[Nasal obstruction and mouth breathing: the ENT's point of view].

Obstructive diseases of children's upper airways are frequent, mostly caused by tonsils and adenoids hypertrophy. A nasal septum deviation or a lower turbinate hypertrophy may also cause a significant obstruction. Tonsillectomy and adenoidectomy must be performed in case of clinical obstruction, sometimes documented by a sleep study. A tonsils' hypertrophy without significant obstruction and clinical symptoms is not an indication of adenotonsillectomy, even in case of snoring or if an orthodontic treatment is planned.