The Beginning in the End - S5-E22
Continuity mistake: At the start, the amount of maggots in the boy's hair changes between shots. (00:00:30)
The Beginning in the End - S5-E22
Continuity mistake: When the skull rolls to a stop there are very few maggots on it. When the camera shows it a few seconds later there are lots. (00:02:00)
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.