From the I-Swear-I'm-Not-Making-This-Up Department:

A dentist Wednesday found the source of the toothache Patrick Lawler was complaining about: a 4-inch nail the construction worker had unknowingly embedded in his skull six days earlier. (Newsday)

Futher:

Lawler's nail gun backfired on Jan. 6 as he worked in Breckenridge, a resort town in central Colorado. The tool sent a nail into a piece of wood nearby, but Lawler didn't realize a second nail had shot through his mouth, said his sister, Lisa Metcalse.