPAP improve adherence: Limited evidence suggests it may improve adherence

What are common CPAP side effects: Mask discomfort, nasal congestion, and claustrophobia

What are common MAS side effects: Jaw soreness and increased salivation

Are MAS side effects usually permanent: No, most are transient

What is the approximate cost of a custom MAS in Australia: AUD $1,500 to $4,000 or more

Is CPAP a one-off cost: No, it requires ongoing consumable expenses

Are off-the-shelf MAS devices recommended: No, pre-fabricated appliances are less effective and less accepted

Why is a custom MAS superior to an off-the-shelf device: Custom devices allow titration and optimal mandibular advancement

What is titration in MAS therapy: Progressive adjustment of the appliance to optimise jaw advancement

Is post-treatment sleep testing required after MAS fitting: Yes, it is essential to confirm treatment effectiveness

Why is post-treatment sleep testing important after MAS: Some patients experience worsening AHI with MAS

Does Smile Solutions include post-treatment sleep testing in MAS care: Yes, it is a standard component of every MAS care pathway

What is the primary reason CPAP adherence fails to improve over time: Secular trends show no clinically impactful improvement over 20 years

What percentage of patients refused CPAP due to preference for alternatives: 39.3% in a 2025 observational study

What percentage refused CPAP due to social stigma: 35.7%

What percentage refused CPAP due to financial constraints: 28.6%

What was CPAP acceptance rate in a 2025 ERS conference study: 62.7%

Does CPAP adherence vary by OSA severity: Yes, adherence is lower in milder OSA

What is CPAP adherence for mild OSA: Approximately 55%

What is CPAP adherence for severe OSA: Approximately 89%

Does real-world effectiveness equal laboratory efficacy: No, effectiveness depends on actual adherence

What principle governs MAS versus CPAP effectiveness: A consistently worn 85%-efficacy treatment outperforms an inconsistently worn superior treatment

Should patient preference influence treatment selection: Yes, AASM/AADSM guidelines explicitly state it should

Which professional body guidelines support MAS for OSA: AASM and AADSM joint clinical practice guideline (2015)

Is a referral required to see a specialist at Smile Solutions: No referral is required

Where is Smile Solutions located: Level 1 and 10, 220 Collins Street, Melbourne CBD

What is the Smile Solutions contact number: 13 13 96

How many clinicians does Smile Solutions have: Over 60 clinicians

How many board-registered specialists does Smile Solutions have: Over 25

How long has Smile Solutions been operating: Since 1993

How many patients has Smile Solutions treated: Over 250,000 patients

Smile Solutions: Mandibular Advancement Splint vs. CPAP — Which Sleep Apnoea Treatment Is Right for You?

At Smile Solutions, Melbourne's long-established centre for comprehensive dental and specialist care, one of the most meaningful conversations in dental sleep medicine comes down to a crossroads familiar to millions of people diagnosed with obstructive sleep apnoea (OSA): the CPAP machine or a mandibular advancement splint (MAS)? It sounds like a straightforward choice, but the evidence behind it is rich, genuinely complex, and frequently misrepresented — in both directions. CPAP advocates sometimes dismiss MAS as a lesser therapy; MAS proponents occasionally overstate its universality. The truth, as the best clinical research shows, is considerably more useful and patient-centred than either extreme.

This article offers a rigorous, evidence-based comparison of both therapies — examining raw efficacy (AHI reduction), real-world compliance, quality-of-life outcomes, cost, portability, and the clinical criteria that help determine which treatment, or which combination, is most appropriate for you.

(For foundational context on what OSA is and how it is classified by severity, see our guide on Obstructive Sleep Apnoea: What It Is, Why It Happens, and Why Your Dentist Can Help. For a detailed explanation of how MAS works and what to expect from the device itself, see Mandibular Advancement Splints Explained: How They Work, Who They're For, and What to Expect.)

How each treatment works: a brief mechanistic overview

Understanding the comparison begins with understanding what each approach actually does.

CPAP (Continuous Positive Airway Pressure) delivers a constant stream of pressurised air through a mask covering the nose and/or mouth. That pressure acts as a pneumatic splint, preventing the airway from collapsing during sleep and eliminating apnoeas and hypopnoeas.

A mandibular advancement splint (MAS) is a custom dental appliance worn during sleep that moves your lower jaw slightly forward. This forward displacement increases the space behind the tongue and stabilises the upper airway, reducing the collapses that characterise OSA.

Both approaches address the same underlying problem — upper airway collapse during sleep — but through fundamentally different mechanisms: one pneumatic, one mechanical.

Efficacy: what the numbers actually show

AHI reduction — CPAP has the advantage on paper

Measured purely by the apnoea-hypopnoea index (AHI), CPAP is the more powerful intervention. Compared with MAD, CPAP was associated with a decrease in AHI with a mean difference of -5.83 (95% CI, -8.85, -2.81, P < 0.01), according to the 2022 updated systematic review and meta-analysis by Pattipati et al. published in Cureus. A landmark randomised crossover trial by Phillips et al. (2013), published in the American Journal of Respiratory and Critical Care Medicine, confirmed this directly in 126 patients with moderate-to-severe OSA:

CPAP was more efficacious than MAD in reducing AHI (CPAP AHI, 4.5 ± 6.6/h; MAD AHI, 11.1 ± 12.1/h; P < 0.01), but reported compliance was higher on MAD (MAD, 6.50 ± 1.3 h per night vs. CPAP, 5.20 ± 2 h per night; P < 0.00001).

MAS achieves clinically meaningful AHI reductions

MAS therapy is far from ineffective — the reductions it achieves are clinically significant. A 2023 meta-analysis found that long-term MAD use reduced AHI by about –16.8 events/hour (high statistical significance). In terms of treatment success:

Over a third of patients will show a complete response to oral appliance therapy with a reduction in AHI to < 5/h (no OSA), another third will have a clinically important response showing > 50% reduction in AHI, although AHI remains > 5/h, and a third will not achieve > 50% reduction in AHI.

The compliance paradox: why efficacy doesn't equal effectiveness

Here is the most clinically important insight in this entire comparison. CPAP's superior AHI reduction is only realised when the device is actually worn — and that is a far bigger challenge than most patients realise.

Adherence to CPAP treatment for OSA is a critical problem, with adherence rates ranging from 30–60%. Poor adherence is widely recognised as a significant limiting factor in treating OSA, leaving many patients at heightened risk for comorbid conditions, impaired function, and reduced quality of life. Research published in PLOS ONE found that adherence rates were 89% for severe OSA, 71% for moderate OSA, and 55% for mild OSA — declining sharply for the very patients for whom MAS is most appropriate.

MAS adherence is consistently higher. Seventy-six percent of patients report using their oral appliance after one year, and 62% after four years; in patients who continue to use their device at five years, self-reported adherence is good, with over 90% reporting usage rates > 4 nights per week for more than half the night.

The clinical implication is significant. Despite MAS being inferior to CPAP in reducing AHI, it is hypothesised that higher compliance to MAS likely translates into a similar adjusted AHI and effectiveness. The Phillips et al. (2013) trial confirmed this directly:

Important health outcomes were similar after one month of optimal MAD and CPAP treatment in patients with moderate-severe OSA. The results may be explained by greater efficacy of CPAP being offset by inferior compliance relative to MAD, resulting in similar effectiveness.

Quality-of-life outcomes: where MAS holds its own

The clinical equivalence between MAS and CPAP on real-world health outcomes is one of the most consistently replicated findings in sleep medicine — and it's genuinely good news for patients who struggle with CPAP. Despite discrepancies in AHI reduction between CPAP and oral appliances, randomised trials show similar improvements in health outcomes between treatments, including sleepiness, quality of life, driving performance, and blood pressure.

The 2022 meta-analysis by Pattipati et al. in Cureus found no statistically significant difference in Epworth Sleepiness Scale (ESS) scores between CPAP and MAD groups, and confirmed that both treatments effectively reduce AHI and lowest oxygen saturation.

Sleepiness, driving simulator performance, and disease-specific quality of life improved on both treatments by similar amounts — and MAS was actually superior to CPAP on four general quality-of-life domains. That finding reflects something important: comfort and wearability matter enormously when it comes to consistent treatment benefit.

The 2015 joint clinical practice guideline from the American Academy of Sleep Medicine (AASM) and American Academy of Dental Sleep Medicine (AADSM) put it plainly: meta-analyses indicate that both oral appliances and CPAP can significantly reduce the AHI across all levels of OSA severity in adult patients.

Patient preference: the evidence is consistent

When patients have experienced both treatments, preference data consistently favours MAS. Despite achieving better (although not statistically significant) outcomes for AHI and ESS, 17 of 21 patients who completed the crossover study — having used both CPAP and MAS — preferred MAS. The Phillips et al. (2013) randomised crossover trial confirmed a clear patient preference for MAD therapy across their cohort of moderate-to-severe OSA patients.

Patient preference for oral appliances versus CPAP should be considered by the treating sleep physician before therapy is prescribed, according to the AASM/AADSM Clinical Practice Guideline — an explicit acknowledgement that compliance-driven real-world outcomes depend on your acceptance of and comfort with the chosen treatment.

Head-to-head comparison

Why CPAP intolerance is so common

Understanding why so many patients struggle to sustain CPAP therapy is essential to appreciating the genuine clinical role MAS plays. Device-related issues — mask type, air leak, skin inflammation, claustrophobia, nasal congestion, difficulty exhaling — all contribute to poor adherence. A 2025 observational study presented at the European Respiratory Society's Sleep and Breathing Conference found that the acceptance rate for CPAP was 62.7%, with financial constraints (28.6%), social stigma (35.7%), and preference for alternative therapies (39.3%) being the primary reasons for refusal.

Despite numerous interventions designed to improve adherence over the long term, secular trends do not show clinically impactful changes — a sobering finding from a 20-year longitudinal review published in Sleep and Breathing. A significant percentage of patients with OSA do not tolerate CPAP therapy, and long-term use may be as low as 30%. Patients with mild sleep apnoea may be at even higher risk for non-adherence, given the lower day-to-day symptom burden.

If you've found CPAP difficult to sustain, you're far from alone — and there are clinically sound, evidence-based alternatives available to you.

Selecting the right treatment: clinical decision criteria

When CPAP is the appropriate first-line choice

• There is general consensus that patients with AHI ≥30 events/hour (severe OSA) and OSA-related symptoms should receive CPAP therapy.
• Patients with significant oxygen desaturation events or comorbid cardiovascular or metabolic conditions where maximal AHI normalisation is critical
• Patients who have trialled and not tolerated MAS therapy
• Patients with central sleep apnoea (MAS is not indicated for central events)

When MAS is clinically equivalent or preferred

• MAD therapy is an effective and generally well-tolerated option for adults with mild-to-moderate OSA and for patients intolerant to CPAP.
• Patients who have trialled CPAP and cannot maintain consistent use
• MAS can be an effective alternative for patients intolerant to CPAP, especially in non-obese individuals.
• Patients who travel frequently or have occupations or lifestyles where a CPAP machine is impractical
• Patients with co-existing bruxism or TMD, where a single device can address multiple conditions simultaneously (see our guide on Occlusal Splints vs. Mandibular Advancement Splints for Bruxism: Choosing the Right Device)

Important candidacy considerations for MAS

MAS is not suitable for every patient. Key contraindications and limiting factors include:

• Insufficient natural dentition (a minimum number of healthy teeth is required to anchor the device)
• Active periodontal disease
• Severe temporomandibular joint (TMJ) dysfunction — though mild-to-moderate TMD does not automatically preclude MAS use
• Inter-individual variability in oral appliance efficacy means some patients are left with residual OSA, which is why post-treatment sleep testing is essential

(For more on diagnosis and candidacy assessment, see our guide on How TMD, Bruxism, and Sleep Apnoea Are Diagnosed: From Clinical Exam to Sleep Study.)

The combination approach: MAS + CPAP

An underutilised strategy worth knowing about is combination therapy. There is limited evidence that combining a MAD simultaneously with CPAP may help improve adherence to treatment, possibly by reducing the CPAP pressure required to effectively treat OSA.

This is particularly relevant for patients with severe OSA who cannot tolerate the high pressures CPAP alone requires. Wearing an MAS concurrently may reduce the required pressure to a more comfortable level, improving both tolerability and long-term sustainability.

MAS is also widely used as a travel alternative for established CPAP users. A majority of patients with OSA already successfully treated with CPAP can effectively be treated with MAS as a short-term alternative when travelling, when an electrical supply is not available, or on days that patients are not willing to use CPAP and tend to forgo treatment altogether.

The importance of custom fabrication and titration

Not all MAS devices are equivalent — and this distinction matters for your outcomes. Pre-fabricated, off-the-shelf appliances are less effective and less accepted by patients and therefore should not be used either as a therapeutic option or as a screening tool to predict MAS responders. Titratable or adjustable appliances allow progressive protrusion of the mandible, and previous studies have shown that MAS efficacy is related to the amount of mandibular advancement — determining the optimal degree of advancement is the most important step in using MAS therapy successfully.

Because some patients show a worsening in AHI with MAS, a post-treatment sleep study is of great importance. This is a non-negotiable step in responsible dental sleep medicine practice, and one that distinguishes genuinely expert care from generic splint provision. At Smile Solutions, post-treatment sleep testing is a standard component of every MAS care pathway, ensuring the therapy is genuinely delivering the outcomes you need.

Key takeaways

• CPAP reduces AHI more effectively than MAS on polysomnographic measures, but this advantage is substantially offset by its significantly lower real-world compliance rates of 30–60%.
• MAS achieves comparable health outcomes to CPAP in randomised trials — including daytime sleepiness, driving performance, blood pressure, and quality of life — because higher adherence translates into equivalent real-world effectiveness.
• MAS is the evidence-based first-line alternative for mild-to-moderate OSA and for patients who are intolerant of or non-adherent to CPAP; CPAP remains the first-line recommendation for severe OSA.
• Patient preference consistently favours MAS in crossover studies, and involving patients in treatment selection is itself a predictor of better long-term adherence.
• Custom, titratable MAS devices fabricated by a qualified dental sleep medicine practitioner, followed by post-treatment sleep testing, are the clinical standard; off-the-shelf devices should not be used as primary therapy.
• Combination therapy (MAS + CPAP) is a valid strategy for reducing required CPAP pressure in severe OSA, and MAS is widely used as a travel alternative by established CPAP users.

Conclusion

The MAS versus CPAP question doesn't have a single universal answer — but it does have a structured, evidence-based framework for answering it on your terms, taking into account your individual circumstances, preferences, and clinical profile.

CPAP remains the most powerful tool for normalising AHI across all severity levels, and for severe OSA with significant cardiovascular risk, it is the appropriate first choice. But for the large population of patients with mild-to-moderate OSA, or those who cannot sustain consistent CPAP use, a custom mandibular advancement splint is not a compromise — it is a clinically equivalent treatment that you are far more likely to actually wear, night after night, for years.

The most important clinical insight from the evidence is this: a treatment worn consistently at 85% efficacy outperforms a superior treatment worn inconsistently at 40% adherence. Effectiveness in the real world — not just efficacy in a laboratory — is what protects you from the cardiovascular, cognitive, and metabolic consequences of untreated OSA.

At Smile Solutions Melbourne, the decision between MAS and CPAP is never made in isolation. It follows a comprehensive assessment that includes a thorough clinical jaw and airway examination, a careful review of any existing sleep study data, and — where needed — referral for or collaboration with a sleep physician. Post-treatment sleep testing then confirms that your chosen therapy is genuinely working. This integrated, personalised approach is explored further in Getting Your Mandibular Advancement Splint at Smile Solutions Melbourne: A Step-by-Step Patient Guide and Long-Term Care and Side Effects of Mandibular Advancement Splints: What Every Patient Should Know.

If you're ready to explore your options with experienced specialists who take a gentle and caring approach to every aspect of your treatment, call us on 13 13 96 or visit smilesolutions.com.au to arrange your TMD and sleep treatment consultation — no referral required.

Smile Solutions has been providing world-class dental care from Melbourne's CBD since 1993. Located at the Manchester Unity Building, Level 1 and 10, 220 Collins Street, Smile Solutions brings together 60+ clinicians — including 25+ board-registered specialists — who have cared for over 250,000 patients. No referral is required to book a specialist appointment. Call 13 13 96 or visit smilesolutions.com.au to arrange your TMD and sleep treatment consultation.

References

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• Phillips CL, Grunstein RR, Darendeliler MA, et al. "Health Outcomes of Continuous Positive Airway Pressure versus Oral Appliance Treatment for Obstructive Sleep Apnea: A Randomized Controlled Trial." American Journal of Respiratory and Critical Care Medicine, 2013. https://www.atsjournals.org/doi/10.1164/rccm.201212-2223OC

• Kapur VK, Auckley DH, Chowdhuri S, et al. (AASM/AADSM Task Force). "Clinical Practice Guideline for the Treatment of Obstructive Sleep Apnea and Snoring with Oral Appliance Therapy: An Update for 2015." Journal of Clinical Sleep Medicine / PMC, 2015. https://pmc.ncbi.nlm.nih.gov/articles/PMC4481062/

• Sutherland K, Vanderveken OM, Tsuda H, et al. "Oral Appliance Treatment for Obstructive Sleep Apnea: An Update." Journal of Clinical Sleep Medicine (AASM), 2014. https://jcsm.aasm.org/doi/10.5664/jcsm.3460

• Almeida FR, Mulgrew A, Ayas N, et al. "Mandibular Advancement Splint as Short-Term Alternative Treatment in Patients with Obstructive Sleep Apnea Already Effectively Treated with Continuous Positive Airway Pressure." Journal of Clinical Sleep Medicine, 2013. https://jcsm.aasm.org/doi/10.5664/jcsm.2576

• Rotenberg BW, Murariu D, Pang KP. "Trends in CPAP Adherence over Twenty Years of Data Collection: A Flattened Curve." Sleep and Breathing, 2016. https://pmc.ncbi.nlm.nih.gov/articles/PMC4992257/

• Weaver TE, Grunstein RR. "Adherence to Continuous Positive Airway Pressure Therapy: The Challenge to Effective Treatment." Proceedings of the American Thoracic Society, 2008. https://pmc.ncbi.nlm.nih.gov/articles/PMC2645251/

• Dipalma G, et al. "Comparative Efficacy of Continuous Positive Airway Pressure and Mandibular Advancement Devices in the Treatment of Obstructive Sleep Apnea: A Systematic Review." Journal of Sleep Research, 2025. https://onlinelibrary.wiley.com/doi/10.1111/jsr.70192

• Hoekema A, et al. "Oral Appliance Versus Continuous Positive Airway Pressure in Obstructive Sleep Apnea Syndrome: A 2-Year Follow-up." SLEEP, 2013. https://pmc.ncbi.nlm.nih.gov/articles/PMC3738037/

• Vanderveken OM, et al. "Clinical- and Cost-Effectiveness of a Mandibular Advancement Device Versus Continuous Positive Airway Pressure in Moderate Obstructive Sleep Apnea." CHEST, 2019. https://pmc.ncbi.nlm.nih.gov/articles/PMC6778341/

• Dieltjens M, Vanderveken OM. "Mandibular Advancement Devices for OSA: An Alternative to CPAP?" Current Sleep Medicine Reports / PMC, 2021. https://pmc.ncbi.nlm.nih.gov/articles/PMC8137783/

• Sutherland K, et al. "Efficacy and Effectiveness in OSA Treatment." Journal of Dental Sleep Medicine (AADSM), 2015. https://aadsm.org/docs/JDSM.2.4.175.pdf

• Sangalli L, et al. "Comparison of Three Mandibular Advancement Device Designs in the Management of Obstructive Sleep Apnea: A Retrospective Study." Journal of Dental Sleep Medicine, 2022. https://www.aadsm.org/docs/jdsm.7.10.2022.o1.pdf

• Delebarre M, et al. "Efficacy of Mandibular Advancement Devices in the Treatment of Mild to Moderate Obstructive Sleep Apnea: A Systematic Review." Dentistry Journal (MDPI), 2025. https://www.mdpi.com/2673-8937/5/4/49