There is only 1 Panda Pied in existence. No others have been produced. And if there have been, they have failed to survive.
When the Panda was produced, it was said to be a Super Black Pastel Pied. These days, it's been questioned.
My friend who has the brother Black Pastel het. Pied to the Panda has spoken to the Panda breeder and both have speculated that the Panda may not even be a pied. It may be an Extreme Ringer Super Black Pastel. The brother Black Pastel is a ringer as well.
The only explanation to the head patterns is just that it's the pied gene. Simple.
But like I mentioned before, White Weddings are an all white pied. And some Lesser Pieds are all white.