Effect of type I tympanoplasty on the resonant frequency of the middle ear: comparison between chondrotympanoplasty and temporalis fascia grafting.

AIMS: To evaluate the effect of type I chondrotympanoplasty on the resonant frequency (RF) of the middle ear and compare it to the respective outcomes of type I tympanoplasty using temporalis fascia grafting (TFG). Hearing results and respective graft integration rates were also assessed.

MATERIALS AND

METHODS

A retrospective comparative study was conducted of patients who had undergone type I tympanoplasty at a tertiary university hospital. Selection criteria included tympanic membrane perforation following chronic otitis media, trauma, or grommet insertion; an intact ossicular chain; a dry ear for at least 3 months; and normal middle ear mucosa. Patients with ossicular discontinuity, ossiculoplasty, cholesteatoma, previous ear surgery, syndromes affecting the middle ear, or younger than 16 years old were excluded.

RESULTS

Sixty-nine patients met the inclusion criteria; chondrotympanoplasty was performed in 39 and TFG in 30. Three patients showed incomplete tympanic membrane closure at follow-up. The graft integration rate was 97.4% in the chondrotympanoplasty group and 93.3% in the TFG group. An air-bone gap closure within 10 dB was achieved in 73.7% of the chondrotympanoplasty patients versus 67.9% of the TFG patients. Hearing gain of 21 to 30 dB in air conduction thresholds was obtained in 65.8% of the chondrotympanoplasty patients and 60.7% of their TFG counterparts. RF was 808 ± 458 Hz in the chondrotympanoplasty group and 628 ± 256 Hz in the TFG group. The RF remained within the normal range in 73.7% of chondrotympanoplasty patients versus 42.9% of TFG patients.

CONCLUSIONS

Chondrotympanoplasty has hearing results comparable to those of TFG myringoplasty. The cartilage can be used without concerns regarding its impact on the middle ear mechanics as the sound-conducive properties of the tympanic membrane remain unchanged.