Continuity mistake: When Booth and Bones are shown the Pimp's scar, the towel the guy is holding switches hands instantly. (00:16:30)
Continuity mistake: When in the diner after going to the Japanese tea room, Booth has his fingers rubbing his temple. Shot changes and his hand is lowered. (00:11:15)
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.