[nemomarx]

The teeth marks look kinda like a skeleton to me. I could see it being part of an effigy but also maybe sewn into a headdress or something?

[Avicebron]

Could be, I'm getting "death mask" vibes. So maybe something someone would be buried with, If we can assume there were fasteners of some sort in the holes around the circumference I can see this being sewn on to burial wrappings.