Here, we examine the literature to determine whether rhinitis, chronic overbreathing and sleeping with the mouth open is a causal factor for snoring and sleep apnoea.
“Open-mouth breathing during sleep is a risk factor for obstructive sleep apnea (OSA) and is associated with increased disease severity and upper airway collapsibility.” The study which involved 52 patients found that “the more elongated and narrow upper airway during open-mouth breathing may aggravate the collapsibility of the upper airway and, thus, negatively affect OSA severity.”1
In another study, 385 patients with obstructive sleep apnoea were examined through a questionnaire. Results showed that upper airway symptoms were common, with 61% of patients reporting mouth dryness, 52% with nasal stuffiness, 51% with dryness of the nose, 30% with sneezing, 24% with mucus in the throat, and 17% with a runny nose.2
Ohki et al. performed a study to determine the relationship between oral breathing and nasal obstruction in patients with obstructive sleep apnea. The study involved 30 normal subjects and 20 patients with snoring or sleep apnoea. Researchers found that chronic nasal obstruction and resultant mouth breathing may induce obstructive sleep apnea.3
In a paper entitled, “How does open-mouth breathing influence upper airway anatomy?”4, Lee et al. tested the hypothesis that open-mouth breathing during sleep may increase the severity of obstructive sleep apnea. After an analysis of 28 patients, researchers concluded that “open-mouth breathing is associated with reduction of the retropalatal and retroglossal areas, lengthening of the pharynx and shortening of the MP-H in the upper airway.”4
After reviewing texts and articles on Medline, the centre for research disorders in Cincinnati, Ohio concluded that obstructive sleep apnoea, sleep fragmentation, and disturbed sleep often result from nasal obstruction.5 The authors of the paper observed that “since breathing through the nose appears to be the preferred route during sleep, nasal obstruction frequently leads to nocturnal mouth breathing, snoring, and ultimately to OSA.”5 The paper advised that allergic rhinitis and other upper respiratory disorders should be treated more aggressively.5
Mouth breathing, snoring, and sleep apnoea in children
A Polish study noted that children with sleep respiratory disorders wake up tired, with blocked noses, were breathing through their mouth, tire easily, have concentration problems, are irritated, and demonstrate hyperactivity that may resemble ADHD symptoms. The paper further states that “long-term disease leads to exacerbation of all-systemic symptoms, results in cardiovascular complications, induces developmental inhibition and cognitive dysfunction, and is responsible for school/social failures and reduced life quality.”6
In a paper entitled, “The nose and sleep disordered breathing: what we know and what we don’t know,” performed an analysis of medical literature on the subject.7 The analysis confirmed that “SDB (sleep disordered breathing) can both result from and be worsened by nasal obstruction.” It was stated that “nasal congestion typically results in a switch to oronasal breathing that compromises the airway.” Furthermore, “oral (mouth) breathing in children may lead to the development of facial structural abnormalities associated with SDB.” The paper concluded that the change to mouth breathing that occurs with chronic nasal obstruction is a common pathway for sleep-disordered breathing.7
Mouth breathing was also recognised to be a factor in a study to determine the prevalence and association of sleep disorders and school performance. Based on a total of 1,164 completed questionnaires on children aged between 7 and 13 years, it was found that the overall prevalence of snoring was 38.9% with 3.5% habitually snoring. “Allergic symptoms, daytime mouth breathing, shaking the child for apnea, restless sleep and hyperactivity were significant and independent risk factors and sleep-related symptoms for HS.”9
A study was conducted to determine the risk factors of habitual snoring and symptoms of sleep-disordered breathing. Based on a study of 1030 children aged from 12 to 17 years, it was found that “habitual snorers had significantly more night time symptoms including observed apneas, difficulty breathing, restless sleep and mouth breathing during sleep compared to occasional and non-snorers.”10
And finally, data from 248 medical charts of mouth-breathing children were analysed to determine the prevalence of obstructive sleep disorders in such children. It was found that 58% of children were primary snorers and 42% had obstructive sleep apnoea. The paper concluded that, “primary snoring and OSAS are frequent findings in mouth breathing children.”11
There is no doubt that mouth breathing is a significant causal factor for snoring and sleep apnea in both adults and children.
- Kim EJ, Choi JH, Kim KW, Kim TH, Lee SH, Lee HM, Shin C, Lee KY, Lee SH.
The impacts of open-mouth breathing on upper airway space in obstructive sleep apnea: 3-D MDCT analysis.Eur Arch Otorhinolaryngol. 2010 Oct 19.
- Kreivi HR, Virkkula P, Lehto J, Brander P.Frequency of upper airway symptoms before and during continuous positive airway pressure treatment in patients with obstructive sleep apnea syndrome. Respiration. 2010;80(6):488-94.
- Ohki M, Usui N, Kanazawa H, Hara I, Kawano K. Relationship between oral breathing and nasal obstruction in patients with obstructive sleep apnea.Acta Otolaryngol Suppl. 1996;523:228-30.
- Lee SH, Choi JH, Shin C, Lee HM, Kwon SY, Lee SH.How does open-mouth breathing influence upper airway anatomy? Laryngoscope. 2007 Jun;117(6):1102-6.
- Scharf MB, Cohen AP Diagnostic and treatment implications of nasal obstruction in snoring and obstructive sleep apnea. Ann Allergy Asthma Immunol. 1998 Oct;81(4):279-87; quiz 287-90.
- Wasilewska J, Kaczmarski M Obstructive sleep apnea-hypopnea syndrome in children [Article in Polish] Wiad Lek. 2010;63(3):201-12.
- Rappai M, Collop N, Kemp S, deShazo R. The nose and sleep-disordered breathing: what we know and what we do not know. Chest. 2003 Dec;124(6):2309-23.
- Izu SC, Itamoto CH, Pradella-Hallinan M, Pizarro GU, Tufik S, Pignatari S, Fujita RR. Obstructive sleep apnea syndrome (OSAS) in mouth breathing children. [Article in English, Portuguese] Braz J Otorhinolaryngol. 2010 Oct;76(5):552-6.
- Sahin U, Ozturk O, Ozturk M, Songur N, Bircan A, Akkaya A. Habitual snoring in primary school children: prevalence and association with sleep-related disorders and school performance. Med Princ Pract. 2009;18(6):458-65. Epub 2009 Sep 30.
- Sogut A, Yilmaz O, Dinc G, Yuksel H, Prevalence of habitual snoring and symptoms of sleep-disordered breathing in adolescents. Int J Pediatr Otorhinolaryngol. 2009 Dec;73(12):1769-73. Epub 2009 Oct 20.
- Izu SC, Itamoto CH, Pradella-Hallinan M, Pizarro GU, Tufik S, Pignatari S, Fujita RR. Obstructive sleep apnea syndrome (OSAS) in mouth breathing children.[Article in English, Portuguese] Braz J Otorhinolaryngol. 2010 Oct;76(5):552-6.