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Published on: February 21, 2018
New method of identifying the internal auditory canal as seen from the middle cranial fossa approach
Ho-Ki Lee1, In Sup Kim, Won-Sang Lee
1Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Korea.
Objectives:
The middle cranial fossa approach allows one to remove acoustic tumors and preserve the facial nerve and hearing. However, there are no consistent landmarks on the surface of the temporal bone to identify the internal auditory canal. This study was designed to identify the internal auditory canal by use of external and internal references as seen during the middle cranial fossa approach.
Methods:
We dissected 32 temporal bones using the middle cranial fossa approach and measured the distances from the posterior origin of the zygomatic arch to an imaginary coronal line between the foramen spinosum and the foramen ovale. We measured the angle between the lines drawn from the posterior origin of the zygomatic root to the foramen spinosum and from the foramen spinosum to the porus of the internal auditory canal.
Results:
The distances were 14.7 mm and 22.9 mm, respectively, and the angle was roughly 90 degrees.
Conclusions:
In this study, we found external and internal landmarks that help to locate the internal auditory canal.
Related Concept Videos
01:16Anatomy of the Ear
01:27Cranial Bones: Lateral View
The temporal bone forms the lower lateral side of the skull. The temporal bone is subdivided into several regions. The flattened upper portion is the squamous portion of the temporal bone. Below this area and projecting anteriorly is the zygomatic process of the temporal bone, which forms the posterior portion of the zygomatic arch. Posteriorly is the mastoid portion of the temporal bone. Projecting...