Twin sisters were very similar in their clinical findings of the normal auricles and external auditorycanals. They had no other abnormalities but conductive hearing loss. Helicalscanning CT successfullyrevealed the stapes superstructures. Careful Stapedectomy was performed in their right earresulted in remarkable hearing improved about 40dB in both cases. Microscopic examination foundthe immature cartilage at the edge of the foot plates suggested the possibility of the cause of thestapes fixation.
