Plaintiff, a practicing dentist, brought an action to enjoin the enforcement of a section of Oregon legislation regulating the practice of dentistry, which defined certain types of advertising and solicitation as unprofessional conduct and, as such, ground for the revocation of a license to practice. The section was upheld by the state supreme court and plaintiff appealed to the United States Supreme Court, alleging that the statute was unconstitutional in that it impaired the obligations of existing contracts and violated the "due process" and "equal protection" clauses of the Fourteenth Amendment. Held, that the statute was a valid exercise of the state police power and constitutional. Semler v. Oregon State Board of Dental Examiners, 294 U.S. 608, 55 S. Ct. 570 (1935).