Adobe Myriad Pro has PostScript outline technology wrapped in the Apple/Microsoft intelligent composition model.
This means that you can select, for instance, for the character DIGIT ONE you can select the default unit of type that stands on the baseline as upper case and alternately select superior 1, inferior 1, lower case 1, tabular 1 that has equal width for alignment in tables, and more.
Intelligent fonts are installed for all users (under Computer), for one user (under Home), or for one application (e.g. internal font folder in Adobe InDesign not seen by Mac OS X). Installing and uninstalling intelligent fonts is done through Apple Font Book.
If you can see Adobe Myriad Pro in Apple Font Book then Adobe Myriad Pro is available to Apple Pages. You can read more about type in an Apple guide prepared in the Apple Mac OS X 10.2 timeframe for people used to Mac OS 9 who are getting used to Mac OS X.
Hope this helps,
Henrik
Reference :
http://www.adobe.com/type/topics/FontsonMacOSX.pdf