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Clinical Trial
. 2024 Nov 1;150(11):1012-1019.
doi: 10.1001/jamaoto.2024.3319.

Mouth Closure and Airflow in Patients With Obstructive Sleep Apnea: A Nonrandomized Clinical Trial

Hyungchae Yang  1   2 , Phillip Huyett  3 , Tsai-Yu Wang  1   4 , Jeffery Sumner  2 , Ali Azarbarzin  2 , Gonzalo P T Labarca  2 , Ludovico Messineo  2 , Laura K Gell  2 , Atqiya Aishah  1 , Wen-Hsin Hu  2 , David P White  2 , Scott A Sands  1 , Andrew Wellman  1 , Daniel Vena  1
Affiliations
Clinical Trial

Mouth Closure and Airflow in Patients With Obstructive Sleep Apnea: A Nonrandomized Clinical Trial

Hyungchae Yang et al. JAMA Otolaryngol Head Neck Surg. .

Abstract

Importance: Mouth breathing is associated with increased airway resistance, pharyngeal collapsibility, and obstructive sleep apnea (OSA) severity. The common belief is that closing the mouth can mitigate the negative effects of mouth breathing during sleep. However, mouth breathing may serve as an essential route to bypassing obstruction along the nasal route (eg, the velopharynx).

Objective: To investigate the role of mouth breathing as an essential route in some patients with OSA and its association with upper airway anatomical factors.

Design, setting, and participants: This nonrandomized clinical trial included participants diagnosed with OSA who underwent drug-induced sleep endoscopy. Patients were stratified into 3 quantiles based on oral-breathing level (quantile 1: oral airflow < 0.05 L/min; quantile 2: oral airflow 0.05-2.2 L/min; quantile 3: oral airflow > 2.2 L/min).

Interventions: Closing the mouth during sleep during alternating breaths by applying pressure to the mentum until teeth are in occlusion.

Main outcomes and measures: The primary outcome was total inspiratory flow defined as the change in airflow in the transition from mouth relaxed to mouth closed, analyzed overall and by 3 oral-breathing quantiles. The association of velopharyngeal obstruction on the change in total inspiratory airflow was also investigated.

Results: Of 66 enrolled patients with OSA, 12 were excluded due to insufficient baseline airflow. The analytic cohort consisted of 54 patients (39 [72%] male; median [IQR] age, 55 [46-64] years; apnea-hypopnea index, 26.9 [17.6-39.9] events/h; and body mass index calculated as weight in kilograms divided by height in meters squared, 28.9 [27.1-31.6]). Mouth closure increased total inspiratory flow by 27.8 percentage points overall (β, 1.0 [95% CI, 0.4-1.9] L/min). However, outcomes varied based on the degree of baseline oral breathing. No association was found for 10 patients with near-zero mouth breathing (0.9 [95% CI, -0.2 to 2.1] L/min). Airflow improved with mouth closure in 32 patients with moderate levels of mouth breathing (2.0 [95% CI, 1.3-2.7] L/min), whereas it worsened in patients with high levels of mouth breathing (-1.9 [95% CI, -3.1 to -0.6] L/min). Velopharyngeal obstruction was associated with increased mouth breathing (0.6 [95% CI, 0.1-3.0] L/min) and reduced airflow with mouth closure (-1.9 [95% CI, -3.1 to -0.7] L/min).

Conclusion and relevance: Although mouth closure increased inspiratory airflow in the overall cohort of this nonrandomized clinical trial, the outcomes were heterogeneous. In patients who breathe primarily through their mouth during sleep and have velopharyngeal obstruction, airflow worsens with mouth closure. Hence, personalized approaches to treating mouth breathing should be considered.

Trial registration: ClinicalTrials.gov Identifier: NCT06547658.

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Conflict of interest statement

Conflict of Interest Disclosures: Dr Huyett reported personal fees (educational consultant) and grants (research support) from Inspire Medical Systems, and grants from Nyxoah, outside the submitted work. Dr Azarbarzin reported personal fees from Apnime, Somnifix, Cerebra, Eli Lilly, Inspire, and Zoll Respicardia; grants from Somnifix; and a pending patent for a system and method for endo-phenotyping and risk stratifying obstructive sleep apnea, outside the submitted work. Dr Labarca reported grants from the National Institute of Health, Chest Foundation, ResMed Foundation, Sleep Research Society, and American Academy of Sleep Medicine, outside the submitted work. Dr Gell reported personal fees from Apnimed, outside the submitted work. Dr White reported non-financial support as a consultant for Bairitone, Cerebra Health, Cryosa, Mosanna, Onera, Philips Respironics, Resonea, Xtrodes, Apnimed, and SleepRes, outside the submitted work. Dr Sands reported grants from Apnimed, Prosomnus, and Dynaflex, and personal fees from Apnimed, Nox Medical, Respicardia, LinguaFlex, Forepont, and Lilly, outside the submitted work. He also holds patents on wearable sleep apnea phenotyping (licensed to Apnimed) and combination pharmacotherapy (royalties from Apnimed). Dr Wellman reported personal fees from Apnimed, Nox, Inspire, Mosanna, and Takeda; grants from Prosomnus; and a financial interest in Apnimed Corp He holds a patent on flow shape analysis for airway collapse detection His interests were reviewed and managed by Brigham and Women’s Hospital and Partners HealthCare. Dr Vena reported grants from NIH National Heart, Lung, and Blood Institute during the study and personal fees from Inspire Medical, outside the submitted work. No other disclosures were reported.

Comment in

References

    1. Medical subject headings (MeSH): mouth breathing. Accessed February 6, 2024. https://www.ncbi.nlm.nih.gov/mesh/68009058.
    1. Fitzpatrick MF, McLean H, Urton AM, Tan A, O’Donnell D, Driver HS. Effect of nasal or oral breathing route on upper airway resistance during sleep. Eur Respir J. 2003;22(5):827-832. doi: 10.1183/09031936.03.00047903 - DOI - PubMed
    1. Fitzpatrick MF, Driver HS, Chatha N, Voduc N, Girard AM. Partitioning of inhaled ventilation between the nasal and oral routes during sleep in normal subjects. J Appl Physiol (1985). 2003;94(3):883-890. doi: 10.1152/japplphysiol.00658.2002 - DOI - PubMed
    1. Suzuki M, Tanuma T. The effect of nasal and oral breathing on airway collapsibility in patients with obstructive sleep apnea: computational fluid dynamics analyses. PLoS One. 2020;15(4):e0231262. doi: 10.1371/journal.pone.0231262 - DOI - PMC - PubMed
    1. Schwartz AR, Barnes M, Hillman D, et al. Acute upper airway responses to hypoglossal nerve stimulation during sleep in obstructive sleep apnea. Am J Respir Crit Care Med. 2012;185(4):420-426. doi: 10.1164/rccm.201109-1614OC - DOI - PMC - PubMed

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