W. Dunsel was a Starfleet officer in the 24th century, who had served under Admiral Leyton.
In 2372, Dunsel was assigned as a Hygienist, Starfleet Dental. The effective date of this assignment was 49274. Dunsel was one of over four hundred officers reassigned in a three week period by Leyton. Dunsel's name was listed in the personnel assignment log that was displayed on a screen in Benjamin Sisko's temporary office in Starfleet Headquarters. (DS9: "Paradise Lost", okudagram)
This character was only mentioned in writing.