Congenital Ossicular Disruption with Fluctuation of Hearing in 3 Patients.

The diagnosis of ossicular disruptions of intact eardrums is not difficult because they have several specific clinical features (large air-bone gap, type Ad tympanogram and negative stapedial reflex). We report 3 patients (4 ears) with congenital ossicular disruption who were difficult to diagnose because of their mild or fluctuating conductive hearing loss. All 3 subjects showed a small air-bone gap when they had otitis media with effusion (OME), but their air-bone gap increased when their OME improved. It was speculated that middle-ear effusion may have influenced the middle-ear sound conduction resulting in a temporarily small air-bone gap.