3/4 motorcycle helmets is exactly the same as open face helmets. It's just another name for them. Quite simply, all it means is that it is not a full helmet, it is three quarters of a helmet. The 3/4 motorcycle helmet lacks the front chin piece that the full face has.

There are many different combinations that you can put together with three quarter helmets. You can put a visor on it, a flip up shield, or a stationary 5 snap flat shield. You can even use this helmet with goggles and bypass all the other accessories. It is all your preference and depends on how and what you ride. These almost always carry a DOT rating and are deemed safe for both road and off road use.