[Anatomical measurements and clinical applications through facial recess approach].

Objective: To provide the anatomic data for the correlated otologic microsurgery by the microdissection of temporal bone through facial recess approach.

Method: Sixteen human temporal bones of eight adult cadaveric heads were dissected under surgical microscope through facial recess approach, and the relative anatomic structures were observed and measured, such as the bony entrance of facial recess approach, facial nerve, stapes, round window, round window niche, pyramidal eminence, cochleariform process, etc. The data were analyzed statistically.

Result: The width of the bony entrance of facial recess approach was (2.94 +/- 0.32) mm, the height was (8.83 +/- 0.84) mm, the depth was (3.51 +/- 0.17) mm. The distances from stapes to tympanic segment of facial nerve, mastoid segment of facial nerve, round window, cochleariform process and anterior ligament of malleus were (1.38 +/- 0.21) mm, (6.94 +/- 0.47) mm, (3.60 +/- 0.55)mm, (2.23 +/- 0.33)mm, (4.93 +/- 0.61) mm, respectively. The distances from pyramidal eminence to tympanic segment of facial nerve, mastoid segment of facial nerve, round window, round window niche and cochleariform process were (1.05 +/- 0.09) mm, (5.63 +/- 0.41) mm, (3.01 +/- 0.34) mm, (3.29 +/- 0.44) mm, (4.13 +/- 0.51) mm, respectively. The distances from round window to cochleariform process and tympanic segment of facial nerve were (5.11 +/- 0.61) mm and (3.97 +/- 0.61) mm. The distances from round window niche to tympanic segment of facial nerve and mastoid segment of facial nerve were (4.13 +/- 0.38) mm and (7.28 +/- 0.29) mm.

Conclusion: The facial recess approach played an important role in modern otologic microsurgery. The position of anatomical structure was constant relatively, including short crus of incus, stapes, pyramidal eminence and cochleariform process, etc. These could be used as reference marks for otologic microsurgery.