Abstract
Although impairment of middle ear ventilation and subsequent middle ear negative pressure have been regarded as important pathogenetic factors in middle ear diseases, impairment of middle ear ventilation has not been proven to necessarily cause progressive negative middle ear pressure. Toynbee phenomenon is another possible cause of active production of negative middle ear pressure. Accordingly, we investigated the incidence and pathophysiology of Toynbee phenomenon in various middle ear diseases.
The incidence of positive Toynbee phenomenon was 75% (18124) in controls. Whereas, the incidence was 14% (8/59) in cases of otitis media with effusion (OME), 50% (13126) in cases of chronic otitis media (COM), 38% (5/13) in cases of adhesive otitis media (Adh), and 30% (3/10) in patients with cholesteatoma. However, the negative pressure induced by the Toynbee maneuver was significantly more profound in cases of Adh (- 116.0±58.6 mmH2O) than in normal ears (-8.05±53.9 mmH2O, p<0.005). Also the average induced negative pressures in the other diseased ears tended to be more profound than in normal ears; -23.6±37.1 mmH2O in OME, -23.1±55.1 mmH2O in COM, -45.0±18.0 mmH2O in cholesteatoma. Considering that middle ear diseases often accompany nasal diseases and are also often induced or aggravated by upper respiratory infections or nasal allergies (when the nose is congested), and that the eustachian tubes in diseased ears often cannot equalize negative middle ear pressure, Toynbee phenomenon may be related to the pathogenesis of these ear diseases.
