Different aspects of respiration: relationships between the upper and lower respiratory tracts, and the middle ear cleft, nasal versus oral breathing.

This paper outlines the normal functioning of the child's upper airway: defending the lower airway by means of air conditioning, filtration, initiation of inflammatory reactions or immune responses. We investigate the hypothetical mechanisms that explain the influence of, and interrelations between, mouth breathing and obstructive sleep apnoea on craniofacial development. We advise orthodontic diagnosis and/or intervention at a young age.