restrict page callback url?
The easiest way would be within your code. 

You could change your 'access callback' =&gt; TRUE, to a function e.g. 'access callback' =&gt; my_access_check,

And within that function you can have an if statement to detect if a 2nd arg existing and if it does return false which would provide an access denied

If you wanted to do a "page not found" or a redirect or something else then you could put this logic into your 'example_page1_callback' function