title: Chi-square analysis.
authors.affiliation: Neurobiology and Anesthesiology Branch, National Institute of Dental Research, National Institutes of Health, Building 30, Room B20, Bethesda, MD 20892 U.S.A.
authors.forename: David A
authors.initials: DA
authors.lastname: Thomas
mesh_terms: D016009:Chi-Square Distribution; D006801:Humans; D010146:Pain / Q000453:epidemiology*