Have you recently had a tooth removed there? (like wisdom teeth)
I know that its pretty common to get bone shards/spurs "floating" in gum tissue with removal. My husband and I both experienced that, where all the sudden a little shard was partially exposed, dentist numbed it up and pulled it out of mine, my husband was able to just pull his out. If they are more imbedded it would depend on how much discomfort its causing whether or not you would want to have it surgically removed. My grandma told me that she had this happen for over a year after a tooth removal.
My younger brother also had an extra tooth come in sideways in his jaw line...
those are my thoughts anyway!