[Mechanical obstruction of the juncture between the eustachian tube and pharynx. Pathogenesis of ear diseases in cleft palate].

The universality of middle ear diseases in infants with cleft lip and palate is well known. Middle ear disease is causally related to an eustachian tube dysfunction due to anatomical variations of the tubal lumen or muscles. Endoscopy of the nasopharynx, microscopic examination and impedance measurement of the ear was performed in 53 children with cleft lip, alveolus and palate. Dynamic and static documentation was performed with a videocamera or a reflex camera. The pharyngeal port of the eustachian tube was mechanically obstructed by the lateral part of the cleft palate muscle in nearly all patients. The degree of the mechanical obstruction seemed to be related to the extent of the cleft. Furthermore there were less pathologic ear findings in patients with less obstructed pharyngeal ports of the eustachian tube.