Clinical anatomy of greater petrosal nerve and its surgical importance.

Background: Surgical approach towards greater petrosal nerve has to be done with caution as many surgeons are unfamiliar with the anatomy of the facial nerve. The anatomical landmarks selected must be reliable and above all easy to identify for identification of the greater petrosal nerve so as to avoid injury to the structures in the middle cranial fossa. Observation and Results: The present study is carried out on 100 temporal bones by examining the following measurements of the right and the left sides a) length of the hiatus for grater petrosal superficial nerve b) distance from superior petrosal sinus c) distance from lateral margin of middle cranial fossa d) arcuate eminence and e) distance from exit to the foramen ovale. Conclusion: The anatomical landmarks selected must be reliable and above all easy to identify. Bony structures are more suitable than soft tissue or cartilaginous landmarks because of their rigid and reliable location. These anatomical landmarks will definitely help the surgeon while performing vidian nerve neurectomy and also the anatomical relationship of the facial nerve in temporal bone. The middle fossa approach involves a temporal craniotomy in cases of perineural spread of adenoid cystic carcinomas hence these anatomical landmarks will serve as useful guide for the surgeons and radiologists. [ABSTRACT FROM AUTHOR]