Do face masks prevent yawning? A key factor to consider in sleep research

Abstract

The COVID-19 pandemic has resulted in widespread face mask usage to curb disease spread. However, an unintended effect is that masks may contribute to sleep disturbances. Since sleep and excessive sleepiness are closely connected to yawning, the typical design of face masks might restrict jaw movement, thereby altering normal yawning behavior. Moreover, masks can interfere with contagious yawning by making it harder to recognize yawns in social and community environments. Yawning influences alertness and facilitates transitions between wakefulness and sleep—particularly through thermoregulation—wearing face masks, theoretically restricts jaw movement. Factually, face masks also impede the occurrence of contagious yawning by obstructing the visual detection of yawns. While altering airflow dynamics, face masks may disrupt the counter-current heat exchange with the external environment, a process integral to yawning. Face masks can potentially introduce clinical uncertainties and subtle statistical biases in epidemiological studies and clinical trials. In this review, these theoretic and factual points are used to support the hypothetical mechanism proposed. This paper explores the possible sources and hypothetical mechanisms of such bias. The proposed hypothesis carries potential implications for ongoing clinical trials, the interpretation of retrospective and prospective data across different contexts, the reassessment of sleep disorder diagnostic criteria, standards for systematic reviews, meta-analyses comparing data from before and after COVID-19, and, crucially, the reevaluation of previous findings and comparative research. This paper provides a conceptual discussion identifying possible sources of bias, rather than a systematic or quantitative analysis.

Keywords

Face mask / Sleep research / Yawning / Jaw motion / Temporomandibular movement

References

[1] Giganti F, Hayes MJ, Akilesh MR, Salzarulo P. Yawning and behavioral states in premature infants. Dev Psychobiol. 2002; 41(3):289-296. doi: 10.1002/dev.10047

[2] Zilli I, Giganti F, Salzarulo P. Yawning in morning and evening types. Physiol Behav. 2007; 91(2-3):218-222. doi: 10.1016/j.physbeh.2007.02.015

[3] Gallup AC, Massen JJ. There is no difference in contagious yawning between men and women. R Soc Open Sci. 2016; 3(9):160174. doi: 10.1098/rsos.160174

[4] Gallup AC. The causes and consequences of yawning in animal groups. Anim Behav. 2022; 187:209-219. doi: 10.1016/j.anbehav.2022.03.011

[5] Casetta G, Nolfo AP, Palagi E. Yawn contagion promotes motor synchrony in wild lions, Panthera leo. Anim Behav. 2021; 174:149-159. doi: 10.1016/j.anbehav.2021.02.010

[6] Gallup AC, Meyers K. Seeing others yawn selectively enhances vigilance: An eye-tracking study of snake detection. Anim Cogn. 2021; 24(3):583-592. doi: 10.1007/s10071-020-01462-4

[7] Giganti F, Zilli I, Aboudan S, Salzarulo P. Sleep, sleepiness and yawning. Front Neurol Neurosci. 2010; 28:42-46. doi: 10.1159/000307078

[8] Catli T, Acar M, Hanci D, Arikan OK, Cingi C. Importance of yawning in the evaluation of excessive daytime sleepiness: a prospective clinical study. Eur Arch Oto-Rhino-Laryngol. 2015; 272(12):3611-3615. doi: 10.1007/s00405-014-3302-1

[9] Provine RR, Hamernik HB. Yawning: effects of stimulus interest. Bull Psychon Soc. 1986; 24(6):437-438. doi: 10.3758/BF03330574

[10] Walusinski O. The mystery of yawning in physiology and disease: Karger. 2010. doi: 10.1159/isbn.978-3-8055-9405-9

[11] Gallup AC, Kret ME, Eldakar OT, Folz J, Massen JJ. People that score high on psychopathic traits are less likely to yawn contagiously. Sci Rep. 2021; 11(1):23779. doi: 10.1038/s41598-021-03159-1

[12] Lobo LL, Neumann BG, Eidman DS, Tufik S. Effects of REM sleep deprivation on ACTH-induced yawning. Pharmacology. 1990; 40(3):174-178. doi: 10.1159/000138656

[13] Walusinski O. Yawning: unsuspected avenue for a better understanding of arousal and interoception. Med Hypotheses. 2006; 67(1):6-14. doi: 10.1016/j.mehy.2006.01.020

[14] Walusinski O. Yawning in diseases. Eur Neurol. 2009; 62(3):180-187. doi: 10.1159/000228262

[15] Walusinski O. Fetal yawning. Front Neurol Neurosci. 2010; 28:32-41. doi: 10.1159/000307075

[16] Menin D, Aureli T, Dondi M. Two forms of yawning modulation in three months old infants during the Face to Face Still Face paradigm. PloS ONE. 2022; 17(2):e0263510. doi: 10.1371/journal.pone.0263510

[17] Menin D, Ballardini E, Panebianco R, et al. Factors affecting yawning frequencies in preterm neonates. PloS ONE. 2022; 17(5):e0268083. doi: 10.1371/journal.pone.0268083

[18] Menin D, Costabile A, Tenuta F, Oster H, Dondi M. Identifying fetal yawns based on temporal dynamics of mouth openings: A preterm neonate model using support vector machines (SVMs). PloS ONE. 2019; 14(12):e0226921. doi: 10.1371/journal.pone.0226921

[19] Guggisberg AG, Mathis J, Herrmann US, Hess CW. The functional relationship between yawning and vigilance. Behav Brain Res. 2007; 179(1):159-166. doi: 10.1016/j.bbr.2007.01.027

[20] Opp MR, Obal Jr F, Krueger JM. Effects of alpha-MSH on sleep, behavior, and brain temperature: interactions with IL 1. Am J Physiol Regul Integr Comp Physiol. 1988; 255(6):R914-R922. doi: 10.1152/ajpregu.1988.255.6.R914

[21] Gallup Jr GG, Gallup AC. Excessive yawning and thermoregulation: two case histories of chronic, debilitating bouts of yawning. Sleep Breath. 2010; 14(2):157-159. doi: 10.1007/s11325-009-0287-x

[22] Teive HA, Munhoz RP, Camargo CHF, Walusinski O.Y awning in neurology: a review. Arq De Neuro-Psiquiatr. 2018; 76(7):473-480. doi: 10.1590/0004-282x20180057

[23] Gupta S, Mittal S. Yawning and its physiological significance. Int J Appl Basic Med Res. 2013; 3(1):11-15. doi: 10.4103/2229-516X.112230

[24] Amez S, Vujić S, Soffers P, Baert S. Yawning while scrolling? Examining gender differences in the association between smartphone use and sleep quality. J Sleep Res. 2020; 29(6):e12971. doi: 10.1111/jsr.12971

[25] Krestel H, Bassetti CL, Walusinski O. Yawning-its anatomy, chemistry, role, and pathological considerations. Prog Neurobiol. 2018; 161:61-78. doi: 10.1016/j.pneurobio.2017.11.003

[26] Minakuchi H. Association of masticatory muscle activity with sleep arousal and other concomitant movements during sleep. J of Oral Rehabil. 2019; 47(3):281-288. doi: 10.1111/joor.12913

[27] Cappa CD, Department SFOC, Ristenpart WD, et al. A highly efficient cloth facemask design. Aerosol Sci Technol. 2021; 56(1):12-28. doi: 10.1080/02786826.2021.1962795

[28] Zuhour M, Ismayilzade M, Dadacı M, Ince B. The impact of wearing a face mask during the COVID-19 pandemic on temporomandibular joint: A radiological and questionnaire assessment. Indian J Plast Surg. 2022; 55(01):058-065. doi: 10.1055/s-0042-1743131

[29] Pietrzyk SJ, Kielczynska E, Kowalczyk M, Mazurek M, Domagala ZA. Potential Impacts of Prolonged Face Mask Use on Temporomandibular Joint Health as Neglected Lifestyle Repercussions of COVID-19 Pandemic-A Narrative Review. Medicina. 2024; 60(9). doi: 10.3390/medicina60091468

[30] Gorgu SO, Yildirim Y, Kaya P, Ergezen G, Uzuner E. Does the use of protective face masks affect temporomandibular joint function? Pak J Med Sci. 2025; 41(2):432. doi: 10.12669/pjms.41.2.10588

[31] Chang C-L, Wang D-H, Yang M-C, Hsu W-E, Hsu M-L. Functional disorders of the temporomandibular joints: Internal derangement of the temporomandibular joint. Kaohsiung J Med Sci. 2018; 34(4):223-230. doi: 10.1016/j.kjms.2018.01.004

[32] Lee Y-H. Functional anatomy of the temporomandibular joint and pathologic changes in temporomandibular disease progression: a narrative review. J Korean Dent Sci. 2024; 17(1):14-35. doi: 10.5856/JKDS.2024.17.1.14

[33] Mandall N, DiBiase A, Littlewood S, et al. Is early Class III protraction facemask treatment effective? A multicentre, randomized, controlled trial: 15‐month follow‐up. J Orthod. 2010; 37(3):149-161. doi: 10.1179/14653121043056

[34] Martinac AD, Waters S, Lloyd RA, Bilston LE. Biomechanics of yawning: insights into cranio-cervical fluid dynamics and kinematic consistency. bioRxiv. 2025. doi: 10.64898/2025.12.17.695005

[35] Gallup AC, Gallup Jr GG. Yawning and thermoregulation. Physiol Behav. 2008; 95(1-2):10-16. doi: 10.1016/j.physbeh.2008.05.003

[36] Gori M, Schiatti L, Amadeo MB. Masking emotions: Face masks impair how we read emotions. Front Psychol. 2021; 12:669432. doi: 10.3389/fpsyg.2021.669432

[37] Baenninger R, Binkley S, Baenninger M. Field observations of yawning and activity in humans. Physiol Behav. 1996; 59(3):421-425. doi: 10.1016/0031-9384(95)02014-4

[38] Regli A, Sommerfield A, von Ungern‐Sternberg B. The role of fit testing N95/FFP2/FFP3 masks: a narrative review. Anaesthesia. 2021; 76(1):91-100. doi: 10.1111/anae.15261

[39] Nassri M, Barari P, Khanizadeh M, et al. The influence of N95 and surgical masks on carbon dioxide levels: A comprehensive systematic review and meta-analysis. Heliyon. 2024; 10(16):e36626. doi: 10.1016/j.heliyon.2024.e36626

[40] Oliver N, Barber X, Roomp K, Roomp K. Assessing the impact of the COVID-19 pandemic in Spain: large-scale, online, self-reported population survey. J Med Internet Res. 2020; 22(9):e21319. doi: 10.2196/21319

[41] Babiloni AH, Dal Fabbro C, Kapos FP, Hachul H, Lavigne GJ. Orofacial pain/headache interlaced to insomnia, sleep apnea and periodic limb movement during sleep/restless leg syndrome: a critical and comprehensive review with insights into social determinants. J Oral Facial Pain Headache. 2025; 39(2):1-22. doi: 10.22514/jofph.2025.023

[42] Patel M, Worrall J. The Crucial Role of Craniofacial Growth on Airway, Sleep, and the Temporomandibular Joint. Nutrition and Integrative Medicine. CRC Press; 2018:227- 259. doi: 10.1201/9781315153155-8

[43] Muslih M, Susanti HD, Rias YA, Chung M-H. Knowledge, attitude, and practice of indonesian residents toward covid- 19: A cross-sectional survey. Int J Environ Res Public Health. 2021; 18(9):4473. doi: 10.3390/ijerph18094473

[44] Howard MC. Gender, face mask perceptions, and face mask wearing: Are men being dangerous during the COVID-19 pandemic? Personal Individ Differ. 2021; 170:110417. doi: 10.1016/j.paid.2020.110417

[45] Bwire GM. Coronavirus: Why Men are More Vulnerable to Covid-19 Than Women? SN Compr Clin Med. 2020; 2(7):874-876. doi: 10.1007/s42399-020-00341-w

[46] Schino G, Aureli F. Do men yawn more than women? Ethol Sociobiol. 1989; 10(5):375-378. doi: 10.1016/0162-3095(89)90026-5

[47] Norscia I, Demuru E, Palagi E. She more than he: gender bias supports the empathic nature of yawn contagion in Homo sapiens. R Soc Open Sci. 2016; 3(2):150459. doi: 10.1098/rsos.150459

[48] Norscia I, Zanoli A, Gamba M, Palagi E. Auditory contagious yawning is highest between friends and family members: Support to the emotional bias hypothesis. Front Psychol. 2020; 11:442. doi: 10.3389/fpsyg.2020.00442

[49] Mickells GE, Figueroa J, West KW, Wood A, McElhanon BO. Adherence to masking requirement during the COVID‐19 pandemic by early elementary school children. J Sch Health. 2021; 91(7):555-561. doi: 10.1111/josh.13033

[50] Tong KK, Chen JH, Yu EWy, Wu AM. Adherence to COVID‐19 precautionary measures: Applying the health belief model and generalised social beliefs to a probability community sample. Appl Psychol Health Well‐Being. 2020; 12(4):1205-1223. doi: 10.1111/aphw.12230

[51] Vancini RL, Camargo-Neto L, Andrade MS, et al. A Sociodemographic Profile of Mask Use During the COVID- 19 Outbreak Among Young and Elderly Individuals in Brazil: Online Survey Study. JMIR Aging. 2021; 4(3):e28989. doi: 10.2196/28989

[52] Nguyen QC, Yardi I, Gutierrez FXM, Mane H, Yue X. Leveraging 13 million responses to the US COVID-19 Trends and Impact Survey to examine vaccine hesitancy, vaccination, and mask wearing, January 2021-February 2022. BMC Public Health. 2022; 22(1):1911. doi: 10.1186/s12889-022-14286-3

[53] Duan Y, Hu C, Lin Z, et al. Individual preventive behaviors of COVID-19 and associated psychological factors among Chinese older adults: A cross-sectional online survey. Front Psychol. 2022; 13:827152. doi: 10.3389/fpsyg.2022.827152

[54] Bartholomew AJ, Cirulli ET. Individual variation in contagious yawning susceptibility is highly stable and largely unexplained by empathy or other known factors. PloS ONE. 2014; 9(3):e91773. doi: 10.1371/journal.pone.0091773

[55] Massen JJ, Dusch K, Eldakar OT, Gallup AC. A thermal window for yawning in humans: yawning as a brain cooling mechanism. Physiol Behav. 2014; 130:145-148. doi: 10.1016/j.physbeh.2014.03.032

[56] Tan W, Hao F, McIntyre RS, et al. Is returning to work during the COVID-19 pandemic stressful? A study on immediate mental health status and psychoneuroimmunity prevention measures of Chinese workforce. Brain Behav Immun. 2020; 87:84-92. doi: 10.1016/j.bbi.2020.04.055

[57] Lai J, Ma S, Wang Y, et al. Factors associated with mental health outcomes among health care workers exposed to coronavirus disease 2019. JAMA Netw Open. 2020; 3(3):e203976. doi: 10.1001/jamanetworkopen.2020.3976

[58] Casagrande M, Favieri F, Tambelli R, Forte G. The enemy who sealed the world: effects quarantine due to the COVID- 19 on sleep quality, anxiety, and psychological distress in the Italian population. Sleep Med. 2020; 75:12-20. doi: 10.1016/j.sleep.2020.05.011

[59] Fatima Y, Bucks RS, Mamun AA, et al. Shift work is associated with increased risk of COVID‐19: Findings from the UK Biobank cohort. J Sleep Res. 2021; 30(5):e13326. doi: 10.1111/jsr.13326

[60] Maidstone R, Anderson SG, Ray DW, et al. Shift work is associated with positive COVID-19 status in hospitalised patients. Thorax. 2021; 76(6):601-606. doi: 10.1136/thoraxjnl-2020-216651

[61] Martyn J, Grabias K, Chmiel Z. Do polish nurses have a problem with sleepiness during the epidemiological threat of the SARS-CoV-2 virus? INQUIRY J Health Care Organ Provis Financ. 2021; 58:00469580211022909. doi: 10.1177/00469580211022909

[62] Wang X, Jiang X, Huang Q, et al. Risk factors of SARS-CoV-2 infection in healthcare workers: a retrospective study of a nosocomial outbreak. Sleep Med X. 2020; 2:100028. doi: 10.1016/j.sleepx.2020.100028

[63] Zhang S, Xu Y, Wu K, et al. Improved night shift schedule related to the mortality of critically ill patients with Corona Virus Disease 2019. Sleep Med. 2020; 75:354-360. doi: 10.1016/j.sleep.2020.08.010

[64] Hao R, Zhang Y, Cao Z, et al. Control strategies and their effects on the COVID-19 pandemic in 2020 in representative countries. J Biosaf Biosecurity. 2021; 3(2):76-81. doi: 10.1016/j.jobb.2021.06.003

[65] Ferdous MZ, Islam MS, Sikder MT, et al. Knowledge, attitude, and practice regarding COVID-19 outbreak in Bangladesh: An online-based cross-sectional study. PloS ONE. 2020; 15(10):e0239254. doi: 10.1371/journal.pone.0239254

[66] Ho H. Use of face masks in a primary care outpatient setting in Hong Kong: knowledge, attitudes and practices. Public Health. 2012; 126(12):1001-1006. doi: 10.1016/j.puhe.2012.09.010

[67] Lee LY-k, Lam EP-w, Chan C-k, et al. Practice and technique of using face mask amongst adults in the community: a cross-sectional descriptive study. BMC Public Health. 2020; 20(1):948. doi: 10.1186/s12889-020-09087-5

[68] Reuben RC, Danladi MM, Saleh DA, Ejembi PE. Knowledge, attitudes and practices towards COVID-19: an epidemiological survey in North-Central Nigeria. J Community Health. 2021; 46(3):457-470. doi: 10.1007/s10900-020-00881-1

[69] Kisielinski K, Giboni P, Prescher A, et al. Is a mask that covers the mouth and nose free from undesirable side effects in everyday use and free of potential hazards? Int J Environ Res Public Health. 2021; 18(8):4344. doi: 10.3390/ijerph18084344

[70] Ayaki M, Tsubota K, Kawashima M, et al. Sleep disorders are a prevalent and serious comorbidity in dry eye. Investig Ophthalmol Vis Sci. 2018; 59(14):DES143-DES150. doi: 10.1167/iovs.17-23467