In the field of Otorhinolaryngology, Neurinoma (neurilemmoma, Schwannoma) is well known as a acoustic tumor.
patient was a 17 year-old male, who denied any head injuries in his past. Inspection and other examination failed to reveal any sign and symptom of Osteogenesis imperfecta.
During operation he was found to have abnormal course of the facial nerve invertical segment of the temporal bone with a little posterior displacement.
Kettel in 1909 recorded 4 segments, where abnormalities located.
And he classified these segments as follows:
Type 1 Abnormality in labyrint hsegment
Type 2 Abnormality in horizont alsegment
Type 3 Abnormality in pyramid alsegment
Type 4 Abnormality in vertica lsegment
Therefore our case belongs to Type 4 according to his classification. The exposed portion of the facial nerve was covered by the temporal fascia. On the 3rd postoperative day t hepatient developed facial paralysis but it disappeared in 4 weeks.
It was thought that our case was one of the so-called asymptomatic auditory organanomaly Takahara without visible malformation of the temporal bone.
