[Orthognathic and orthodontic consequences of mouth breathing].

There is a large controversy about the causal relations between dento-facial deformities and mouth-breathing habits. Some postural and morphological changes during long-term adaptation to oral respiration are evoked: opening of the bite with a lowered postural position of the mandible, reduction of upper arch width, downward and backward rotation of the mandible, increased lower facial height and changes in the inclination of the lower and upper incisors. It seems that the altered postural position of the tongue and of the mandible, needed for oral ventilation, could, by soft-tissue stretching, change the growth pattern of the face.