INTRODUCTION: In this study, we aimed to investigate whether the spine of Henle could a new landmark for the localization of the superior semicircular canal (SCC).
METHODS: Between March 2014 and March 2015, a total of 30 adult cadaveric temporal bones were used in this study. All temporal bones were positioned and, then, canal-wall up mastoidectomy and facial recess approach were performed. The landmarks such as sigmoid sinus (SS), middle cranial fossa dura (MCFD), posterior cranial fossa dura (PCFD), SCCs, short process of the incus, facial nerve (FN), and chorda tympani nerve were identified. The shortest distances between the spine of Henle and the following structures were measured: (i) superior SCC; (ii) lateral SCC; (iii) posterior SCC; (iv) MCFD; (v) PCFD; (vi) SS; and (vii) FN. All measurements were performed using a digital caliper.
RESULTS: After excluding three temporal bones with absent spine of Henle, 27 temporal bones were studied. The mean distances between the spine of Henle and the superior, lateral and posterior SCCs, MCFD, PCFD, SS, and FN were 20.3±2.4, 15.9±2.1, 17.8±2.0, 13.7±2.9, 19.0±2.7, 14.9±3.6, and 15.8±1.7 mm, respectively. The distances between the spine of Henle and superior SCC were higher in the temporal bones, while the distances between the spine of Henle and MCFD were higher than the mean values. Similar differences were found for the distances between the spine of Henle and the lateral and posterior SCCs and PCFD.
DISCUSSION AND CONCLUSION: Based on our study results, the spine of Henle can be used as a landmark for the localization of the superior SCC during mastoidectomy and superior SCC surgeries.