We were just saying that we don't think you can. Here is what AADSAS says about formatting
The best practice for you to compose your personal statement is to copy the essay from Word and paste it into Notepad.
Note: To open Notepad, click Start, point to All Programs, point to Accessories, and then click Notepad. From Notepad you can view how the text looks and be able to edit it (such as adding or removing line feeds) before saving it as a .txt file in a known folder. You can then copy the text from Notepad and paste it into the textbox in the application.
Some formatting characters and indentation used in programs like Word will not display properly. Take the time to review the final document before you submit your application to AADSAS.
Your personal essay will be formatted and printed in standard paragraph form before being sent to your designated dental schools as a part of your AADSAS application. It will not be sent to your designated dental schools in the format you view in the on-line application.
It seems like they will format it after you submit it. To be on the safe side I think I am still going to leave an extra space between paragraphs so no confusion is made and I end up with a 1 paragraph PS.