I shot this hog in Texas about 15 years ago. The jaw on the other side was damaged (bone cancer?). Wife didn't want it on a wall so I put it on a pedistal and donated it to a middle school science room.
I will have to look at the other half to see for sure. I donated the other half to a high school biology teacher. It clearly shows the brain cavity, the inner ear and the spiral bones in the nostrils.
It appears there are sinus cavities or some other hollow structures above the brain. With hide, fur and ears it might be possible to overestimate how high up the brain is in a live animal.