Continuity mistake: When telling the sheriff about the cannibal he raises his cup. Camera cuts and he raises his cup again. (00:15:30)
Continuity mistake: The way Bones positions the bones on the tray change between shots when she photographs them for her team. (00:06:40)
Continuity mistake: When Booth tells Bones that she isn't done yet near the start, Bones puts a pen in her mouth with the back of her hand away from the camera. Camera changes and now it's facing the camera. (00:02:40)
Continuity mistake: Bones photographs the arm on a silver tray and sends the photos to Zack and Angela. When they view the photos, they are on a blue background. (00:08:00)
Visible crew/equipment: When Booth and Bones are driving at the start a square light screen is reflected in Booth's sunglasses. (00:04:40)
Continuity mistake: When Zac is signing for his package, the courier has her hands on the top of the box. Camera cuts and they are no longer on the box. (00:18:05)
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.