The Skull in the Desert - S1-E17
Other mistake: When Bones, Booth and Angela are in the desert looking for the crime scene and sheriff's sister, Booth mentions they are at least five days walking distance from the highway. A few moments later you can see trucks and other vehicles go by on a highway in the far background. (00:30:02 - 00:31:22)
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.