Trivia: Throughout the show, almost all documents, including things that most people would just write on a Post-It note, are on the Jeffersonian Medico-Legal lab letterhead. That is very unusual behaviour for documents that are not official, legally-required. Day-to-day paperwork would be on regular, standard white blank pages. The cost of their fancy, logo letterhead being used all the time would be prohibitive in any other workplace.
Trivia: The number 447 frequently appears in the show. An example of the number appearing is in season 9 episode, The Secrets in the Proposal - At the very end of the episode, after Brennan and Booth reconcile, the clock in their kitchen reads 4:47, but then switches to 7:35. Booth's alarm clock shows that time in The End in the Beginning, and it appears as a room number and in a newspaper headline in The Crack in the Code. It is also the time (4:47) that the bombs go off in the final episode.
Answer: Since the palatine bone is a bone that helps form the mouth it has a lot to do with speaking. The shape of it differs a lot depending on your ethnic background. I would guess that they, in the show, meant that the person's bone tells that they were Japanese and that it was "made for the purpose of speaking Japanese." That's what I'd assume anyway. I've studied molecular biology though, so I'm not an expert on bones.