>>725612879
For whatever reason the way Ganon's jaw just kind of flops around made me think that Ganondorf's jaw got broken when the castle collapsed with him in it.
His mouth has a similar unhinged look in the N64 version but it's more like normal panting in the 3DS version, probably because there's not enough darkness to hide the injury anymore.
Maybe they didn't want him looking too corpse-y.