As Samspon has replied already, the retopo tools in Maya are very good and quad draw will let you retain a good shape providing you you know exactly how and where to place your geometry.

We do cover retopology in our Batman head tutorial here at Simply Maya: https://simplymaya.com/autodesk-maya...al/?tut_id=377

However, if you are after a very quick fix without the fuss I suggest you could use the reduce option in Maya or if you have access to zbrush, you can use zremesher as well.

cheers
Jay