Multires: Is there a way to know when one side of a cube face has completely loaded?

Greetings

I would like to know if there's a method to know if one side of a cube face has completely loaded in multires setup. I'm trying to overlay some graphics hotspots and I'm afraid it will not look right if all the tiles of a face has not loaded so I would like to hide the graphic until the face has finished loading.

Thanks again.