Agency veteran Rob Buchner has been promoted to chief marketing office at Fallon Worldwide. In the role, vacated by Mark Goldstein in May, Buchner will spearhead new business efforts in North America. Previously he was managing director of the agency's interactive and marketing services divisions. ... Senior copywriter Brian Tierney has returned to Crispin Porter + Bogusky in Miami following a stint at Minneapolis agency Carmichael Lynch. ... Designer Jeff Stewart has been promoted to art director at Atlanta agency BrightHouseLIVE.