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

Abstract 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. 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. 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. 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.