Tide Mark & Tooth Mark
If your recorder looks like this after you have played it you should review your technique.
A tide mark shows that you habitually put too much into your mouth.
Doing this hinders your tonguing and leads to clogging problems.
Keep the recorder well in front of your teeth at all times.
Here is another good reason for keeping your recorder in front of your teeth.
This one has been used for less than a fortnight.
Not a pretty sight. I don't suppose it sounded very nice either.