Why are there no branches? did they die and fall off?

If the tree is still alive, it will back-bud from the trunk in the spring and grow new branches. At any rate, there is nothing you can do at this point but wait. Maples are pretty durable trees.

I have a JM 'Ueno Homare' (4 foot) and a 'Tsusaka Silhouette' (8 foot) that were snapped off at the main trunk, about 2 1/2 feet from the ground by ice falling off the neighbors building.
They back budded out in the spring, and grew well, but they will be kind of funky looking for a few years (if I dont chop them and make bonsais out of them!)

No branches or no leaves????.......makes a BIG difference!! Maples are deciduous and so lose their leaves in winter and enter a period of dormancy. If it has just lost its leaves, then expect it to leaf out quite normally in spring.

No branches... I know they are deciduous, I was expecting it to lose its leaves, just not the branches. It only had a few because it was a young tree, so I'm guessing its just dormant because of the winter and being such a young, small and freshly planted tree.

When you say "baby" how tall is it? With shade trees people mean anything from a 10cm whip to a 5' tree when they call something a "seedling". ;)

Trees don't normally lose branches. The branches might die off, but if they are gone entirely either they died off and you had a storm prune them for you, or I'd look to some kind of mechanical damage.

It's probably just a little over a metre at the moment. It's very small, like when you first buy a young tree from a plant nursery. We did have some wild weather when it was first planted... I've seen dormant trees planted in winter with no branches so I didn't think it was too unusual. When we bought it, it only had very few branches anyway.

If the branches have died off and snapped off during a storm, could the tree itself still be alive? The trunk seems to have grown a little since it was first planted.

I'm going to wait until early summer to determine whether it is alive or not. Obviously if it has no leaves or branches by late November, early December it's failed.

Currently, it wouldn't even be near the size of the trees I've attached in the image below to give a perspective. It would be half the size of the ones in the pots.

Well I noticed the tree is sprouting its first leaf tonight. But it's got an odd colour for Spring, it should be green... Any ideas?

Leaves aren't usually green...give it a couple weeks.

You mean not green in the beginning when they first sprout? I just hoped it wasn't some kind of disease causing them to be that colour.

AB leaves will ALWAYS be red when breaking bud and enlarging. They don't turn green until they get closer to full size. Your tree is behaving normally.