I came across this abstract: Bilateral laryngoceles in a young trumpet player: case report. While I was looking for information for a friend whose daughter is suffering from puffing her cheeks out while playing. Whilst not wanting to frighten her it does seem to be a risk and I wonder if any of the teachers here have had students suffer this sort of damage from trumpet playing? Buck Clayton suffered from it as well and had to have surgery for it in the end. I notice that balloon modelers also suffer from it.