I have a partial denture - not many upper teeth left. Also have my lips cut across by multiple operation scars for a cleft lip and palate. I'm not the greatest on the flute but I can do it. I find alto flute easier than the normal size. Latest thing I've picked up is the dizi (D soprano size, or G in Chinese nomenclature) and I haven't found any insuperable problem with that, though the high notes aren't really there yet.

So - I'm affected and it's not serious.