Background: Telementoring is the technology for providing surgical instruction from a remote place via a network. To demonstrate the use of telementoring in craniofacial surgery, Skype and a mixed reality device HoloLens were adopted, and 3-layer facial models had been developed. Methods: A resident in hospital A used the model surgery under remote guidance by a mentor surgeon in hospital B 4 times on different dates. The straight-line between hospitals A and B is 250 km. The mentor gave the resident guidance via Skype and HoloLens, communicating by voice, and video of the surgical field, and providing reference data. Results: There was no delay in voice communication and a delay of <0.5 seconds in the video. The resident was able to confirm the main landmarks of the surgical field and to grasp the situation without problems. The mentor could send appropriate instructions by voice, could point out a specific part by telestration function, and could draw lines on the 2-dimentional images pasted on the operator's field of vision. Discussion: With the use of HoloLens, Skype, and the 3-layer models, it was possible to demonstrate telementoring. The risk of personal information leakage due to data interception seems to be very low because its data communication is encrypted with advanced encryption standard. Conclusion: This telementoring system has various advantages and many improvable aspects in the field of craniofacial surgery.

Background: We made realistic, three-dimensional, computer-assisted 3-layered elastic models of the face. The surface layer is made of polyurethane, the intermediate layer is silicone, and the deep layer is salt, representing the skin, subcutaneous tissue, and the bone. We have applied these 3-layer models to congenital anomaly cases and have understood that these models have a lot of advantages for simulation surgery. Methods: We made 8 models. The models consisted of 2 models of 2 cases with Crouzon disease, 1 model of Binder syndrome, 1 model of facial cleft, 2 models of one case with Goldenhar syndrome, 1 model of cleft lip and palate, and 1 model of the hemifacial macrosomia. Results: We could try several methods, could recognize whether the graft size is adequate, and could visualize the change of the facial contour. We could analyze how to approach the osteotomy line and actually perform osteotomy. The changes of the lower facial contour can be observed. We grafted the models of the graft and confirmed that the incisions could be closed well. We were able to visualize the change in the soft tissue contour by simulating distraction. Conclusions: The most versatile merit of our models is that we could visualize the change of the soft tissue by movement of the hard tissue with bone graft, distraction osteogenesis, and so on. We must improve the model further to make it more realistic.

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Summary: Preoperative understanding of the running pattern of blood vessels is an important factor to approach surgical fields safely. In 2 cases where the vascular abnormalities were estimated, we projected the blood vessels onto the surgical field using an augmented reality device HoloLens. A splint was made to allow the patient to be fixed while undergoing computed tomographic angiography. Three-dimensional (3D) data on the blood vessels, skin surfaces, bones, and the 3 chosen points for alignment were segmented and then projected onto the body surfaces as holograms using the HoloLens. Two types of projection for holograms were used: projection type 1—where the body contours were projected as a line, and projection type 2—where the body surface was projected as meshed skin type. By projecting projection type 2 rather than projection type 1, we gained a better understanding of the 3D anatomic findings and deformation characteristics, including the anatomic blood vessel variation and positional relationships between the organs and body surfaces. To some extent, we could make sure that the depth perception can be obtained by recognizing the bone, vessels, or tumor inside the meshed skin surface. Our new method allows the 3D visualization of blood vessels from the body surface, and helps understand the 3D anatomic variation of the blood vessels to be applied as long as the blood vessels can be visualized.