Can Babies Breathe Through Their Mouths?
Babies are not obligatory nasal breathers and can breathe through their mouths when necessary, though they preferentially breathe through their nose. 1
Evidence on Infant Breathing Patterns
Research clearly demonstrates that infants can utilize oral breathing when needed, contrary to the traditional belief that they are obligate nasal breathers. The evidence shows:
- In a study of 19 infants (1-230 days old), all subjects were able to initiate oral breathing when their nasal passages were occluded 1
- When nasal breathing is blocked, infants initially maintain tight apposition of the soft palate and tongue (closing the oropharyngeal isthmus), but after a variable time (mean 7.8 seconds), the soft palate rises and oral breathing begins 1
- Older and/or awake infants respond faster to nasal occlusion by switching to oral breathing compared to younger and/or sleeping infants 1
- In another study of 30 healthy term infants (1-3 days old), 40% initiated and sustained oral breathing in response to nasal occlusion 2
Spontaneous Oral Breathing in Infants
Even without forced nasal occlusion, some infants demonstrate oral breathing:
- Three out of ten infants studied during undisturbed sleep exhibited spontaneous oronasal breathing during both active and quiet sleep 2
- During these episodes, approximately 70% of tidal volume was nasal and 30% was oral 2
- Episodes of oronasal breathing were also observed after crying in six infants 2
Clinical Implications
Understanding that infants can breathe through their mouths has important clinical implications:
- Respiratory support in newborns: During neonatal resuscitation, bag-mask ventilation is preferable to other methods, but providers should be skilled in using various interfaces available at their institution 3
- Nasal obstruction management: While infants can switch to oral breathing when necessary, they may experience respiratory distress before making this switch, particularly during sleep 4
- Potential consequences: Chronic mouth breathing in infants and children can lead to facial development issues, including longer faces with narrower maxillae and retruded jaws 5
Important Caveats
Several factors affect an infant's ability to switch to oral breathing:
- Age and state of consciousness: The time required to initiate mouth breathing varies with age and alertness, with younger and sleeping infants taking longer to make the switch 1
- Sleep state: Nasal occlusion during sleep typically causes arousal before the switch to oral breathing 1, 4
- Potential hypoxemia: In animal studies, the switch to oral breathing after nasal occlusion occurred only after considerable hypoxemia developed 4
Conclusion for Clinical Practice
While infants can breathe through their mouths, they strongly prefer nasal breathing and may experience distress during the transition to oral breathing. Clinicians should be aware that nasal obstruction in infants requires prompt attention, even though most infants will eventually compensate by switching to oral breathing. This ability to mouth-breathe develops with maturation and varies between individual infants.