Anomalous facial nerve: the otologic surgeons' abyss.

Iatrogenic injury to the facial nerve is certainly the most apparent if not the most feared complication faced by the otologic surgeon. The temporal bone with its tightly packed sensory structures is no place for the "occasional operator". A thorough knowledge of temporal bone anatomy is of course required. On occasion, as in other areas of life, one encounters the unexpected and must be prepared to "adjust" to the situation at hand. An instructional case involving an anomalous facial nerve is presented. A review of the developmental anatomy of the facial nerve, preoperative diagnostic imaging and landmarks for determining the course of the main facial nerve trunk are discussed.