Combination Therapy (Oral Appliance + CPAP)

Overview

Combination therapy refers to the use of an oral appliance in conjunction with continuous positive airway pressure (CPAP).
This approach is designed for patients who achieve partial improvement with oral appliance therapy (OAT) alone or who find full-pressure CPAP uncomfortable.

By advancing the mandible and stabilizing the upper airway, the oral appliance decreases pharyngeal collapsibility. As a result, lower CPAP pressures are required to maintain airway patency—typically 35–45% less than when CPAP is used alone.<sup>[1]</sup>
Patients often report improved comfort, reduced dryness, and fewer air leaks, while maintaining full control of obstructive sleep apnea (OSA).

Mechanism of Action

  • The mandibular advancement device (MAD) increases upper airway volume and tension, particularly in the velopharyngeal segment.

  • With the airway partially splinted open, CPAP can operate at a lower pressure, minimizing expiratory resistance and leak.

  • This synergistic effect decreases negative intrathoracic pressure swings and enhances overall ventilatory stability.<sup>[1][2]</sup>

Clinical Indications

Combination therapy may be appropriate when:

  • OAT significantly reduces—but does not eliminate—respiratory events (residual AHI >5).

  • The patient experiences pressure intolerance, dryness, or aerophagia with standard CPAP.

  • There is a clinical need for maximal OSA control with improved adherence potential.

  • The patient demonstrates favorable oral appliance tolerance and stable dentition.

Clinical Benefits

  • Improved therapeutic efficacy: Reduces residual AHI in OAT partial responders.<sup>[2][3]</sup>

  • Lower pressure requirements: Allows a more comfortable CPAP experience, improving long-term adherence.<sup>[1]</sup>

  • Reduced leak and dryness: Lower airflow pressures minimize mask leak and mucosal irritation.

  • Customizable integration: May be paired with positional or nasal therapies for individualized care.

Considerations and Contraindications

  • Requires coordination between the dental sleep provider and sleep physician for titration and data review.

  • Initial in-lab or home titration is recommended to determine optimal CPAP pressure while using the oral appliance.

  • Caution in patients with acute temporomandibular joint (TMJ) dysfunction, unstable dentition, or untreated nasal obstruction.

Treatment Process

  1. Confirm that OAT alone provides partial improvement and is well-tolerated.

  2. Introduce CPAP at a reduced starting pressure; titrate gradually for optimal comfort and AHI control.

  3. Perform follow-up testing (home or lab) to confirm therapeutic success and assess leak, adherence, and symptom improvement.

Evidence Summary

Peer-reviewed studies have demonstrated that:

  • Combining CPAP with OAT reduces the required pressure by 35–45% while maintaining or improving AHI control.<sup>[1]</sup>

  • The combination improves comfort, adherence, and patient satisfaction compared to CPAP alone.<sup>[2]</sup>

  • Stepwise, endotype-informed approaches further individualize therapy for complex or refractory OSA cases.<sup>[3]</sup>

  • This multimodal strategy aligns with the AASM/AADSM Clinical Practice Guideline (2015) supporting individualized, combination-based management of OSA.<sup>[4]</sup>

References

  1. Tong BKY, Tran C, Ricciardiello A, et al. CPAP combined with oral appliance therapy reduces CPAP requirements and pharyngeal pressure swings in obstructive sleep apnea. J Appl Physiol. 2020;129(5):1084–1093.

  2. Lai V, Tong BKY, Tran C, et al. Combination therapy with mandibular advancement and expiratory positive airway pressure valves reduces obstructive sleep apnea severity. Sleep. 2019;42(8):zsz119.

  3. Aishah A, Tong BKY, Osman AM, et al. Stepwise Add-On and Endotype-Informed Targeted Combination Therapy to Treat Obstructive Sleep Apnea: A Proof-of-Concept Study. Ann Am Thorac Soc. 2023;20(9):1316–1325.

  4. Ramar K, Dort LC, Katz SG, et al. Clinical Practice Guideline for the Treatment of Obstructive Sleep Apnea and Snoring With Oral Appliance Therapy: An Update for 2015. J Clin Sleep Med. 2015;11(7):773–827.