[Non-obstructive etiology of mouth breathing].

Besides nose obstruction other etiological factors can be advanced to explain the development of oral respiration: malformation of the face (Binder's syndrome, Bimler's microrhinodysplasia, Apert's and Crouzon's syndrome); alterations or deviations of the tongue (Robin's syndrome, macroglossia, ankyloglossia); lip closure problems.