Objective: All tobacco products carry established or probable adverse oral health effects. This study highlights several examples of actions by transnational tobacco corporations to obscure those effects, including several in which they were aided by the oral health community. Methods: Information was derived primarily from a search of records in the Truth Tobacco Industry Documents Database, supplemented by other published material and the author’s personal experiences. Results: Tobacco companies attempted to interfere with oral cancer research and dissemination of its findings the 1950s and 1960s. Philip Morris, Inc. partnered with the American Dental Association’s periodontal research centre until 1973 and the Council for Tobacco Research supported its dental student research program until 1972. Swedish Match funded much of the Swedish research on oral health effects of its smokeless tobacco products and helped foster the current “tobacco harm reduction” strategy. Electronic nicotine delivery devices are the current focus of that strategy, though data on oral health effects are sparse. Conclusions: The transnational tobacco industry has a long history of deception, corruption, and devastation, and oral health was no exception. Organized dentistry may have unwittingly aided and abetted the tobacco industry during a critical period of history.