Mouth Breathing and Asthma

MOUTH BREATHING AND ASTHMA

We speculate that asthmatics may have an increased tendency to switch to oral breathing, a factor that may contribute to the pathogenesis of their asthma.
Chest. 1999 Dec;116(6):1646-52. Route of breathing in patients with asthma. Kairaitis K, Garlick SR, Wheatley JR, Amis TC
http://chestjournal.chestpubs.org/content/116/6/1646.full
http://www.ncbi.nlm.nih.gov/pubmed/10593789
Enforced oral breathing causes a decrease in lung function in mild asthmatic subjects at rest, initiating asthma symptoms in some. Oral breathing may play a role in the pathogenesis of acute asthma exacerbations.
Respirology. 2008 Jun;13(4):553-8. Enforced mouth breathing decreases lung function in mild asthmatics. Hallani M, Wheatley JR, Amis TC.
http://www.ncbi.nlm.nih.gov/pubmed/18494947
In the first step of a study of the relation of nasal and oral breathing during moderate treadmill exercise to the onset of bronchoconstriction in young patients with perennial bronchial asthma, it was observed that most subjects spontaneously breathed with their mouths open when instructed to breathe "naturally." Subsequently, when they were required to breathe only through the nose during the exercise, an almost complete inhibition of the postexercise bronchoconstrictive airway response was demonstrated. When instructed to breathe only through the mouth during exercise, an increased bronchoconstrictive airway response occurred, as measured by spirometry, flow-volume relationships, and body plethysmography. These findings suggest that the nasopharynx and the oropharynx play important roles in the phenomenon of exercise-induced bronchoconstriction.
Am Rev Respir Dis. 1978 Jul;118(1):65-73. The beneficial effect of nasal breathing on exercise-induced bronchoconstriction. Shturman-Ellstein R, Zeballos RJ, Buckley JM, Souhrada JF.
http://www.ncbi.nlm.nih.gov/pubmed/677559?dopt=Abstract
The effect of nasal as well as oral breathing during level-ground running for 6 min on the post exercise bronchial response was studied in fifteen people (five asthmatics with exercise liability, five asthmatics with no such liability and five normals). Each patient did the exercise twice; once with the nose clipped and once with the mouth closed. FEV1 was measured before exercise, immediately after exercise and at 5, 10, 15, 20 and 30 min thereafter. A fall in FEV1 of 20% or more from the basal level was taken as evidence of bronchoconstriction. When the patients were required to breath only through the nose during the exercise, the post-exercise bronchoconstrictive response was markedly reduced as compared with the response obtained by oral breathing during exercise, indicating a beneficial effect of nasal breathing. Nasal breathing was beneficial as compared with oral breathing in normals as well. In the five asthmatics with no exercise liability no appreciable difference was observed. This study suggests that the oropharynx and nasopharynx play important roles in the causation of exercise-induced asthma.
Clin Allergy. 1981 Sep;11(5):433-9. Effect of nasal and oral breathing on exercise-induced asthma. Mangla PK, Menon MP.
http://www.ncbi.nlm.nih.gov/pubmed/7318162
Mouth breathing is a trait of hyperventilation. Bronchoconstriction was induced in asthmatic patients by means of isocapnic hyperventilation with dry air. Responses both within a day and between days did not differ significantly and corresponded closely with those observed after exercise. The mean fall in forced expiratory volume in one second (FEV1) observed with both techniques was equivalent to 36%. Isocapnic hyperventilation with dry air, as used in this study, was a potent stimulus and provoked a reproducible response. The method was physically less demanding than exercise and was more acceptable to patients.
Thorax. 1981 Aug;36(8):596-8. Hyperventilation of exercise to induce asthma? Tweeddale PM, Godden DJ, Grant IW.
http://www.ncbi.nlm.nih.gov/pubmed/7314034
Mouth breathing is a trait of hyperventilation. The appearance of an asthmatic crisis in the minutes following physical exercise is common in symptomatic asthma. Exercise induced asthma (EIA) is linked to hyperventilation; voluntary isocapnic hyperventilation is capable of triggering a crisis. It is well established at present that EIA and post-hyperventilation asthma (HIA) are triggered by a rise in heat and water loss by the airways, which is inherent in hyperventilation. The respective role of water loss and cooling the airways are uncertain but one tends to think at the present time that the primary stimulus is the variation in osmolality of the liquid lining the epithelium. However, a relationship between the quantity of energy dissipated in the airways and the severity of EIA or HIA exists, although it is less tight than was once thought. Hyperventilation lends itself better than exercise to establishing dose-effect curves linking bronchial response to minute ventilation.
Rev Mal Respir. 1987;4(5):217-23. [Bronchial provocation tests using hyperventilation]. [Article in French] Lockhart A.
http://www.ncbi.nlm.nih.gov/pubmed/3324231
A link between the upper and lower airways has been convincingly demonstrated both in health and disease. To what extent the nose may be involved in children's asthma, has so far not been thoroughly investigated. In this study, we compared symptoms and signs from the upper airways in children with asthma and in children without to find out more about this. Methods The study group included 27 asthmatic children, the control group 29 age and sex-matched healthy volunteers. The children were investigated by a senior ENT-specialist. Their parents completed questionnaires about symptoms and signs of upper airway disorders. Skin prick tests, total IgE, acoustic rhinometry, and an X-ray of the epipharynx were performed. The data from the groups were compared. Results Nasal blockage, mouth breathing, day time sleepiness, apnoeas, itching, sneezing, and hearing impairment were more prevalent in asthmatics compared with controls (p<0.05). For nasal blockage the mean VAS-scores were 52.4 and 30.6 for asthmatics and controls, respectively. For daytime sleepiness the corresponding figures were 34.6 and 23.1. The adenoid-nasopahrynx-index was larger, indicating reduced palatal airway in the former compared with the latter (p<0.05). Conclusions As the site of upper airway obstruction in asthmatic children appears to be the epipharynx, the adenoids may play a key-role.
Nasal symptoms and signs in children suffering from asthma. S.K. SteinsvågemaiL, B. Skadberg, K. Bredesen
http://www.ijporlonline.com/article/S0165-5876%2807%2900006-7/abstract
The use of mouth taping, to encourage nose breathing, is currently being recommended by some Buteyko practitioners, but its effects on physiology are unknown. This preliminary study aimed to investigate the effects of mouth taping on end-tidal carbon dioxide (ETCO2). Design Preliminary study with an experimental single group repeated measures design. Setting Nine university students and staff with mild stable asthma. Interventions Physiological data were recorded before and during two experimental breathing conditions: oral breathing and nasal breathing (encouraged by mouth taping), carried out on two separate occasions 5–14 days apart. Between visits, participants familiarised themselves with the mouth taping technique. Outcome measures Primary outcome was ETCO2. Secondary outcomes were respiratory rate, pulse rate, oxygen saturation and lung function. Results There was an increase in ETCO2 from baseline during both breathing conditions. The mean ETCO2 for oral breathing was 4.4 kPa versus 4.7 kPa for nasal breathing, with mean difference of 0.3 kPa (95% confidence interval −0.2 to 0.8 kPa). It was also found that ETCO2 increased more in ‘natural’ oral breathers than ‘natural’ nasal breathers. Conclusions The results of this pilot study provide data to power a larger study and suggest ETCO2 may be increased in people with asthma during nasal breathing, particularly in those who normally primarily breathe through the mouth. The methodology was found to be acceptable to this sample of people with mild asthma.
The use of mouth taping in people with asthma: a pilot study examining the effects on end-tidal carbon dioxide levels
Ajay Bishop, Michelle Rawle, Anne Bruton. School of Health Professions and Rehabilitation Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, UK
http://www.sciencedirect.com/science/article/pii/S0031940606001921
Enhanced perception of nasal loading may trigger increased oral breathing in asthmatics, potentially enhancing exposure to nonconditioned inhaled gas and contributing to the occurrence and/or severity of bronchoconstrictive exacerbations.
Eur Respir J. 2008 Apr;31(4):800-6. Epub 2007 Nov 21. Initiating oral breathing in response to nasal loading: asthmatics versus healthy subjects. Hallani M, Wheatley JR, Amis TC.
http://www.ncbi.nlm.nih.gov/pubmed/18032447
Airway dehydration triggers exercise-induced bronchoconstriction in virtually all patients with active asthma. Dehydration of the expired air is present in asthmatic patients in the emergency department. The bronchoconstriction triggered by dry-air tachypnea challenge in the laboratory can be prevented by humidifying the inspired air.
Airway Dehydration* A Therapeutic Target in Asthma? Edward Moloney, MB; Siobhan O’Sullivan, PhD; Thomas Hogan, MD; Leonard W. Poulter, DSc; and Conor M. Burke, MD, FCCP
http://www.ncbi.nlm.nih.gov/pubmed/12065342

Mouth Breathing affects sports performance

The research within this article seeks to verify and demonstrate the consequences of mouth breathing versus nasal respiration and to view supposed postural alterations in groups of children within specific age ranges. The authors state that children with nasal respiration, age 8 and above, present with better posture than those who continue oral breathing beyond age 8. The importance of picture documentation is stressed in order to provide the most information regarding postural changes. A review of research and literature is provided in the article. Int J Orofacial Myology. 2000 Nov;26:13-23.Relationship between mouth breathing and postural alterations of children: a descriptive analysis. Krakauer LH, Guilherme A. http://www.ncbi.nlm.nih.gov/pubmed/11307345
Chronic and habitual mouth breathing is also associated with postural changes resulting in decreased muscle strength, reduced chest expansion and impaired pulmonary ventilation. In 2011, Brazilian researchers Okuro and colleagues from Campinas State University conducted a study to evaluate exercise tolerance, respiratory muscle strength and body posture in mouth breathing compared to nasal breathing children. Children with asthma, obesity, chronic respiratory diseases, neurological and orthopedic disorders, and cardiac conditions were excluded. Of the 107 children, 45 were mouth breathers and 62 were nasal breathers. Examination revealed that 80% of mouth breathing and 48.4% of nasal breathing children had abnormal cervical posture and breathing pattern. Researchers concluded that “mouth breathing children had cervical spine postural changes and decreased respiratory muscle strength compared with nasal breathing.”3 Braz J Otorhinolaryngol. 2011 Sep-Oct;77(5):656-62. Exercise capacity, respiratory mechanics and posture in mouth breathers. Okuro RT, Morcillo AM, Sakano E, Schivinski CI, Ribeiro MÂ, Ribeiro JD.
http://www.ncbi.nlm.nih.gov/pubmed/22030977
In another study to evaluate submaximal exercise tolerance and respiratory muscle strength in mouth breathing and nasal breathing children. A total of 92 children aged between 8 and 12 years were studied, of which 30 were mouth breathers and 6 were nasal breathers. Following the study, the paper concluded that respiratory biomechanics and exercise capacity were negatively affected by mouth breathing.4 J Bras Pneumol. 2011 Jul-Aug;37(4):471-9.Mouth breathing and forward head posture: effects on respiratory biomechanics and exercise capacity in children. Okuro RT, Morcillo AM, Ribeiro MÂ, Sakano E, Conti PB, Ribeiro JD.
http://www.ncbi.nlm.nih.gov/pubmed/21881737
Results from the above studies are confirmed by another paper entitled “Assessment of the body posture of mouth-breathing children and adolescents.” It was reported following a study of 306 mouth breathing and 124 nasal breathing children that “postural problems were significantly more common among children in the group with mouth breathing syndrome, highlighting the need for early interdisciplinary treatment of this syndrome.” Interestingly, researchers noted that mouth breathers were more likely to be male.5 J Pediatr (Rio J). 2011 Jul-Aug;87(4):357-63. Epub 2011 Jul 18. Assessment of the body posture of mouth-breathing children and adolescents. Conti PB, Sakano E, Ribeiro MA, Schivinski CI, Ribeiro JD.
http://www.ncbi.nlm.nih.gov/pubmed/21769416
Mouth-breathing is a common clinical condition among school-age children and some studies have correlated this condition with quality of life and postural alterations. Therefore, the objective of this study was to investigate the orientation and position of the scapula, thoracic spine and head posture among mouth-breathing (MB) children and nasal-breathing (NB) children.
Mouth Breathing children increased scapular superior position in comparison to Nasal Breathing children due probably to the position of forward head, leading to an alteration in the positioning of the mandible. The absence of significantly difference in posture pattern between groups in the present study could attributed to height-weight development in this age, as the posture of children changes in order to adapt to new body proportions, regardless of health status. The results observed in this study demonstrate the importance of using reliable measurements in the postural assessment of MB and NB children helping physical therapists to focus their strategies during rehabilitation in more specific conditions. Int J Pediatr Otorhinolaryngol. 2009 Feb;73(2):227-36. Epub 2008 Dec 3. Orientation and position of head posture, scapula and thoracic spine in mouth-breathing children. Neiva PD, Kirkwood RN, Godinho R. Source Biological Science and Health Institute, Pontifícia Universidade Católica de Minas Gerais, Minas Gerais, Brazil.
http://www.ncbi.nlm.nih.gov/pubmed/19056131

Abnormal growth of the face due to mouth breathing

Did you know that if your child grows up breathing through their mouth, their face may develop abnormally? In summary, mouth breathing causes unattractive and unhealthy children.
Please read extracts from medical papers below.
1) ‘116 paediatric patients who had undergone orthodontic treatment. Mouth breathers demonstrated considerable backward and downward rotation of the mandible, increased overjet (buck teeth), increase in the mandible plane angle (longer face), a higher palatal plane (affects upper airways), and narrowing of both upper and lower arches at the level of canines and first molars compared to the nasal breathers group (overcrowding of teeth). The prevalence of a posterior cross bite was significantly more frequent in the mouth breathers group (49%) than nose breathers (26%)(P = .006). Abnormal lip-to-tongue anterior oral seal was significantly more frequent in the mouth breathers group (56%) than in the nose breathers group (30%).’ Doron Harari DMD et al. 2010 The effect of mouth breathing versus nasal breathing on dentofacial and craniofacial development in orthodontic patients. The American Laryngological, Rhinological, and Otological Society, Inc. 2010 Oct;120(10):2089-93.
http://www.ncbi.nlm.nih.gov/pubmed/20824738
2) ‘a mouth breather lowers the tongue position to facilitate the flow of air in to the expanding lungs. The resultant effect is maldevelopment of the jaw in particular and deformity of the face in general. Setting of the teeth on the jaw is also affected. All these make the face look negative.’ Care of nasal airway to prevent orthodontic problems in children J Indian Med association 2007 Nov; 105 (11):640,642)
http://www.ncbi.nlm.nih.gov/pubmed/18405091
3) ‘the switch from a nasal to an oronasal (mouth and nose combined) breathing pattern induces functional adaptations that include an increase in total anterior face height and vertical development of the lower anterior face’ Tourne. The long face syndrome and impairment of the nasopharyngeal airway. Angle Orthod 1990 Fall 60(3) 167- 76