Dementia patient has started chewing on everything. Shirt sleeves, collar, bedding, stuffed animals, even her hands. Any idea why?

Chewing like this comes along with advanced dementia for many who suffer. Nothing you can or should do about it but give her safe things TO chew on like wash cloths and towels.

UPDATE

We got some "chewlery". Lasted less than 24 hours.
I think we are going to try wash clothes.

Has anyone considered Pica, a condition which causes people to chew on something other than food?  

https://www.nationaleatingdisorders.org/learn/by-eating-disorder/other/pica

"Pica often occurs with other mental health disorders associated with impaired functioning (e.g., intellectual disability, autism spectrum disorder, schizophrenia). "

This is a good site; it's worth reading.

Oh...I know what you are going through!!!
This was my Husband to a "T"
I found children's teething toys that were soft.
I also got soft dog toys.
He did not like the hard teething rings.
I also would give him a napkin at meals and he would chew on the napkin. (to this day I have several napkins with holes) Real funny story. The napkins I gave to him were a blue and white check. One day the caregiver and I took him out to lunch and when we sat down at the table the tablecloth was a blue and white check, he immediately picked it up and started chewing on it! I removed the tablecloth and gave him "his" napkin and we had lunch.
Just make sure that the things that she is chewing on are not a choke hazard. You are not going to get her to stop so make the chewing safe.
I decided it was a comforting measure for my Husband.
By the way he was also non verbal and with the chewing he made noises.

Her doctor said she is perfectly healthy, so unless she has a fever or some emergency there isn't any thing they can do. We tried getting her a very pricey mouth guard. The thing was really "tough " but she chews with such force that it was shredded in a few hours. She has broken a few of her front teeth. The dentist can't do much. She will shatter any crown they put on and there is no way she will keep a denture in. We really are lost.

I will look at the link you posted. Willing to try anything if it helps.

Thanks

You see sometimes this not only in dementia but in other kinds of brain disorders. I did a little digging and found a similar post from several years ago
https://www.agingcare.com/Questions/wife-wants-to-chew-on-everything-186826.htm

I've looked up the "chewlery" mentioned
https://www.amazon.com/chewelry/s?k=chewelry
but I would first get her doctor's approval, you may also want to try some type of anti anxiety med. Good luck.

I can't answer this with any expertise. It feels like there may be a few reasons: but only having her see a doctor or other professional would give you some factual recourses.
Anyway, I'm thinking that, perhaps, the regression has occasionally put her back to a very early stage of childhood.
or: maybe her teeth (gums) hurt: or she thinks they hurt.
or: she is missing something in her diet
or: she thinks she is hungry
or; it is an emotional 'crutch', since she is not vocal
or:.... there are so many reasons.
To narrow it down, a professional would need to assess her.

I am sorry that I could not help you. What a hard thing to endure.