Human Temporal Bone Removal: Skull Base Block Method

Objective: This study aims to describe a novel technique for the efficient harvest of larger temporal bone specimens from human cadavers. Our technique is directly compared with the previously described Modified Block Method (MBM). This practice is intended for the training of otolaryngology residents and fellows on the various approaches to the lateral and posterolateral skull base.

Study Design: This study is a human cadaveric study.

Method: The calvarium was excised 6 cm above the superior aspect of the ear canal using an autopsy saw. The brain and cerebellum were carefully removed and the cranial nerves were cut sharply near the brain stem. Two bony cuts were performed, one in the midsagittal plane and the other in the coronal plane at the level of the optic foramen. The remaining soft tissue attachments were sharply dissected in an axial plane at the level of the oral commissure until the entire temporal bone specimen was only attached by the cervical vertebrae. The C1 vertebrae was then dislocated from C2 to free the temporal bone specimen.

Results: Larger temporal bone specimens containing portions of the parietal, occipital, and sphenoidal bones were consistently obtained using this technique of two bone cuts. All specimens were inspected and contained pertinent surface and skull base landmarks.

Conclusion: The skull base block method allows for larger temporal bone specimens using a two bone cut technique that is efficient and reproducible. These specimens have the necessary anatomical bony landmarks for studying the complexity, utility, and limitations of lateral and posterolateral approaches to the skull base. Understanding the anatomy of the vital structures coursing through the temporal bone is important in reducing common postsurgical complications of the lateral and posterolateral approaches to the skull base. This new technique will enhance otolaryngology resident and fellow education.