3D-printed paediatric temporal bones as an alternative tool for otological training

Objectives: Temporal bone dissection is an essential part of otological surgical training. Ethical reasons prevent the use of cadaveric paediatric temporal bones and diseased temporal bones harbour different anatomiy to most models or healthy specimens. Ideal preoperative preparation should allow the surgeon to undertake the actual operative procedure in a simulated manner. The use of 3D printed models based on high resolution computed tomography (HRCT) scans has already being trialled for adults, but may be of greater benefit for paediatric cases.

Methods: Non-identifiable HRCT scans of paediatric temporal bones were segmented and converted into surface representations using open source software and self-made algorithms. Several 3D prints of paediatric temporal bones were created, mounted in modelling clay and drilled by ENT surgeons using an electric drill.

Results: 3D printing of paediatric temporal bones has proved both economical and anatomically faithful. Use of HRCT scans allow specific cases to be selected for printing. The 3D printed models enabled cortical mastoidectomy to be undertaken but lacked sufficient resolution of the inner ear and facial nerve. With a price of £16, the cost of the bones is much lower than that of traditional plastic cast models.

Conclusion: Further anatomical delineation of 3D printed temporal bones from HRCT images will provide the opportunity for improved paediatric temporal bone surgical training. It will also provide preoperative simulation opportunities in cases with challenging anatomy. Selection of appropriate materials potentially offers improved haptics. Further research in alternative segmentation and additive manufacturing methods will lead to improved temporal bone models.