I spooke to both of the schools taht I am alternate/wailisted at and this is what I was told.
MWU: there is no numbering system. An alternate/waitlist is comprised after each acceptance notification goes out (there are 3 total and now there are 2 left). Once the list of alternate/waitlisted is made then they review each applicant again to select spots for openings that may become available. But again NO number is assigned.
ASDOH: there is noofficial alternate/waitlist. All applicants that did not get rejected are still being considered until the first day of school. That is all I was told.
Good luck to all and may a butt load of people bail on dental school this year.