How do I import music from a CD into iTunes on OS X when the dialogue does not appear?
Assuming that the CD shows up fine on your computer, you should be able to manually start the import process by opening iTunes and going to: File &gt; Add to Library  

In the file dialog that opens, you should see your CD listed on the left side under "Devices". Click this, select all songs, and click "Open" to import the songs. 

Also:
To try and clarify what the other answer says, when a CD is inserted, a CD icon usually appears in the upper left hand corner of the main iTunes window. Clicking or right-clicking on this should give some import options.