抄録
Hearing was tested in 49 ears with intact stapes superstructure 1-12 months after ossicular reconstruction and tympanoplasty. Audiograms were recorded not only at speech frequenices but at all seven frequencies from 125 to 8000Hz. Thirty bone autografts (preserved ossicles and mastoid cortical bone), 17 cartilage autografts and 2 hydroxyapatite ossicular prostheses (Apaceram-P) were used as columellae.
1. Overall success rates according to the criteria of Clinical Otology Japan (1987) were 82.9% at 6 months and 83.9% at 12 months after surgery.
2. Postoperative hearing gains were obtained at all frequencies except 8000Hz, and hearing improvement was greater at low and middle frequencies.
3. Hearing improvement was greatest 6 months after surgery, and it declined gradually until 12 months after surgery at both low and high frequencies.
4. The evaluation of postoperative hearing after modified type III tympanoplasty, which includes ossiculoplasty, should be done about 12 months after surgery.
