Anatomical variations of the chorda tympani nerve

The author studied anatomical variations of the origin of the chorda tympani nerve from the mastoid portion of the facial nerve. The studies were performed on 200 specimens of human temporal bone. It was found that the chorda tympani may arise from the facial nerve in three levels: most commonly from the mid third of its mastoid segment [70%], less commonly from the proximal third [20%], and very rerly from the distal third [10%]. Knowledge of these variations has a certain value in surgical intervention of the middle ear