Data Modelling with differing levels of data granularity

I came across this in a discussion on Linkedin's Microsoft Business Intelligence group, the initial post asked

 "Join Fact and Dimension Tables that are at Two Different Grains

I have a fact table that is based off the source system at a order level. My dimension is at a order line detail level. Would creating a bridge table work to join the fact and dimension or should I create another order dimension table at the order level?"

Click here for a Kimball Group cheat sheet with examples suggested by Assaf Mentzer which answers this question.