I found that getting "mouth furniture" affected my voice.   i.e. having any teeth removed and replaced on a "plate", or "partial".    So I imagine a full denture would also change things .....

Full-time medications too - e.g. like V.Tam said, Blood Pressure meds tend to cause a cough.

Trying to sing in noisy, smokey venues doesn't go well.

Being overweight, under-exercized - and Aging - can all take their toll :(

But the worst destroyer by far has been vocal chord cysts, which can happen "almost overnight" and in my case meant I could no longer sing in my three a cappella harmony combos. That was the absolute pits.

R-J

PS    Wilfried's post reminded me that a friend who is a professional singer has just had her voice wrecked by the tube put down her gullet for a gall bladder operation. Apparently, she should have asked for a narrow diameter one to help offset any potential lasting damage!!!    Who Knew??!!