Please know this is what I was told from my former dentist who was also a brass player. I'm sure some other dentists that post here may correct me -just posting what I was told. Whenever you have teeth removed, it creates empty space in the gum. Over time, teeth can slowly "reset" their location. And, depending on how much you play and with how much pressure, it can be like putting braces on your teeth. they can actually be moved. I'm a player that has always used too much pressure -as I am sure many of us do. 25 years ago when I stopped playing for a number of years, my dentist noticed I suddenly started getting cavities where I hadn't had them for years. Teeth moved a little from no longer being under pressure -exposing areas not previously exposed. Again, just telling you what the dentist told me. But, I can clearly understand how a person that plays 4-5 hours a day (as I once did) could have teeth moved to a different position than where they were without playing. Apparently this isn't your issue. Was just tossing out a possibility.