Sometimes maya will save an extra file during a crash, not always an MA into the temp folder but in the same directory as the original but its not always obvious unless you select 'all files' in the drop down file type menu.
It does occasionally save an invisible mb file but will look something like this example:
'my model name'.mbxf12hfhakfjflslslswxef
so its worth looking for that at well. the file will be bigger too but if you do have one reopen it and just save as something else.
Jay
I would also recommend that you save with .ma from then on if you do this, just in case there is some creeping file corruption. Remember, it was written out by a crashing program 
Imagination is more important than knowledge.