I thought this was going to be a thread about Quentin's barbeque or some cooking facility....never heard that term before.
Anyway, good that you bring that up, I've been wondering the same thing every time I see him now. Seriously, it doesn't look like a chip, it's just appears to be a small space... so what the hell happened? (although looking at that last picture maybe it could be a chip?)
His appearance did change a bit over the last 6 or 7 years, I just thought maybe his head was getting bigger and his teeth expanded as a result, haha.