“Livy” as a long weanling after surgery. As an adult she became a high-level eventer. | Photo: Courtesy Alison Gardner, DVM

Remember fifth-grade paper mâché projects? You inflated a balloon and covered it in strips of glue-soaked paper that dry hard. Then you popped the balloon while keeping the hollow shell and decorated it into a cute little r-ound-bellied rabbit or penguin?

Well, your horse’s skull is kind of like that hollow shell—at least right over the sinus cavities, according to one equine surgical team. And all it takes is a good kick to that skull bone to leave a dent into the hollow space beneath it, just like it would if someone kicked your paper mâché penguin.

To return that dented skull bone back to the right shape and protect the structures beneath, surgeons can follow the paper mâché concept: inflate a balloon