You have my sympathy, Jillybird
My teeth (and gums) are healthy, but have been migrating for years.
The problem is that I am still teething, with two of my four wisdom teeth still only partially erupted some 25 to 30 years after first appearing. As a result, my already overcrowded teeth are still being pushed over to make room for them, causing increasingly crooked and badly aligned teeth at the front of my mouth!
I can't bite into something like a biscuit without it disintegrating, and recently, I have noticed that I am increasingly likely to accidently spit as I talk - horrible!