[Malformations of chorda tympani nerve].

OBJECTIVE

To analyze the characteristics of anomalies of chorda tympani nerve.

METHOD

Chorda tympani nerve and its adjacent structure were investigated during microsurgery in 667 cases of congenitally malformed external-middle ear.

RESULT

Anomalies of chorda tympani nerve were found in 433 cases (64.91%). In the group of isolated middle ear malformation of chorda tympani nerve was 16/147 (10.88%); in the group of stenosis of external auditory canal 22/95 (23.15%); and in the group of atresia 394/394 (100%). In 385 cases (97.7%) chorda nerve were not discovered during operations; It were situated at atresia plate (far from malleoincudal interspace) in 9 cases (2.28%). Different feature were found such as: elongation of chorda tympani posterior canaliculus, high or low position, reduplication of chorda tympani nerve, significant low position of chorda tympani nerve in the atresia plate.

CONCLUSION

Malformation of chorda tympani nerve is related to the embryologic development of the facial nerve, ossicle, oval window et. It is imparative to identify and to protect the ectopic chorda tympani nerve during operation early.