“The Impact of Open-Mouth Breathing on Upper Airway Space in Obstructive Sleep Apnea: 3-D MDCT Analysis”
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.
Eur Arch Otorhinolaryngol. April 2011, Volume 268, Issue 4, pp 533-539
Mouth breathing and forward head posture: effects on respiratory biomechanics and exercise capacity in children
92 children aged between 8 and 12 years were studied, of which 30 were mouth breathers and 62 were nasal breathers. The study concluded that mouth breathing negatively affected respiratory biomechanics and exercise capacity.
Okuro RT, Morcillo AM, Ribeiro MÂ, Sakano E, Conti PB, Ribeiro JD. J Bras Pneumol.2011;(Jul-Aug;37(4)):471-9
Influences of the breathing route on upper airway dynamics properties in normal awake subjects with constant mouth opening
When compared with nasal breathing, mouth breathing decreases the stability of the lower airway independent of mouth opening.
This effect of mouth opening and moving from nasal breathing to mouth breathing may add to the effects of sleep on upper airway muscle tonic activity to worsen upper airway stability and favor the occurrence of upper airway obstruction during sleep.
Clinical Science (2006) 111, 349–355
This slide shows the importance of proper head position. A forward head position allows for easier breathing but at the same time creates a significant muscle imbalance which can affect overall athletic performance. A forward head position is also and indication of an improper swallowing pattern, mouth breathing and tongue position.
Apnea: A new training method in sport?
The physiological responses to apnea training exhibited by elite breath-hold divers may contribute to improving sports performance. Breath-hold divers have shown reduced blood acidosis, oxidative stress and basal metabolic rate, and increased hematocrit, erythropoietin concentration, hemoglobin mass and lung volumes. We hypothesise that these adaptations contributed to long apnea durations and improve performance. These results suggest that apnea training may be an effective alternative to hypo-baric or normobaric hypoxia to increase aerobic and/or anaerobic performance.
Frédéric Lemaître, Fabrice Joulia, Didier Chollet, Medical Hypotheses 74 (2010) 413–415