If you filter your Official Notes, and include Status: Pending - and no notes come up, this means there are no notes requiring approval. 

If you change the Status to All, then click View and notes are displayed, this means these are notes not requiring approval. You can click Review so they can be opened/read, Deleted, Saved or Emailed - but there would be no option to Approve or Deny an Official Note if it does not require approval.

Note: If a status on a Comment Type is set to Require Approval, then later changed to NOT require approval, the code will not go back and re-classify any Official Notes that were written while the Comment Type required approval.