Evaluation of 3D Printed Temporal Bone Models in Preparation for Middle Cranial Fossa Surgery

Patient-specific 3D printed models are useful presurgical planning tools because they accurately represent the anatomy and drilling characteristics of the middle cranial fossa (MCF) approach to the internal auditory canal (IAC).

The MCF approach to the IAC can be challenging due to variability of the bony architecture along the floor of the middle fossa. Patient-specific 3D printed models may enhance surgeon knowledge of a given patient's anatomy when preparing for MCF surgery.

Six temporal bone models were printed from photoacrylic resin based on CT data obtained from cadaveric specimens using a desktop stereolithography 3D printer. Critical structures to avoid injuring, the facial nerve and membranous labyrinth, were modeled as hollow cavities and filled with indicator paint. Two neurotologists each drilled three 3D printed models and the corresponding cadaveric specimens, and then completed a 41-item visual analog scale questionnaire (score range of each item: 0-10) to assess the model's accuracy, utility, and potential as a training tool.

Drilling the model was favorably rated (median score 9.2; range 7.3-9.6) for its ability to provide surgeons with an accurate mental image of the corresponding cadaveric anatomy. Overall similarity of feel of drilling the model in comparison to human bone was moderate (median 7.6; range 6.6-9.0). Surgeons would use this model to prepare for future cases (median 9.4; range 5.1-9.9) and felt it had excellent utility for training purposes (median 9.3; range 8.4-9.9).

Patient-specific 3D printed models provide an anatomically accurate and favorable tool for preparing for MCF surgery.