Anatomy Study Of Related Parameters Of Temple Bone Structure In The Surgery Of Cochlear Implantation

Objective: To investigate the correlation parameters of temple bone structure in the surgery of cochlear implantation so we can provide the anatomic data for the surgery.Method: Eighteen temple bones were dissected. By opening the mastoid cavity and removing the lateral wall of external auditory canal and tympanic scutum, the related anatomic structures were well exposed. Under the surgical microscope we measured the parameters of the distance from the anterior of the facial nerve canal to the anterior of the round window, the distance of the highest point of the facial nerve canal to the bottom of posterior mastoid sinus, the height of pyramidal eminence and the distance between the stapes head and round window niche.Result: The distance from the anterior of the facial nerve canal to the anterior of the round window was 4. 75~7. 85(5. 89±0. 92)mm, the distance of the highest point of the facial nerve canal to the bottom of posterior mastoid sinus was 4. 85~8. 79(7.02 ± 0.93)mm, the height of pyramidal eminence was 0. 85~2. 73(1. 90 ± 0. 50)mm, and the distance between the stapes head and round window niche was 2. 32~3. 71 (3. 00±0. 38)mm.Conclusion: Pyramid segment of facial canal are the important surgical marks while the pyramidal eminence is a very important landmark for identify the posterior mastoid sinus. The measurements of parameters between the round window niche to the related structure could help us to determine the position of cochlear implant electrode into the scala tympani.