[Results of chorda tympani nerve application or no in tympanoplasty]

To demonstrate the effect of chorda tympani nerve used in tympanoplasty.

One hundred and forty-one cases (154 ears) were divided into 3 groups: (1) chorda applying group (CA) 35 cases (41 ears): had perforation in pars tensa but chorda nerve still exist, the nerve were applied to spring and press a PORP or TORP prosthesis which were made by auto-osseous tissue and had a fine groove for nerve inlay. (2) residual pars tensa applying group (RTP) 67 cases (72 ears): residual pars tensa was used to spring and press prosthesis. (3) no applying group. (NA) 39 cases (41 ears). The effect measurement: ABG over 30 dB as excellent over 15 dB as effective; less than 10 dB as noneffective. Three groups were analyzed by S- t test.

Excellent, effective and noneffective ears (%): CA group: 29.3%, 51.2%, 19.5%; RPT group: 22.2%, 50.0%, 27.8%; NA group: 19.5%, 36.6%, 43.9%; the previous two groups contrast with NA group, P < 0.01. Pre- and post-operation ABG odds and paired contract: CA and NA, P < 0.05; RTP and NA, P < 0.05. In CA group only one ear had taste letdown temporarily and another ear had delayed and mild facial paralysis, both were auto-recovered within two weeks.

Chorda tympani nerve applied in tympanoplasty for spring and press prosthesis can make PORP or TORP prosthesis more steady and improve hearing.